Final answer:
Neural tube defects such as spina bifida and anencephaly are caused by low folate levels in the mother prior to conception and during pregnancy.
Step-by-step explanation:
Neural tube defects such as spina bifida and anencephaly are associated with low folate levels in the mother prior to conception and during pregnancy.
Folate, also known as vitamin B9, is crucial for the healthy development of the neural tube in the growing embryo. A deficiency in folate during the early stages of pregnancy can result in incomplete closure of the neural tube, leading to these birth defects.