Hi Dr Rassman,
This question concerns Propecia and pregnancy-although I don’t believe this specific issue has been raised before on your site.
In the UK, the British National Formulary is a publication which provides UK healthcare professionals with authoritative and practical information on the selection and clinical use of medicines. General Practitioners routinely refer to the BNF for advice on prescribing, contraindications etc.
Re Propecia, the following guidelines are given;
Cautions
‘Dutasteride and finasteride decrease serum concentration of prostate cancer markers such as prostate-specific antigen; reference values may need adjustment. Both dutasteride and finasteride are excreted in semen and use of a condom is recommended if sexual partner is pregnant or likely to become pregnant. Women of childbearing potential should avoid handling crushed or broken tablets of finasteride and leaking capsules of dutasteride.‘
Now what concerns me is that I am having unprotected sex with my girlfriend. She is taking the contraceptive pill, but if there is even a small chance she could get pregnant, shouldn’t I stop taking Propecia or use a condom?
Given that GP’s are advised to recommend men who are on Propecia to wear a condom if the woman is likely to become pregnant, what are the risks for the foetus/child if she becomes pregnant?
I’m aware that you have written about this before, but with the British medical guidelines, it seems more serious than initially realised.
Thanks.
The British medical guidelines and American medical guidelines are similar.
It is always a good idea to use a condom to be ‘extra safe’. The Merck material shows minimal if any, Propecia (finasteride) in the male ejaculate. The following statement is made on the Propecia website: “Contact with the semen from a man being treated with PROPECIA is not a risk to the unborn child of a pregnant woman“.
Officially, you can continue taking Propecia while trying to conceive a child.
However, some doctors and patients are still cautious about using Propecia when trying to conceive. Because of this, some doctors recommend you temporarily stop taking the medication during the fertile period when you are trying to conceive with your partner and best to stop for only a week when your wife is fertile. You can also stop taking Propecia for two weeks and I doubt it will have any significant negative impact on hair.
I received 2 recent emails relating to the same thing, so I’ve combined them into one post…
Despite the fact that your hair loss was due to medication changes or thyroid problems or other undetermined medical conditions, female hair loss is very difficult to treat or stop. Many women who are going through menopause will also notice some degree of hair loss. With respect to treatments for hair loss, there is only one medication proven to work for women — Rogaine (minoxidil), though its effects are minimal and you do not get drastic results. 
