Unit 113 - Unit 4 - Intrapartum Abnormal Pt. 2


Newborn weights greater than 4,000-4,500g (8.8-9.2lbs) at birth- Associated with obesity, diabetes, and cardiovascular disorders later in lifeRisk Factors- Maternal diabetes- Obesity- Suspicion of macrosomia via ultrasoundPotential Complications- Postpartum hemorrhage- Shoulder dystocia- Low APGAR scores- Dysfunctional labor- Fetopelvic disproportion- Vaginal lacerations- Fetal injuries or fractures- Perinatal asphyxia

Macrosomia - Management

- C-section often scheduled for primigravida women- Vacuum and forceps assisted births are common

Hypertonic Uterine Dysfunction

Uterus never fully relaxes during contractions, causing fetal distress- More common in nulliparous women- UC's are ineffective, erratic, and poorly coordinated- Prolonged latent phase (no dilation past 2-3cm)- Oxygen to fetus is reduced due to no relaxation period

Hypertonic Uterine Dysfunction - Management

- Therapeutic rest with the use of sedatives to promote relaxation and stop abnormal contraction pattern- Onset of normal labor pattern usually occurs after 4-6 hour rest period- Possible AROM to augment labor- C-section if normal labor pattern is not achieved

Hypotonic Uterine Dysfunction

Uterus relaxes too much during contractions, making them ineffective- Risk factors: over-stretching of the uterus, macrosomia, multiple gestation, bowel or bladder distention, excessive anesthesia- Presents as weak, mild, and infrequent UC's- Complications: postpartum hemorrhage due to uterine atony

Hypotonic Uterine Dysfunction - Management

- Possible AROM and oxytocin infusion to stimulate effective contractions- C-section if normal pattern is not achieved, or if fetus is in distress

Precipitate Labor

Uterus contracts with such intensity that it causes a very rapid birth (less than 3 hours)- Identified based on rapid progress through all stages of labor- Fetal complications: head trauma, intracranial hemorrhage, nerve damage, hypoxia- Woman typically has soft perineal tissues that stretch easily, and abnormally strong UC's- If birth occurs and the cervix is not completely dilated, cervical lacerations or uterine rupture may occur- Healthcare team must be prepared for birth at all times

Protraction Disorders

Slower than normal labor progress (often due to cephalopelvic disproportion).- Vaginal birth is still possible if given adequate time.

Fetal Malpresentation

Any fetal presentation other than occiput anterior.- Increases probability for dystocia (abnormal or difficult labor, characterized by slow and abnormal progression)- By 35-36 weeks, majority of fetuses will be in the vertex (cephalic) position.

Occiput Posterior

sunny side up baby"- Most common malpresentation. - May be caused by poor head flexion or poor uterine contractions.

Face/Brow Presentation

Baby's face comes out first- (rare) associated with fetal anomalies, pelvic contractures, high parity, placenta previa, polyhydramnios, low birth weight, and macrosomia.

Preterm Labor

Occurrence of regular uterine contractions, cervical dilation, and effacement prior to 37 weeks gestation.- UC's must be persistent, effacement greater than 80%, and dilation > 1cm

Preterm Labor - Risk Factors

- Multiple gestations- Prior preterm birth- Low socioeconomic status- Maternal medical disorders- Maternal infections- Maternal age extremes (younger than 16 or older than 40)

Preterm Labor - Fetal Risks

- Respiratory distress syndrome- Infection- Congenital heart defects- Thermoregulation problems- Intraventricular hemorrhage- Jaundice- Hypoglycemia- Feeding difficulties- Neurological disorders (due to hypoxia)- Birth trauma (cerebral palsy, intellectual impairment, vision/hearing defects)

Preterm Labor - Labs and Diagnostics

- Fetal Fibronectin: useful marker for predicting impending spontaneous rupture of membranes within the next 7-14 days.- Negative: Strong predictor that preterm labor within the next 2 weeks is unlikely- Positive: Preterm labor may occur within the next 2 weeks- Test results may be altered in the presence of lubricants, blood, recent intercourse, or cervical manipulation within the last 24 hours.- Cervical length measurement: a cervical length of > 3cm may indicate that delivery within the next 2 weeks is unlikely.- Cervical length of < 2.5cm during mid-gestation may indicate a risk of preterm birth (prior to 35 weeks gestation)

Preterm Birth - Education

- Avoid lifting heavy objects- Wait 18 months between pregnancies- Avoid use of substances- Avoid sexual activity during pregnancy- If having any symptoms of preterm labor: drink plenty of water, lie down on side for one hour, palpate abdomen for strength of contractions, and call HCP

Preterm Labor - Management

- Tocolytic drugs: promote uterine relaxation- Antibiotics for GBS+ women- Steroid administration to promote fetal lung maturity

Tocolytic Therapy

Attempt to delay birth, usually in order to reduce the severity of respiratory distress syndrome in preterm labor (before 34 weeks).- Does not ultimately prevent labor, but delays it.- Goals: delay birth long enough to initiate corticosteroid therapy to stimulate fetal lung maturity, and to arrange for maternal-fetal transport to tertiary care hospital.- Medications: magnesium sulfate, Indomethacin, Nifedipine

