Effect of the sexual abstinence period recommended by the World Health Organization on clinical outcomes of fresh embryo transfer cycles with normal ovarian response after intracytoplasmic sperm injection.

This study was to investigate whether the sexual abstinence period (SAP) recommended by the World Health Organization (WHO) affects clinical outcomes. We compared the rate of clinical outcomes between 2-7 and ≥8 days of SAP in first fresh embryo transfer after intracytoplasmic sperm injection (ICSI) in groups of young maternal age (YMA: <38 years) and old maternal age (OMA: ≥38 years). We conducted a retrospective study of 449 first ICSI cycles with a normal ovarian response. SAP was identified before collecting the semen samples. Semen analysis was performed based on the guidelines recommended by WHO (2010). Sperm preparation was made using the swim-up method. Patients' baseline characteristics in the YMA and OMA groups did not differ. The rates of fertilisation, top-quality embryos on day 3, biochemical pregnancy, clinical pregnancy, ongoing pregnancy, abortion and implantation per cycle were not significantly different between 2-7 and ≥8 days of SAP in the YMA or OMA group. In conclusion, SAP beyond the recommended period by WHO was not associated with the rates of a lower fertilisation and pregnancy in human in vitro fertilisation (IVF). We think that a new criterion of SAP for clinical application in human IVF needs to be considered by WHO.