Published: 21-05-2014 08:45 | Updated: 21-05-2014 09:05

Increased risk of asphyxia in babies born to overweight women

The risk of experiencing an oxygen deficit at birth (birth asphyxia) increases for babies born to women who are overweight or obese, according to a study by Swedish and US researchers published in the journal PLOS Medicine.

“These findings are important given the high prevalence of overweight and obesity worldwide, and suggest that preventing women of reproductive age from becoming overweight or obese is important to the health of their children”, says Dr. Martina Persson at Karolinska Institutet’s Department of Medicine, Solna, Clinical Epidemiology Unit, who led the study.

Researchers used information from the Swedish medical birth registry – a database including nearly all the births occurring in Sweden since 1973 – for all births of single babies that took place between 1992 and 2010, resulting in over 1.7 million births. They found that although mothers with normal weight gave birth to the majority of infants with the lowest Apgar scores (a measure of oxygen deficit at birth), the proportion of low Apgar scores was greater in babies of overweight and obese mothers.

Increased with maternal BMI

Overall, the authors found that the rates of low Apgar scores increased with maternal Body Mass Index (BMI): overweight (BMI 25.0–29.9) was associated with a 55% increased risk of low Apgar scores at 5 minutes; obesity grade I (BMI 30–34.9) and grade II (BMI 35.0–39.9) was associated with a 2-fold increased risk; and obesity grade ΙII (BMI ≥ 40.0) was associated with a more than 3-fold increase in risk.

The study was funded with a Distinguished Professor Award from Karolinska Institutet to Professor Sven Cnattingius. Dr. Martina Persson also works as a pediatrician at the Sachs' Children and Youth Hospital in Stockholm.


Maternal Overweight and Obesity and Risks of Severe Birth-Asphyxia-Related Complications in Term Infants: A Population-Based Cohort Study in Sweden
Martina Persson, Stefan Johansson, Eduardo Villamor, Sven Cnattingius
PLOS Medicine, 11(5): e1001648, doi:10.1371/journal.pmed.1001648,online 20 May 2014