Conditions · Obstetrics and gynecology
Premature rupture of membranes (PROM and PPROM) !
The amniotic sac breaks before labour starts. Before 37 weeks it is called PPROM and raises the risk of infection and preterm birth.
Updated 2026-11-01
Structures involved
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In embryology
- Fetal membranes: amnion, chorion, yolk sac and allantois
- Amniotic fluid: polyhydramnios and oligohydramnios
- Pulmonary hypoplasia
Why it happens
- Prematurity and fetal growth restriction
- Collagen
- Extracellular matrix: collagen types, elastin, ground substance
What it is
Rupture of the fetal membranes before the onset of labour. When it happens before 37 weeks it is called preterm prelabour rupture of membranes (PPROM); at or after 37 weeks it is term PROM. The longer the interval to delivery, the higher the risk of infection.
Who gets it
Term PROM is common and usually followed by labour within a day. PPROM is less frequent but causes about a third of preterm births, making it an important contributor to neonatal morbidity in Colombia and worldwide.
Causes
- Ascending infection and inflammation that weaken the membranes
- Physiological weakening of the membranes near term
- Uterine overdistension (multiple pregnancy, polyhydramnios)
- Mechanical stress, bleeding behind the membranes, or invasive procedures (amniocentesis)
Risk factors
- Previous PPROM or preterm birth
- Genital tract infection, including bacterial vaginosis and sexually transmitted infections
- Short cervix and previous cervical surgery or cerclage
- Vaginal bleeding in pregnancy
- Smoking
- Low socio-economic status and low body weight
Pathophysiology
The amnion and chorion depend on collagen for strength. Infection-related cytokines, proteases and apoptosis degrade this matrix, mostly over the cervix, until the membranes give way. Once open, the barrier against vaginal bacteria is lost, which leads to chorioamnionitis, and the loss of amniotic fluid can compress the cord and, very early in pregnancy, impair lung development.
Classification
- Term PROM: at or after 37 weeks
- Preterm PROM (PPROM): before 37 weeks
- Previable PPROM: before about 23–24 weeks
- Prolonged rupture: more than 18–24 hours before delivery
Symptoms and signs
- Sudden gush or continuous leak of clear or pale fluid from the vagina
- Wet underwear or a feeling of constant dampness
- Possibly contractions after the rupture
Diagnosis
- Clinical
- History of fluid loss and a sterile speculum examination showing fluid pooling in the posterior vaginal fornix or leaking from the cervical os with coughing. Digital cervical examination is avoided in PPROM because it shortens the latency period and increases infection.
- Tests
- Nitrazine test (amniotic fluid is alkaline and turns the paper blue), ferning of dried fluid under the microscope, and immunoassays for placental proteins when unclear. Maternal temperature, pulse and white cell count, vaginal-rectal group B streptococcus swab, and fetal heart rate monitoring.
- Imaging
- Ultrasound shows reduced amniotic fluid (oligohydramnios) and confirms gestational age, presentation and estimated fetal weight; it supports but does not prove the diagnosis.
Differential diagnosis
- Urinary incontinence, common late in pregnancy
- Increased physiological vaginal discharge or loss of the mucus plug
- Vaginal infection (bacterial vaginosis, candidiasis, trichomoniasis)
- Semen or vaginal douching fluid
Goal of treatment
Balance the risks of infection against those of prematurity: deliver at term or when infection appears, and in PPROM prolong pregnancy safely while preparing the fetus with corticosteroids and antibiotics.
Treatment
- Procedure
- Term PROM: induction of labour (or waiting a short time for spontaneous labour) to reduce maternal and neonatal infection; from about 34 weeks delivery is usually recommended as well.
- Medical
- PPROM before 34 weeks: latency antibiotics (classically ampicillin plus a macrolide such as erythromycin or azithromycin) to prolong pregnancy and reduce infection; amoxicillin-clavulanate is avoided because of a link to necrotising enterocolitis.
- Medical
- Antenatal corticosteroids for fetal lung maturity, magnesium sulfate for neuroprotection before about 32 weeks, and group B streptococcus prophylaxis in labour.
- Acute
- Prompt delivery with broad-spectrum antibiotics if chorioamnionitis, abruption, cord prolapse or fetal compromise develops, regardless of gestational age.
- Follow-up
- Nursing priorities: temperature and maternal pulse every few hours, colour and odour of the fluid, uterine tenderness, contractions and fetal heart rate; limit vaginal examinations.
Complications
- Chorioamnionitis (intra-amniotic infection) and maternal postpartum endometritis or sepsis
- Preterm birth and its neonatal complications
- Umbilical cord compression or prolapse and fetal distress
- Placental abruption
- Neonatal sepsis
- Pulmonary hypoplasia and limb deformities after very early, prolonged oligohydramnios
Prognosis
Most women with term PROM deliver within 24 hours with good outcomes. In PPROM, outcome depends on gestational age at rupture, the latency period and infection; the earlier the rupture, the higher the neonatal mortality and morbidity, and PPROM tends to recur in later pregnancies.
Prevention
- Treating genital and urinary infections in pregnancy
- Stopping smoking
- Progesterone or cerclage in selected women with a history of preterm birth
Test yourself
Think of the answer, then tap the question to see it.
What is PPROM?
Rupture of the fetal membranes before the onset of labour and before 37 weeks of gestation.
Which examination should be avoided when PPROM is suspected, and why?
Digital cervical examination, because it introduces infection and shortens the latency period; a sterile speculum examination is used instead.
Which two bedside tests support the diagnosis of ruptured membranes?
Nitrazine paper turning blue (alkaline fluid) and ferning of the dried fluid under the microscope.
What is the most common serious maternal complication of prolonged rupture of membranes?
Chorioamnionitis (intra-amniotic infection), which can progress to endometritis and sepsis.
Which antibiotic combination is avoided in PPROM because of neonatal necrotising enterocolitis?
Amoxicillin-clavulanate.
Related conditions
- Preterm labour and birth
- Puerperal infection (postpartum endometritis and maternal sepsis)
- Placental abruption
- Bacterial vaginosis
- Sepsis and septic shock
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Premature rupture of membranes (MedlinePlus (U.S. National Library of Medicine), 2024); Preterm birth (World Health Organization, 2023).
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