RESUMEN
OBJECTIVE: To evaluate the feasibility of self-reported ethnicity using the gestation-related optimal growth (GROW) classification in a contemporary multicultural antenatal population. DESIGN: Cross-sectional study. SETTING: Tertiary obstetric hospital in Melbourne, Australia. POPULATION: Pregnant women attending the antenatal clinic. METHODS: We surveyed pregnant women during April-June 2016 regarding their understanding of the term 'ethnicity', and how they would classify the ethnicity of themselves, their partner, and family members according to the Australian GROW classification. RESULTS: Two hundred and thirty-five women completed the survey. When describing 'ethnicity', most women (103, 44%) chose multiple descriptors, most frequently country of birth (54%) and region of ancestry (47%). Interpretation of 'ethnicity' varied significantly between ethnic groups: those choosing 'country of birth' were more likely to identify as Indian (odds ratio, OR 3.5, P = 0.03), whereas those choosing 'physical appearance' were more likely to identify as Chinese (OR 3.0, P = 0.047). Thirty participants (13%) were unable to describe their ethnicity from the available GROW options. Sixty-one (26%) respondents' ethnicity was inconsistent with that of their parents' heritage. A further 35% had a partner of different ethnicity. The agreement between country of birth and self-reported ethnicity was only fair (kappa 0.73, 95% confidence interval, 95% CI 0.64-0.82). CONCLUSION: This study confirms the complexity of defining ethnicity in contemporary multicultural settings. Self-reported ethnicity is often inaccurate, concepts of ethnicity vary by ethnic group, and country of birth is a poor descriptive surrogate. Adjustment for maternal ethnicity should be undertaken with caution in the customised assessment of fetal growth. TWEETABLE ABSTRACT: Is self-reported maternal ethnicity reliable? We think not.
