Alcohol, Drugs & Pregnancy


Alcohol and drug use during pregnancy is a major cause of preventable miscarriage, birth defects and other adverse outcomes. In addition to alcohol, other common drugs used by pregnant women include amphetamines, cocaine, marijuana and heroin. Because about half of all pregnancies are unplanned, women may unknowingly harm their developing baby before they even know they are pregnant.


Alcohol use during pregnancy is responsible for a host of problems with the baby. Excessive use early in pregnancy can cause miscarriage. Use of moderate amounts of alcohol at any time during pregnancy increases the chance for fetal demise and stillbirth. Babies that survive the pregnancy face increased chances for many problems including low birthweight, preterm birth, facial malformations such as clefts, heart defects and neural tube defects, openings along the spine or head that cause neurological damage. Problems after birth include attention disorders, language delays and learning disabilities.

Although no amount of alcohol is known to be safe for the baby, very small amounts, such as one drink every few days, are unlikely to cause problems.


Amphetamines and methamphetamines are artificial stimulants referred to by many names, including “uppers,” “bennies,” “speed” and “meth.” Tired mothers may turn to these drugs to increase their energy and stamina. However, regular use increases the risk for several pregnancy complications, including miscarriage, preterm delivery and placental abruption, a life-threatening condition where the placenta prematurely separates from the wall of the uterus. Babies exposed to amphetamines can have defects of the heart and bones and poor growth. According to a study published in “Pediatrics Clinics of North America” in 1995, babies exposed to amphetamines during pregnancy have an increased chance for low birthweight, small body size and small head size. Babies born underweight and small for their age can develop other problems down the road, including breathing problems, behavioral issues and learning disabilities.


Like the use of alcohol and amphetamines, the use of cocaine during pregnancy can cause miscarriage, stillbirth, poor fetal growth and preterm birth. Unlike alcohol and amphetamines, where minimal use is unlikely to cause problems for the baby, cocaine can cause major problems even if used only once. Cocaine reduces blood flow, which can mean that insufficient blood reaches the developing baby. Babies exposed to cocaine during pregnancy can develop brain malformations, limb reduction defects (where an arm or leg fails to develop completely) and brain hemorrhage. Cocaine use also increases the chance of placental abruption. According to the Organization of Teratology Information Specialists (OTIS), newborns of mothers who used cocaine during pregnancy can experience withdrawal symptoms including irritability, shakiness, muscle rigidity, problems sleeping and tiredness.


The risks to a pregnancy from the use of marijuana, commonly referred to as “pot,” are essentially the same as those from cigarette smoke. Both cigarette smoke and marijuana contain toxins that reach the baby through the mother’s bloodstream. These toxins increase the risk for miscarriage, poor fetal growth, low birthweight and preterm birth. As mentioned previously, small, underweight babies and those born before they are full-term (less than 37 weeks gestation) face risks for health and development problems after birth. Exposure to marijuana near the time of birth can result in withdrawal-like symptoms, such as jitteriness and sleeping problems.


Heroin is a highly addictive drug taken to create feelings of relaxation and euphoria. When used during pregnancy, heroin can cause premature birth, poor fetal growth, low birthweight, bleeding in the brain and increased risk of HIV infection if the mother shares drug needles. Most babies exposed to heroin during pregnancy exhibit withdrawal symptoms after birth, including severe irritability, excessive crying and restlessness. The risk for health problems continues after birth, with increased rates of hyperactivity, sleep abnormalities, seizures and behavioral and developmental problems.

About this Author

Based in Los Angeles, Roxanne Maas holds a master’s degree in genetic counseling with more than 12 years of experience communicating complex genetics and pregnancy information. She has published several abstracts in scientific journals, presented posters at national genetics meetings, and published health-related articles on