Delayed interval delivery of preterm multiples: experience from a large specialized twin center.

Objective: Preterm delivery is a recognized complication of twins and higher order multiple pregnancies. Delayed interval delivery is a rarely used management option for pre- or peri-viable preterm labor in these pregnancies. We describe the management and outcomes of 7 delayed interval deliveries over an 8-year period in a large specialized twin center.

Study Design: A retrospective cohort study of all delayed interval deliveries of preterm multiples from 2009 to 2016, defined as >24 h between deliveries of twins 1 and 2.

Results: During the study period there were 68,845 deliveries with 1377 multiple pregnancies comprising 1331 sets of twins and 46 sets of higher-order multiples. 7 of these were identified as being delayed interval deliveries - 6 twin pregnancies and 1 triplet pregnancy. The mean gestation of delivery of the first infant was 23 + 4 weeks (range 22 + 3 to 30 + 0 weeks) with a mean interval of 10 days (range 1.5-39 days). Outcomes for the first infant delivered were poor, with 5 out of 7 (71%) dying from extreme prematurity. However, out of the remaining twins or triplets, 5/8 (62%) survived. The mean gestation of delivery of the remaining infant (or infants in the triplets) was 25 + 0 weeks (range 23 + 0 to 30 + 2 weeks). Only one mother (16%) developed clinical chorioamnionitis requiring iatrogenic delivery of the remaining infant with subsequent neonatal death due to extreme prematurity. There were no cases of severe maternal morbidity - however, there was one maternal death in the cohort due to an amniotic fluid embolism. The neonatal follow up of the surviving infants to date is mostly normal.

Conclusion: Delayed interval deliveries can offer hope for survival for the remaining infant(s) with an acceptable risk profile to the mother. Close clinical and laboratory monitoring is essential to reduce the risk of severe maternal morbidity.