Smoking and Fertility
CIGARETTE SMOKING IN WOMEN
Studies have documented the following effects on reproduction in women smokers:
1) They have double the risk of being infertile.
2) They have diminished egg quality and number.
3) They have lower anti-mullerian hormone (AMH) levels.
4) They are more likely to have short and irregular menstrual cycles.
5) Byproducts contained in cigarette smoke such as cotinine, cadmium, and oxygen peroxide are found in the fluid that bathes the egg (follicular fluid).
6) Hydrocarbons found in cigarette smoke have been shown to cause destruction of egg cells
7) Estrogen levels in women smokers is lower during stimulation for IVF, and fewer eggs and embryos are obtained.
8) The outer membrane surrounding the egg (zona pellucida) is thicker in women who smoke.
CIGARETTE SMOKING IN MEN
1) Males exposed to tobacco during embryonic life have an increased chance that one of the testicles will not drop into the scrotum properly before birth (cryptorchidism)
2) Males exposed to cigarette during embryonic life have 20% reduction in the total number of spermatozoa per ejaculate as adults, and have a reduction in testicular volume.
3) Males who smoke have increased chromosomal aberrations in their sperm resulting in a greater number of miscarriages.
4) When ART (assisted reproductive technology) is used, smokers have 40% reduction in pregnancy rates.
5) ICSI (intra-cytoplasmic sperm injection) fails 3 times as often when the male is a smoker.
6) In those who have smoked for greater than 5 years, the risk IVF/ICSI failure is four times greater
MARIJUANA USE IN MEN
Men who smoke marijuana several times per week for 5 or more years show the following changes in their sperm counts:
1) Decreased count
2) Decreased sperm motility
3) Increased numbers of sperm showing hyperactivity
4) Decreased sperm fertilizing capacity
5) Reduced testosterone production.
6) Decreased libido
7) More erectile dysfunction
8) More than one third of chronic marijuana users have reduced sperm counts (oligospermia)
MARIJUANA USE IN WOMEN
1) Reduced numbers of eggs are obtained from women who use marijuana
2) Disturbed menstrual cycles are more common in marijuana users
3) Babies born to women who use marijuana are more likely to be born prematurely
As physicians working with infertile couples, it is imperative that we seek out lifestyle factors that influence fertility. Clearly, the available scientific literature indicates that both marijuana and cigarette smoking have significant detrimental effects on reproductive processes, and should be strongly discouraged among couples trying to conceive.
Source: Alvarez, S. “Do Some Addictions Interfere With Fertility”. Fertility and Sterility 2015; 103: 23-26