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Prelabour rupture of membranes (PROM and PPROM)
Rupture of the membranes before labour places the pregnancy between two risks — infection if it continues, prematurity if the baby is delivered; the dividing line is 34 weeks: above it deliver, and below it wait with antibiotics and steroids as long as there is no infection.
Why it matters in the exam
Questions present a woman leaking fluid and first ask about the diagnosis: a sterile speculum examination showing pooling of fluid in the vagina, an alkaline pH (nitrazine) and a ferning pattern under the microscope, and when in doubt a biochemical test. No digital examination is done, because it shortens the time to delivery and increases infection. Next comes management by gestational age, which is the central question.
At term, induction with oxytocin is preferred. With preterm rupture between 24 and 34 weeks, expectant management is done in hospital: antibiotics for 7 days (IV ampicillin and erythromycin, then oral) which prolong pregnancy and reduce infection, betamethasone, magnesium before 32 weeks and GBS prophylaxis. Amoxicillin-clavulanate must not be given, as it is linked to NEC in the newborn. Intra-amniotic infection (chorioamnionitis) — maternal fever with fetal tachycardia, uterine tenderness or purulent discharge — requires broad antibiotics and delivery, but is not by itself a reason for caesarean section. Other complications: placental abruption, cord prolapse, and pulmonary hypoplasia with rupture before 24 weeks.
Key points
- Diagnosis: sterile speculum, nitrazine, ferning; no digital examination.
- 34 weeks or more → delivery.
- 24 to 34 → antibiotics for 7 days, steroids, magnesium before 32.
- Intra-amniotic infection → antibiotics and delivery.
- Complications: infection, abruption, cord prolapse, pulmonary hypoplasia.
Summary table
| Gestational age | Management | Antibiotics | Exam notes |
|---|---|---|---|
| 37 or more (PROM) | Induction with oxytocin | GBS by carrier status | Prolonged waiting increases infection |
| 34 to 36+6 | Delivery | GBS by carrier status | Consider steroids if not given |
| 24 to 33+6 (PPROM) | Expectant care in hospital until 34 weeks | IV ampicillin and erythromycin for 48 hours, then oral amoxicillin and erythromycin, 7 days in total | Betamethasone; magnesium before 32 weeks; no amoxicillin-clavulanate |
| Before 24 | Counselling; expectant care or termination | Individual decision | Risk of pulmonary hypoplasia |
| Intra-amniotic infection | Delivery, whatever the gestational age | IV ampicillin and gentamicin | Not by itself an indication for caesarean |
A free exam question
הרה בשבוע 30 פונה עקב ירידת מי שפיר. בבדיקה חום 37.9 דופק 90 לחץ דם 120/85 . רחם ללא טונוס מוגבר. בבדיקה וגינלית אובחנה ירידת מים. צוואר אחורי סגור. ניטור עוברי תקין. מה נכון בנוגע לתוצאות ד ?יקור מי שפיר במקרה זה (the question as examined, in Hebrew)
- א. שיעור התרביות החיוביות צפוי לה י ות כ 60%
- ב. המחולל השכיח ביותר הוא U. Urealyticum
- ג. ב נוכחות תרבית מי שפיר חיובית, הסיכוי לבקרטרמיה עוברית היא למעלה מ 90%
- ד. בהעדר צמיחה חיובית במי שפיר, יש לטפל בסטרואידים ולילד תוך שבוע
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Sources
- ACOG Practice Bulletin No. 217, 2020 — Prelabor Rupture of Membranes
- ACOG Committee Opinion No. 712, 2017 — Intrapartum Management of Intraamniotic Infection
- ACOG Committee Opinion No. 797, 2020 — Prevention of Group B Streptococcal Early-Onset Disease in Newborns
- Williams Obstetrics, 26th edition (2022) — Preterm Birth
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.