Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice
Received 31 August 2007; received in revised form 5 December 2007; accepted 5 December 2007. published online 05 March 2008.
Objective
To determine the effects of sildenafil citrate, a cyclic monophosphate–specific type 5 phosphodiesterase inhibitor known to affect sperm function, on fertilization and early embryo cleavage.
Design
This acute mammal study included male and female mice assigned randomly, the females sacrificed after mating and their oocytes/embryos evaluated at four time periods after treatment.
Setting
Academic research environment.
Animal(s)
Male and female CBAB6 mice.
Intervention(s)
Female mice were injected intraperitoneally with 5 IU gonadotropin (hCG) to stimulate follicular growth and induce ovulation. They were each caged with a male that had been gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. After 12, 36, 60, and 84 h, females were killed, their oviducts were dissected out, and retrieved embryos were assessed for blastomere number and quality.
Main Outcome Measure(s)
Fertilization rates and numbers of embryos were evaluated after treatment.
Result(s)
Fertilization rates (day 1) were markedly reduced (−33%) in matings where the male had taken sildenafil citrate. Over days 2–4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance.
Conclusion(s)
The impairments to fertility caused by sildenafil citrate have important implications for infertility centers and for couples who are using this drug precoitally while attempting to conceive.
aObstetrics and Gynaecology, Institute of Clinical Science, School of Medicine, Belfast, United Kingdom
bDivision of Infection and Immunity, School of Biomedical Science, Queen's University, Belfast, United Kingdom
Reprint requests: Sheena E. M. Lewis, Obstetrics & Gynaecology, Institute of Clinical Science, Grosvenor Road, Belfast, United Kingdom (FAX: 44 2890328247).
D.R.J.G. has nothing to disclose. N.McC. has nothing to disclose. S.L.C. has nothing to disclose. M.S. has nothing to disclose. S.E.M.L. has nothing to disclose.
Presented at the British Fertility Society Spring meeting, Cheltenham, United Kingdom, April 2004.
Dr. Glenn was supported with a Royal Clinical Research Fellowship from the Royal Maternity Hospital.
ABSTRACT