Final answer:
Risks for preterm birth and low birth weight in infants are heightened by the intake of certain medications and exposure to teratogens during pregnancy. Smoking, undernutrition, and specific drugs like thalidomide and warfarin are associated with such risks. Adequate maternal nutrition is critical to counteract these risks and support healthy fetal development.
Step-by-step explanation:
Risks for preterm birth and low birth weight in infants can increase due to the ingestion of certain medications and substances during pregnancy. Counseling on the safe use of medications during pregnancy is an essential component of prenatal care. Thalidomide, warfarin, heroin, and cocaine, among others, are recognized teratogens, which can interfere with the development of the fetus, leading to various birth defects or fetal growth restrictions.
There is a correlation between maternal lifestyle, such as smoking, and adverse outcomes like preterm labor and low birth weight. Exposure to teratogens can significantly affect the fetal growth rate and gestational length, two major determinants of an infant's birth weight. Adequate nutrition, particularly the intake of folic acid, has been shown to reduce the incidence of neural tube defects, showcasing the importance of a healthy maternal diet and the avoidance of harmful substances.
Preterm birth, a result of less time for in utero growth, is a leading cause of neonatal mortality. Babies born with a weight lower than 2.5 kg are at a higher risk of health complications. There is evidence suggesting that preterm and low birth weight infants tend to face a multitude of challenges, such as increased susceptibility to diseases and developmental delays during early childhood. While genetic factors play a significant role in birth defects, environmental factors including maternal health, nutrition, infection, and exposure to toxicants also contribute substantially.