Normal structures

• Placenta: gas exchange, transfer of nutrients and wastes, hormone production (hCG, human placental lactogen, estrogen, progesterone), and partial barrier function. It does not block all infections — cytomegalovirus, rubella, Toxoplasma, syphilis, HIV, and Zika can cross, as can many drugs and IgG antibodies
• Umbilical cord: two arteries (carry deoxygenated blood from fetus to placenta) and one vein (carries oxygenated blood to the fetus), protected by Wharton's jelly
• Amniotic fluid: cushions the fetus, allows movement and lung development, prevents cord compression; produced mainly by fetal urine and swallowed by the fetus

Placental problems

Cord problems

• Umbilical cord prolapse: the cord slips ahead of or beside the presenting part after membranes rupture and is compressed → fetal hypoxia. Risks: rupture of membranes with an unengaged presenting part, breech or transverse lie, preterm or small fetus, polyhydramnios, multiple gestation, amniotomy with a high head
• Vasa previa: fetal vessels run through the membranes over the cervix; rupture causes fetal hemorrhage — painless bleeding at membrane rupture with sudden fetal bradycardia or sinusoidal pattern
• Velamentous cord insertion (vessels in membranes), single umbilical artery (SUA) — associated with fetal anomalies (cardiac, renal) and growth restriction; true knots; nuchal cord

Amniotic fluid and membranes

• Oligohydramnios (deepest pocket < 2 cm or AFI ≤ 5 cm): fetal renal agenesis or obstruction, ruptured membranes, placental insufficiency, post-term pregnancy, maternal NSAIDs or ACE inhibitors. Consequences: cord compression, pulmonary hypoplasia, limb contractures
• Polyhydramnios (deepest pocket ≥ 8 cm or AFI ≥ 24–25 cm): maternal diabetes, fetal GI obstruction (esophageal or duodenal atresia — fetus cannot swallow), neural tube defects, fetal anemia, twin–twin transfusion. Consequences: rapid abdominal enlargement, dyspnea, preterm labor, malpresentation, cord prolapse or abruption when membranes rupture, postpartum hemorrhage from overdistension
• Prelabor rupture of membranes (PROM): rupture before labor at term; preterm PROM (PPROM) before 37 weeks. Main risks: intraamniotic infection, cord prolapse, preterm birth
• Intraamniotic infection (chorioamnionitis): ascending infection of fluid, membranes, or placenta

• Previa vs. abruption: pain, uterine tone, color of bleeding, fetal status (see table)
• PAS: often no symptoms; suspected on ultrasound in a client with previa and prior cesarean
• Suspected intraamniotic infection (ACOG): maternal temperature ≥ 39.0 °C (102.2 °F), or 38.0–38.9 °C (100.4–102.0 °F) plus another sign — fetal tachycardia (> 160 bpm), maternal leukocytosis, or purulent/foul fluid. A 2024 ACOG update allows a suspected diagnosis without fever when other signs are present
• Cord prolapse: cord seen or felt in the vagina, or sudden variable decelerations or prolonged bradycardia after membranes rupture (occult prolapse)
• Polyhydramnios: fundal height larger than dates, tense abdomen, difficulty palpating fetal parts, shortness of breath

• Ultrasound: placental location (a transvaginal scan is safe for previa), PAS signs, cord insertion and vessel count, amniotic fluid volume, Doppler for vasa previa
• MRI in selected PAS cases
• No digital vaginal exam with previa or unexplained bleeding
• PROM: sterile speculum exam (pooling, nitrazine, ferning); avoid digital exams in PPROM unless in active labor
• Amniocentesis for suspected infection (low glucose, high white cells, positive Gram stain or culture) when the diagnosis is unclear
• Detailed anatomy scan and fetal echocardiography when SUA is found

Placenta accreta spectrum

• Planned cesarean hysterectomy at a center with blood bank and multidisciplinary team, commonly at 34 0/7–35 6/7 weeks; the placenta is left in place — attempting forced manual removal can cause massive hemorrhage
• If unexpectedly found at vaginal birth: do not pull; call for help, prepare for hemorrhage and surgery

Vasa previa: planned cesarean at 34 0/7–35 6/7 weeks (SMFM/ACOG) before labor or membrane rupture; corticosteroids beforehand.

