TABLE OF CONTENTS

I. INTRODUCTIONII. OBJECTIVESIII. PATIENT’S PROFILE

A. Personal DataB. Chief ComplaintC. History of Past IllnessD. History of Present IllnessE. Family Health HistoryF. Activities of Daily Living

IV. PHYSICAL ASSESSMENTV. DIAGNOSIS

A. Clinical DiagnosisB. Laboratory and Diagnostic Result

VI. ANATOMY AND PHYSIOLOGYVII. PATHOPHYSIOLOGYVIII.NURSING CARE PLANIX. DRUG STUDYX. DISCHARGE PLANNING

INTRODUCTION

Polyhydramnios (polyhydramnion, hydramnios, polyhydramnios) is a medical condition

describing an excess of amniotic fluid in the amniotic sac. It is seen in about 1% of pregnancies.

It is typically diagnosed when the amniotic fluid index (AFI) is greater than 24 cm .There are

two clinical varieties of polyhydramnios:

Chronic polyhydramnios where excess amniotic fluid accumulates gradually.

Acute polyhydramnios where excess amniotic fluid collects rapidly.

The opposite of polyhydramnios is oligohydramnios, a deficiency in amniotic fluid.

Most cases of polyhydramnios are mild and result from a gradual buildup of amniotic fluid

during the second half of pregnancy. Severe polyhydramnios may cause shortness of breath,

preterm labor or other signs and symptoms.

If you're diagnosed with polyhydramnios, your health care provider will carefully monitor your

pregnancy to help prevent complications. Treatment depends on the severity of the condition.

Mild polyhydramnios may go away on its own. Severe polyhydramnios may require treatment,

such as draining the excess amniotic fluid.

OBJECTIVES

At the end of the 12 hours duty I will be able to:

Appreciate trends and issues related to reproductive and child health problems during

pregnancy.

Apply the concepts and principles in midwifery for maternal and child problems.

Describe the various components of Reproductive health problems about Polydramnios.

Perform maternal health assessment and plan maternal care related to patient with

Polydramnios.

Apply the role and responsibilities of midwife in implementing interventions with

Polyhydramnios .

Demonstrate competencies in providing maternal and child health care independently.

PATIENT’S PROFILE

A. Personal DataMy patient B.V. was 43 years old lives in Citrus City of San Jose del Monte Bulacan.

She was born December 24, 1972. She only finished first year high school. She was single and a plain housewife having 8 children with her live-in partner. She has no previous occupation since she started to be with her partner. She was a Filipino and her religion was Born-Again Christian. The date of interview was on March 11, 2012. The informant was her mother L.B.

B. Chief Compalint“Madaming tubig na lumabas nung pinanganak ko itong baby ko” as verbalized by

the mother.-Polyhydramnios

C. History of Past IllnessPatient is known for multiple pregnancies. She was Gravida 9 and Para 9. She was

experienced fetal death on her first baby it happens 20 years ago when she was able to give birth. She said that she was diagnosed Goiter before she started to be pregnant with her first baby and the doctor advised her to take some medicines that she cannot remembered. She said that she has no allergies in food and medications.

D. History of Present IllnessDuring her pregnancy she was able to check-up 5 times due to some complications

that she was experienced according to her like increased of her blood pressure.

E. Family Health HistoryAccording to patient they have previous history of hypertension and diabetes in their

family occur in her uncle and brother. The father of the patient was died due to leukemia told by the mother of the patient.

F. Activities of Daily livingShe said that her family was very supportive on her. She had open relationship mostly to her mother because when she felt any problem or was thinking something she talked to her family. She smoked the time when she’s not pregnant and she consumed 5sticks-1pack per day but she was drinking alcoholic beverages before and she stopped 5 years ago because she wasn’t found satisfaction on it according to her. She stayed at home, watched television and took care of their children. She went outside to their house to chit chat with her neighbors and friends. She was about health conscious according to her because every time she feels uncomfortable she went to

medical doctor to seek advices but she admitted sometimes she’s non-complying with the doctor’s advices due to lack of resources or money. She believed on some traditional beliefs when she’s pregnant like should not drink some medicine that she know that it will affect the baby. She drank a lot of fluid in a day when she’s pregnant she estimated 8000-10000L per day it includes water, coffee and milk. She ate 3meals a day and in 1-2 cup of rice. She wasn’t take any medications or vitamins when she’s pregnant also she has no allergies. She had no difficulty in defecating. She defecated every morning sometimes 2x a day but she had difficulty in urinating according to her because the amount of fluid she intake was not proportionate when she urinated. She estimated half of her fluid intake and urinated 4-5 times a day maybe the reason for her was uncomfortable to urinate.

PHYSICAL ASSESSMENT

.A. GENERAL APPEARANCE

My client’s general appearance was medium frame body built, had an upright posture and had smooth rhythmic gait. Appropriately dressed. She had no body odor and obvious physical deformities. Her clinical measurements were follows; approximately 5’2 ft. weighs approximately 56kgs. Her vital signs were as follows; body temperature was 36.7◦C/ axilla,. Respiratory was 21 cpm, pulse rate was 79 bpm and 110/90 mmhG.

B. MENTAL STATUS

My client’s mental status was conscious and was oriented to time, place and person. She was cooperative enough in our interactive interview and uses complex words for communication.

C. SKIN

My client’s skin color was brown complexion. She had no any abrasions or lesion found. Temperature was warm, dry, rough elastic turgor and mobile. Her hair was evenly distributed and variable in amount.

