Post on 16-Jul-2020
Dr Ahmed El-Gendy
Journey of Pregnancy
By
Dr.Ahmed El-Gendy
Objectives What’s meant by pregnancy?
Fertilization and implantation
Placenta
Physiological changes in mother
Dr Ahmed El-Gendy
What’s Pregnancy? It’s a physiological condition in a child
bearing woman in which a growth of
fertilized ovum occur leading to full term
baby.
38-42 weeks
Three trimesters
Dr Ahmed El-Gendy
Sex Cycles in Females Ovarian cycle :
Maturation of primordial follicle = Graffian follicle.
ovulation: rupture of the follicle
It occurs at 14 th day of the cycle
Development of corpus luteum:
it secrete large amount of estrogen &progestrone.
Dr Ahmed El-Gendy
Dr Ahmed El-Gendy
Fate of Corpus Luteum
IF Pregnancy doesn’t
occur
the corpus luteum
degenerate
Menstruation
If Pregnancy occurs
The corpus luteum continues
to grow &secretes
hormones
Dr Ahmed El-Gendy
The fimbriae of the fallopian tube picks up the ovum
after its release in the peritoneal cavity during
ovulation.
Transport of The Ovum
Dr Ahmed El-Gendy
Dr Ahmed El-Gendy
Dr Ahmed El-Gendy
Pregnancy
Fertilization Fusion of the sperm with the
membrane of the ovum
fusion initiates cell division & zygote formation
Implantation IT occurs about 7 days after
ovulation
The ovum becomes embedded in the endometrium
The zygote takes its nutrition from the decidua
Dr Ahmed El-Gendy
The site of
fertilization:
Outer third of fallopian
tube
Time of
fertilization:
14 days after first day of
last menstruation
The site of
implantation:
The endometrium of
uterus
Time of
implantation:
1week after fertilization
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a- Fetal part: chorion (derived from trophoblast).
b- Maternal part: decidua.
Formation of the placenta
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1-Respiratory function.
2-Nutrition & metabolic function.
3-Excretory function.
4-Protective function.
5-Endocrine function of placenta.
Functions of the Placenta
Dr Ahmed El-Gendy
The placenta secretes: 1. Human chorionic gonadotropin (HCG)
2. Estrogen
3. Progesterone
4. Human chorionic somatotropin
5. Relaxin.
Dr Ahmed El-Gendy
Endocrine Functions of Placenta
HCG
Site of release:
syncitiotrophoblast
Start of secretion:
after one week from fertilization
Its peak:
12-16 week
Its measurement:
in urine and blood
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Function of HCG
1. It maintains the function of C.L for 12 weeks (secret
estrogen & progesterone to prepare all
reproductive system for baby and cause inhibition
of FSH and LH from pitutary-------- inhibit further
ovulation
2. Stimulates male fetal testis to secrete testosterone
(causes the testis to descend into scrotum).
3. To test for pregnancy
Dr Ahmed El-Gendy
Progesterone: from CL
and placenta
• Formation of decidual cells
• Inhibit uterine contraction
• In the Breast : stimulate
the growth of lobule
&secretary alveoli
• Increase secretion of
fallopian tube
Estrogen: from CL and
placenta
• Enlargement of the uterus
• Effect on breast:
growth of the duct
system
Dr Ahmed El-Gendy
Progesterone relaxes all smooth
muscles.
Responsible for many minor disorders:
Heart burn, constipation, fainting, backache, frequency of
micturation, varicose veins……..
• Estrogen causes salt and fluid
retention : oedema
Dr Ahmed El-Gendy
Human Chorionic Somatotropin Functions:
1. Lactogenic effect
2. Has anabolic effect on protein metabolism like growth hormone
3. Mobilize free fatty acids from stores of the mother to spare
glucose for fetal tissues
Dr Ahmed El-Gendy
Function:
1- Relaxation of the pelvic ligaments & joints.
2- uterine contractions.
Relaxin Hormone
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Response of the Mother Body to
Pregnancy 1. Weight gain by an average 12.5Kg. 2. Increased B M R due to excess metabolism of the fetus. 3. G. I .T changes:
• Some women have nausea &vomiting this is related to level of (HCG).
• Increased level of progesterone lead to decreased motility of G.I.T -------------Constipation.
• Appetite is usually increased, sometimes with specific cravings.
• Progesterone causes relaxation of the lower oesophageal sphincter and increased reflux, making many women prone to heartburn.
• Gums become spongy, friable and prone to bleeding. Good dental care is important.
• Pregnancy also predisposes to the precipitation of cholesterol gallstones.
Dr Ahmed El-Gendy
Dr Ahmed El-Gendy
Response of the Mother Body to
Pregnancy 4-Urinary tract : renal blood flow GFR
Increase pores-----Glucosuria and Proteinuria
Ureters stretches -----relax----stasis of urine and urinary tract infection (UTI)
Pressure of uterus on bladder-----frequent urination
Approximately 5% of pregnant women have bacteriuria, often asymptomatic, and there is a greater risk of developing pyelonephritis in pregnancy.