Cord prolapse — obstetric emergency

• Delivery, usually by emergency cesarean, unless vaginal birth is imminent

PROM at term: induction (usually oxytocin) is generally recommended rather than prolonged waiting; GBS prophylaxis per status.

PPROM before 34 weeks (expectant management)

• Latency antibiotics (e.g., IV ampicillin plus erythromycin for 48 hours, then oral amoxicillin plus erythromycin for 5 days; azithromycin is often substituted) — prolong pregnancy and reduce infection
• Antenatal corticosteroids; magnesium sulfate for neuroprotection if birth is expected < 32 weeks (monitor reflexes, respiratory rate, urine output — see Complications of Labor); GBS prophylaxis
• Delivery is recommended for intraamniotic infection, abruption, or nonreassuring fetal status; otherwise delivery is considered from 34 0/7 weeks

Intraamniotic infection: IV ampicillin plus gentamicin (add clindamycin or metronidazole for cesarean); acetaminophen for fever; infection itself is not an indication for cesarean. Inform the neonatal team.

Polyhydramnios: treat cause (glucose control), amnioreduction for severe symptoms; indomethacin is rarely used. Oligohydramnios: hydration, more frequent surveillance, delivery timing; amnioinfusion in labor for recurrent variable decelerations.

Drug safety

• Gentamicin: nephrotoxicity and ototoxicity; check kidney function; once-daily dosing is common
• Erythromycin/azithromycin: GI upset, QT prolongation
• Ampicillin: allergy — ask about penicillin reactions

Listed in priority order.

1. Cord prolapse
   • Call for help; do not leave the client
   • With a sterile gloved hand, elevate the presenting part off the cord and keep it there until delivery
   • Position knee-chest or steep Trendelenburg (or exaggerated Sims) to use gravity
   • Do not handle or push the cord back; if outside the vagina, cover with warm sterile saline-soaked gauze
   • Stop oxytocin, continuous FHR, IV access; prepare for immediate cesarean; bladder filling or tocolytic may be used per protocol to relieve pressure
2. Bleeding (previa/abruption/vasa previa/PAS)
   • No vaginal exam; lateral position; two large-bore IVs; type and crossmatch; continuous FHR; quantify blood loss; watch for DIC (oozing from IV sites, low fibrinogen) in abruption
3. After any membrane rupture: check FHR immediately, then COAT; temperature every 2 hours (hourly if elevated) per facility policy; limit vaginal exams
4. Infection: give antibiotics on time; monitor maternal temperature, pulse, and FHR; watch for sepsis
5. Polyhydramnios: semi-Fowler's or lateral position for dyspnea; monitor for preterm labor; at membrane rupture, watch for cord prolapse and abruption
6. Third stage: inspect the placenta for completeness, accessory lobes, and three vessels

• Previa: no intercourse or anything in the vagina; report bleeding immediately. Strict activity or bed rest is not routinely recommended because it lacks proven benefit and raises VTE risk — follow the individual plan
• Most clients with PPROM are managed in hospital; home care is uncommon and only under a specific protocol. If at home: check temperature twice daily; report fever, foul discharge, contractions, decreased movement; no tampons, intercourse, or baths
• Daily fetal movement awareness when fluid is low
• Explain the reason for planned early delivery with PAS or vasa previa

• Cord: 2 arteries, 1 vein; SUA → look for anomalies
• Placenta does not block all infections (CMV, rubella, Toxoplasma, syphilis)
• Previa = painless bright red; abruption = painful, rigid uterus
• No vaginal exams with previa or unexplained bleeding
• Cord prolapse: elevate presenting part, knee-chest/Trendelenburg, don't touch or replace cord, emergency cesarean
• Polyhydramnios → dyspnea, rapid uterine growth, diabetes, GI atresia
• Oligohydramnios → renal anomaly, ROM, placental insufficiency
• PPROM: antibiotics + steroids + magnesium (< 32 weeks)
• Intraamniotic infection: fever + fetal tachycardia; ampicillin + gentamicin
• PAS: planned cesarean hysterectomy; no forced placental removal