I have been smoking pot steadily since I was 20. I am 28 now and my husband and I want to try to conceive. I was pregnant 1yr and 1/2 ago and I misscarried in my 1st trimester. I gave up smoking immediately when I found out that I was pregnant. Since then though I have been smoking. I have read some studies on how it affects mice and monkeys in early pregnancy and preconception. I have just quit and was wondering how long it takes to to leave the ovaries and how soom it will be safe to try to conceive.

Several studies have shown that THC the active ingredient in marijuana can adversely affect sperm motility and fertilization. It has also been shown that THC can be found in bodily fluids such as vaginal fluid and secretions after smoking. It has been suggested that THC may affect the pituitary gland and hypothalmus leading to ovulatory dysfunction and change in egg health. In one study of fertility patients, the effects were so dramatic that the researchers now require anyone undergoing fertility treatments at their institution to stop smoking one year in advance of the treatments. While there is no set amount of time that is considered the correct amount in terms of when to stop, it would be prudent for all couples to stop smoking as soon as they are considering becoming pregnant. A few studies implicated marijuana in low birth weight of the newborns even when the marijuana was discontinued at the time of conception. Women who smoke and consume alcohol had an even more dramatic reduction in fertility than women using either substance alone. Cigarette smoking has been associated with premature aging of the oocyte (egg) as well. Clearly, abandoning use of all illicit and unnecessary substances is the key to optimizing a couple's fertility and this applies to both the men and the women. In addition, the longer the interval between the cessation of use and conception, the better off the outcome will be.

Answered by Dr. Lynn Friedman, M.D.