Abstract Introduction Arterial hypertension affects about 5-10% of pregnancies and has detrimental effects on pregnancy outcomes in both the mother and fetus. The study aimed to analyse the outcomes of pregnancy in women treated for arterial hypertension in pregnancy in the Czech Republic. Methodology Nationwide data on all births and abortions in the period 2012-2022 in the Czech Republic were obtained from the National Registry of Reproductive Health (NRRZ) and the National Registry of Reimbursable Health Services (NRHZS). Women who had the diagnosis I10 within one year before pregnancy and were prescribed any antihypertensive drug from selected ATC groups (C02, C03, C07, C08, C09) were classified as pre-existing hypertension. Women diagnosed with O13 or I10 during pregnancy were classified as pregnancy induced hypertension. Hypoxia in the new-born was defined as pH <7.1 or Apgar score <8 present after delivery. For all factors, univariate logistic regression was used to calculate the odds ratios (OR) of adverse outcomes. Results There were total of 1,154,648 deliveries in the 11-year period. 95,215 women had hypertension in pregnancy, out of these 21,094 (22.2%) were treated with antihypertensive drugs. Odds ratios for caesarean section, pre-term delivery, low birth weight, new-born hypoxia and pre-eclampsia in women using different antihypertensive classes and drugs are shown in the Table. Risk of maternal and fetal complications was found to be higher with calcium channel blockers (mainly amlodipine) compared to methyldopa and beta blockers. Among beta blockers, bisoprolol had the most favourable safety profile. Although used in limited numbers, diuretics, verapamil, ACE-inhibitors and angiotensin receptor blockers (ARBs) appeared to be comparably safe to methyldopa. Combination of multiple antihypertensive drugs was associated with higher risk of adverse outcomes. Conclusion Bisoprolol, verapamil and diuretics seem to have the risk of adverse maternal and fetal outcomes comparable to methyldopa. Amlodipine and multiple antihypertensive drug combinations are associated with increased risk.Table