New research from UCL and King’s College London (KCL) and Tommy’s National Centre for Preterm Birth Research has found that women and birthing people who had a caesarean section at full cervical dilatation during premature labour are at a significantly higher risk of giving birth prematurely again in a future pregnancy.
Premature or preterm birth - before 37 weeks - can pose risks to a newborn baby, as many organs are still developing in the final weeks of pregnancy. A premature baby may have difficulty staying warm, feeding, or experience developmental delays, among other risks.
The study, published in Acta Obstetricia Et Gynecologica Scandinavica journal, found that those who had a full dilatation caesarean delivery (FDCD) before 37 weeks were 4 times more likely to have another spontaneous premature birth compared to those who previously gave birth prematurely via vaginal birth, and 5 times more likely than those who had a caesarean at an earlier stage in premature labour.
This risk of recurrent very early premature birth was even higher. Women who had a premature FDCD were over 16 times more likely to give birth again before 34 weeks, compared to those whose earlier premature birth was vaginal.
Previous research has shown that caesareans performed at full dilatation in a full-term pregnancy can increase the risk of premature birth in later pregnancies. This new study is the first to show that the same risk applies – and may be even greater – when the caesarean is performed at full dilatation during premature labour.
Researchers believe this may be because surgery at this advanced stage of labour can cause damage to the cervix, making it harder for the cervix to stay closed in future pregnancies.
In a smaller group of women who had previously had a premature full dilatation caesarean, researchers used transvaginal ultrasound scans during pregnancy to examine the caesarean scar.
The findings highlight the importance of recognising premature FDCD as a major risk factor for future premature birth. This evidence will enable healthcare professionals to improve counselling of women with increased risk of premature birth, inform and improve monitoring, and guide decisions around different interventions during pregnancy.
Senior author of the study Professor Anna David (UCL EGA Institute of Women’s Health) who is supported by the BRC, said: “Women who need a caesarean section during advanced premature labour often have no alternative – these procedures can be lifesaving. But our findings show that this type of caesarean can have important consequences for future pregnancies. Identifying those at highest risk using transvaginal ultrasound allows us to better monitor them during pregnancy and explore new ways to prevent premature birth.”
Image: Adobe Stock / Mechastock
