Study suggests demographic factors can predict risk of operative births in UK women

Independent maternal demographic factors such as social status, ethnicity and maternal age can predict the likelihood of operative births in the UK, according to a new study published today (20 March) in BJOG: An International Journal of Obstetrics and Gynaecology.

The study, conducted by researchers in the Department of Health Sciences at the University of York, explores which women are at an increased risk of an operative birth, including caesarean section (CS) or instrumental vaginal birth. It looks at data from the Millennium Cohort Study of babies born in the UK between 2000-2002 and includes 18,239 mother-infant pairs.

Rates of CS in the UK have increased since the 1980s, however, there has been no associated decrease in instrumental vaginal births. Operative births can lead to longer hospital stays and poorer psychological wellbeing, and represent a substantial financial cost to the NHS.

The researchers looked at four categories of mode of birth, including unassisted vaginal birth, instrumental vaginal birth, emergency CS and planned CS, and the impact of demographic factors such as age, ethnicity and socio-economic status, while controlling for a wide range of individual factors.

Findings showed that age played a significant role in determining mode of birth for all women, with operative birth rates rising with increasing maternal age. For example, 9.4% of first-time teenage mothers required an emergency CS compared with 30.3% of first-time mothers aged 35 or older.

Researchers found that some independent maternal factors differed when comparing primiparous (first-time mothers) to multiparous (have had one or more previous births) women.

Factors such as social status, ethnicity, and the mother’s age can predict the likelihood of caesarean section and other operative births in the UK, finds research published in BJOG: An International Journal of Obstetrics and Gynaecology.

These factors may explain the wide discrepancies in caesarean section rates across England, speculate the authors.

The researchers assessed data from 18,239 mother-infant pairs who were part of the Millennium Cohort Study of babies born in the UK between 2000-2002 to see which women run a greater risk of an operative birth, including caesarean section or instrumental vaginal birth.

C-section rates in the UK have increased since the 1980s, but there has been no associated decrease in instrumental vaginal births. Operative births can lead to longer hospital stays and poorer psychological wellbeing, and are costly for the NHS.

Socio-economic factors impacted women differently, with first-time mothers from lower occupational status households 1.5 times more likely to have an instrumental vaginal birth and over twice as likely to have a planned CS.

While for multiparous women, educational level was more predictive of mode of birth in women with A-level qualifications at a reduced risk of planned CS compared to women with degree-level qualifications.