Smoking weed or marijuana while pregnant may increase the risk for various problems with the baby. Many studies have examined this topic with conflicting results, but at least some studies, noted below, have identified certain risks. Although an ultrasound can be performed during pregnancy to check the baby's health, it is not possible to determine with certainty before birth whether a baby will have problems caused by marijuana.
Gastroschisis
Marijuana passes into the mother's bloodstream and reaches the baby through the placenta. This drug may be responsible for some cases of birth defects, including gastroschisis. Gastroschisis is an opening in the abdominal wall in which the intestines and other organs can be pushed outside of the abdomen. A study published in the journal "Teratology" found a significant association between smoking marijuana and having a baby with gastroschisis. However, another study, published in the "Journal of Toxicology and Environmental Health," reported that marijuana likely did not play a significant role in the cause of gastroschisis.
Heart Defects
A study published in the journal "Birth Defects Research" investigated lifestyle factors that might be associated with a type of heart defect called a ventral septal defect (VSD). This study found that marijuana use within three months of conception doubled the chance of a VSD in the baby. This risk increased with regular use of marijuana, which was defined as three or more days per week.
Reduced Gestational Age and Weight
Marijuana use of six or more times per week during pregnancy has been associated with a slight reduction in the length of gestation and a corresponding decrease in birth weight. Babies born at less than 40 weeks gestation and those born at lower birth weights face increased risks for various problems after birth, including breathing problems, infections, jaundice and behavior problems.
Withdrawal Symptoms
After birth, babies that were exposed to marijuana prenatally may develop temporary signs of withdrawal from the drug, including tremulousness, altered visual response patterns to light stimulus, and excessive crying. Although these symptoms typically go away by 30 days after birth and are not thought to cause long-term harm, they can be alarming to new parents.
References
- "Teratology"; A population-based study of gastroschisis: Demographic, pregnancy, and lifestyle risk factors; CP Torfs et al; July 1994
- "Journal of Toxicology and Environmental Health"; Comparison of trends in gastroschisis and prenatal illicit drug use rates; MB Forrester and RD Merz; July 2006
- "Birth Defects Research"; Maternal lifestyle factors and risk for ventricular septal defects; LJ Williams et al; Feb. 2004
- "American Journal of Obstetrics and Gynecology"; Marijuana use during pregnancy and decreased length of gestation; PA Fried et al; Sept. 1984
- "Government Reports Announcements & Index"; Alcohol, tobacco, and other drugs may harm the unborn; PS Cook et al; 1991
