Abnormal Labor

Barbara M. O’Brien, M.D.

Maternal Fetal Medicine

Clinical Genetics

Women and Infants Hospital

Brown University

Abnormal Labor

• Dystocia: difficult labor– characterized by abnormally slow progress of

labor – common whenever there is disproportion

between the presenting part of the fetus and the birth canal

Abnormal Labor

• Dystocia:

– can result from several distinct abnormalities • involving the cervix, uterus, fetus, maternal

bony pelvis, or other obstructions in the birth canal.

Abnormal Labor

• Consequence of 4 distinct abnormalities that may exist singly or in combination:

• (1) Abnormalities of the expulsive forces- --either uterine forces insufficiently strong to

efface and dilate the cervix (uterine dysfunction) – inadequate voluntary muscle effort during the

second stage

Abnormal Labor

• (2) Abnormalities of the maternal bony pelvis- that is, pelvic contraction

• (3) Abnormalities of presentation, position, or development of the fetus

• (4)Abnormalities of soft tissues of the reproductive tract that form an obstacle to fetal descent

Abnormal Labor• ACOG simplified these abnormalities to:

– (1) Abnormalities of the powers (uterine contractility and maternal expulsive effort)

– (2) Abnormalities of the passenger (fetus)– (3) Abnormalities of the passage (the pelvis)

Abnormal Labor

• Common Clinical Findings in Women with Ineffective Labor:– Inadequate cervical dilation or fetal

descent• protracted labor-slow progress• arrested labor-no progress• inadequate expulsive effort-ineffective

“pushing”

Abnormal Labor

– Fetopelvic disproportion

• excessive fetal size

• inadequate pelvic capacity

• malpresentation or position of the fetus

– Ruptured membranes without labor

Abnormal Labor

• failure to progress :lack of progressive cervical dilation or fetal descent

• cephalopelvic disproportion: obstructed labor due to disparity between fetal head and maternal pelvis

• cesarean delivery is necessary with both cases

Abnormal Labor

• Friedman curve: subdivided labor into phases and depicted it onto curves

• Divides 1st stage into – latent and active phase

Abnormal Labor

– latent phase: onset of labor is defined according to Friedman as the point at which the mother perceives regular contractions• regular contractions take place along with

cervical softening and effacement• prolonged latent phase: defined as greater

than 20 hours in a nullipara and greater than 14 hours in a parous woman

Abnormal Labor

– Active phase:• cervical dilation rate of 1.2 cm/hr for

nulliparas and 1.5 cm/hr for parous women• cervical dilation of 3 or 4 cm or more, in the

presence of uterine contractions can be taken to reliably represent the threshold for active labor

• nullipara on average dilate 1.2 cm/hour and multips on average dilate 1.5 cm/hour (minimum)

Abnormal Labor• Active Phase Cont’d:

– Protraction: slow rate of cervical dilation or descent

• For nulliparas: <1.2 cm dilatation/hr or < 1 cm descent/hr• For multiparas: <1.5 cm dilatation/hr or <2 cm descent/hr• Treat with expectant management/oxytocin

– Arrest: complete cessation of dilatation or descent• Arrest of dilatation: 2 hours with no cervical change• Arrest of descent: 1 hour without fetal descent

Abnormal Labor

• Second Stage: begins when cervical dilation is complete and ends with expulsion of fetus

• Median duration for nullips: 50 min– Until recently, limited to 2 hours without epidural and

to 3 hours with epidural

• Median duration for multips: 20 min– Until recently, limited to 1 hour without an epidural

and to 2 hours with an epidural

• Can be longer with bigger babies and regional anesthesia

Abnormal Labor

• interventions other than cesarean delivery must be considered before resorting to this method of delivery for failure to progress– i.e operative vaginal delivery

Abnormal Labor

• Diagnosis of Inadequate Labor:– Active phase disorders: – (1)Protraction disorders – (2)arrest disorders

Abnormal Labor

– Before the diagnosis of arrest during the first stage of labor is made, both these criteria must be met:• Latent phase has been completed, with the

cervix dilated 4 cm or more• A uterine contraction pattern of 200

Montevideo units or more in a 10-minute period has been present for 2 hours without cervical change

Should there be a “2 hour” Rule?

