[Why are babies born at night at increased risk of early neonatal mortality?]

Association between time of day and performance, indications, and outcomes of obstetric interventions among nulliparous women delivering at term

OBJECTIVE

The objective of this study is to determine whether there is an association between delivery time and obstetric interventions, as well as maternal and perinatal outcomes.

STUDY DESIGN

Retrospective cohort study of nulliparous women delivering singleton, vertex, live births at ≥37 weeks gestation at a single center from 2014 to 2015. Nighttime deliveries were designated as those occurring between 18:00 and 05:59 h. The primary outcomes were obstetrical interventions (cesarean delivery, operative vaginal delivery, episiotomy). Secondary outcomes included indications for operative deliveries, as well as maternal and perinatal outcomes.

RESULTS

Of 7691 women eligible for inclusion, 3707 (48.2%) delivered during the nighttime. Women who experienced nighttime deliveries had no demographic or clinical differences compared with women delivering during the daytime. Women delivering during the nighttime had greater odds of cesarean delivery (OR 1.27, 95% CI 1.14-1.43) and operative vaginal delivery (OR 1.83, 95% CI 1.20-2.78). Women who delivered at night were also more likely to have neonates with a 5 min Apgar score <7 (OR 1.59, 95% CI 1.08-2.32) and umbilical artery pH < 7.0 (OR 1.76, 95% CI 1.18-2.63). There were no differences observed in any of the other outcomes examined.

CONCLUSIONS

Delivery during the nighttime is associated with alterations in some obstetric interventions and perinatal outcomes.

Statement by the OEGGG with Review of the Literature on the Mode of Delivery of Premature Infants at the Limit of Viability

In 2017, the Austrian Society for Paediatric and Adolescent Medicine (ÖGKJ) published a guideline on the primary care of premature infants at the limit of viability. In this guideline, it is recommended that a Caesarean section be preferred as mode of delivery with regard to an early preterm birth (22 + 0 – 24 + 6 weeks of pregnancy) due to an allegedly lower perinatal risk of cerebral haemorrhage. In contrast to this, the Austrian Society for Gynaecology and Obstetrics (OEGGG) considers there to be no clinical and scientific basis for this recommendation and the mode of delivery in the case of early preterm birth must be adapted to the individual maternal and foetal clinical situation. The international data available from the generally retrospective investigations show heterogeneous results regarding the mode of delivery. The prospective and randomised data in this regard are insufficient. A Cochrane analysis does not show any advantage in favour of a Caesarean delivery. The German-language guidelines (AWMF and Switzerland) make analogous recommendations for adapting the mode of delivery with regard to an early preterm birth individually to the respective clinical situation. In the case of an early preterm birth and a singleton in cephalic presentation, the OEGGG therefore recommends individual management of the delivery which takes the maternal and foetal clinical situation into account and also includes vaginal delivery as a mode of delivery in the clinical decision process.

Is time of birth a predictor of adverse perinatal outcome? A hospital-based cross-sectional study in a low-resource setting, Tanzania

Background

Inconsistent evidence of a higher risk of adverse perinatal outcomes during off-hours compared to office hours necessitated a search for clear evidence of an association between time of birth and adverse perinatal outcomes.

Methods

A cross-sectional study conducted at a tertiary referral hospital compared perinatal outcomes across three working shifts over 24 h. A checklist and a questionnaire were used to record parturients’ socio-demographic and obstetric characteristics, mode of delivery and perinatal outcomes, including 5th minute Apgar score, and early neonatal mortality. Risks of adverse outcomes included maternal age, parity, referral status and mode of delivery, and were assessed for their association with time of delivery and prevalence of fresh stillbirth as a proxy for poor perinatal outcome at a significance level of p = 0.05.

Results

Off-hour deliveries were nearly twice as likely to occur during the night shift (odds ratio (OR), 1.62; 95% confidence interval (CI), 1.50–1.72), but were unlikely during the evening shift (OR, 0.58; 95% CI, 0.45–0.71) (all p < 0.001). Neonatal distress (O.R, 1.48, 95% CI; 1.07–2.04, p = 0.02), early neonatal deaths (OR, 1.70; 95% CI, 1.07–2.72, p = 0.03) and fresh stillbirths (OR, 1.95; 95% CI, 1.31–2.90, p = 0.001) were more significantly associated with deliveries occurring during night shifts compared to evening and morning shifts. However, fresh stillbirths occurring during the night shift were independently associated with antenatal admission from clinics or wards, referral from another hospital, and abnormal breech delivery (OR 1.9; 95% CI, 1.3–2.9, p = 0.001, for fresh stillbirths; OR, 5.0; 95% CI 1.7–8.3, p < 0.001, for antenatal admission; OR, 95% CI, 1.1–2.9, p < 0.001, for referral form another hospital; and OR 1.6; 95% CI 1.02–2.6, p = 0.004, for abnormal breech deliveries).

