19.4 Premature rupture of the membranes (PROM) and intrauterine infection

When labour is normal, regular contractions start and the cervix begins to dilate before the membranes rupture and amniotic fluid escapes. Sometimes, the membranes rupture first, before contractions start, either <36 weeks (preterm rupture), or at term (prelabour rupture). When the membranes rupture early, the risks are: (1) Intrauterine infection, which is much the most important but is usually not common, and (2) Premature labour.

The advantages of expectant treatment (not inducing labour) are that: (1) It increases the maturity of the fetus, which is important if gestation is <36 weeks. (2) It avoids the risks of induction, which are: (a) Failure, which means that you will have to do a Caesarean section, because you will have done repeated vaginal examinations. (b) The complications of oxytocin (22.6). The disadvantage of expectant treatment is the risk of infection (chorioamnionitis) which may kill her and her baby. You can minimize this risk by: (1) Totally avoiding vaginal examination with your fingers until contractions are well established. (2) Avoiding speculum examinations as much as possible. (3) Practising reasonable vulval hygiene. (4) Observing carefully for signs of infection, inducing labour and treating with antibiotics at the very first sign of infection.

Intra-uterine infection is such a serious risk, after premature rupture of the membranes, that it far outweighs any benefit that might follow from expectant treatment. What are you going to do? If there is little puerperal infection in your hospital, you can manage mothers expectantly. If puerperal infection is common, both mother and child are best delivered within 24 hours. Fortunately, labour usually starts successfully within this time. If in doubt, induce labour!

Midwives often justify vaginal examinations by saying that they are necessary to exclude prolapse of the cord. Tell them that: (1) The risk of prolapse of the cord is small, but the risk of infection is great. (2) Cord prolapse will only harm the baby, but infection will endanger his mother also. (3) If her cervix is sill closed, as it often is, vaginal examination will not rule out cord prolapse. Teach them that premature rupture of the membranes calls for the suppression of vaginal curiosity!

Avoid steroids, and use antibiotics only on the indications below.