Expectant management of incomplete, spontaneous first-trimester miscarriage: outcome according to initial ultrasound criteria and value of follow-up visits

Abstract

Objectives: To assess whether the presence of a gestational sac or the width of the endometrium, can be used to predict the outcome of expectant management for an incomplete, first-trimester miscarriage, and to determine an appropriate schedule for follow-up visits.

Subjects: Consecutive women with a spontaneous miscarriage, who were attending an early pregnancy assessment unit.

Methods: Transvaginal ultrasonography was used at the first visit to identify those women with an incomplete miscarriage--defined as the presence of heterogeneous products of conception within the uterus and distinguishable from a missed miscarriage or an anembryonic pregnancy. The sonographic end-points were the presence of a gestational sac or the thickness of the endometrium. All subjects were offered the choice of surgical evacuation of the uterus under general anesthesia or expectant management with a follow-up visit within a few days of the cessation of transvaginal bleeding, or weekly monitoring for 4-5 weeks. The main outcome measures were the number of women with a complete miscarriage (defined as the absence of transvaginal bleeding and an endometrial thickness of < 15 mm without surgical intervention) and the proportion of women completing their miscarriage within each week of management.

Results: Of the 312 women who participated, 234 (75%) chose expectant management; of these 13 were lost to follow-up leaving data from 221 for analysis. Two-hundred and one (91%) completed their miscarriage without intervention; the mean time from diagnosis to completion was 9 (range, 1-32) days. By the end of week 2, 184 women (83%) had miscarried. There was no statistically significant relationship between the initial presence of a gestational sac or endometrial thickness, and the success rate of expectant management. The odds of a woman completing a miscarriage spontaneously were 1 : 1 for week 1, 2 : 1 for week 2, 1 : 2 for week 3, and 1 : 5 for week 4. Twenty women had surgical treatment (19 elective with no serious prior complications, one emergency who was admitted to the accident and emergency department on day 21 of management). There were eight elective operations during week 1, and 11 over the following 3 weeks.

Conclusions: Most women with an incomplete, spontaneous miscarriage chose expectant management and had a successful outcome. Neither the presence of a gestational sac, nor the endometrial thickness at diagnosis can be used to predict the likelihood of management failure. The current schedule of regular routine follow-up visits could be safely reduced to one or two fortnightly visits as appropriate, provided that patients have ready access to clinical advice by telephone.