Final answer:
The lack of folate during early pregnancy is linked with neural tube defects such as spina bifida and anencephaly. Pregnant women should ensure sufficient folic acid intake to reduce the risk of these defects.
Step-by-step explanation:
The lack of folate during the earliest stage of pregnancy is linked with neural tube defects. Folate, which is one of the B vitamins, is crucial for the healthy development of the neural tube. A deficiency of maternal folate in the first weeks of pregnancy can result in neural tube defects, such as spina bifida and anencephaly. It is important for pregnant women to ensure they have sufficient folic acid intake during the early stages of pregnancy to reduce the risk of these neurological defects.