• Rose et al (1999) recently challenged the “2 hour” rule on the grounds that a longer time, i.e. 4 hours is necessary before concluding that the active phase of labor has failed and William Obstetrics agrees

Abnormal Labor

• Causes of inadequate expulsive forces:– Heavy sedation or conduction analgesia

– Maternal exhaustion

• Maternal Effects of Dystocia:– Intrapartum infection– especially in the setting of ROM

– Uterine rupture– esp with prior C/S

– Fistula formation

– Pelvic floor injury

– Fistula formation

Abnormal Labor

• Fetal Effects of Dystocia:• Caput Succedaneum:

– If the pelvis is contracted during labor a large caput succedaneum frequently develops on the most dependent part of the fetal head

– This can lead to diagnostic errors; the caput can reach almost to the pelvic floor while the head is still not engaged

– An inexperienced physician may make premature and unwise attempts at forceps delivery

Abnormal Labor

• Fetal Head Molding:– Under the pressure of the strong uterine

contractions, cranial plates overlap one another at the major sutures,a process referred to as molding

Abnormal Labor

• In nearly 97% of pregnancies, at the time of delivery, the fetus is entering the pelvis as a cephalic presentation

• Compound presentation: an extremity prolapses alongside the presenting par, with both presenting in the pelvis simultaneously (1/700)

• Persistent occiput posterior position: most often undergoes spontaneous rotation to anterior rotation followed by NVD

Cesarean section

• proceed with c/s with:– Transverse lie

– Placenta previa

– Non-reassuring fetal heart rate when an operative delivery is not attainable

– Nonvertex presenting twin

– Breech

– Many more indications, including repeat s( decline TOL) ands elective cesarean section

Cesarean Section

Cesarean Section

Indications for Vacuum-Assisted Delivery

• Maternal indications • Need to avoid voluntary

maternal expulsive efforts (e.g., the mother has cardiac or cerebrovascular disease)

• Inadequate maternal expulsive efforts

• Maternal exhaustion or lack of cooperation

• Fetal indications • Nonreassuring fetal

heart tracing • Prolonged second

stage of labor • Failure to progress in

second stage of labor

Comparative Advantages of Vacuum

Extractors and Forceps

• Vacuum extractors • Easier to learn

• Quicker delivery

• Less maternal genital trauma

• Less maternal discomfort • Fewer neonatal

craniofacial injuries • Less anesthesia needed

• Forceps • Fewer neonatal

injuries, including cephalohematoma, retinal hemorrhage and transient lateral rectus palsy

• Higher rate of successful vaginal delivery

Vacuum

Vacuum

Procedure Using Soft-Cup

Vacuum Extraction

• Empty bladder

• Ensure complete dilation

• Adequate anesthesia

• fetal presentation, position and station are then confirmed

How to Apply a Vacuum

• apply the soft cup by spreading the patient's labia, compressing the cup and inserting it gently by pressing inward and downward with the inferior edge over the posterior fourchette.

• When contact is made with the fetal scalp, the center of the cup should be over the sagittal suture and about 3 cm (1.2 in) in front of the posterior fontanelle. As a practical guide, the cup is generally placed as far posteriorly as possible

How to Apply a Vacuum

• Avoid anterior fontanelle

• Do not attempt for more than 20 minutes. • The procedure should be abandoned if

delivery is not achieved or the labor does not progress.

• Under ordinary circumstances, the procedure should be abandoned after three cup detachments.

What are some complications of the Vacuum?

• Fetal complications:– Subgaleal hemorrhage:

• occurred in 1.0 to 3.8 percent of vacuum extractions in one series but has been much less common in more recent studies.

• Infants with subgaleal hemorrhage present with a boggy scalp, swelling crossing the suture lines and an expanding head circumference.

• may also have signs of hypovolemia, pallor, tachycardia and a falling hematocrit.

What are some complications of the Vacuum?

• Fetal Complications• Cephalohematoma

– incidence of 6 percent (range: 1 to 26 percent) in vacuum-assisted deliveries.

• Intracranial hemorrhage » one of every 860 vacuum-assisted deliveries compared

with one of every 1,900 spontaneous deliveries (a statistically significant difference).

» the comparative rate of intracranial hemorrhage is not statistically different when vacuum extraction, forceps delivery and cesarean section during labor are compared.

» Perhaps the abnormal labor that necessitated the assisted delivery may be an underlying cause for a portion of the morbidity attributed to operative deliveries.6

What are some complications of the Vacuum?

• Retinal hemorrhages – may be more common in vacuum-assisted deliveries but are

most often associated with duration of labor– resolve within several weeks and are to be associated with

long-term morbidity.

Transient neonatal lateral rectus paralysis found to occur in:* 3.2% of vacuum-assisted deliveries * 2.4 percent of forceps assisted deliveries * 0.1 percent normal spontaneous vaginal deliveries * 0% cesarean sections (0 percent * the paralysis resolves spontaneously and is unlikely to be of

clinical importance

(0.1 percent)

Vacuum

• Vacuum extraction has not been found to result in significant intellectual or neurologic disability!

Relative Contraindications for Vacuum Extraction

• Fetal prematurity (<34 weeks of gestation) Fetal scalp trauma Unengaged head Incomplete cervical dilatationActive bleeding or suspected fetal coagulation defects Suspected macrosomia

• Nonvertex presentation or other malpresentation Cephalopelvic disproportion Delivery requiring rotation or excessive traction Inadequate anesthesia

Forceps

• Forceps are metal surgical instruments, similar to tongs, with rounded edges that fit around the fetus's head.

