The facts about recreational drugs
For both men and women, taking cocaine, heroin, ecstasy, cannabis and other recreational drugs can reduce the chance of having a baby. Taken over a long period of time, recreational drugs can cause permanent problems with the reproductive system and infertility.
Recreational drugs can also cause serious problems in pregnancy. All drugs pass into the bloodstream. Some directly affect sperm or eggs and reduce fertility. Some pass directly into the baby’s bloodstream across the mother’s placenta, which can cause health problems for the baby.
How drugs affect a woman’s fertility
In women, heavy cannabis use can cause hormone changes which affect ovulation and reduce the chance of pregnancy.
Other legal drugs such as Diazepam (Valium) and opiate painkillers (whether prescribed or not) can cause problems. If you're trying for a baby it is important to discuss the medicines you’re using with your doctor or pharmacist.
How drugs affect pregnancy
In pregnancy, cannabis use can cause problems for the baby’s development and even stillbirth. In pregnant women, cocaine and heroin can cause:
- placental abruption (a serious complication where the placenta detaches from the wall of the uterus)
- low birth weight
- premature birth
- stillbirth or neonatal death (death around the time of birth).
How drugs affect a man’s fertility
Taking anabolic steroids for body building or competitive sports causes testes to shrink and stops the production of sperm. You can read more about steroids causing sterility here.
If you’re planning to be a parent, be aware that it generally takes about two years for sperm to return to normal after stopping steroids.
A man’s fertility can also be harmed by other drugs like cannabis, cocaine and heroin, as they reduce testosterone levels and sex drive (libido). There is some proof that cannabis can lower a man’s sperm count, decrease the amount of semen and reduce sperm motility (ability to ‘swim’). All of these things reduce the chance of sperm fertilising an egg.
How drugs affect pregnancy
Research shows that partners of men who use cannabis once or more weekly during pre-conception, have increased risk of miscarriage.
- Fronczak, C. M., E. D. Kim and A. B. Barqawi (2012). "The Insults of Illicit Drug Use on Male Fertility." Journal of Andrology 33(4): 515-528.
- Harlow, AF, Wesselink, AK, Hatch, EE, Rothman, KJ, Wise, LA (2020) Male Preconception Marijuana Use and Spontaneous Abortion: A Prospective Cohort Study. Epidemiology.
- Sansone, A., C. Di Dato, C. de Angelis, D. Menafra, C. Pozza, R. Pivonello, A. Isidori and D. Gianfrilli (2018). "Smoke, alcohol and drug addiction and male fertility." Reproductive biology and endocrinology : RB&E 16(1): 3-3.
- Tommy’s, Drugs, alcohol and trying to conceive, https://www.tommys.org/pregnancy-information/planning-pregnancy/are-you-ready-conceive/drugs-alcohol-and-trying-conceive