Does hyperandrogenism explain lower in vitro fertilization (IVF) success rates in smokers?

BACKGROUND

Our aims were to elucidate whether a decreased fertility in smoking women treated by in vitro fertilization (IVF) could be related to a divergent hormonal response to the controlled stimulation prior to IVF, to study the effect of smoking on the ovarian endocrine milieu and to possibly identify factors that might be detrimental to oocyte fertilization.

METHODS

Serum and follicular fluid concentrations of estradiol-17 beta (E2), progesterone (P), testosterone (T), 4-androstene-3,17-dione (A-4), dehydroepiandrosterone (DHA), DHA sulfate (DHAS), sex hormone-binding globulin (SHBG) and serum cortisol were studied in 50 non-smoking and 50 smoking women in an IVF program. Follicular fluid concentrations were also compared in follicles which gave rise to cleaved oocytes (TYPE I) and follicles which failed to yield fertilized oocytes (TYPE II) in the same woman.

RESULTS

The fertilization rate did not differ significantly between the two groups, but the live birth rate was 30% in non-smokers and 4% in smokers. During treatment, serum A-4, DHAS and the T/SHBG-ratio were significantly higher in smokers than in non-smokers. In the TYPE I follicles, smokers had higher follicular fluid concentrations of A-4 and DHA and a higher E2/P ratio. The TYPE II follicles in smokers had higher A-4 and T and lower E2 levels.

CONCLUSIONS

Smoking women have a relative hyperandrogenism of ovarian origin, which may contribute to the lower pregnancy rate at IVF in this group.