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Optimal timing of delivery in pregnancies with pre‐existing hypertension
Author(s) -
Hutcheon JA,
Lisonkova S,
Magee LA,
Von Dadelszen P,
Woo HL,
Liu S,
Joseph KS
Publication year - 2011
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.2010.02754.x
Subject(s) - medicine , population , apgar score , pregnancy , gestational hypertension , obstetrics , gestational age , gestation , pediatrics , preeclampsia , environmental health , biology , genetics
Please cite this paper as: Hutcheon J, Lisonkova S, Magee L, von Dadelszen P, Woo H, Liu S, Joseph K. Optimal timing of delivery in pregnancies with pre‐existing hypertension. BJOG 2011;118:49–54. Objective To determine the optimal timing of delivery in pregnancies with pre‐existing (chronic) hypertension by quantifying the gestational age‐specific risks of stillbirth associated with ongoing pregnancy and the gestational age‐specific risks of neonatal mortality or serious neonatal morbidity following the induction of labour. Design Population‐based cohort study. Setting USA. Population A total of 171 669 singleton births to women with pre‐existing hypertension between 1995 and 2005. Pregnancies additionally complicated by diabetes mellitus, cardiac, pulmonary or renal disease were excluded. Methods The week‐specific risks of stillbirth between 36 and 41 completed weeks of gestation were contrasted with the week‐specific risks of neonatal mortality or serious neonatal morbidity among births following induction of labour in women with pre‐existing hypertension. Main outcome measures Stillbirth, neonatal mortality or serious neonatal morbidity (defined as a composite outcome which included any of the following: neonatal seizures, severe respiratory morbidity or 5‐minute Apgar score ≤3). Results The risk of stillbirth in women with pre‐existing hypertension remained stable at 1.0–1.1 per 1000 ongoing pregnancies until 38 weeks, before rising steadily to 3.5 per 1000 [95% confidence interval (CI): 2.4, 5.0] at 41 weeks. The risk of serious neonatal morbidity/neonatal mortality decreased sharply between 36 and 38 weeks from 137 [95% CI: 127, 146] to 26 [95% CI: 24, 29] per 1000 induced births, before stabilising beyond 39 weeks. Conclusions Among women with otherwise uncomplicated pre‐existing hypertension, delivery at 38 or 39 weeks appears to provide the optimal trade‐off between the risk of adverse fetal and adverse neonatal outcomes.