Expectant mothers are being advised to monitor their obesity levels after it was found that these may be a factor in stillbirths.
Previous studies had found that the risk of a woman giving birth to a stillborn baby increased if she had previously undergone a caesarean.
But the latest findings from a study at the University of Calgary in Alberta, Canada, showed that maternal obesity levels had a greater impact on her risk of stillbirth.
"Our study strongly suggests that previous caesarean section does not increase the risk of stillbirth in subsequent pregnancies," said Dr Steven Wood, from the university's Department of Obstetrics and Gynaecology.
"Although previous research has made a link between the two, it is likely that maternal obesity played a part as it was not controlled for."
The study included 157,929 second births and took into account other information on factors that could impact on the results such as maternal diabetes, maternal weight, hypertension and smoking during pregnancy.
"The increase in stillbirth risk previously reported was especially concerning, so it is somewhat reassuring that the study by Dr Wood and his team suggests that this may have been due to the confounding factor of maternal obesity," said Professor Philip Steer, editor-in-chief of BJOG: An International Journal of Obstetrics and Gynaecology, which published the research.