Smoking marijuana in early pregnancy can cause infertility. A study at Vanderbilt University found that marijuana influences a signal that helps embryos pass safely from the ovary to the lining of the uterus.
Investigators found that when mice were given tetrahydrocannabinol, the major active component of marijuana, the embryos failed. They speculated that the chemical caused a fatty acid deficiency triggering a breakdown in the signaling system and making the embryo miss the crucial window for implantation in the uterus.
“We have shown before if you tinker with the normal timing of implantation in the uterus, it can create adverse ripple effects throughout the course of pregnancy leading to compromised pregnancy outcome,” said Dr. Sudhansu Dey of Vanderbilt University. Now the scientists are learning what happens on the molecular level that influences implantion.
“The take-home message would be, if you have fertility problems and you are smoking either marijuana or tobacco cigarettes, stop,” said Herbert Schuel, professor emeritus of anatomy and cell biology in the School of Medicine at the University of New York at Buffalo. “The same kinds of effects are produced by nicotine and tobacco smokers.”

Source NewsMax.com Sept.2006