Forceps Delivery

Forceps

Technique of Applying low and outlet forceps

• Identify blades and their application– The instrument should be placed in front of the

pelvis with the tip pointing upward and pelvic curve forwards

– First the left blade should be applied guided by the right hand and then the right blade with the left hand

– Locking of blades: the blades should articulate with ease

Technique of Applying low and outlet forceps

• Clinical checks for correct forceps applications:– Sagital suture lies in the midline of the shanks– The operator is unable to place more than a

fingertip between the fenestration of the blade and the fetal head on either sidethe posterior fontanelle is not more than one finger breathe above the plane of the shanks of the forceps

Complications of Forceps

• Mostly due to poor application

• Maternal: – Extension of episiotomy or cervical tears– PP hemorrhage due to trauma– Anesthesia hazards

Complications of Forceps

• Fetal:– Poor oxygenation– Trauma

• Intracranial hemorrhage

• Cephalohematoma

• Facial palsy

• Skull fracture

• Injury to soft tissue of face

Breastfeeding

• Infant feeding practices have changed dramatically during this century

• In the early 1900s, nearly 100% of the newborns in the U.S. were breastfed

• By the 1970s, only 30% of the newborn were breastfed at one week and less than 5% at 6 months

Breastfeeding

• Breastfeeding is recognized as the best method for promoting healthy growth and development and successful bonding between mother and child

• the decline in breastfeeding has been particularly problematic in developing countries

• formula is expensive

Breastfeeding

• As of 1992 about 50% of all US infants were breastfed initially and nearly 20% continued to breastfeed at 6 mo

• BENEFITS OF BREASTFEEDING:– Many moms find it a wonderful and challenging

experience

– Mothers who breastfeed often frequently establish a stronger and faster let-down response and may ensure healthy uterine involution due to oxytocin release

Breastfeeding

– Practical Benefits:• Low cost• Convenient and readily available in the correct quantity, at the

right temperature, and without the need for complicated sterilizing and preparation procedures

– Benefits to Infant’s Health:• Provides nourishment in a form that is easier for babies to digest

than formula• Provides exactly the the right combination of nutrients:

– Lactose as primary source of carbohydrates provides energy and correct balance of intestinal acids

– Fat levels in breast milk are better digested and cholesterol levels in breast milk may protect infant from excessively high cholesterol later

Breastfeeding

– Benefits to Infant’s Health:• Protein levels in early breast milk, especially

colostrum, are vital to infant’s nutritional needs and more easily used than proteins in formula

• High water content and low salt levels in breast milk ensure that infant does not need supplementary water to prevent dehydration and excrete salt

• Vitamin supplements: except, occasionally vit D, are unnecessary for breastfed infants

• Mineral content of breast milk is perfectly balanced and more easily absorbed

Breastfeeding

• Benefits to Mother’s Health:– Lactation helps the mother get back in shape

following pregnancy in part because milk production consumes fat reserves built up during pregnancy

– Breastfeeding-induced release of oxytocin helps the uterus to contract normally postpartum

Breastfeeding

• Emotional benefits:– Breastfeeding facilitates physical and emotional

bonding between mother and child, partly because:• It stimulates maternal release of prolactin-related to increase in

maternal caretaking behavior

• It stimulates maternal release of beta-endorphin-associated with increased sense of well being

• Periods of close contact with mother combined with the opportunity to suckle enhances the infant;s sense of security

Breastfeeding

• Inhibited Let-Down:– Starting a week or two after delivery, the

mother experiences the let-down reflex as a tingling and a feeling of fullness in the breast

– It results from the release of oxytocin in the posterior pituitary

General Postpartum Care

• After a Vaginal Delivery:– Greet the patient and congratulate her and the

family– Check vitals– temp, pulse, BP

• Can detect endometritis, PE. Preeclampsia

– Evaluate fundus and lochia• The abdomen should be palpated/massaged every 15

minutes or so during the first hour post delivery and the fundus is at around the umbilicus at this stage

General Postpartum Care

• Lochia Rubra: Lochia Rubra is bright red blood, mucus and tissue discharged from the uterus. Normal discharge appears bloody with clots and had a fleshy odor.

• Abnormal discharge has a foul smell, numerous or large clots.

• Excessive lochial flow indicates postpartum hemorrhage, uterine atony, or retained placental fragments

General Postpartum Care

• Perineum:– Ice packs generally help reduce swelling

• The mother should be instructed to clean the perineum with water and without soap after voiding– and to change the perineal pad frequently

General Postpartum Care

• Post cesarean section:– IV fliuds– BP, temp, pulse, urine output (for first 24

hours)– Monitor wound site for cellulitis and fundus for

tenderness• This may indicate endometritis

– No heavy for 6 weeks– No driving for 4 weeks