Related Experiment Video
Updated: Jun 18, 2026
Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats
Published on: November 20, 2015
Impact of obstetric factors on outcome of extremely preterm births in Sweden: prospective population-based
Karin Källén1, Fredrik Serenius2,3, Magnus Westgren4
1Centre for Reproductive Epidemiology, Lund University, Lund, Sweden.
Insights
Obstetric factors significantly impact extremely preterm infant survival. Antenatal corticosteroids and gestational age reduce mortality, while vaginal breech delivery is linked to developmental delays.
Area of Science:
- Neonatalogy
- Obstetrics
- Developmental Pediatrics
Background:
- Investigated obstetric factors' contribution to survival and postnatal development in extremely preterm infants.
- Utilized a population-based observational study design.
Purpose of the Study:
- To analyze the impact of various obstetric factors on mortality and neurodevelopment in infants born before 27 weeks gestation.
- To identify risk factors for early and late mortality, as well as developmental outcomes.
Main Methods:
- Evaluated mortality up to 1 year and neurodevelopment at 2.5 years (Bayley-III, cerebral palsy, vision, hearing).
- Analyzed data from 1011 infants born between 2004-2007 in Sweden using logistic regression.
- Included factors like gestational age, delivery mode, Apgar scores, and hospital level.
Main Results:
- Risk of early death (within 24h) decreased with gestational age, antenatal corticosteroids, and cesarean section.
- Early death risk increased with multiple births, vaginal breech delivery, low Apgar score, and birth at level II hospitals.
- Gestational age and corticosteroids reduced mortality up to 1 year; mental developmental delay was associated with vaginal breech delivery.
Conclusions:
- Obstetric factors, including delivery mode, influenced early mortality but not later survival.
- Antenatal corticosteroids and gestational age are key protective factors for mortality up to one year.
- Vaginal breech delivery is a significant risk factor for mental developmental delay in extremely preterm infants.
Introduction:
A population-based observational study investigated the contribution of obstetric factors to the survival and postnatal development of extremely preterm infants.
Material And Methods:
Mortality up to 1 year and neurodevelopment at 2.5 years (Bayley-III test, cerebral palsy, vision, hearing) were evaluated in infants born before 27 weeks of gestation in Sweden 2004-2007 (n = 1011), using logistic regression analyses of risk factors.
Results:
Of 844 fetuses alive at admission, 8.4% died in utero before labor, 7.8% died intrapartum. Of 707 live-born infants, 15% died within 24 h, 70% survived ≥365 days, 64% were assessed at 2.5 years. The risk of death within 24 h after birth decreased with gestational age [odds ratio (OR) 0.3; 95% CI 0.2-0.4], antenatal corticosteroids (OR 0.3; 95% CI 0.1-0.6), and cesarean section (OR 0.4; 95% CI 0.2-0.9); it increased with multiple birth (OR 3.0; 95% CI 1.5-6.0), vaginal breech delivery (OR 2.3; 95% CI 1.0-5.1), 5-min Apgar score <4 (OR 50.4; 95% CI 28.2-90.2), and birth at a level II hospital (OR 2.6; 95% CI 1.2-5.3). The risk of death between 1 and 365 days remained significantly decreased for gestational age and corticosteroids. The risk of mental developmental delay at 2.5 years decreased with gestational age, birthweight and fetal growth; it increased with vaginal breech delivery (OR 2.0; 95% CI 1.2-7.4), male gender, low Apgar score and high Clinical Risk Index for Babies score.
Conclusion:
Several obstetric factors, including abdominal delivery, influenced the risk of death within the first day of life, but not later. Antenatal corticosteroids and gestational age decreased the mortality up to 1 year. Mental developmental delay was related to vaginal breech delivery.
Related Concept Videos
01:52Regression Toward the Mean
01:28Development of the Oral Microbiota