Conclusion

Off-hours deliveries, particularly during the night shift, were significantly associated with higher proportions of adverse perinatal outcomes, including low Apgar score, early neonatal death and fresh stillbirth, compared to morning and evening shifts. Labour room admissions from antenatal wards, referrals from another hospital and abnormal breech delivery were independent risk factors for poor perinatal outcome, particularly fresh stillbirths.

Effects of hospital delivery during off-hours on perinatal outcome in several subgroups: a retrospective cohort study

Background

Studies have demonstrated a higher risk of adverse outcomes among infants born or admitted during off-hours, as compared to office hours, leading to questions about quality of care provide during off-hours (weekend, evening or night). We aim to determine the relationship between off-hours delivery and adverse perinatal outcomes for subgroups of hospital births.

Methods

This retrospective cohort study was based on data from the Netherlands Perinatal Registry, a countrywide registry that covers 99% of all hospital births in the Netherlands. Data of 449,714 infants, born at 28 completed weeks or later, in the period 2003 through 2007 were used. Infants with a high a priori risk of morbidity or mortality were excluded. Outcome measures were intrapartum and early neonatal mortality, a low Apgar score (5 minute score of 0–6), and a composite adverse perinatal outcome measure (mortality, low Apgar score, severe birth trauma, admission to a neonatal intensive care unit).

Results

Evening and night-time deliveries that involved induction or augmentation of labour, or an emergency caesarean section, were associated with an increased risk of an adverse perinatal outcome when compared to similar daytime deliveries. Weekend deliveries were not associated with an increased risk when compared to weekday deliveries. It was estimated that each year, between 126 and 141 cases with an adverse perinatal outcomes could be attributed to this evening and night effect. Of these, 21 (15-16%) are intrapartum or early neonatal death. Among the 3100 infants in the study population who experience an adverse outcome each year, death accounted for only 5% (165) of these outcomes.

Conclusion

This study shows that for infants whose mothers require obstetric interventions during labour and delivery, birth in the evening or at night, are at an increased risk of an adverse perinatal outcomes.

Impact of timing of birth and resident duty-hour restrictions on outcomes for small preterm infants

OBJECTIVE

The goal was to examine the impact of birth at night, on the weekend, and during July or August (the first months of the academic year) and the impact of resident duty-hour restrictions on mortality and morbidity rates for very low birth weight infants.

METHODS

Outcomes were analyzed for 11,137 infants with birth weights of 501 to 1250 g who were enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network registry in 2001-2005. Approximately one-half were born before the introduction of resident duty-hour restrictions in 2003. Follow-up assessments at 18 to 22 months were completed for 4508 infants. Mortality rate, short-term morbidities, and neurodevelopmental outcome were examined with respect to the timing of birth.

RESULTS

There was no effect of the timing of birth on mortality rate and no impact on the risks of short-term morbidities except that the risk of retinopathy of prematurity (stage > or =2) was higher after the introduction of duty-hour restrictions and the risk of retinopathy of prematurity requiring operative treatment was lower for infants born during the late night than during the day. There was no impact of the timing of birth on neurodevelopmental outcome except that the risk of hearing impairment or death was slightly lower among infants born in July or August.

CONCLUSION

In this network, the timing of birth had little effect on the risks of death and morbidity for very low birth weight infants, which suggests that staffing patterns were adequate to provide consistent care.

Infant births during the internal night are at increased risk for operative delivery and NICU admission

PURPOSE

The purpose of the present study was to compare neonatal morbidity between night and the rest of day and investigate potential differences of birth outcomes during the internal night.

METHODS

We conducted a retrospective study based on maternal and neonatal data of period 2004-2007, enrolling exclusively spontaneous deliveries of term (≥ 37 weeks), singleton pregnancies with cephalic presentation that were in labor. Time of day was divided into the night-shift period, from 11.00 p.m. to 7.00 a.m. (period 1) and the rest-of-day period, from 7.00 a.m. to 11.00 p.m. (period 2). The night-shift period was further sub-divided into period 1a (11.00 p.m.-3.00 a.m.) and period 1b (3.00 a.m.-7.00 a.m.). Epidemiological and obstetric characteristics as well as neonatal outcomes were initially compared between periods 1 and 2 and thereafter between sub-periods 1a and 1b.

RESULTS

There were 3,055 cases with complete data meeting our inclusion criteria, of which 871 (28.5%) were delivered during period 1 and 2,184 (71.5%) during period 2. Furthermore, 51.3% of night-born infants were delivered during period 1a and the remaining 48.7% during period 1b. All examined parameters were not significantly different between periods 1 and 2. Analyzing night internally, the rate of emergent CS was significantly higher for period 1a (13.2%), compared with period 1b (4%). Furthermore, incidence of NICU admission was significantly higher for the first half of the night-shift period (2.7%) compared to the relative of the second half (0.5%).

CONCLUSIONS

Neonatal morbidity was comparable between night-shift and rest-of-day periods, but the rates of emergent CS and NICU admission were significantly increased in the first half of the night-shift period (11.00 p.m.-3.00 a.m.).