Rupture in an unscarred uterus during second trimester pregnancy termination with mifepristone and misoprostol

Abstract

Second-trimester abortions performed with mifepristone and misoprostol (Mifegest and Cytolog, Zydus-Alidac, India) may occasionally result in rupture in an unscarred uterus, though this complication is more frequent in women who have undergone a prior cesarean [1–3]. Rupture occurred in a 27-year-old, fourth gravida at 20 weeks with three previous vaginal deliveries and no uterine surgery or curettage. She had been receiving prednisolone, azathioprine and spironolactone for crescentric glomerulonephritis for 2 years. Mifepristone (200 mg, oral) was followed 48 h later by 6 doses of vaginal misoprostol 200 μg 6-hourly. Initially, her cervix was 1 cm, soft and 50% effaced. At the sixth dose, it was 2.5 cm and fully effaced, and mild contractions (two to three in 10 min) were present. She aborted 6 h later (induction–abortion interval 36 h). Spontaneous placental expulsion was followed by profuse bleeding unresponsive to oxytocics. At laparotomy, a right lateral uterine wall rupture with broad ligament hematoma necessitated hysterectomy. Philips et al. [1] reported unscarred uterine rupture in a fourth gravida at 18 weeks with mifepristone and vaginal misoprostol (600 μg 6-hourly). Rupture was detected after expulsion of the fetus and placenta 4 1/2 h after the second dose of misoprostol. Similarly, ruptures have been reported with 1400 μg accumulated oral dose of misoprostol at 25 weeks and in a grand multiparous woman with misoprostol and oxytocin [2,3]. Rupture and death occurred with misoprostol in a second gravida at 16 weeks but it was not specified whether she had an unscarred uterus [4]. Rupture in an unscarred uterus is possibly related to the dose, dose-interval, gestation and parity. Based upon pharmacokinetics of misoprostol, a dosage interval of 6 h is common (range 3–12 h) [5]. Uterine rupture occurred in the present case, even though the accumulated dose of misoprostol (1200 μg over 30 h) was lower than some reported regimens (2400 μg over 24 h) [5]. Retrospectively, it was felt that the sixth dose should have been withheld, as the cervix was favorable and contractions were established. Corticosteroid therapy is listed as a contraindication to mifepristone (but not misoprostol), possibly because of its glucocorticoid antagonistic effect. Whether prolonged corticosteroid therapy can result in a weakened myometrium susceptible to rupture remains to be determined. Subsequently in our hospital, misoprostol is limited to 200 μg 6-hourly to a maximum of three doses in 24 h. Once regular contractions develop or cervical dilatation of 2.5 cm is achieved, further misoprostol is withheld. If required, oxytocin is used to augment contractions. Women with uterine surgery, repeated curettage, or who are grandmultiparas or on corticosteroid therapy are not offered this method.