INTRODUCTION Knowledge about the time of birth and its impact on premature infants is essential when planning perinatal and neonatal care and resource allocation. We studied the time of birth and its contribution to early death and morbidity in preterm infants. METHODS We explored the time and mode of birth of infants with birthweight of <1,500 g and gestational age of <32+0/7 weeks. Additionally, we divided the infants into three groups stratified by their time of birth, i.e., during office hours, evening, and nighttime and assessed associations between these groups and mortality and morbidity. RESULTS The study comprised 1,610 infants of whom 156 (10%) died during their stay in neonatal intensive care unit. The highest number of deliveries occurred on Fridays (21%, n = 341/1,610), primarily due to high number of cesarean sections. Deliveries peaked on workdays at 10 a.m. and 2:00 p.m. Mortality was lowest among infants born on Fridays (6%, n = 21/341) and highest on Mondays (13%, n = 28/218). Intraventricular hemorrhage (IVH) (odds ratio [OR]: 1.50, 95% CI: 1.10-2.03, p = 0.010) and necrotizing enterocolitis (NEC) (OR: 2.11, 95% CI: 1.13-3.91, p = 0.019) were more common among infants born at nighttime. These associations attenuated after adjustment for covariates. CONCLUSION Deliveries of premature infants peaked on Fridays. Mortality was lower among those born on Fridays, compared with Mondays. Many low-risk deliveries on Fridays may decrease, and the tendency to postpone high-risk deliveries to Mondays, increase the proportional risk of mortality. Indication of higher risk of IVH and NEC among infants born during nighttime may be due to different patient population.

中文翻译：

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分娩时间会导致早产儿的死亡率和发病率。

简介 在规划围产期和新生儿护理以及资源分配时，了解出生时间及其对早产儿的影响至关重要。我们研究了出生时间及其对早产儿早期死亡和发病的影响。方法 探讨出生体重<1500g、胎龄<32±0/7周的婴儿的出生时间和方式。此外，我们根据出生时间（即办公时间、晚上和夜间）将婴儿分为三组，并评估了这些组与死亡率和发病率之间的关联。结果 该研究纳入了 1,610 名婴儿，其中 156 名（10%）在新生儿重症监护病房期间死亡。周五的分娩数量最多（21%，n = 341/1,610），主要是由于剖腹产数量较多。工作日上午 10 点和下午 2:00 的分娩高峰周五出生的婴儿死亡率最低 (6%, n = 21/341)，周一最高 (13%, n = 28/218)。脑室内出血 (IVH)（比值比 [OR]：1.50，95% CI：1.10-2.03，p = 0.010）和坏死性小肠结肠炎 (NEC)（OR：2.11，95% CI：1.13-3.91，p = 0.019）在夜间出生的婴儿中更为常见。调整协变量后，这些关联性减弱。结论 早产儿的分娩在周五达到顶峰。与周一出生的人相比，周五出生的人死亡率较低。许多周五的低风险分娩可能会减少，而将高风险分娩推迟到周一的趋势会增加死亡风险的比例。夜间出生的婴儿发生 IVH 和 NEC 的风险较高可能是由于不同的患者群体所致。