Since the embryo’s neural tube closes between the 24th and 28th day after conception ​ — long before many women realize that they are pregnant — ​ some women who are planning to become pregnant take folic acid.
मगर इससे बहुत हद तक बचा जा सकता है अगर गर्भ धारण करनेवाली स्त्रियाँ भरपूर मात्रा में फॉलिक एसिड लेना शुरू कर दें ।