Premature Rupture Of Membranes (PROM)

Symptoms

• A sudden gush of clear or pale-yellow fluid from the vagina.
• A continuous, slow trickle or leak of watery fluid from the vagina.
• A sensation of a "pop" followed by fluid leakage.
• Increased amount of watery vaginal discharge.
• Fever or chills (may indicate infection).
• Foul-smelling vaginal discharge (may indicate infection).
• Uterine tenderness (may indicate infection).
• Feeling or seeing the umbilical cord in the vagina (umbilical cord prolapse, an emergency).
• Significant vaginal bleeding (may indicate placental abruption).
• A significant decrease in fetal movement (non-reassuring fetal status).

Causes & Risk Factors

• Pathological weakening and rupture of the fetal membranes due to biochemical changes.
• Subclinical or clinical intra-amniotic infection (chorioamnionitis), where bacteria can degrade the membrane's collagen matrix.
• Mechanical stress on the uterus, such as from multiple gestation (twins, triplets) or polyhydramnios (excess amniotic fluid).
• An imbalance between matrix metalloproteinases (MMPs), which break down the extracellular matrix, and their tissue inhibitors (TIMPs).
• Genetic factors that may predispose to membrane weakness.
• In a significant number of cases, no specific cause is identified (idiopathic).
• Prior PPROM (strongest predictor, with a recurrence risk of 13-32%).
• Genital tract infections, including bacterial vaginosis, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Group B Streptococcus.
• Antepartum bleeding, especially in the second and third trimesters.
• Short cervical length (measured by transvaginal ultrasound, less than 25 mm).
• Uterine overdistension, such as from polyhydramnios (excess amniotic fluid) or multiple gestation (twins, triplets).
• Cigarette smoking during pregnancy.
• Low socioeconomic status.
• Previous cervical procedures, such as conization or cerclage.
• Poor maternal nutrition, including deficiencies in vitamin C or copper (possible).
• Connective tissue disorders, such as Ehlers-Danlos syndrome (possible).
• Maternal trauma (possible).
• Iatrogenic causes, such as following invasive procedures like amniocentesis (possible).
• Illicit drug use (modifiable).
• Uterine anomalies (non-modifiable).
• Genetic predisposition (non-modifiable).

Diagnosis

• Patient's subjective report of fluid leakage from the vagina.
• Sterile speculum examination to visualize fluid pooling in the vagina or leaking from the cervical canal, sometimes provoked by coughing or bearing down.
• Nitrazine test: A pH test where amniotic fluid (alkaline, pH 7.1–7.3) turns nitrazine paper from yellow/orange to blue. (Note: False positives can occur due to blood, semen, bacterial vaginosis, or alkaline antiseptics).
• Ferning test: A sample of vaginal fluid is air-dried on a microscope slide, showing a characteristic "fern-like" crystallization pattern due to high electrolyte concentration in amniotic fluid. (Note: False positives from cervical mucus; false negatives if contaminated with blood).
• Biomarker immunoassays: High-sensitivity tests for proteins found in amniotic fluid, such as PAMG-1 (Placental Alpha Microglobulin-1) or IGFBP-1 (Insulin-like Growth Factor Binding Protein-1).
• Transabdominal ultrasound: Used to assess amniotic fluid volume (e.g., Amniotic Fluid Index - AFI), fetal presentation, estimated weight, and well-being. Oligohydramnios (low fluid) supports the diagnosis, but its absence does not rule out PROM.
• Diagnosis is confirmed by visualization of amniotic fluid passing from the cervical canal and pooling in the vagina, or a positive ferning test, or a positive result on a commercial test for specific amniotic fluid proteins (ACOG criteria).
• Differential diagnosis includes urinary incontinence, normal physiologic vaginal discharge, loss of cervical mucus plug, semen, or vesicovaginal fistula.

Treatment Options

• Term PROM (at or after 37 weeks): Induction of labor is generally recommended over expectant management to reduce the risk of maternal and neonatal infection. Induction typically uses oxytocin. Expectant management for a short period (e.g., 12-24 hours) may be an option for select patients. Intrapartum antibiotics are given for Group B Streptococcus (GBS) if the patient is a known carrier or status is unknown.
• Late Preterm PROM (34 0/7 to 36 6/7 weeks): Proceeding with delivery (induction of labor) is generally recommended, as the risks of infection with expectant management are considered to outweigh the small risks of late preterm birth. There is insufficient evidence to routinely recommend corticosteroids in this gestational age window.
• Preterm PROM (PPROM) (24 0/7 to 33 6/7 weeks): Expectant management in a hospital setting is recommended if there are no maternal or fetal contraindications. This includes: Antenatal Corticosteroids: A single course (e.g., betamethasone) is recommended to enhance fetal lung maturity and reduce neonatal complications. Latency Antibiotics: A 7-day course of antibiotics is recommended to prolong the time until delivery and reduce infectious complications. ACOG recommends a 48-hour IV course of ampicillin and erythromycin, followed by a 5-day oral course of amoxicillin and erythromycin. RCOG recommends a 10-day course of oral erythromycin, noting that amoxicillin-clavulanate is not recommended. Magnesium Sulfate: Recommended for fetal neuroprotection if delivery is anticipated before 32 0/7 weeks. Tocolysis: Prophylactic medications to stop contractions are not routinely recommended, but a short course (48 hours) may be considered to allow time for corticosteroids to take effect. Delivery is generally recommended at 34 0/7 weeks, or earlier if complications like chorioamnionitis, non-reassuring fetal status, or placental abruption develop.
• Previable PPROM (before 23-24 weeks): Management is complex and highly individualized. Extensive counseling is required regarding the high risks of neonatal mortality and severe complications versus maternal risks (infection, sepsis, placental abruption). Options include expectant management or induction of labor/termination. Latency antibiotics and corticosteroids are not routinely recommended but may be considered on a case-by-case basis, often starting from 22 0/7 weeks.
• Emergency Treatment: Immediate delivery, regardless of gestational age, is indicated for clinical chorioamnionitis (infection), placental abruption, non-reassuring fetal testing, or umbilical cord prolapse (which requires immediate cesarean delivery).

Frequently Asked Questions