Angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) are not recommended during the second and third trimester because of the significant risk of congenital anomalies associated with their use. However, data are scarce, especially regarding their use in the first trimester and about the impact of stopping just before pregnancy. Our study illustrates the profile of the women who used ACE-Is or ARBs during pregnancy and evaluates the impact on perinatal outcomes. The Registry of Pregnancy and Cardiac Disease is a prospective, global registry of pregnancies in women with structural heart disease. Outcomes were compared between women who used ACE-Is or ARBs and those who did not. Multivariable regression analysis was performed to assess the effect of ACE-I or ARB use on the occurrence of congenital anomalies. ACE-Is (n = 35) and/or ARBs (n = 8) were used in 42 (0.7%) of the 5,739 Registry of Pregnancy and Cardiac Disease pregnancies. Women who used ACE-Is or ARBs more often came from a low-or-middle-income country (57% vs 40%, p = 0.021), had chronic hypertension (31% vs 6%, p <0.001), or a left ventricular ejection fraction <40% (33% vs 4%, p <0.001). In the multivariable analysis, ACE-I use during the first trimester was associated with an increased risk of congenital anomaly (odds ratio 3.2, 95% confidence interval 1.0 to 9.6). Therefore, ACE-Is should be avoided during pregnancy, also in the first trimester, because of a higher risk of congenital anomalies. However, there is no need to stop long before pregnancy. Preconception counseling is crucial to discuss the potential risks of these medications, to evaluate the clinical condition and, if possible, to change or stop the medication.