Résumé
Progesterone, a key hormone for implantation, is mostly prescribed vaginally in Reproductive Medicine. Low serum concentrations during the luteal phase are associated with reduced chances of birth. Sexual intercourse significantly might reduce vaginal progesterone absorption. This study assesses the impact of intercourse, with or without a condom, during a cycle of hormone replacement therapy (HRT) on vaginal progesterone absorption in infertile couples.Material and methods: this prospective, monocentric, randomized, crossover study included 38 volunteer infertile couples, 29 of whom could be analyzed. Standard HRT was used. We measured serum progesterone (Pg) levels after sexual abstinence on D2 of progesterone initiation, after condom-protected intercourse and after unprotected intercourse (order determined by randomization, on D3 and D7). The primary endpoint was the difference between the level measured on D2 and that measured after intercourse, with or without a condom.Results: on average, the difference in variations (Pg D2−Pg with condom) and (Pg D2−Pg without condom) was 1.83±5.34 ng/mL (p=0.08).Conclusion: sexual intercourse does not appear to modify vaginal progesterone absorption during an HRT cycle. However, condom use could improve vaginal progesterone absorption. Infertile couples who have recourse to these treatments need to be fully informed.