D. NAILS

My client’s nail plate shape was convex 160; nail condition was smooth and nail bed color was pale, capillary refill within 3 seconds.

E. HEAD AND FACE

My client’s skull was proportionate to body size. Scalp was non-tender and no lesions found. Hair was evenly distributed. Face was symmetrical as well as facial movement.

F. EYES

My client’s eyes are straight normal, eyebrows are thin, eyelids and eyelashes have effective closure. Blink response was bilateral, eyeballs were symmetrical, Bulbar Conjunctiva was clear while Palpebral Conjunctiva was pink and scleras were white. Pupils were equally reacting to light and accommodation. Visual acuity was good he can identify the object 12-14 inches away with a 20/20 vision on Snellen chart and can able to read news print. Lacrimal Gland, Lacrimal Sac, and Nasolacrimal Duct are no edema and excess tearing.

G. EARS

My client’s ear auricle color was the same with his skin color. Symmetrically align with outer cantus and elastic and firm. Pinna recoils when folded. Responds to normal voice and no

difficulty in hearing. Sound was heard in both ears or was localized at the center of the head and air-conducted hearing is greater than bone-conducted. External canal was present of some cerumen.

H. NOSE

My client’s nose her external color also the same with her skin there no lesions found. Septum was on the midline. Mucosa is pink, both patent because air moves freely, nasal cavity was moist and non-tender of sinuses.

I. MOUTH

My client’s lip was dark gray, tongue was on the midline, texture was rough color was pink and movable. She has 4 missing teeth such molars located one in upper right side also one in lower left side and two on right side and presence of dental caries in the remaining molars and teeth. Gums were dark gray in color.

J. PHARYNX

My client’s uvula was on the midline. Mucosa was pink, tonsils were not inflamed, and as well as the posterior pharynx was not congested, and gag reflex was present.

K. NECK

My client’s neck muscles were equal in size symmetrical strength of muscles. Lymph nodes were not palpable as well as thyroid gland and trachea was on the midline.

L. BREAST AND AXILLA

My clients breast was rounded in shape and symmetrical in size. The same color to her skin. No discharge or lesions found. Areola was round and bilaterally the same. Color varies widely, from brown to dark brown. Nipples were not inverted and equal in size. No tenderness, masses, or nodules.

M. CHEST AND LUNGS

My client’s chest is AP to lateral ratio 1:2, lung expansions are symmetrical. Fremitus was symmetrical. Have regular breathing pattern. Breath sounds heard over vesicular, bronchial, bronchovesicular. Resonant when percussed. Costal angle is 45 degrees heart sounds over aortic, pulmonic, tricuspid but accurately heard on apical area.

N. ABDOMEN

My client’s abdomen was same on her skin color. There are no lesions found and presence of striae gravidarum or stretch marks and no lesions. The movement was symmetrical. She had hyperactive bowel sounds of 39 times/minutes that time. Absence of arterial bruits and friction rub.

O. UPPER EXTRIMITIES

My client‘s upper extremities have 5/5 muscle tone and 5/5 muscle strength. There are no deformities. As palpated all the pulse in her upper extremities it was regular in rhythm of peripheral pulses and strong in quality. Lymph nodes were not palpable.

P. LOWER EXTRIMITIES

My client‘s upper extremities have 5/5 muscle tone and 5/5 muscle strength. There are no deformities. As palpated all the pulse in her lower extremities it was regular in rhythm of peripheral pulses and strong in quality. Lymph nodes were not palpable.

Q. GENITALIA

Genitalia of my client were shaved and skin of vulva is darker than the rest of the body. Labia were hyprertrophy and relatively symmetric but it were loose. Inflammation and swelling, and bloody discharge are still present due to 1st day postpartum. No enlargement or tenderness.

DIAGNOSIS

A. CLINICAL DIAGNOSIS

Polyhydramnios means you have too much amniotic fluid in your uterus (womb). It happens in

about one in 500 pregnancies in the UK, so it isn't common. Most cases of polyhydramnios are

mild or moderate. 

The amniotic fluid surrounding your baby protects him from being hurt if you have a blow, or if

your tummy is squashed. The fluid also protects your baby against infection, as well as helping

his lungs to develop. 

The amount of fluid around your baby gradually increases until there is about one litre (1.76

pints) surrounding him at 38 weeks. This amount decreases to about 800ml (1.4 pints) by 40

weeks. Your baby will regularly swallow amniotic fluid, which then passes out of his body as

urine. This is how he controls the volume of amniotic fluid around him. 

When this delicate balance is disturbed, the volume of amniotic fluid can increase rapidly. In

severe cases of polyhydramnios, there may be as much as three litres (5.3 pints) of fluid, or three

times the normal amount, around your baby. 

You may notice that your tummy is getting large and feeling taut, and that your skin is stretched

and shiny. You might feel uncomfortable and breathless and find it hard to climb a flight of

stairs. 

Polyhydramnios usually starts from about 30 weeks of pregnancy and will develop gradually.

However, in rare cases, usually at about 20 weeks, it comes on very rapidly over the course of

just a few days. 

Polyhydramnios tends to make the following pregnancy symptoms worse:

indigestion

heartburn

constipation

swollen legs

varicose veins

stretch marks

Diagnosed

If you have polyhydramnios, when your midwife or doctor carries out an examination, you'll appear to be large for dates (macrosomia). She may find it difficult to feel your baby or hear his heartbeat. That's because there's so much fluid around your baby that he can easily move around. 

