Pregnant women who smoke marijuana have more than two fold higher risk of having a stillbirth, researchers have found.
Moms-to-be who smoke cigarettes or use other illegal drugs, too, have higher risk of having a complicated pregnancy, according to HealthDay.
"Even when [findings are] controlled for cigarette smoking, marijuana use is associated with an increased risk of stillbirth," said Dr. Michael Varner, associate director of women's health, obstetrics and gynecology at University of Utah School of Medicine and lead researcher of the study, Healthday reported.
THC (delta-9-hydrocannabinol), the psychoactive ingredient in marijuana can pass from mother to fetus via the placenta. Research has shown that mothers doing pot while pregnant have higher risk of babies with low birth weight, delayed birth, poor eyesight and even a condition known as ventricular septal defect ( hole in the heart).
In the present study, researchers found that about 94 percent of mothers who had given birth to stillborn babies had used some illegal drug.
Marijuana was the 'drug of choice for many of the study participants. The study found that marijuana use was linked with a 2.8 times increased risk for stillbirth.
"Because marijuana use may be increasing with increased legalization, the relevance of these findings may increase as well," he added, Healthday reported.
For the study, researchers obtained medical records on stillbirths between March 2006 and September 2008 five geographically diverse areas, Medscape reported. Blood samples were obtained from mother and unborn baby. Laboratory workers tested for the presence of drugs in umbilical cord and fetal tissues. There were over 600 cases of stillbirth in the study.
"We don't want our patients, either before they become pregnant or during pregnancy, to either smoke or use anything that is not medically necessary, like marijuana or even prescription drugs," said Dr. Jill Rabin, chief of ambulatory care, obstetrics and gynecology at the Long Island Jewish Medical Center in New Hyde Park, N.Y., according to HealthDay.
The study is published in the journal Obstetrics & Gynecology.