Researchers are studying how the timing of cannabis exposure during pregnancy affects fetal development

With the increasing use of cannabis for recreational purposes, attitudes toward the drug have changed. For example, research has shown that dispensaries often recommend cannabis — also referred to as marijuana — to pregnant women to relieve pregnancy symptoms, especially morning sickness.

There is a growing body of literature attesting to poor child outcomes if cannabis is taken during pregnancy. However, the exact effects on fetal development remain unclear. Researchers in the US have now studied how the timing of cannabis exposure during pregnancy affects fetal development.

“We showed that even when marijuana use occurred only in the first trimester of pregnancy, birth weight was significantly reduced, by more than 150 grams on average,” said Dr. Beth Bailey, professor and director of Population Health Research at Central Michigan University and senior author. From the study published in Frontiers in Pediatrics. “If this use continued until the second trimester, the newborn’s head circumference decreased as well.”

Constant exposure leads to the biggest shortcomings

“These findings are important because newborn size is one of the strongest predictors of a child’s health and later development,” added Dr. Rainbow Children’s Hospitals and Children’s Hospital of Cleveland.

Recent work, including research by Dodge et al.have shown significant effects of cannabis use on newborn size.

The magnitude deficit was greatest among newborns exposed to marijuana throughout pregnancy.

Dr. Beth Bailey, Professor and Director of Population Health Research, Central Michigan University

Babies born after continuous intrauterine exposure were about 200 grams lighter and had a head circumference of about 1 cm less than babies without exposure. Cannabis use during pregnancy did not significantly predict neonatal length in this study.

The effects the scientists observed also shed light on usage patterns. Their study showed that occasional use, such as for morning sickness in the first trimester, may reduce fetal growth in the same way as continuous use throughout pregnancy. The same is true for other uses in the early stages, including cases where someone uses cannabis without knowing they are pregnant.

Quitting smoking before pregnancy is the best recommendation

The authors noted that in their study they had no information about how much or how often the participants used cannabis. Their results were based on whether or not people used it at certain times of pregnancy. Therefore, the study could not determine whether there was a relationship between heavy use and more pronounced outcomes in neonatal development.

They write that more studies are needed to determine whether the timing or amount of use is most important when it comes to effects on newborn size.

The best recommendation is that women should be advised to stop using marijuana before they become pregnant.” However, quitting as soon as possible after pregnancy is the second best option for avoiding negative long-term health and developmental outcomes. “There are some benefits to quitting,” she continued. smoking among those who initiate pregnancy using marijuana.