This study sought to determine the relative contribution of demographic factors (ethnicity, deprivation, DHB of domicile and maternal age with timing of prenatal screening, i.e. first versus second trimester) in pregnant women screened in New Zealand between 2010 and 2013. The majority (88%) of completed prenatal screens were completed in the first trimester. Ethnicity, age, deprivation and DHB were all significant predictors of completed first versus second trimester screening. In multivariate analyses, Māori women were almost 60% less likely (adjusted OR 0.37; 95% CI, 0.35 to 0.39) and Pacific women almost 80% less likely (adjusted OR 0.23; 95% CI, 0.21 to 0.24) than NZ European women to have completed first versus second trimester screening. Women aged <30 years and those living in more deprived areas were less likely to have completed first trimester screening. There was variation by DHB, with women living in Whanganui DHB less likely to have completed first versus second trimester screening than women living in Auckland (adjusted OR 0.76; 95% CI, 0.71 to 0.81). Women living in Bay of Plenty DHB were more likely to be screened in the first versus second trimester compared with women living in Auckland (adjusted OR 1.55; 95% CI, 1.38 to 1.74). In analyses adjusting for ethnicity, deprivation and maternal age, women living in Counties Manukau DHB were less likely to be screened in the first versus second trimester than women living in Auckland DHB.
