Sleep and idiopathic infertility: a case-control study of 360 participants.

RESEARCH QUESTION: Does an association exist between subjective sleep parameters and idiopathic infertility?

DESIGN

A non-matched case-control multicentre observational study (ALIFERT [Alimentation et Fertilité] ClinicalTrials.gov identifier: NCT01093378) was conducted between September 2009 and December 2013. The study included 94 infertile and 85 fertile men, as well as 95 infertile and 86 fertile women, aged 32.6 ± 4.4 years (mean ± SD). The participants and controls completed the HD-43 sleep questionnaire, the Pittsburgh Sleep Quality Index (PSQI) and sleep logs.

RESULTS

Bedtime was significantly later for infertile compared with fertile male participants (P = 0.03). Infertile women had significantly later wake-up time, greater sleep latency and sleep apnoea symptoms compared with fertile women (P < 0.02). Differences in wake-up time between partners were significantly greater among infertile couples (P < 0.01). Fertile participants of both sexes were more frequently moderate morning types compared with infertile participants (P ≤ 0.04). Infertile couples had more frequently different chronotypes than fertile couples (P = 0.02). Sleep quality as measured by PSQI components was worse among infertile compared with fertile participants (P < 0.02).

CONCLUSIONS

Poor sleep quality and extreme or differing chronotypes might be associated with male and female fertility. Further studies, including objective measures of sleep such as actimetry or polysomnography, could clarify this relationship.