Chromosomal abnormalities, alcohol use during pregnancy and environmental factors are all potential causes of birth defects. A birth defect is a problem with the formation of body parts, how the body parts work or how the body uses food for energy, states KidsHealth.
A healthy person has 23 pairs of chromosomes, according to Genetics Home Reference. If a baby is born with the wrong number of chromosomes or damage to any of the chromosomes, that child might have a birth defect, reports KidsHealth. Tay-Sachs disease, Down syndrome and cystic fibrosis are examples of birth defects caused by chromosomal abnormalities.
Because a developing fetus receives nutrients via the umbilical cord, it is exposed to whatever the mother puts in her body. Women should not drink alcohol during pregnancy to reduce the risk of fetal alcohol spectrum disorders, as recommended by the Centers for Disease Control and Prevention. Fetal alcohol spectrum disorders cause problems such as low body weight, difficulty paying attention, speech delays, hearing or vision problems, hyperactivity and poor coordination. Some prescription drugs also affect fetal development.
Babies also develop birth defects as the result of exposure to certain infections in the womb. If a pregnant woman develops toxoplasmosis, chickenpox or rubella, there is a chance her baby might have a birth defect at birth, reports KidsHealth.