Ultrasound scans can confirm a diagnosis of polyhydramnios. The sonographer will measure the amount of fluid in four areas around your baby to work out your amniotic fluid index (AFI). This is normally in the range of 10cm (4in) to 25cm (10in) in yourthird trimester. So an AFI over 25cm means you have polyhydramnios. The higher the AFI, the more severe the problem is. 

Sometimes the scan may also reveal a reason for the condition, such as a multiple pregnancy or a pregnancy complication. 

Causes

It's difficult to find the cause of polyhydramnios. In about two thirds of cases, no cause can be

found. The extra fluid could be due to a problem with your baby, the placenta, or with your own

health. 

Possible causes are: 

Diabetes, when your blood sugar levels aren't well controlled. Your baby produces more

urine, which increases the volume of amniotic fluid. Your doctor will give you a glucose

tolerance test to check your blood sugar levels.

Being pregnant with identical twins, where twin-to-twin transfusion syndrome has

developed.

A complication with your baby which is stopping the fluid going through his system.

This could be due to a blockage in his food pipe (oesophagus) or a problem with his

muscle control. This will mean he can't swallow amniotic fluid and regulate the amount

that's around him.

A chromosomal abnormality, such as Down's syndrome or Edwards' syndrome.

If you have an infection such as parvovirus (known as slapped cheek disease)

or toxoplasmosis.

Management 

This depends on the severity of your condition and whether a cause has been found. In mild

cases where a cause can't be found, your condition is likely to get better on its own as your

pregnancy progresses. 

Your doctor and midwife will advise you to rest as much as possible, which may mean starting

your maternity leave early. You may need to be admitted to hospital. 

If your blood sugar levels are high, and you're not already being treated for diabetes, you may be

referred to a diabetes specialist. That way your blood sugar levels will go down and this will

reduce the amount of fluid. 

You will have regular checks on your progress, either in hospital if you've been admitted, or as

an outpatient at the antenatal clinic. 

An ultrasound scan may spot other problems with your baby and will keep track of your fluid

levels. If a detailed scan shows that nothing is wrong, your baby is almost certainly fine and the

polyhydramnios will be caused by something else. 

If a problem with your baby is identified, your treatment will be similar to the treatment for twin-

to-twin transfusion syndrome. Depending on the cause of the extra fluid, you may be prescribed

a drug which reduces the amount of urine your baby produces. 

If your baby has an abnormality which can be operated on, your labour may need to be induced.

Your baby will then be transferred to a neonatal surgical unit. In the unit, a specialist surgeon

will perform an operation to help your baby. Rest assured that your doctor will talk to you about

the best course of action for you and your baby. 

In severe cases, it may be possible to drain some of the amniotic fluid to reduce the volume. This

may reduce the risk of you going into premature labour or the placentastarting to come away

from the wall of your uterus. 

But there is a risk with this technique. The procedure increases your chance of infection and may

also cause you to go into labour. Also, the fluid often builds up again, meaning the procedure

will need to be repeated. 

Even if you do rest, because your uterus is swollen, you may still go into labour prematurely. 

Your midwife will explain the signs of premature labour to you so you can contact the hospital

immediately if your waters break or if you start to have contractions. 

Effects

Your labour is likely to be normal. However, the weight of your baby and the extra fluid may

cause you to give birth early. If your waters break before labour starts, call an ambulance. 

If your contractions start before 37 weeks, call the delivery suite and tell them what's happening.

If there's nobody who can take you to hospital, call an ambulance. 

If you're known to be having problems with your baby, you'll be booked into a regional referral

centre to give birth. That's where they'll have the best facilities for looking after your baby. 

Even if your baby seems fine, and you don't have to go to a specialist hospital, you will be very

carefully monitored during labour. This is for a number of reasons:

The extra fluid in the uterus makes it difficult for your baby to settle his head down into

your pelvis. So if your waters break, the umbilical cord may be pulled down into your

vagina and in front of his head. If this happens, you may need an emergency caesarean

section.

The placenta may come away early if your uterus suddenly shrinks as the amniotic fluid

is released.

You have an increased risk of heavy bleeding (haemorrhage) after your baby is born, so

a managed third stage will be recommended.

If you have diabetes, or if you have a big baby, your midwife will make sure that your

baby moves steadily down through your pelvis. This means he won't get stuck, though his

shoulder may become caught. If this happens, an obstetrician will help you get into

a position that frees your baby.

If your symptoms are getting worse and you are in late pregnancy, your obstetrician may

recommend your labour is induced. 

Your obstetrician may also suggest in advance that you have an elective caesarean. This may be

the case if:

you are carrying twins

your baby is lying across your uterus (transverse lie)

your baby won't settle into any particular position (unstable lie)

Try to remember that most women with polyhydramnios go on to have healthy babies,

particularly if the condition is mild. 

If you feel breathless: 

keep everything you need for the daytime downstairs

do household chores in small bursts, and take your time

if help is offered, accept it, and get plenty of rest

It may be that you have heartburn because your uterus is pushing against your stomach. To ease

this:

Eat small amounts, regularly.

Try not to lie down straight after a meal, and don't eat just before going to bed.

Don't eat or drink anything which makes your heartburn worse, such as spicy food.

Try to sleep propped up in bed.

Ask your doctor for an antacid prescription.

Polyhydramnios will probably make you may feel anxious, as well as on the large side. But there

are ways to lessen your anxiety:

Gather as much information as you can, as early as you can, at your antenatal classes.

