A Kaiser Permanente study analyzed the use of cannabis among future mothers. The researchers found that it is more common among women with severe problems of nausea being more prone. The rate of consumption is instead lower among women who do not suffer from morning sickness.
The study explores earlier work, which showed an increase in cannabis use among pregnant women. None of these, however, focused on the "why" of this increase. The reasons would be in morning sickness. According to the researchers, it is likely that many women use the substance as self-medication.
The researchers involved over 220,000 pregnant women, collecting data on substance use and possible discomforts. This is the largest study done to date on the subject. The team of Dr. Kelly Young-Wolff found that women with severe nausea had 4 times more chance of consuming cannabis. The rate was 2 times higher among those complaining of mild nausea.
The percentage of prenatal marijuana use among women was 5.3%. 2.3% of the over 220,000 women complained of severe nausea. 11.3% of these used cannabis to alleviate the inconveniences. On the other hand, women with mild problems of nausea were 15.3%, 8.4% of whom consumed marijuana during pregnancy. Among women without problems of nausea, however, consumption was 4.5%.
Doctors do not recommend cannabis use during pregnancy. The substance may have consequences on the neural development of the fetus and birth weight. However, further studies will also be needed on these data.