Premature rupture of membranes
|Prelabor Rupture of Membranes|
|Classification and external resources|
Prelabor rupture of membranes (PROM), or premature rupture of membranes, is a condition that occurs in pregnancy when there is rupture of the membrane of the amniotic sac and chorion more than one hour before the onset of labor. PROM is considered prolonged when it occurs more than 18 hours before labor. PROM is considered preterm when it occurs before 37 weeks gestation, and is called Preterm Premature Rupture of Membranes (or PPROM). Risk factors for PROM include 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 PROM occurs, it is necessary that the mother receives treatment to avoid possible infection in the newborn.
Maternal risk factors for a premature rupture of membranes include chorioamnionitis or sepsis. Association has been found between emotional states of fear and prelabor rupture of membranes at term. Fetal factors include prematurity, infection, cord prolapse, malpresentation or genetic mutations.
PROM vs PPROM
PROM is rupture of the membranes prior to the onset of labor, while PPROM (Preterm Premature Rupture of Membranes) is rupture of the membranes with a gestation less than 37 weeks, prior to the onset of labor. These are two distinct entities with different causes, different management, and different outcomes—PROM is a variation of normal, whereas PPROM is often caused by subclinical infection and is quite dangerous. PPROM occurs in about 1% of all pregnancies, and about 1/3 of preterm births are associated with PPROM. The outcome is dependent on the gestational age, with those fetuses under 32 weeks gestation having increased risk of pulmonary problems due to lack of lung maturity. In a fetus under 32 weeks gestation with PPROM, antenatal steroids can be given in an effort to enhance lung maturity. If the risk of infection is thought to be less than the risk of premature delivery, then expectant management is done. The risk of premature delivery is thought to less than the risk of infection after 34 weeks, so delivery is performed. The main determinant of lung maturity of the fetus is amniotic fluid (usually sampled from vaginally pooled fluid) that has phosphatidyl glycerol present.
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 dipstick tests on fluid or discharge, such as Actim Prom or Amnisure.
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 (GBS) prophylaxis at 18 hours.
- 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.
- 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. 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.
- Deering SH, Patel N, Spong CY, Pezzullo JC, Ghidini A (2007). "Fetal growth after preterm premature rupture of membranes: is it related to amniotic fluid volume?". J. Matern. Fetal. Neonatal. Med. 20 (5): 397–400. doi:10.1080/14767050701280249. PMID 17674244.
- Simhan H, Canavan T (March 2005). "Preterm premature rupture of membranes: diagnosis, evaluation and management strategies". BJOG 112 (Supplement 1): 32–37. doi:10.1111/j.1471-0528.2005.00582.x. PMID 15715592.
- Santos Leal, Emilio; Odent, Michel R (December 2006). "Premature Rupture of Membranes and Madrid Terrorist Attack". Birth 33 (4): 341. doi:10.1111/j.1523-536X.2006.00136 1.x. More than one of
- 
- "Actim Prom" at medixbiochemica.com
- "Amnisure" at amnisure.com
- Melis GB, Orrù M, Uras R, et al. (October 2007). "Chorioamnionitis". J Chemother. 19 Suppl 2: 17–9. PMID 18073173.