Find enjoyable distractions. If you're too self-conscious about your size to go out, invite

friends over, or catch up on DVDs.

Talk to other mums-to-be in the BabyCentre community who have experienced what

you're going through.

If you have polyhydramnios and notice new symptoms, or if your existing symptoms become

worse, call your midwife or go to your nearest hospital immediately. 

B. LABORATORY AND DIAGNOSTIC RESULTS

The complete blood count or CBC test is used as a broad screening test to check for such disorders as anemia, infection, and many other diseases. It is actually a panel of tests that examines different parts of the blood and includes the following:

White blood cell (WBC) count   is a count of the actual number of white blood cells per volume of blood. Both increases and decreases can be significant.

White blood cell differential  looks at the types of white blood cells present. There are five different types of white blood cells, each with its own function in protecting us from infection. The differential classifies a person's white blood cells into each type: neutrophils   (also known as segs, PMNs, granulocytes, grans), lymphocytes, monocytes, eosinophils, and basophils.

Red blood cell (RBC) count   is a count of the actual number of red blood cells per volume of blood. Both increases and decreases can point to abnormal conditions.

Hemoglobin   measures the amount of oxygen-carrying protein in the blood. Hematocrit   measures the percentage of red blood cells in a given volume of whole blood. The platelet count   is the number of platelets in a given volume of blood. Both increases and

decreases can point to abnormal conditions of excess bleeding or clotting. Mean platelet volume (MPV) is a machine-calculated measurement of the average size of your platelets. New platelets are larger, and an increased MPV occurs when increased numbers of platelets are being produced. MPV gives your doctor information about platelet production in your bone marrow.

Mean corpuscular volume (MCV) is a measurement of the average size of your RBCs. The MCV is elevated when your RBCs are larger than normal (macrocytic), for example in anemia caused by vitamin B12 deficiency. When the MCV is decreased, your RBCs are smaller than normal (microcytic) as is seen in iron deficiency anemia or thalassemias.

Mean corpuscular hemoglobin (MCH) is a calculation of the average amount of oxygen-carrying hemoglobin inside a red blood cell. Macrocytic RBCs are large so tend to have a higher MCH, while microcytic red cells would have a lower value.

Mean corpuscular hemoglobin concentration (MCHC) is a calculation of the average concentration of hemoglobin inside a red cell. Decreased MCHC values (hypochromia) are seen in conditions where the hemoglobin is abnormally diluted inside the red cells, such as in iron deficiency anemia and in thalassemia. Increased MCHC values (hyperchromia) are seen in conditions where the hemoglobin is abnormally concentrated inside the red cells, such as in burn patients and hereditary spherocytosis, a relatively rare congenital disorder.

Red cell distribution width (RDW) is a calculation of the variation in the size of your RBCs. In some anemias, such aspernicious anemia, the amount of variation (anisocytosis) in RBC size (along with variation in shape – poikilocytosis) causes an increase in the RDW.

^ Back to topPurpose:

The CBC is a very common test. Many patients will have baseline CBC tests to help determine their general health status. If they are healthy and they have cell populations that are within

normal limits, then they may not require another CBC until their health status changes or until their doctor feels that it is necessary.

If a patient is having symptoms such as fatigue or weakness or has an infection, inflammation, bruising, or bleeding, then the doctor may order a CBC to help diagnose the cause. Significant increases in WBCs may help confirm that an infection is present and suggest the need for further testing to identify its cause. Decreases in the number of RBCs (anemia) can be further evaluated by changes in size or shape of the RBCs to help determine if the cause might be decreased production, increased loss, or increased destruction of RBCs. A platelet count that is low or extremely high may confirm the cause of excessive bleeding or clotting and can also be associated with diseases of the bone marrow such as leukemia.

Many conditions will result in increases or decreases in the cell populations. Some of these conditions may require treatment, while others will resolve on their own. Some diseases, such as cancer (and chemotherapy treatment), can affect bone marrow production of cells, increasing the production of one cell at the expense of others or decreasing overall cell production. Some medications can decrease WBC counts while some vitamin and mineral deficiencies can cause anemia. The CBC test may be ordered by the doctor on a regular basis to monitor these conditions and drug treatments.

Interpretaions:

The following table explains what increases or decreases in each of the components of the CBC may mean. 

Expand TableComponents of the CBC

TEST NAME INCREASED/DECREASED

WBC White Blood Cell May be increased with infections, inflammation,

cancer, leukemia; decreased with some medications

(such as methotrexate), some autoimmune conditions,

some severe infections, bone marrow failure,

and congenital marrow aplasia (marrow doesn't

develop normally)

%

Neutrophil

Neutrophil/Band/Seg/Gran This is a dynamic population that varies somewhat

from day to day depending on what is going on in the

body.  Significant increases in particular types are

associated with different Lymphs Lymphocyte

TEST NAME INCREASED/DECREASED

temporary/acute and/or chronic conditions.  An example

of this is the increased number of lymphocytes seen with

lymphocytic leukemia. For more information, see Blood

Smear and WBC.

