Obstetric complications do not explain why pregnant women over 30 years of age are more likely than younger women to end up with a caesarean section.
Researchers from the Aberdeen Maternity Hospital evaluated the factors influencing the high caesarean rate among older women by analysing data from 23,806 deliveries registered in the Aberdeen Maternal and Neonatal Databank.
They found that, while the baby's position and mother's caesarean history influenced the association between maternal age and caesarean rates, when these and other potential risk factors were adjusted for, the caesarean rate for older mums was still greater than for younger women.
The study raises more questions than it answers. While maternal request may play a part in the high rate of caesareans among older mothers, it is unlikely to be the only explanation.
The researchers noted that further research is now needed which takes into account women's views towards increased intervention, the variation in rates for caesarean section among obstetricians, and how maternal age intersects with these factors (BMJ, 2001; 322: 894-5).