Which one of the following anti-hypeensive drugs is contraindicated in pregnancy?
**Core Concept**
ACE inhibitors are a class of antihypertensive medications that work by inhibiting the conversion of angiotensin I to angiotensin II, thereby reducing vasoconstriction and blood pressure. However, this mechanism also affects fetal development in pregnant women, making certain ACE inhibitors contraindicated during pregnancy.
**Why the Correct Answer is Right**
ACE inhibitors, such as Lisinopril, can cause oligohydramnios (reduced amniotic fluid), fetal growth restriction, and other congenital anomalies due to their effect on fetal renal function and blood pressure regulation. This is because the fetus's kidneys rely on the renin-angiotensin-aldosterone system for development, which is affected by ACE inhibitors. In pregnant women, the use of ACE inhibitors can also lead to maternal hypertension, pre-eclampsia, and renal dysfunction.
**Why Each Wrong Option is Incorrect**
**Option A:** Methyldopa is actually a commonly used antihypertensive medication in pregnancy, particularly for chronic hypertension. It is considered safe for both mother and fetus.
**Option B:** Hydralazine is a vasodilator that is often used in pregnancy for acute hypertension management. It is not contraindicated in pregnancy.
**Option C:** Labetalol is a mixed alpha/beta-adrenergic antagonist that is commonly used in pregnancy for hypertension management. It is considered safe for both mother and fetus.
**Clinical Pearl / High-Yield Fact**
ACE inhibitors should be discontinued at least 3 months before pregnancy or as soon as pregnancy is confirmed to minimize fetal risks. Women of childbearing age taking ACE inhibitors should be advised on the importance of contraception and the need for regular pregnancy testing.
**Correct Answer: C. Lisinopril**