% Mono  Monocyte

% Eos Eosinophil  

% Baso Basophil

Neutrophil Neutrophil/Ban/Seg/Gran 

Lymphs Lymphocyte 

Mono Monocyte 

Eos Eosinophil 

Baso Basophil 

RBC Red Blood Cell  Decreased with anemia; increased when too many

made and with fluid loss due to diarrhea, dehydration,

burns

Hgb Hemoglobin Mirrors RBC results

Hct Hematocrit Mirrors RBC results

MCV Mean Corpuscular Volume Increased with B12 and Folate deficiency; decreased

with iron deficiency andthalassemia

MCH Mean Corpuscular

Hemoglobin

Mirrors MCV results

MCHC Mean Corpuscular

Hemoglobin Concentration

May be decreased when MCV is decreased; increases

limited to amount of Hgb that will fit inside a RBC

RDW RBC Distribution Width Increased RDW indicates mixed population of RBCs;

TEST NAME INCREASED/DECREASED

immature RBCs tend to be larger

Platelet Platelet Decreased or increased with conditions that affect

platelet production; decreased when greater numbers

used, as with bleeding; decreased with some inherited

disorders (such as Wiskott-Aldrich, Bernard-Soulier),

withSystemic lupus erythematosus, pernicious anemia,

hypersplenism (spleen takes too many out of

circulation), leukemia, and chemotherapy

MPV Mean Platelet Volume  Vary with platelet production; younger platelets are

larger than older ones

Results:Date: 03-05-12 Blood Type: O+

HEMATOLOGIC RESULTS

Hemoglobin 145 F 120-150 g/LM 140-170 g/L

Normal

Hematocrit 0.46 F 0.37-0.47M 0.40- 0.50

Normal

WBC Count 11.4 5-10x109 Infections

DIFFERENTIAL COUNT:

Segmenters 0.69 0.55-0.65

Lymphocytes 0.31 0.25-0.35

Date: 03-10-12HEMATOLOGIC RESULTS

Hemoglobin 154 F 120-150 g/LM 140-170 g/L

Hematocrit 0.49 F 0.37-0.47M 0.40- 0.50

WBC Count 13.9 5-10x109

DIFFERENTIAL COUNT:

Segmenters 0.81 0.55-0.65

Lymphocytes 0.19 0.25-0.35

The Urinalysis is used as a screening and/or diagnostic tool because it can help detect substances or cellular material in the urine associated with different metabolic and kidney disorders. It is ordered widely and routinely to detect any abnormalities that require follow up. Often, substances such as protein or glucose will begin to appear in the urine before patients are aware that they may have a problem. It is used to detect urinary tract infections (UTI) and other disorders of the urinary tract. In patients with acute or chronic conditions, such as kidney disease, the urinalysis may be ordered at intervals as a rapid method to help monitor organ function, status, and response to treatment.

Purpose:

A routine urinalysis may be done when you are admitted to the hospital. It may also be part of a wellness exam, a new pregnancy evaluation, or a work-up for a planned surgery. A urinalysis will most likely be performed when you see your health care provider complaining of symptoms of a UTI or other urinary system problem such as kidney disease. Somesigns and symptoms may include: abdominal pain

back pain

painful or frequent urination

blood in the urine

This test can also be useful when monitoring certain conditions over time.

Interpretation:

Urinalysis results can have many interpretations. Abnormal findings are a warning that something may be wrong and should be evaluated further. Generally, the greater the concentration of the atypical substance, such as greatly increased amounts of glucose, protein, or red blood cells, the more likely it is that there is a problem that needs to be addressed. But the results do not tell the doctor exactly what the cause of the finding is or whether it is a temporary or chronic condition.

A normal urinalysis does not guarantee that there is no illness. Some people will not release elevated amounts of a substance early in a disease process, and some will release them sporadically during the day, which means that they may be missed by a single urine sample. In very dilute urine, small quantities of chemicals may be undetectable.

For additional details on what certain results may mean, click on the links below:

Visual examination Chemical examination Microscopic examination

What are Obstetric Ultrasound Scans?

Obstetric Ultrasound is the use of ultrasound scans in pregnancy. Since its introduction in the late 1950’s ultrasonography has become a very useful diagnostic tool in Obstetrics.

Currently used equipments are known as real-time scanners, with which a continous picture of the moving fetus can be depicted on a monitor screen. Very high frequency sound waves of between 3.5 to 7.0 megahertz (i.e. 3.5 to 7 million cycles per second) are generally used for this purpose.

They are emitted from a transducer which is placed in contact with the maternal abdomen, and is moved to "look at" (likened to a light shined from a torch) any particular content of the uterus. Repetitive arrays of ultrasound beams scan the fetus in thin slices and are reflected back onto the same transducer.

The information obtained from different reflections are recomposed back into a picture on the monitor screen (a sonogram, or ultrasonogram). Movements such as fetal heart beat and malformations in the feus can be assessed and measurements can be made accurately on the images displayed on the screen. Such measurements form the cornerstone in the assessment of gestational age, size and growth in the fetus.

A full bladder is often required for the procedure when abdominal scanning is done in early pregnency. There may be some discomfort from pressure on the full bladder. The conducting gel is non-staining but may feel slightly cold and wet. There is no sensation at all from the ultrasound waves.

A short history of the development of ultrasound in pregnancy can be found in the History pages.

Why and when is Ultrasound used in Pregnancy?

Ultrasound scan is currently considered to be a safe, non-invasive, accurate and cost-effective investigation in the fetus. It has progressively become an indispensible obstetric tool and plays an important role in the care of every pregnant woman. 

The main use of ultrasonography are in the following areas:

1. Diagnosis and confirmation of early pregnancy.

The gestational sac can be visualized as early as four and a half weeks of gestation and the yolk sac at about five weeks. The embryo can be observed and measured by about five and a half weeks. Ultrasound can also very importantly confirm the site of the pregnancy is within the cavity of the uterus.