Tocolytic Therapy - Contraindications

- Abruptions- Fetal distress or death- Fetus before viability- Severe preeclampsia- PPROM- Active vaginal bleeding- Dilation > 6cm- Chorioamnionitis (amniotic infection)- Maternal hemodynamic instability

Magnesium Sulfate

Relaxes uterine muscles to stop irritability and uterine contractions during preterm labor- Administration: IV; loading dose 4-6g over 15 to 30 minutes, then maintain at 1-4g/hour.Assessment- Vital signs: monitor for hypotension and respiratory depression (<12)- Deep tendon reflexes: decreased or absent may indicate overdose- Monitor for decreased consciousness and slurred speech- Monitor urine output- Monitor FHR: may cause decreased variabilityReversal: calcium gluconate


Inhibits prostaglandins, which stimulate uterine activity, in order to arrest preterm labor.- Not commonly given due its many side effects- Administration: rectalAssessment- Continuous monitoring of vital signs, uterine activity, and FHR- Contraindications: >32 weeks gestation, fetal growth restriction, history of asthma, or allergies to aspirin or NSAIDs- Neonatal adverse effects: constriction of ductus arteriosus, premature ductus close, necrotizing entercolitis, oligohydramnios, pulmonary hypertension


Inhibits uterine activity by blocking calcium influx to the cells to arrest preterm labor.- Sometimes given along with magnesium sulfate- Administration: OralAssessment- Monitor BP hourly, especially if given with magnesium sulfate (increased risk of hypotension)- Report pulse rate of >110- Monitor for decreased uteroplacental perfusion, indicated by fetal bradycardia- Contraindications: heart disease, hemodynamic instability


Given to mother in preterm labor to help prevent or reduce the severity of respiratory distress syndrome in infants between 24-34 weeks.- Betamethasone- Promotes fetal lung maturity by stimulating surfactant production.Administration- Given to mom IM; two doses given 24 hours apart.- If infant is not delivered within 7 days of first dose, another two doses can be administered.

Post-Term Pregnancy

Any pregnancy greater than 42 weeks gestation- As the placenta ages, it begins to calcify and breakdown, causing decreased perfusion- Amniotic fluid begins to decrease after 38 weeks

Post-Term Pregnancy - Complications

Maternal Risks- Related to a large fetus (macrosomia)- C-section- Dystocia- Birth trauma- Post-partum hemorrhage- InfectionFetal Risks- Macrosomia- Shoulder dystocia- Brachial plexus injuries- Low APGAR scores- Cephalopelvic disproportion (head too large to pass through maternal pelvis)- Meconium aspiration- Uteroplacental insufficiency

Post-Term Pregnancy - Management

Focus: monitor fetal wellbeing- Patient should do daily fetal movement counts- Estimate accurate gestational age via ultrasound- Conduct non-stress tests with amniotic fluid assessments

Umbilical Cord Prolapse

Rare emergency in which the umbilical cord protrudes either alongside or ahead of the presenting part of the fetus.- Usually leads to partial or total occlusion of the cord- Perfusion deteriorates rapidly, and fetus will die if cord compression is not quickly relieved

Umbilical Cord Prolapse - Risk Factors

- Malpresentation- Fetal growth restriction- Prematurity- Rupture of membranes with fetus at high station- Polyhydramnios- Multiparity- Multiple gestation

Umbilical Cord Prolapse - Management

- Recognize first sign of cord prolapse: sudden fetal bradycardia or recurrent variable decelerations that become progressively more severe- Call for help IMMEDIATELY, but do not leave mom- Assist with measures to relieve compression1. Place a sterile gloved hand into the vagina hold the presenting part off of the umbilical cord until delivery (emergency C-section)2. Change woman's position to left lateral, trendelenburg, or knee-chest3. Monitor FHR4. Maintain bedrest5. Administer oxygen

Amniotic Fluid Embolism

Amniotic fluid containing debris (hair, skin, meconium) enters maternal circulation and obstructs pulmonary vessels, causing sudden respiratory distress and circulatory collapse.- VERY rare, but VERY life-threatening

Amniotic Fluid Embolism - Pathophysiology

- Abnormal maternal response to fetal tissue exposure associated with breaches of the maternal-fetal physiological barrier during the postpartum period- Usually, amniotic fluid does not enter maternal circulation because it is contained within the uterus and sealed off by the amniotic sac- Embolus occurs when the barrier between maternal circulation and amniotic fluid is broken and amniotic fluid enters the venous system via the endocervical veins, placental site, or site of uterine trauma

Amniotic Fluid Embolism - Risk Factors and Symptoms

Risk Factors- Placental abruption- Over-distended uterus- Fetal demise- Uterine trauma- Induced labor- Amnioinfusion- Multiparity- Rupture of membranes- Advanced maternal ageSymptoms- Sudden hypotension- Hypoxia- Coagulopathy (blood doesn't clot as it should, or at all)- Uterine atony with hemorrhage

Amniotic Fluid Embolism - Management

- Early recognition of condition is key- Supportive care: maintain oxygenation, hemodynamic function, and correct coagulopathy- Use vasopressors to maintain blood pressure- Oxytocin infusions to address uterine atony