ArticlesImmediate delivery versus expectant monitoring for hypertensive disorders of pregnancy between 34 and 37 weeks of gestation (HYPITAT-II): an open-label, randomised controlled trial
Introduction
Hypertensive disorders of pregnancy, such as gestational hypertension, pre-existing or chronic hypertension during pregnancy, pre-eclampsia, and superimposed pre-eclampsia,1 occur in roughly 10% of all pregnancies.2, 3 These disorders cause substantial maternal and neonatal morbidity and mortality worldwide.4, 5
Delivery of the placenta is the only definitive treatment for hypertensive disorders of pregnancy; it will stop progression and therefore has the potential to prevent adverse pregnancy outcomes. However, immediate delivery also has potential disadvantages. First, it can result in preterm or early term birth, which increases the risk of neonatal complications.6 Second, induction of labour might increase the risk of a need for caesarean section.7 Therefore, management of hypertensive disorders should be based on the balance between the risks of immediate delivery versus the risks of continuing the pregnancy. In severe pre-eclampsia before 34 weeks of gestation, delivery decreases the proportion of neonates born small for gestational age, while the effect on other neonatal morbidity and maternal outcomes is uncertain.8, 9, 10, 11 The first HYPITAT study showed that delivery reduces the risk of adverse maternal outcomes for women with mild gestational hypertension or pre-eclampsia beyond 37 weeks of gestation, without affecting neonatal outcomes or risk of caesarean section.12 However, for women at 34–37 weeks of gestation who have hypertensive disorders, little is known of the risks and benefits of immediate delivery versus continuing pregnancy.13 Dutch guidelines do not advise about timing of delivery for women with hypertensive disorders of pregnancy and both strategies are practised in Netherlands.14 Therefore, we investigated the effect of immediate delivery versus expectant monitoring on maternal and neonatal outcomes for women with hypertensive disorders between 34 and 37 weeks' gestation.
Section snippets
Study design and participants
We did an open-label, randomised controlled trial in seven academic hospitals and 44 non-academic hospitals in Netherlands.15 Women were eligible if they had gestational hypertension, pre-eclampsia, deteriorating pre-existing hypertension, or superimposed pre-eclampsia, and had a gestational age of 340/7 weeks up to and including 366/7 weeks (in Netherlands, gestational age is routinely measured by first trimester ultrasound).
We defined gestational hypertension as a diastolic blood pressure of
Results
Between March 1, 2009, and Feb 21, 2013, 897 women were invited to participate (figure 1). Of the 193 women who did not give informed consent to be randomly assigned, 176 gave informed consent for us to extract data from their medical files; 168 of them (95%) were monitored expectantly. 704 women gave informed consent to be randomly assigned and were allocated to immediate delivery (n=353) or expectant monitoring (n=351). One woman withdrew after being randomised to immediate delivery, which
Discussion
In our study population, immediate delivery led to fewer adverse maternal outcomes than expectant monitoring. But although the RR suggests a large effect, the fact that the absolute risk of adverse maternal outcomes was lower than assumed in our sample size calculation resulted in a difference that was not statistically significant. The effect of immediate delivery on maternal outcomes therefore remains uncertain. However, given the low absolute risk, the potential benefit of immediate delivery
References (26)
- et al.
Epidemiology of pre-eclampsia and the other hypertensive disorders of pregnancy
Best Pract Res Clin Obstet Gynaecol
(2011) - et al.
Global and regional estimates of preeclampsia and eclampsia: a systematic review
Eur J Obstet Gynecol Reprod Biol
(2013) The global impact of pre-eclampsia and eclampsia
Semin Perinatol
(2009)- et al.
WHO analysis of causes of maternal death: a systematic review
Lancet
(2006) - et al.
Aggressive versus expectant management of severe preeclampsia at 28 to 32 weeks' gestation: a randomized controlled trial
Am J Obstet Gynecol
(1994) - et al.
Induction of labour versus expectant monitoring for gestational hypertension or mild pre-eclampsia after 36 weeks' gestation (HYPITAT): a multicentre, open-label randomised controlled trial
Lancet
(2009) - et al.
Temporising versus interventionist management (preterm and at term)
Best Pract Res Clin Obstet Gynaecol
(2011) The HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets): much ado about nothing?
Am J Obstet Gynecol
(1990)- et al.
HYPITAT and the fallacy of pregnancy interruption
Lancet
(2010) - et al.
The classification and diagnosis of the hypertensive disorders of pregnancy: statement from the International Society for the Study of Hypertension in Pregnancy (ISSHP)
Hypertens Pregnancy
(2001)
A systematic review of severe morbidity in infants born late preterm
Am J Obstet Gynecol
Use of labour induction and risk of cesarean delivery: a systematic review and meta-analysis
Can Med Assoc J
Aggressive or expectant management for patients with severe preeclampsia between 28–34 weeks' gestation: a randomized controlled trial
Obstet Gynecol
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