{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T00:12:10Z","timestamp":1789085530915,"version":"build-2803163510"},"reference-count":29,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,7,5]],"date-time":"2025-07-05T00:00:00Z","timestamp":1751673600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Male infertility can arise from various causes, accounting for 30\u201350% of infertility cases. The aim of this systematic review is to establish paternity outcomes in men treated for cryptorchidism during childhood, and to evaluate the optimal age for surgical intervention in relation to fertility. Methods: This systematic review is conducted according to the PRISMA guidelines and registered in PROSPERO (CRD420251010710). The electronic databases Medline, Embase, and PubMed were searched for eligible studies from 1990 to February 2025. All types of original published human studies examining paternity outcomes in men treated for cryptorchidism during childhood were included. This review focused on comparing paternity rates between men treated for unilateral versus bilateral cryptorchidism. Additionally, studies were required to assess the influence of age at the time of treatment on the likelihood of achieving paternity later in life. Risk of bias was assessed using the Newcastle\u2013Ottawa Scale. Six studies were included. Results: Five out of six studies found higher paternity rates in men treated for unilateral cryptorchidism compared to bilateral cryptorchidism. Early intervention is preferable, although delayed treatment in early childhood may still preserve fertility. One large study showed a 5% increase in the need for assisted reproductive treatment (ART) for every six-month delay in surgery, with a significantly higher use of ART observed when surgery was performed after 18 months. Conclusions: Bilateral cryptorchidism and delayed orchiopexy are linked to lower fertility and the increased use of ART. Future studies should focus on high-quality research to define the optimal age for orchiopexy in relation to paternity.<\/jats:p>","DOI":"10.3390\/jcm14134768","type":"journal-article","created":{"date-parts":[[2025,7,7]],"date-time":"2025-07-07T06:03:13Z","timestamp":1751868193000},"page":"4768","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Paternity After Treatment of Cryptorchidism: A Systematic Review"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-6594-3327","authenticated-orcid":false,"given":"Anna Lund","family":"Henriksen","sequence":"first","affiliation":[{"name":"Centre of Andrology & Fertility Clinic, Department D, Odense University Hospital, DK-5000 Odense, Denmark"},{"name":"Department of Clinical Medicine, University of Southern Denmark, DK-5000 Odense, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ida-Marie","family":"Poulsen","sequence":"additional","affiliation":[{"name":"Centre of Andrology & Fertility Clinic, Department D, Odense University Hospital, DK-5000 Odense, Denmark"},{"name":"Department of Clinical Medicine, University of Southern Denmark, DK-5000 Odense, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3719-5372","authenticated-orcid":false,"given":"Freja","family":"S\u00f8rensen","sequence":"additional","affiliation":[{"name":"Centre of Andrology & Fertility Clinic, Department D, Odense University Hospital, DK-5000 Odense, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5383-5501","authenticated-orcid":false,"given":"Jens","family":"Fedder","sequence":"additional","affiliation":[{"name":"Centre of Andrology & Fertility Clinic, Department D, Odense University Hospital, DK-5000 Odense, Denmark"},{"name":"Department of Clinical Medicine, University of Southern Denmark, DK-5000 Odense, Denmark"},{"name":"Centre of Andrology & Fertility Clinic, Horsens Hospital, DK-8700 Horsens, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,5]]},"reference":[{"key":"ref_1","first-page":"390","article-title":"Infertility and assisted reproduction in Denmark. 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