A mother comes with history of antenatal fetal death due to neural tube defect in first child. What is the amount of folic acid you will prescribe during pre-conceptional counseling?
**Core Concept**
The question is testing the understanding of the role of folic acid in preventing neural tube defects (NTDs) in pregnancies. Folic acid is a B-vitamin that plays a crucial role in DNA synthesis and repair, and its supplementation is recommended to prevent NTDs, which occur early in fetal development.
**Why the Correct Answer is Right**
The recommended dose of folic acid for preventing NTDs is 4 mg/day, starting at least 1 month before conception. This is because NTDs occur during the first few weeks of embryonic development, and folic acid supplementation during this period can significantly reduce the risk of these defects. The neural tube forms within the first 28 days of gestation, and folic acid is crucial for its closure.
**Why Each Wrong Option is Incorrect**
* **Option A:** 0.4 mg/day is the recommended daily allowance (RDA) for folic acid, which is insufficient to prevent NTDs.
* **Option B:** 4 mg/day is the correct answer, but it's mentioned that it should be started 1 month before conception. Starting folic acid after conception is already underway will not prevent NTDs.
* **Option D:** There is no standard recommendation for folic acid supplementation in pregnancy beyond the first trimester.
**Clinical Pearl / High-Yield Fact**
It's essential to note that women with a history of a previous child with an NTD, like the mother in this scenario, should receive a higher dose of folic acid (4 mg/day) for at least 1 month before conception and continue it throughout the first trimester.
**Correct Answer:** C. 4 mg/day.