PREMATURE RUPTURE OF THE MEMBRANES

HISTORY The patient complains of loss of fluid from her vagina, before the onset of regular painful contractions. If you are not sure of her dates, estimate them from her fundal height (23-15). This is not precise, but it may be the best you can do.

EXAMINATION. Start by separating her labia and asking her to cough: Is liquor discharging from her vagina? Is urine coming from her urethra?

If you don’t see any fluid, repeat the examination after a few hours, so as not to miss intermittent loss of liquor from a small leak. Do one sterile speculum examination, to make sure that her membranes have ruptured, and that she really is draining liquor. Make sure that a senior person does this, so that it need not be repeated. Ask her to cough: you may see it escaping from her cervix. Observe: (1) The dilatation of her cervix. (2) Its degree of effacement. (3) Confirm the presenting part—you may see it if her cervix is open. (4) Exclude prolapse of the cord.

CAUTION! Don’t do a vaginal examination with your fingers: the risk of infection is too high. Alternatively, avoid this examination, and merely ‘wait and see’. If she continues to lose fluid (as shown by checking her pads), she has obviously ruptured her membranes.

If you are not quite sure if the fluid that is draining is liquor or urine: (1) smell it, (2) test its pH (urine and vaginal discharge are acid, amniotic fluid is alkaline), and (3) leave some to dry on a slide. Look at it under a microscope. Liquor, but not urine, or a discharge, will dry as a pattern of ferns. If you have not done this test before, try it with some known liquor.

MANAGEMENT If the diagnosis is confirmed or suspected, admit the patient, provide her with a clean perineal pad or cloth, make sure she keeps her vulva and perineum clean, check her temperature 4hrly, and inspect her liquor daily by asking her to collect the liquor in a kidney dish.

If no liquor can be seen escaping more than 5 days, the diagnosis is not confirmed, so discharge her. 25% of patients stop leaking liquor in 5 days and can be discharged. 75% go into spontaneous labour during this time.

If she is less than 28 weeks, with a live baby, and has no signs of infection, opinions differ on what you should do. Much depends on how common puerperal sepsis is in your hospital: see above. The chances of her pregnancy continuing long enough for the fetus to survive are small, but not zero. If you are worried about the risk of infection, induce labour. If the risk of infection seems small, leave her. She will probably go into labour soon, but she might be lucky, and her pregnancy may continue.

If she is 28–36 weeks and her membranes have been ruptured for less than 48 hours, and she has no infection, wait 48 hours. If her liquor stops draining, don’t intervene. If it continues to drain at 48 hours, induce labour, if the risk of infection in your hospital is high. If it is not so high, wait until the fetus is more mature at 36 weeks. Culture her amniotic fluid at delivery. One contributor waits 5 days, by which time nearly all mothers have gone into labour, or stopped draining.

If she is more than 36 weeks. If labour does not start spontaneously in 24 hours, induce labour with oxytocin.

CAUTION! Be sure to induce labour if: (1) Her baby is dead at any stage of pregnancy. (2) She has signs of infection at any stage of pregnancy. (3) She is more than 36 weeks, and has not gone into labour spontaneously in 24 hours. (3) Infection is common in your hospital.

CAUTION WITH OXYTOCIN! Remember the precautions for the use of oxytocin (22.6): (1) Don’t put up an oxytocin IV if there are any contraindications to its use. CPD is unlikely to be a problem in preterm babies. (2) If she is a grand multipara, avoid oxytocin, and await the spontaneous onset of labour. (3) If she has signs of infection, use oxytocin with extreme caution, and stop the IV as soon as she is having regular contractions, or you do a Caesarean section. Infection increases the dangers of section, so balance the risks as best you can.

INTRA–UTERINE INFECTION

DIAGNOSIS (1) Fetal tachycardia. (2) Maternal pyrexia and tachycardia. (3) Uterine tenderness. (4) Offensive, blood-stained liquor.

TREATMENT She will probably be septicaemic, and may be in septic shock (53.4). If necessary, resuscitate her with IV fluids. Treat her with broad-spectrum IV antibiotics; chloramphenicol and metronidazole are suitable (2.9). Empty her uterus as soon as possible, whatever the duration of pregnancy. It will often empty spontaneously. If it does not, give her an oxytocin infusion with caution, and stop the IV as soon as she has regular contractions. Her baby usually dies, if he is not already dead when she becomes infected.

DIFFICULTIES WITH INTRAUTERINE INFECTION

If bubbles of GAS come from the cervix, or you feel crepitus of the cervix or abdominal wall, she has GAS GANGRENE. The uterus and abdominal wall may be distended with gas. Treat her with large doses of penicillin, chloramphenicol, and metronidazole (6.24), and evacuate the uterus. If the infection has spread to the wall of the uterus, consider hysterectomy.