Health professionals do not recommend Caesareans
Having a Caesarean does not raise the risk of a stillbirth in a subsequent pregnancy, a study has found.
The University of Calgary study contradicts previous research which suggested an increased risk.
The study suggests a mother's obesity - not whether she has a Caesarean - may instead be the key factor.
The study, which appears in the journal BJOG, suggests that previous research has failed to take this factor properly into account.
However, health professionals advise woman not to opt for a Caesarean lightly, as it is a major surgical procedure, with a risk of complications.
Researcher Dr Stephen Wood said the finding was particularly important as the number of Caesareans had increased in recent years.
He said obesity had been consistently linked to both Caesareans and stillbirths, but it had proved difficult to tease out its independent effect on each.
The Calgary study examined 157,029 second births, and took potentially confounding factors, such as maternal weight, into consideration.
Once they had done that they found that, among women who had previously had a Caesarean, the stillbirth rate was 2.1 per 1,000, compared with 1.6 per 1,000 in women who had no Caesarean history - not a statistically significant difference.
The researchers admit that they were not able to completely account for maternal weight, but had done so far more than previous research.
Dr Wood said: "Our study strongly suggests that previous Caesarean section does not increase the risk of stillbirth in subsequent pregnancies.
"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."
Professor Philip Steer, editor-in-chief of BJOG, said: "Caesarean section rates are increasing across the developed world and the increase in risks for subsequent pregnancies have been well-documented.
"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."