King's College London

In England, more than one in three babies are delivered by c-section, and 24% of all deliveries are by emergency caesarean, of which 5% are performed on women at full cervical dilatation in the late stage of labour.

Women have life-saving caesareans at this stage of labour as complications arise, but it can have important ramifications for subsequent pregnancies. If the caesarean is needed during labour, the surgical incision is more likely to be near or within the cervical tissue due to physiologoical changes the cervix undergoes during labour. As labour progresses and the cervix dilates, the babies’ head is lower in the mother’s pelvis and can be more difficult to deliver, which increases the risk of surgical trauma to the cervix.

In a piece written by Professor Andrew Shennan and Dr Laura van der Krogt for PLOS Medicine, the authors highlight the risk for women and mid-trimester loss associated with in-labour caesareans.

He added: "We now know that those performed in labour can increase the subsequent risk of early birth. Premature birth is one of the most serious health problems in the world, and this is one reason why it isn’t getting better.”

Dr Laura van der Krogt, Clinical Research Fellow in Preterm Birth, said: "This perspective highlights the association between in-labour caesarean section with mid-trimester loss and preterm birth in subsequent pregnancies. This problem may be caused by cervical caesarean damage. Clinicians and women both need to bear these possible risks when considering the potential merits of an in-labour caesarean section."