Examining the Magnitude of Maternal Ethnic and Socioeconomic Inequalities on Foetal Growth Restriction and Preterm Birth: A Cohort Study Set in North West England.

OBJECTIVE

To calculate population attributable fractions (PAFs) for the effect of ethnicity and deprivation on foetal growth restriction (FGR) and preterm birth (PTB). PAF estimates the risk reduction of FGR and PTB if ethnic and socioeconomic inequalities did not exist.

DESIGN

A retrospective cohort study using routinely recorded electronic health records, 2016-2021, Manchester, UK.

METHODS

Women with singleton pregnancies greater than 22 weeks' gestation. Logistic regression models were fitted to explore the association between maternal self-reported ethnicity, or deprivation (index of multiple deprivation) on the odds of developing foetal growth restriction (FGR) and preterm birth (PTB). PAFs were estimated from (un)adjusted logistic regression models.

MAIN OUTCOME MEASURES

The PAF of FGR and PTB cases associated with ethnicity and deprivation.

RESULTS

A total of 48,930 pregnancies were included in the analysis with FGR and PTB rates of 8.5% and 6.9%, respectively. Forty-five percent were from ethnic minority backgrounds with 33% living in the most deprived postcode wards. In adjusted models, 22.8% (95% CI 19.6-25.9%) of FGR cases were attributable to ethnicity (using White British/Irish as comparison group). There was no effect of ethnicity on the PAF of PTB cases. In comparison to women living in the least deprived tertile of our population, 9.1% (95% CI 4.6-13.5%) of FGR cases and 11.2% (95% CI 6.2-15.9%) of PTB cases were attributable to deprivation.

CONCLUSIONS

In our population, there is a disparity in pregnancy outcomes for women of ethnic minorities and those living in deprived areas. Targeted interventions such as antenatal caseload models and improved screening in high-risk women could contribute to the efforts to reduce maternal and perinatal morbidity in the UK.