Chapter 36 Preterm prelabour rupture of membranes
Definitions. Prelabour (premature) rupture of membranes (PROM) refers to membrane rupture before the onset of uterine contractions irrespective of gestational age. Preterm prelabour rupture of membranes (PPROM) refers to membrane rupture before the onset of uterine contractions in a pregnancy that is <37 completed weeks of gestation.
Aetiology of PPROM
• The pathogenesis of PPROM is poorly understood and in the majority of cases the exact aetiology is unknown.
• There are multiple possible aetiologies that probably share a common final pathway leading to membrane rupture. Such factors include those leading to membrane stretch, membrane degradation, uterine contractility, local inflammation, and increased susceptibility to ascending genital tract infection.
Risk factors of PPROM
Most cases of PPROM occur in women without risk factors and there is currently no reliable way of predicting and preventing PPROM.
Clinical significance of PPROM
Both mother and fetus are at risk from complications associated with PPROM.
Maternal risks
Fetal risks
• preterm delivery
• most cases of PPROM will deliver within 1 week after membrane rupture; however, latency increases with decreasing gestational age
• morbidities associated with preterm delivery: hyaline membrane disease, intraventricular haemorrhage, periventricular leukomalacia and other neurologic sequelae, infection (e.g. sepsis, pneumonia, meningitis), necrotising enterocolitis and retinopathy of prematurity; rates vary with gestational age and are increased by the presence of chorioamnionitis
• pulmonary hypoplasia: hydrostatic pressure from amniotic fluid is essential to lung development and maturation in the mid-second trimester; loss of amniotic fluid at this stage of development can irreversibly arrest lung development and result in pulmonary hypoplasia; associated with significant neonatal mortality regardless of gestational age at birth
