4 February 2011
Obese women are more likely to have overdue pregnancies and require induction of labour than women of normal weight, but their delivery outcomes are similar, a large UK study shows.
British researchers studied the medical records of nearly 30,000 women, of whom about 3000 had a prolonged pregnancy, defined as more than 41 weeks and 3 days.
They found obese women were 50% more likely to have a prolonged pregnancy than women of normal weight (British Journal of Obstetrics and Gynaecology 2011; online 26 Jan).
And among women having their first baby, more than one-third of those who were obese had an induced labour that ended in a caesarean section, compared with less than a quarter of women with normal weight.
However, obese women did not experience more delivery complications than women of normal weight.
Length of labour and complications such as bleeding after the birth, severe tears, low Apgar scores (indicating a possible health problem in the baby) and shoulder dystocia (difficult labour) were all similar across the different weight groups. But obese women did have bigger babies.
Last Reviewed: 04 February 2011