2. Vaginal bleeding in early pregnancy.

The viability of the fetus can be documented in the presence of vaginal bleeding in early pregnancy. A visible heartbeat could be seen and detectable by pulsed doppler ultrasound by about 6 weeks and is usually clearly depictable by 7 weeks. If this is observed, the probability of a continued pregnancy is better than 95 percent. Missed abortions and blighted ovum will usually give typical pictures of a deformed gestational sac and absence of fetal poles or heart beat.

Fetal heart rate tends to vary with gestational age in the very early parts of pregnancy. Normal heart rate at 6 weeks is around 90-110 beats per minute (bpm) and at 9 weeks is 140-170 bpm. At 5-8 weeks a bradycardia (less than 90 bpm) is associated with a high risk of miscarriage.

Many women do not ovulate at around day 14, so findings after a single scan should always be interpreted with caution. The diagnosis of missed abortion is usually made by serial ultrasound scans demonstrating lack of gestational development. For example, if ultrasound scan demonstrates a 7mm embryo but cannot demonstrable a clearcut heartbeat, a missed abortion may be diagnosed. In such cases, it is reasonable to repeat the ultrasound scan in 7-10 days to avoid any error.

The timing of a positive pregnancy test may also be helpful in this regard to assess the possible dates of conception. A positive pregnancy test 3 weeks previously for example, would indicate a gestational age of

at least 7 weeks. Such information would be useful against the interpretation of the scans. Please read the FAQs for more comments.

In the presence of first trimester bleeding, ultrasonography is also indispensible in the early diagnosis of ectopic pregnancies and molar pregnancies.

3. Determination of gestational age and assessment of fetal size.

Fetal body measurements reflect the gestational age of the fetus. This is particularly true in early gestation. In patients with uncertain last menstrual periods, such measurements must be made as early as possible in pregnancy to arrive at a correct dating for the patient. See FAQ. In the latter part of pregnancy measuring body parameters will allow assessment of the size and growth of the fetus and will greatly assist in the diagnosis and management of intrauterine growth retardation (IUGR).

The following measurements are usually made:

a) The Crown-rump length (CRL)

This measurement can be made between 7 to 13 weeks and gives very accurate estimation of the gestational age. Dating with the CRL can be within 3-4 days of the last menstrual period. (Table) An important point to note is that when the due date has been set by an accurately measured CRL, it should not be changed by a subsequent scan. For example, if another scan done 6 or 8 weeks later says that one should have a new due date which is further away, one should not normally change the date but should rather interpret the finding as that the baby is not growing at the expected rate.

b) The Biparietal diameter (BPD)

The diameter between the 2 sides of the head. This is measured after 13 weeks. It increases from about 2.4 cm at 13 weeks to about 9.5 cm at term. Different babies of the same weight can have different head size, therefore dating in the later part of pregnancy is generally considered unreliable. (Chart and further comments) Dating using the BPD should be done as early as is feasible.

c) The Femur length (FL)

Measures the longest bone in the body and reflects the longitudinal growth of the fetus. Its usefulness is similar to the BPD. It increases from about 1.5 cm at 14 weeks to about 7.8 cm at term. (Chart and further comments) Similar to the BPD, dating using the FL should be done as early as is feasible.

d) The Abdominal circumference (AC)

The single most important measurement to make in late pregnancy. It reflects more of fetal size and weight rather than age. Serial measurements are useful in

monitoring growth of the fetus. (Chart and further comments) AC measurements should not be used for dating a fetus.

Other important measurements are discussed here.

The weight of the fetus at any gestation can also be estimated with great accuracy using polynomial equations containing the BPD, FL, and AC. computer softwares and lookup charts are readily available. For example, a BPD of 9.0 cm and an AC of 30.0 cm will give a weight estimate of 2.85 kg. (comments)

4. Diagnosis of fetal malformation.

Many structural abnormalities in the fetus can be reliably diagnosed by an ultrasound scan, and these can usually be made before 20 weeks. Common examples

include hydrocephalus, anencephaly, myelomeningocoele, achondroplasia and other dwarfism, spina bifida, exomphalos, Gastroschisis, duodenal atresia and fetal hydrops. With more recent equipment, conditions such as cleft lips/ palate and congenital cardiac abnormalities are more readily diagnosed and at an earlier gestational age. (Also see the FAQ and Anomalies pages).

First trimester ultrasonic 'soft' markers for chromosomal abnormalities such as the absence of fetal nasal bone, an increased fetal nuchal translucency (the area at the back of the neck) are now in common use to enable detection of Down syndrome fetuses.

Read also: Soft Markers - A Guide for Professionals and Ultrasonographic "soft markers" of fetal chromosomal defects.

Ultrasound can also assist in other diagnostic procedures in prenatal diagnosis such as amniocentesis, chorionic villus sampling, cordocentesis (percutaneous umbilical blood sampling) and in fetal therapy.

5. Placental localization.

Ultrasonography has become indispensible in the localization of the site of the placenta and determining its lower edges, thus making a diagnosis or an exclusion of placenta previa. Other placental abnormalities in conditions such as diabetes, fetal hydrops, Rh isoimmunization and severe intrauterine growth retardation can also be assessed.

