Finasteride (Propecia): Do men need to stop when fathering a child?

Do men need to stop when fathering a child?

This is an important question and I generally advise patients to review on a case by case basis with their physicians. There is no one perfect answer and this needs to be reviewed carefully with each patient. Stopping may be an option for some males and transition to a topical finasteride may be an option for others.

Finasteride is found in semen at very, very low concentrations. If it weren't found in semen, the issue would not even be an issue. But finasteride is found in semen at doses either undetectable to up to 21 ng/mL. Studies have shown these concentrations do not appear to harm a developing baby. Many men have fathered healthy children while using finasteride. At the present time, there is no evidence whatsoever that the children (either sons or daughters) of men taking finasteride have a higher risk of birth defects.
However, finasteride may lower sperm counts and cause temporary infertility in some men.  Couples having difficulty conceiving need to be aware of the possibility that the man's use of finasteride could be problematic.

The most important part of this question is that this information should be frequently reviewed with the prescribing doctor for updated information as it may change over time as new information emerges. At the present time, there is no evidence that use of finasteride by men increases the risk of birth defects in his children. 1-3 % of all children in the world are born with birth defects and this rate at present seems similar in finasteride users compared to non users. About 1 out of every 100 men who use finasteride while fathering a child will have a baby with a birth defect of some kind - but that rate is similar to men who did not use finasteride.

Several agencies currently advise that finasteride not be used by males whose partners are trying to conceive. Several agencies state that there is no reason for it to be stopped. There is no evidence at present to support either the recommendation not to take or the recommendation to take. References are stated below this page.

Finasteride: Does it affect spermatogenesis and pregnancy?

Men with a genetic deficiency of 5 alpha reductase (i.e. men with genetic mutations) may have hypospadias (abnormal opening of urethra), cryptorchidism (undescended testes) and abnormal genitalia. These side effects do not appear increased in men using finasteride based on information available today. Many of these side effects are common in the general population. For example, 3 % of all boys in the world are born with cryporchidism making it a very common abnormality in the world’s population. Similarly 1 in 200 boys are born with hypospadius making it also one of the more common birth defects. In fact, hypospadius is the second most common congenital abnormality after cryptorchidism. We do not have evidence at present to suggest that men using finasteride have a higher than 3 % risk of having a boy with cryptorchidism or higher than a 1:200 risk of hypospadius. At present, all evidence would suggest that 3% of all men who use finasteride would have a baby boy born with cryptorchidism -the same rate as the general population. Similarly, all evidence would suggest that 1 in 200 men who use finasteride would have a baby boy born with hypospadius - the same rate as the general population.

It's important to be aware that finasteride can lower semen volume in some men.  Therefore, men may wish to stop finasteride if there is any issues regarding fertility in the couple.  Women, however, must never use finasteride during pregnancy and must never touch crushed tablets.

REFERENCES

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2. Mowszowicz I, Melanitou E, Doukani A, Wright F, Kuttenn F, Mauvais-Jarvis P. Androgen binding capac- ity and 5 alpha-reductase activity in pubic skin fibro- blasts from hirsute patients. J Clin Endocrinol Metab1983;56:1209-13.

3. Cather JC, Lane D, Heaphy MR Jr, Nelson BR. Finasteride: an update and review. Cutis 1999;64:167-72.

4. Merck Frosst Canada & Co. Propecia—discontinuation prior to/during pregnancy. Dorval, Que: Merck Frosst Canada; 2000.
5. Overstreet JW, Fuh WL, Gould J, Howards SS, Lieber

MM, Hellstrom W, et al. Chronic treatment with finasteride daily does not affect spermatogenesis or semen production in young men. J Urol 1999;162:1295-300.

6. Imperato-McGinley J, Guerrero L, Gautier T, Peterson RE. Steroid 5α-reductase deficiency in man: an inherited form of male pseudohermaphroditism. Science1974;186:1213-5.

7. Walsh PC, Madden JD, Harrod MJ, Goldstein JL, MacDonald PC, Wilson JD. Familial incomplete male pseudohermaphroditism, type 2. Decreased dihydrotestosterone formation in pseudovaginal perineo- scrotal hypospadias. N Engl J Med 1974;291:944-9.

8. Katz MD, Kligman I, Cai LQ, Zhu YS, Fratianni CM, Zervoudakis I, et al. Paternity by intrauterine insemination with sperm from a man with 5 α-reductase 2 deficiency. N Engl J Med 1997;336:994-7.

9. Ivarrson SA, Nielsen MD, Lindberg T. Male pseudoher- maphroditism due to 5 alpha-reductase deficiency in a Swedish family. Eur J Pediatr 1988;147:532-5.

10. Moghetti P, Castello R, Magnani CM, Tosi F, Negri C, Armanini D, et al. Clinical and hormonal effects of 5 α-reductase inhibitor finasteride in idiopathic hirsutism. J Clin Endocrinol Metab 1994;79:1115-21.

11. Serafini P, Ablan F, Lobo RA. 5 alpha-reductase activity in the genital skin of hirsute women. J Clin Endocrinol Metab 1985;60:349-55.