Marijuana use implicated in pregnancy problems
September 12, 2012
Science Daily/Cincinnati Children's Hospital Medical Center
New research indicates marijuana-like compounds called endocannabinoids alter genes and biological signals critical to the formation of a normal placenta during pregnancy and may contribute to pregnancy complications like preeclampsia.
A study in the Sept. 14 edition of the Journal of Biological Chemistry offers new evidence that abnormal biological signaling by endocannabinoid lipid molecules produced by the body disrupts the movement of early embryonic cells important to a healthy pregnancy, in particular trophoblast cells that form the placenta. Abnormal placental function is common in preeclampsia -- a medical condition of unknown cause that is a danger to mother and child.
The research -- from scientists in the Division of Reproductive Sciences at Cincinnati Children's Hospital Medical Center -- analyzed mouse preimplantation embryos mutated to alter endocannabinoid signaling. They found that either silencing or enhancing endocannabinoid signaling adversely affects trophoblast stem cell migration.
"The findings or our investigation raise concerns that exposure to cannabis products may adversely affect early embryo development that is then perpetuated later in pregnancy," said Sudhansu K. Dey, PhD., principal investigator on the study and division director. "Also, given that endocannabinoid signaling plays a key role in the central nervous system, it would be interesting in future studies to examine whether affected cell migration-related genes in early embryos also participate in neuronal cell migration during brain development."
Along with co-first authors Huirong Xie and Xiaofei Sun, Dey and other members of the research team studied mouse embryos that had not yet implanted inside the uterus of the mother. Previous research by Dey's laboratory has shown the timing of critical events in early pregnancy, including when and how well an embryo implants in the uterus, is vital to a healthy pregnancy and birth.
In the current study, researchers conducted DNA microarray analyses to determine how the expression levels of genes important to healthy embryo development were affected in embryos with abnormal endocannabinoid signaling.
In one group of embryos endocannabinoid signaling was silenced by deleting the gene Cnr1, which activates endocannabinoid signaling processes. A second group of mice was mutated to produce elevated endocannabinoid levels similar to that observed in wild type mice treated with tetrahydrocannabinol (THC), the active psychotropic agent in cannabis. This was done by deleting the gene Faah, which breaks down molecules that activate endocannabinoid signaling.
In both groups, the expression of numerous genes known to be important to cell movement and embryo development was lower than in normal wild type mice. This included the development and migration of trophoblast stem cells. Trophoblast cells help anchor the conceptus with the uterus and also form much of the placenta, critical to establishment of maternal-fetal circulation and exchange of nutrients.
Researchers said mouse models developed for the current study (with silenced and elevated endocannabinoid signaling) may help advance more extensive studies on the causes of preeclampsia.
https://www.sciencedaily.com/releases/2012/09/120912101806.htm
Marijuana use does not lower chances of getting pregnant
January 22, 2018
Science Daily/Boston University School of Medicine
Marijuana use -- by either men or women -- does not appear to lower a couple's chances of getting pregnant, according to a new study led by Boston University School of Public Health (BUSPH) researchers.
The study, published in the Journal of Epidemiology and Community Health (JECH), was the first to evaluate the link between fecundability -- the average per-cycle probability of conception -- and marijuana use.
About 15 percent of couples experience infertility. Infertility costs the US healthcare system more than $5 billion per year, and thus identifying modifiable risk factors for infertility, including recreational drug use, is of public health importance. Marijuana is one of the most widely used recreational drugs among individuals of reproductive age. Previous studies have examined the effects of marijuana use on reproductive hormones and semen quality, with conflicting results.
"Given the increasing number of states legalizing recreational marijuana across the nation, we thought it was an opportune time to investigate the association between marijuana use and fertility," says lead author Lauren Wise, professor of epidemiology.
In Pregnancy Study Online (PRESTO), a web-based prospective cohort study of North American couples, the researchers surveyed 4,194 women aged 21 to 45 living in the United States or Canada. The study specifically targeted women in stable relationships who were not using contraception or fertility treatment. Female participants were given the option to invite their male partners to participate; 1,125 of their male partners enrolled.
The researchers found that during the period from 2013 through 2017, approximately 12 percent of female participants and 14 percent of male participants reported marijuana use in the two months before completing the baseline survey. After 12 cycles of follow-up, conception probabilities were similar among couples that used marijuana and those that did not.
The researchers stressed that questions about the effects of marijuana use remain. As one example, they said, classifying people correctly according to the amount of marijuana used, especially when relying on self-reported data, is challenging. "Future studies with day-specific data on marijuana use might better be able to distinguish acute from chronic effects of marijuana use, and evaluate whether effects depend on other factors," they wrote.
https://www.sciencedaily.com/releases/2018/01/180122150813.htm