Effect of delayed interval delivery of remaining fetus(es) in multiple pregnancies on survival: a systematic review and meta-analysis

Background: The management of the pregnancy after delivery of the first fetus during a second-trimester miscarriage or very early preterm birth has not been well defined.

Objective: The objective of the study was to evaluate whether delayed interval delivery of the remaining fetus(es) in twins/triplets is associated with improved survival, when compared with immediate delivery, after miscarriage or very preterm birth of the first fetus in multiple pregnancy.

Data sources: PubMed, MEDLINE, and Cochrane Library were systematically searched through January 2019. STUDY ELIGIBILITY CRITERIA (STUDY DESIGN, POPULATIONS, AND INTERVENTIONS): The following eligibility criteria applied: full-text original article; included at least 5 cases of delayed interval delivery for remaining fetus(es); and reported the survival rate of the first-born and the remaining fetus(es).

Study appraisal and synthesis methods: K.W.C. and W.W. searched, screened, and reviewed the articles. The quality of the studies was assessed according to the Strengthening the Reporting of Observational studies in Epidemiology checklist. If possible, data were stratified for assigned chorionicity. Effect sizes were pooled through a meta-analysis.

Results: A total of 2295 published article and abstracts were identified. Only 16 studies met inclusion criteria. Meta-analysis of 492 pregnancies (432 twins [88%], 56 triplets [11%], 3 quadruplets and 1 quintuplets) showed that delayed interval delivery significantly improved the perinatal survival of remaining fetus(es) compared with the first born (odds ratio, 5.22, 95% confidence interval, 2.95-9.25, I² = 53%), before 20+0 weeks (odds ratio, 6.32, 95% confidence interval, 1.99-20.13, I² = 0%), between 20+0 and 23+6 weeks (odds ratio, 3.31, 95% confidence interval, 1.95-5.63, I² = 0%), and after 24+0 weeks (odds ratio, 1.92, 95% confidence interval, 1.21-3.05, I² = 0%), in dichorionic twin pregnancy (odds ratio, 14.89, 95% confidence interval, 6.19-35.84, I² = 0%), and unselected triplet pregnancy (odds ratio, 2.33, 95% confidence interval, 1.02-5.32, I² = 0%. ). Among the survivors, there were no significant differences in the short-term and long-term neonatal morbidities between the first-born and the remaining fetus(es). Serious maternal morbidity was reported in 39% of pregnancy after delayed interval delivery (71 of 183). In addition, 2 cases were managed by postpartum hysterectomy and 1 reported postoperative uterovaginal fistula. There were no recorded cases of maternal mortality.

Conclusion: Delayed interval delivery when a fetus has delivered in a multiple pregnancy is an effective management option to increase the survival rate of the remaining fetus(es). About 39% of women may experience morbidity following this management option.