Influence of morning versus midnight initiation of induction of labour in late-term pregnancy on perinatal outcome and time of birth

Abstract

<p><strong>Objective. </strong>The aim of this study was to assess and compare morning vs. midnight initiation of induction of labor (IOL) on time of birth and perinatal outcome.</p><p><strong>Study Design. </strong>A retrospective study performed at University Hospital Merkur, Zagreb, Croatia; in period between 2006 to 2017. The participants were low-risk nulliparous women with gestational age over 41 weeks who had labor induced by a prostaglandin E2 analogue dinoprostone applied intracervically. Two groups were compared; the first one had IOL initiated in the morning and the second one at midnight.</p><p><strong>Results. </strong>A total of 206 pregnant women were included in the study. Women with IOL starting at midnight (n=103) gave birth more often during daytime (7am-6.59pm) compared to women with IOL starting in the morning (n=103) (p<0.01). The midnight group also gave birth more often during regular hospital working hours (7.30am-3.30pm), but this result was not statistically significant (p=0.091). The rate of epidural analgesia was higher among women in the midnight group, while no other differences were observed in predefined perinatal outcome between the two groups.</p><strong>Conclusions. </strong>Initiation of IOL at midnight compared to morning results in giving birth more often during daytime. This presents a favourable option for reducing out of hours and night work.