BACKGROUND:Two prenatal screening tests for congenital anomalies are offered to all pregnant women in the Netherlands on an opt-in basis: the Combined Test (CT) for Down syndrome at twelve weeks, and the Fetal Anomaly Scan (FAS) at around twenty weeks. The CT is free for women who are 36 or older; the FAS is free for all women. We investigated factors associated with the CT and FAS uptake. METHOD:This study is part of the DELIVER study that evaluated primary care midwifery in the Netherlands. Associations between the women's characteristics and the CT and FAS uptake were measured using multivariate and multilevel logistic regression analyses. RESULTS:Of 5216 participants, 23% had the CT and 90% had the FAS, with uptake rates ranging from 4% to 48% and 62% to 98% respectively between practices. Age (OR: 2.71), income (OR: 1.38), ethnicity (OR: 1.37), being Protestant (OR: 0.25), multiparous (OR: 0.64) and living in the east of the country (OR: 0.31) were associated with CT uptake; education (OR: 1.26), income (OR: 1.66), being Protestant (OR: 0.37) or Muslim (OR: 0.31) and being multiparous (OR: 0.74) were associated with FAS uptake. Among western women with a non-Dutch background, first generation (OR: 2.91), age (OR: 2.00), income (OR: 1.97), being Protestant (OR: 0.32) and living in the east (OR: 0.44) were associated with CT uptake; being Catholic (OR: 0.27), Protestant (OR: 0.13) were associated with FAS uptake. Among non- western women with a non-Dutch background, age (OR: 1.73), income (OR: 1.97) and lacking proficiency in Dutch (OR: 2.18) were associated with CT uptake; higher education (OR: 1.47), being Muslim (OR: 0.37) and first generation (OR: 0.27) were associated with FAS uptake. CONCLUSION:The uptake of the CT and FAS varied widely between practices. Income, parity and being Protestant were associated with uptake of both tests; ethnicity, age and living in the east were associated with CT uptake, and education and being Muslim with FAS uptake. These findings help to explain some differences between women choosing or declining early and late screening, but not the large variation in test uptake among practices, nor between the Netherlands and other countries.