Increased water retention causes a reduction of plasma osmolality.
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5- Endocrine glands
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Dr Ahmed El-Gendy
Pituitary
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FSH/LH fall to low
levels.
ACTH and melanocyte-
stimulating hormone
increase.
Prolactin increases.
5- Endocrine glands
Serum calcium levels decrease in pregnancy, which stimulates an increase in parathyroid hormone (PTH). Colecalciferol (vitamin D3) is converted to its active metabolite, 1,25-dihydroxycolecalciferol, by placental 1α-hydroxylase.
Dr Ahmed El-Gendy
Parathormone Hormone &
Vitamin D3
5- Endocrine Glands
Response of the Mother Body to
Pregnancy
6-Hematological: • Increased blood volume----50%.
• Increased RBCs ----20%.
• Dilutional anaemia is caused by the rise in plasma volume. Elevated erythropoietin levels increase the total red cell mass by the end of the second trimester but haemoglobin concentrations never reach pre-pregnancy levels.
• A modest leukocytosis is observed.
• Increased need for iron about 1000 mg .
• Increased clotting factors(VII, VIII, IX and X) and fibrinogen increase
• Serum albumin decreases.
• Serum alkaline phosphatase increases during pregnancy - due to placental production.
•
.
Dr Ahmed El-Gendy
Response of the Mother Body to
Pregnancy
7-C.V.S: Heart rate (HR)
Stroke volume(SV)
Cardiac output(COP) increases by about 40%.
Edema in the lower extremities due to increased circulating angiotensin II .
Progesterone reduces systemic vascular resistance by about 20% early in pregnancy. Postural hypotension may result.
Diastolic and systolic blood pressure tend to fall during mid pregnancy and then return to normal by week 36.
Advise women not to take up unaccustomed, vigorous exercise in pregnancy as there is a risk of diversion of uterine blood flow to the skeletal muscles.
Dr Ahmed El-Gendy
Response of the Mother Body to
Pregnancy
8-Respiratory system: 40% in tidal volume
Decreased functional residual capacity.
The gravid uterus hinder the descent of diaphragm.
Dyspnea common complaint
Dr Ahmed El-Gendy
Tidal volume increases by about 200 ml, increasing vital capacity and decreasing residual volume. In later stages of pregnancy, splinting of the diaphragm may occur with some decrease in tidal volume. Respiratory rate does not alter significantly.
Increased oxygen consumption by approximately 20%.
State of compensated respiratory alkalosis - arterial pCO2 drops, arterial pO2 remains unchanged and decrease in bicarbonate prevents pH change. Lower maternal pCO2 facilitates oxygen/carbon-dioxide transfer to/from the fetus.
Dr Ahmed El-Gendy
8-Respiratory system
Response of the Mother Body to
Pregnancy
9- Metabolic Changes
Dr Ahmed El-Gendy
The basal metabolic rate increases slowly over the course of pregnancy, by 15-20%.
In women with normal BMIs, energy requirement does not increase significantly during the first trimester, increases by about 350 kcal/day in the second trimester and 500 kcal/day in the third.[7]
Active energy expenditure tends to fall over pregnancy.
Normal weight gain is approximately 12.5 kg (usually at a rate of 0.5 kg per week for the final 20 weeks). 5 kg is the fetus, placenta, membranes and amniotic fluid and the rest is maternal stores of fat and protein and increased intra- and extra-vascular volume.
10- Skin Changes
Dr Ahmed El-Gendy
Hyperpigmentation of the umbilicus, nipples,
abdominal midline (linea nigra) and face
(chloasma) are common due to the hormonal
changes of pregnancy.
Hyperdynamic circulation and high levels of
oestrogen may cause spider naevi and palmar
erythema.
Striae gravidarum ('stretch marks') are common.
11-Musculoskeletal Changes
Dr Ahmed El-Gendy
Increased ligamental laxity caused by increased levels of
relaxin contribute to back pain and pubic symphysis
dysfunction.
Shift in posture with exaggerated lumbar lordosis
leading to the typical gait of late pregnancy.
Integrated Medical Sciences :Shansa Prera , Stephen
Anderson, Ho Leung &Rousseau Gama , 2007 ,
pages 211-243
Dr Ahmed El-Gendy
References
1. Jamjute P, Ahmad A, Ghosh T, et al; Liver function test and pregnancy. J Matern Fetal Neonatal Med. 2009 Mar;22(3):274-83.
2. Lazarus JH, Premawardhana LD; Screening for thyroid disease in pregnancy; J Clin Pathol. 2005 May;58(5):449-52.
3. Butte NF; Carbohydrate and lipid metabolism in pregnancy: normal compared with gestational diabetes mellitus.; Am J Clin Nutr. 2000 May;71(5 Suppl):1256S-61S.
4. Thornburg KL, Jacobson SL, Giraud GD, et al; Hemodynamic changes in pregnancy.; Semin Perinatol. 2000 Feb;24(1):11-4.
Dr Ahmed El-Gendy
Further Reading & References
Dr Ahmed El-Gendy