Factors influencing the duration of late first and second-trimester termination of pregnancy with prostaglandin derivates

Objective

To examine the time interval between first induction and fetal expulsion in fetal defect-related termination of pregnancy and to determine the relevant factors that influence this time interval.

Study design

Retrospective study involving singleton pregnancies that were terminated due to fetal abnormalities between 2005 and 2009. Induction was done by either 200 μg misoprostol, 1 mg gemeprost or in case of a previous caesarean section by 0.5 mg dinoprostone gel or 1 mg gemeprost. The length of the induction interval between first induction and fetal expulsion was examined according to different maternal and fetal characteristics. Univariate and multivariate logistic regression analyses were used to determine the significant contributors for a delivery within 24 h.

Results

One hundred and eighty-four singleton pregnancies fulfilled the inclusion criteria. The median gestational age at first induction was 19.2 weeks of gestation. The median time interval between first induction and expulsion was 18 h (25-75th centile, 11-30 h) and in 59 (32.1%) cases, the induction interval was longer than 24 h. Multivariate logistic regression analysis in the prediction of fetal expulsion within 24 h after first induction indicated significant contribution from gestational age and history of spontaneous delivery without previous caesarean section.

Conclusions

The only relevant contributors to an estimation of the time interval were gestational age and previous history of spontaneous delivery. By combining this information it was possible to correctly anticipate fetal expulsion within 24 h after first induction in 90% of the cases.