Premature rupture of membranes

Premature rupture of membranes (PROM) is a condition that occurs in pregnancy when there is rupture of the membranes (rupture of the amniotic sac and chorion) more than an hour before the onset of labor. PROM is prolonged when it occurs more than 18 hours before labor. PROM is preterm (PPROM) when it occurs before 37 weeks gestation.^[1] Risk factors for PROM can be a bacterial infection, smoking, or anatomic defect in the structure of the amniotic sac, uterus, or cervix. In some cases, the rupture can spontaneously heal, but in most cases of PROM, labor begins within 48 hours. When this occurs, it is necessary that the mother receives treatment to avoid possible infection in the newborn.^[2]

Risk factors

Maternal risk factors for a premature rupture of membranes include chorioamnionitis or sepsis. Association has been found between emotional states of fear in a population and prelabor rupture of membranes at term.^[3] Fetal factors include prematurity, infection, cord prolapse, or malpresentation.

Note

This entry mistakenly includes both PROM and PPROM; PROM refers to term ROM and is incorrectly applied to preterm (under 37 weeks gestation) ROM. These are 2 very distinct entities with different causes, different management, and very different outcomes—PROM is a variation of normal, PPROM is often caused by subclinical infection and is quite dangerous.

Assessment

Assessment of a rupture of membranes involves taking a proper medical history, a gynecological exam using a speculum, nitrazine, cytologic (ferning) tests, and ultrasound. Amniotic fluid, when dried for 10 minutes on a slide and then viewed under a microscope, shows a characteristic fernlike pattern. Cervical mucus can also show ferning, but the fern-like shapes are usually smaller. Assessment for rupture of membranes can also involve a test called "Amnisure".

Management

In a term pregnancy where premature rupture of membranes has occurred, spontaneous labor can be permitted. Current obstetrical management includes an induction of labor at approximately 12 hours if it has not already begun though many physicians believe it to be safe to induce labor immediately, and consideration of Group B Streptococcal prophylaxis at 18 hours. In light of evidence linking increased risk of cesarean births to inductions, some hospitals, birth centers and midwives do not induce labor at any point after PROM, but rather watch carefully for any signs of infection and ensure that nothing is introduced into the vagina after the PROM, including sterile vaginal exams.

• Preterm birth:
  • Tocolysis is also sometimes used, though its use in this context is controversial. The mother should be admitted to hospital and put under careful surveillance for preterm labor and chorioamnionitis. Induction of labor should happen at around 34 weeks.
  • antenatal steroids if the gestational age is less than 32 weeks.

• Infection
  • Maternal: If chorioamnionitis is present at the time of PPROM, antibiotic therapy is usually given to avoid sepsis, and delivery is indicated. If chorioamnionitis is not present, prompt antibiotic therapy can significantly delay delivery, giving the fetus crucial additional time to mature.^[4] In preterm premature rupture of membranes (PPROM), antibiotic therapy should be given to decrease the risk of sepsis. Ampicillin or erythromycin should be administered for 7 days
  • Fetal: If the GBS status of the mother is not known, Penicillin or other antibiotics may be administered for prophylaxis against vertical transmission of Group B streptococcal infection.

References

See also

• Placental_alpha_microglobulin-1_(PAMG-1)
• Rupture of membranes
• Nitrazine