**Question:** Which of the following antihypertensives is NOT used in the management of Pregnancy Induced Hypeension in the first trimester

A. Losartan
B. Amlodipine
C. Nifedipine
D. Enalapril

**Core Concept:**
Pregnancy-induced hypertension (PIH), also known as preeclampsia, is a complication of pregnancy characterized by new-onset hypertension (>140/90 mmHg) and proteinuria (>300 mg/24 hours) after 20 weeks gestation. In the first trimester, the focus is on managing the risk factors and preventing progression to preeclampsia.

**Why the Correct Answer is Right:**
Enalapril is a selective angiotensin-converting enzyme (ACE) inhibitor, which is commonly used in the management of hypertension, including pregnancy-induced hypertension. However, it is not recommended in the first trimester due to the potential risk of congenital abnormalities, particularly cardiovascular malformations. The risk is highest during the first trimester, with a decrease in risk as pregnancy progresses.

**Why Each Wrong Option is Incorrect:**

A. Losartan is a selective angiotensin II receptor blocker (ARB), which also belongs to the class of antihypertensive drugs that target the renin-angiotensin-aldosterone system (RAAS). It is contraindicated in the first trimester as well due to the same risk of congenital abnormalities, particularly cardiovascular malformations.

B. Amlodipine is a calcium channel blocker (CCB), which also belongs to the class of antihypertensive drugs that target vascular smooth muscle relaxation. Although amlodipine is generally safe in pregnancy, it is not recommended in the first trimester due to the potential risk of congenital abnormalities, particularly cardiovascular malformations.

C. Nifedipine is another calcium channel blocker (CCB), similar to amlodipine. It is also contraindicated in the first trimester due to the potential risk of congenital abnormalities, particularly cardiovascular malformations.

**Clinical Pearl:**
The use of ACE inhibitors and angiotensin II receptor blockers (ARBs) in the first trimester has been associated with a higher risk of cardiovascular malformations in the fetus compared to other antihypertensive agents. Therefore, it is important to choose an alternative antihypertensive agent during this period to minimize the risk to the developing fetus. Calcium channel blockers like amlodipine and nifedipine are safer alternatives in pregnancy, but should also be avoided in the first trimester due to potential congenital malformations.