Introduction: The aim of this study was to compare blood pressure and prevalence of pregnancy-induced hypertension in women with polycystic ovary syndrome and the reference group throughout pregnancy. Material and methods: This retrospective study was part of the prospective study Odense Child Cohort. Pregnant women were recruited from January 2010 to December 2012. Blood pressure was measured in 200 women with polycystic ovary syndrome and in 2197 in the reference group. Main outcome measures were blood pressure and pregnancy-induced hypertension. Pregnancy-induced hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg occurring after gestational week 20 at two separate visits. Mann-Whitney U test and Chi-square test were used to test differences between women with polycystic ovary syndrome and the reference group. Associations between polycystic ovary syndrome status (PCOS; the reference group) and blood pressure were tested using random mixed-effect linear regression analyses with subjects as random effect to comply with repeated blood pressure measurements. Results: Median blood pressure was comparable in women with polycystic ovary syndrome and the reference group throughout pregnancy: systolic blood pressure 116 (111-123) vs 119 (112-124) (P =.06), diastolic blood pressure 72 (69-77) vs 73 (69-78) (P =.23) and mean arterial pressure 87 (83-93) vs 88 (84-92) (P =.13). In first trimester where systolic blood pressure was lower in polycystic ovary syndrome, median systolic blood pressure was 116 (111-123) vs 119 (112-124) mmHg (P =.04). The prevalence of pregnancy-induced hypertension was similar in polycystic ovary syndrome and the reference group: 17/200 (8.5%) vs 178/1997 (8.9%) (P =.84). Regression analyses showed no significant associations between polycystic ovary syndrome and blood pressure. Conclusions: Blood pressure and prevalence of pregnancy-induced hypertension were comparable in pregnant women with polycystic ovary syndrome and the reference group.