What is a significant indication of increased levels of AFP during pregnancy?

Alpha-fetoprotein (AFP) is a protein produced by the fetal liver, and its levels in the maternal blood can provide valuable insights into fetal development. During pregnancy, significantly elevated levels of AFP are particularly associated with neural tube defects, which are serious congenital conditions affecting the development of the brain and spinal cord. Conditions like spina bifida and anencephaly can cause an abnormal increase in AFP as the protein leaks into the amniotic fluid and then into the mother’s bloodstream due to defects in the fetal neural tube.

Monitoring AFP levels is part of routine prenatal screening, often performed between the 15th and 20th weeks of gestation. Elevated AFP levels can serve as a warning sign, prompting further diagnostic testing, such as ultrasound or amniocentesis, to assess for potential neural tube defects or other anomalies.

The other options do not correctly correlate with significant increases in AFP levels during pregnancy. For instance, while gestational diabetes may affect mother and baby, it is not indicated by changes in AFP levels. Similarly, heart defects and low birth weight are not directly linked to elevated AFP, making these choices less relevant in the context of this specific biomarker and its most significant indication in prenatal screening.