PROM is classified according to the gestational age at which it occurs and the interval between rupture of the fetal membranes and the onset of true labour.
Preterm PROM occurs after 28 weeks of gestational age and before 37 weeks.
Term PROM occurs after 37 completed weeks of gestational age, including post-term cases occurring after 40 weeks.
Preterm and term PROM are further divided into:
- Early PROM (less than 12 hours has passed since the rupture of fetal membranes)
- Prolonged PROM (12 or more hours has passed since the rupture of fetal membranes).
The major reason for classifying PROM into term, preterm, early and prolonged PROM is for effective management decisions. The earlier the occurrence (preterm PROM) and the longer the interval between the rupture of fetal membranes and onset of labour, the more complications there are likely to be. We will describe the actions you should take to manage cases of PROM in Section 17.6 of this study session. First, we discuss the risk factors for PROM and then the complications that can result for the mother and the fetus.