Prelabor rupture of membranes
Prelabor rupture of membranes (PROM), previously known as premature rupture of membranes, is breakage of the amniotic sac before the onset of labor. Women usually experience a painless gush or a steady leakage of fluid from the vagina. Complications in the baby may include premature birth, cord compression, and infection. Complications in the mother may include placental abruption and postpartum endometritis.
| Prelabor rupture of membranes | |
|---|---|
| Other names | Premature rupture of membranes |
| Positive fern test with amniotic fluid as seen under the microscope | |
| Specialty | Obstetrics |
| Symptoms | Painless gush or a steady leakage of fluid from the vagina |
| Complications | Baby: Premature birth, cord compression, infection Mother: Placental abruption, postpartum endometritis |
| Types | Term, preterm |
| Risk factors | Infection of the amniotic fluid, prior PROM, bleeding in the later parts of pregnancy, smoking, a mother who is underweight |
| Diagnostic method | Suspected based on symptoms and examination, supported by testing the fluid or ultrasound |
| Differential diagnosis | Urinary incontinence, bacterial vaginosis |
| Treatment | Based on how far along a woman is in pregnancy and whether complications are present |
| Frequency | ~8% of term pregnancies, ~30% of preterm pregnancies |
Risk factors include infection of the amniotic fluid, prior PROM, bleeding in the later parts of pregnancy, smoking, and a mother who is underweight. Diagnosis is suspected based on symptoms and speculum exam and may be supported by testing the vaginal fluid or by ultrasound. If it occurs before 37 weeks it is known as PPROM (preterm prelabor rupture of membranes) otherwise it is known as term PROM.
Treatment is based on how far along a woman is in pregnancy and whether complications are present. In those at or near term without any complications, induction of labor is generally recommended. Time may also be provided for labor to begin spontaneously. In those 24 to 34 weeks of gestation without complications corticosteroids and close observation is recommended. A 2017 Cochrane review found waiting generally resulted in better outcomes in those before 37 weeks. Antibiotics may be given for those at risk of Group B streptococcus. Delivery is generally indicated in those with complications, regardless of how far along in pregnancy.
About 8% of term pregnancies are complicated by PROM while about 30% of preterm births are complicated by PROM. Before 24 weeks PROM occurs in fewer than 1% of pregnancies. Prognosis is primarily determined by complications related to prematurity such as necrotizing enterocolitis, intraventricular hemorrhage, and cerebral palsy.