Association Between Birth Timing and Early Clinical Outcomes in Very Preterm Infants: A Retrospective Cohort Study
- 1Department of Pediatrics, Istanbul Medipol University, Istanbul 34214, Turkey
- 2Clinics of Neonatology, Department of Pediatrics, Gazi Yasargil Training and Research Hospital, Diyarbakır 21090, Turkey
- 3Department of Pediatrics, Gazi Yasargil Training and Research Hospital, Diyarbakır 21090, Turkey
Abstract
Background: The effect of birth timing on outcomes in very preterm infants remains controversial. This study evaluated the association between birth timing and early morbidity and mortality in infants born before 32 weeks of gestation. Methods: In this retrospective single-center cohort study, inborn infants born at <32 weeks’ gestation between January 2021 and May 2023 were categorized as in-hours (weekdays 08:01–16:00) or out-of-hours (weekdays 16:01–08:00, weekends, official holidays). The primary outcome was a composite of early mortality (≤72 h) or severe intraventricular hemorrhage (grades III–IV). Multivariable logistic regression adjusted for baseline confounders (Model 1); delivery-room resuscitation, a potential mediator, was added in Model 2. Results: Of 363 infants, 160 (44.1%) were born in-hours and 203 (55.9%) out-of-hours. The composite outcome occurred in 19.7% versus 12.5% (p = 0.091; Model 1 aOR 1.46, 95% CI 0.77–2.77). Overall mortality (32.5% vs. 21.3%, p = 0.023), early mortality (8.4% vs. 2.5%, p = 0.022), delivery-room resuscitation (56.7% vs. 36.9%, p < 0.001), and respiratory distress syndrome (69.0% vs. 55.6%, p = 0.012) were higher out-of-hours. Out-of-hours birth was associated with higher mortality in Model 1 (aOR 1.88, 95% CI 1.11–3.20), but the estimate was attenuated and imprecise in Model 2 (aOR 1.58, 95% CI 0.91–2.75). Conclusions: Out-of-hours birth was not significantly associated with the composite primary outcome but was associated with higher crude and baseline-adjusted mortality. Because delivery urgency, illness severity, and staffing at delivery were incompletely measured, residual confounding cannot be excluded.
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BibTeX
@article{asena2026association,
title = {{Association Between Birth Timing and Early Clinical Outcomes in Very Preterm Infants: A Retrospective Cohort Study}},
author = {Muhammet Asena and Duygu Tunçel and Leyla Şero and Nilüfer Okur},
journal = {Journal of Clinical Medicine},
year = {2026},
month = oct,
doi = {10.3390/jcm15218282},
url = {https://www.mdpi.com/2077-0383/15/21/8282},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Association Between Birth Timing and Early Clinical Outcomes in Very Preterm Infants: A Retrospective Cohort Study
AU - Muhammet Asena
AU - Duygu Tunçel
AU - Leyla Şero
AU - Nilüfer Okur
PY - 2026
DA - 2026/10/24
JO - Journal of Clinical Medicine
DO - 10.3390/jcm15218282
UR - https://www.mdpi.com/2077-0383/15/21/8282
AB - Background: The effect of birth timing on outcomes in very preterm infants remains controversial. This study evaluated the association between birth timing and early morbidity and mortality in infants born before 32 weeks of gestation. Methods: In this retrospective single-center cohort study, inborn infants born at <32 weeks’ gestation between January 2021 and May 2023 were categorized as in-hours (weekdays 08:01–16:00) or out-of-hours (weekdays 16:01–08:00, weekends, official holidays). The primary outcome was a composite of early mortality (≤72 h) or severe intraventricular hemorrhage (grades III–IV). Multivariable logistic regression adjusted for baseline confounders (Model 1); delivery-room resuscitation, a potential mediator, was added in Model 2. Results: Of 363 infants, 160 (44.1%) were born in-hours and 203 (55.9%) out-of-hours. The composite outcome occurred in 19.7% versus 12.5% (p = 0.091; Model 1 aOR 1.46, 95% CI 0.77–2.77). Overall mortality (32.5% vs. 21.3%, p = 0.023), early mortality (8.4% vs. 2.5%, p = 0.022), delivery-room resuscitation (56.7% vs. 36.9%, p < 0.001), and respiratory distress syndrome (69.0% vs. 55.6%, p = 0.012) were higher out-of-hours. Out-of-hours birth was associated with higher mortality in Model 1 (aOR 1.88, 95% CI 1.11–3.20), but the estimate was attenuated and imprecise in Model 2 (aOR 1.58, 95% CI 0.91–2.75). Conclusions: Out-of-hours birth was not significantly associated with the composite primary outcome but was associated with higher crude and baseline-adjusted mortality. Because delivery urgency, illness severity, and staffing at delivery were incompletely measured, residual confounding cannot be excluded.
SN - 2077-0383
ER -