Table 1.

Electronic database search strategies

Database	Search strategy
PubMed (MEDLINE)	((“Sexual Abstinence“[MeSH] OR abstinence[tiab] OR “ejaculatory abstinence“[tiab] OR “abstinence period“[tiab] OR “ejaculation frequency“[tiab] OR “ejaculatory frequency“[tiab]) AND (“Semen“[MeSH] OR semen[tiab] OR “semen quality“[tiab] OR sperm[tiab] OR “sperm quality“[tiab] OR “sperm concentration“[tiab] OR “sperm motility“[tiab] OR “sperm morphology“[tiab] OR “total sperm count“[tiab] OR “DNA fragmentation“[tiab]) AND (humans[MeSH]))
Scopus	TITLE-ABS-KEY ( (“ejaculatory abstinence” OR “sexual abstinence” OR “abstinence period” OR “ejaculation frequency” OR “ejaculatory frequency”) AND (“semen quality” OR semen OR sperm OR “sperm quality” OR “sperm concentration” OR “sperm motility” OR “sperm morphology” OR “total sperm count” OR “sperm DNA fragmentation”) ) AND (LIMIT-TO (DOCTYPE, “ar”)) AND (LIMIT-TO (SUBJAREA, “MEDI”))
Web of Science (Core Collection)	TS=((“ejaculatory abstinence” OR “sexual abstinence” OR “abstinence period” OR “ejaculation frequency” OR “ejaculatory frequency”) AND (“semen quality” OR semen OR sperm OR “sperm concentration” OR “sperm motility” OR “sperm morphology” OR “total sperm count” OR “DNA fragmentation”))