6. Multiple pregnancies.

In this situation, ultrasonography is invaluable in determining the number of fetuses, the chorionicity, fetal presentations, evidence of growth retardation and fetal anomaly, the presence of placenta previa, and any suggestion of twin-to-twin transfusion.

7. Hydramnios and Oligohydramnios.

Excessive or decreased amount of liquor (amniotic fluid) can be clearly depicted by ultrasound. Both of these conditions can have adverse effects on the fetus. In both these situations, careful ultrasound examination should be made to exclude intraulterine growth retardation and congenital malformation in the fetus such as intestinal atresia, hydrops fetalis or renal dysplasia. See also FAQ and comments.

8. Other areas.

Ultrasonography is of great value in other obstetric conditions such as:

a) confirmation of intrauterine death. b) confirmation of fetal presentation in uncertain cases.c) evaluating fetal movements, tone and breathing in the Biophysical Profile.d) diagnosis of uterine and pelvic abnormalities during pregnancy e.g. fibromyomata and ovarian cyst.

Transvaginal ScansWith specially designed probes, ultrasound scanning can be done with the probe placed in the vagina of the patient. This method usually provides better images (and therefore more information) in patients who are obese and/ or in the early stages of pregnancy. The better images are the result of the scanhead's closer proximity to the uterus and the higher frequency used in the transducer array resulting in higher

resolving power. Fetal cardiac pulsation can be clearly observed as early as 6 weeks of gestation.

Vaginal scans are also becoming indispensible in the early diagnosis of ectopic pregnancies. An increasing number of fetal abnormalities are also being diagnosed in the first trimester using the vaginal scan. Transvaginal scans are also useful in the second trimester in the diagnosis of congenital anomalies. Read one of my presentations at OBGYN.net-Ultrasound.

Doppler UltrasoundThe doppler shift principle has been used for a long time in fetal heart rate detectors. Further developments in doppler ultrasound technology in recent years have enabled a great expansion in its application in Obstetrics, particularly in the area of assessing and monitoring the well-being of the fetus, its progression in the face of intrauterine growth restriction, and the diagnosis of cardiac malformations.

Doppler ultrasound is presently most widely employed in the detection of fetal cardiac pulsations and pulsations in the various fetal blood vessels. The "Doptone" fetal pulse detector is a commonly used handheld device to detect fetal heartbeat using the same doppler principle.

Blood flow characteristics in the fetal blood vessels can be assessed with Doppler ' flow velocity waveforms ' . Diminished flow, particularly in the diastolic phase of a pulse cycle is associated with compromise in the fetus. Various ratios of the systolic to diastolic flow are used as a measure of this compromise. The blood vessels commonly interrogated include the umbilical artery, the aorta, the middle cerebral arteries, the uterine arcuate arteries, and the inferior vena cava.

The use of color flow mapping can clearly depict the flow of blood in fetal blood vessels in a realtime scan, the direction of the flow being represented by different colors. Color doppler is particularly indispensible in the diagnosis of fetal cardiac and blood vessel

defects, and in the assessment of the hemodynamic responses to fetal hypoxia and anemia.

A more recent development is the Power Doppler (Doppler angiography). It uses amplitude information from doppler signals rather than flow velocity information to visualize slow flow in smaller blood vessels. A color perfusion-like display of a particular organ such as the placenta overlapping on the 2-D image can be very nicely depicted. Doppler examinations can be performed abdominally and via the transvaginal route. The power emitted by a doppler device is greater than that used in a conventional 2-D scan. Its use in early pregnancy is therefore cautioned.

Doppler facilities are generally an integral part of modern ultrasound scanners. They merely would need to be switched on to function. One does not need to 'go' to another machine for the doppler investigations.

3-D and 4-D Ultrasound3-D ultrasound can furnish us with a 3 dimensional image of what we are scanning. The transducer takes a series of images, thin slices, of the subject, and the computer processes these images and presents them as a 3 dimensional image. Using computer

controls, the operator can obtain views that might not be available using ordinary 2-D ultrasound scan. 3-dimensional ultrasound is quickly moving out of the research and developmentstages and is now widely employed in a clinical setting. It too, is very much in the News. Faster and more advanced commercial models are coming into the market. The scans requires special probes and software to accumulate and render the images, and the rendering time has been reduced from minutes to fractions of a seconds.

A good 3-D image is often very impressive to the parents. Further 2-D scans may be extracted from 3-D blocks of scanned information. Volumetric measurements are more accurate and both doctors and parents can better appreciate a certain abnormality or the absence of a certain abnormality in a 3-D scan than a 2-D one and there is the possibility of increasing psychological bonding between the parents and the baby.

An increasing volume of literature is accumulating on the usefulness of 3-D scans and the diagnosis of congenital anomalies could receive revived attention. Present evidence has already suggested that smaller defects such as spina bifida, cleft lips/palate, and polydactyl may be more lucidly demonstrated. Other more subtle features such as low-set ears, facial dysmorphia or clubbing of feet can be better assessed, leading to more effective diagnosis of chromosomal abnormalities. The study of fetal cardiac malformations is also receiving attention. The ability to obtain a good 3-D picture is nevertheless still very much dependent on operator skill, the amount of liquor (amniotic fluid) around the fetus, its position and the degree of maternal obesity, so that a good image is not always readily obtainable.

More recently, 4-D or dynamic 3-D scanners are in the market and the attraction of being able to look at the face and movements of your baby before birth was also enthusiastically reported in parenting and health magazines. This is thought to have an important catalytic effect for mothers to bond to their babies before birth. What are known as 're-assurance scans' and the rather misnamed 'entertainment scans' have quickly become popular.

