20 Termination of pregnancy for hypertensive disorders in the peri-viable period and accuracy of estimated fetal weight

Abstract

Introduction The decision to terminate a pregnancy for hypertensive disorders in the periviable period is made based on the severity of the maternal condition on the one hand and the prospects for healthy neonatal survival on the other hand. These pregnancies are often complicated by severe intrauterine growth restriction. Ultrasound parameters are used to assess fetal condition and prognosis. Estimated fetal weight (EFW) is one of these parameters. Objective This study investigated the accuracy of EFW in women with severe preeclampsia where the decision was made to terminate the pregnancy without fetal surveillance and refraining from active neonatal support. Methods Eligible for this study are all women who underwent termination of pregnancy for preeclampsia in The Netherlands between January 2000 and January 2014. EFW is derived from ultrasound parameters using the Hadlock 3 formula. Actual birth weight is collected from the original medical files. Results 161 women fulfilled the inclusion criteria. 48 pregnancies were terminated 24 weeks’gestation. In these cases EFW had not an important role in counselling of the parents and decision making. 113 pregnancies were terminated beyond 24 weeks’gestation (mean 25 + 2 weeks, SD 9.4 days). The mean EFW in this group was 495 gram (SD 113 g). The mean birth weight was 508 g (SD 117). The mean difference EFW and actual birth weight was 13.3 g 95% CI −24.30 to −2.30, p = 0.018. In 25 cases the EFW was more than 10% underestimated (22%) and in 10 cases the EFW was more than 10% overestimated (9%). Conclusion The decision to refrain from interventions on fetal indication and active neonatal support is based on propects for healthy survival of the fetus. Birth weight was accurately predicted in 68% of the cases. This should be taken into account when counselling the parents in these rare cases.