Most experts do not consider that 3-D and 4-D ultrasound will be a mandatory evolution of our conventional 2-D scans, rather it is an additional piece of tool like doppler ultrasound. Most diagnosis will still be made with the 2-D scans. 3-D ultrasound appears to have great potential in research and in the study of fetal embryology. Whether 3-D ultrasound will provide unique information or merely supplemental information to the conventional 2-D scans will remain to be seen.

Click here   for some good sample images courtesy of Dr. Bernard Benoit. Visit the GE 4D site for more pictures and information. Dr. Najeeb Layyous's 3-D and 4-D website also has many more pictures and clips. Read also the FAQ page.

A short history of the development of 3-D ultrasound in pregnancy can be found in the History pages.

The ScheduleThere is no hard and fast rule as to the number of scans a woman should have during her pregnancy. A scan is ordered when an abnormality is suspected on clinical grounds. Otherwise a scan is generally booked at about 7 weeks to confirm pregnancy, exclude

ectopic or molar pregnancies, confirm cardiac pulsation and measure the crown-rump length for dating.

A second scan is performed at 18 to 20 weeks mainly to look for congenital malformations, when the fetus is large enough for an accurate survey of the fetal anatomy. multiple pregnancies can be firmly diagnosed and dates and growth can also be assessed. Placental position is also determined. Further scans may be necessary if abnormalities are suspected.

Many centers are now performing an earlier screening scan at around 11-14 weeks to measure the fetal nuchal translucency and to evaluate the fetal nasal bone (and more recently, to detect tricuspid regurgitation) to aid in the diagnosis of Down Syndrome. Some centers will do blood test biochemical screening at the same visit.

Further scans may sometimes be done at around 32 weeks or later to evaluate fetal size (to estimate the fetal weight) and assess fetal growth. Or to follow up on possible abnormalities seen at an earlier scan. Placental position is further verified. The most common reason for having more scans in the later part of pregnancy is fetal growth retardation. Doppler scans may also be necessary in that situation.

The total number of scans will vary depending on whether a previous scan has detected certain abnormalities that require follow-up assessment. What is often referred to as a Level II scan merely indicates a "targeted" examination where it is done when an indication is present or when an abnormality is suspected in a previous examination. In fact professional bodies such as the American Institute of Ultrasound in Medicine does not endorse or encourage the use of these terms. A more "thorough" examination is usually done at an a perinatal center or specialised clinic where more expertise and better equipments may be present.

One should not dwell too much on the definitions or guidelines for a level II ultrasound scan. The prenatal sonologist should always try very hard to look for and assess any abnormality that may be present in the fetus. It is not very meaningful to be talking about level III or even level IV scans.

That a pregnancy should be scanned at 18 to 20 weeks as a rule is gradually becoming a matter of routine practice. Please go to the FAQ page and News page for other discussions. A rather thorough discussion paper on Ultrasound screening in pregnancy can be found here. Read also the RCOG's paper on routine screening in pregnancy.

What about Safety?It has been over 40 years since ultrasound was first used on pregnant women. Unlike X-rays, ionizing irradiation is not present and embryotoxic effects associated with such irradiation should not be relevant. The use of high intensity ultrasound is associated with the effects of "cavitation" and "heating" which can be present with prolonged insonation in laboratory situations.

Although certain harmful effects in cells are observed in a laboratory setting, abnormalities in embryos and offsprings of animals and humans have not been unequivocally demonstrated in the large amount of studies that have so far appeared in the medical literature purporting to the use of diagnostic ultrasound in the clinical setting. Apparent ill-effects such as low birthweight, speech and hearing problems, brain damage and non-right-handedness reported in small studies have not been confirmed or substantiated in larger studies from Europe. The complexity of some of the studies have made the observations difficult to interpret. Every now and then ill effects of ultrasound on the fetus appears as a news item in papers and magazines. Continuous vigilance is necessary particularly in areas of concern such as the use of pulsed Doppler in the first trimester.

The greatest risks arising from the use of ultrasound are the possible over- and under- diagnosis brought about by inadequately trained staff, often working in relative isolation and using poor equipment.

A discussion on the various possible effects of ultrasound on the human fetus can be found here. Ultrasound scans should best be performed when there is a clear indication to do so. When there is, safety considerations should not be an issue to prevent its prudent use.

It should be bornt in mind that prenatal ultrasound cannot diagnose all malformations and problems of an unborn baby (reported figures range from 40 to 98 percent), so one should never interpret a normal scan report as a guarantee that the baby will be completely normal. Some abnormalities are very difficult to

find or to be absolutely certain about.

Some conditions, like for example hydrocephalus, may not have been obvious at the time of the earlier scan. The position of the baby in the uterus has a great deal to do with how well

one sees certain organs such as the heart, face and spine. Sometimes a repeat examination has to be scheduled the following day, in the hopes the baby has moved.

Images tend also to be strikingly clear in skinny patients with lots of amniotic fluid, and frustratingly fuzzy in obese women, particularly if there is not much amniotic fluid as in cases of growth restriction. As in almost every endeavor, there is also a wide difference in the skill, training, talent, and interest of the sonographer or sonologists. The improvements in equipment has also lead to the earlier detection of abnormal structures in the fetus bringing along with it "false positives" and "difficult-to-be-sure-what-will-happen" diagnosis that could generate huge amount of undue anxiety in patients.