{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T01:35:13Z","timestamp":1787016913818,"version":"build-2736575974"},"reference-count":37,"publisher":"BMJ","issue":"6559","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["BMJ"],"published-print":{"date-parts":[[1986,11,29]]},"DOI":"10.1136\/bmj.293.6559.1401","type":"journal-article","created":{"date-parts":[[2009,4,2]],"date-time":"2009-04-02T15:19:55Z","timestamp":1238685595000},"page":"1401-1404","source":"Crossref","is-referenced-by-count":79,"title":["Cryptorchidism: an apparent substantial increase since 1960. John Radcliffe Hospital Cryptorchidism Study Group."],"prefix":"10.1136","volume":"293","member":"239","reference":[{"key":"ref_1","article-title":"Padwov ofdoe testis","author":"Pugh, R.C.B.","year":"1976","unstructured":"Pugh RCB, ed. Padwov ofdoe testis. Oxford: Blackwell Scientific Publications, 1976."},{"key":"ref_2","first-page":"158","article-title":"Bilateral germ cell tumours of the testis","volume":"52","author":"Sokal, M.; Peckham, M.J.; Hendry, W.F.","year":"1980","unstructured":"Sokal M, Peckham MJ, Hendry WF. Bilateral germ cell tumours of the testis. Br I Urol 1980;52:158-62."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"516","DOI":"10.1016\/S0140-6736(72)91909-5","article-title":"Possible carcoma in situ of the testis","volume":"ii:","author":"Skakkebak, N.E.","year":"1972","unstructured":"Skakkebak NE. Possible carcoma in situ of the testis. Lancet 1972;ii:516-7.","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1016\/S0094-0143(21)01352-5","article-title":"Carcinoma in-situ of the undescended testis","volume":"9","author":"Skakkebek, N.E.; Berthelsen, J.G.; Muller, J.","year":"1982","unstructured":"Skakkebek NE, Berthelsen JG, Muller J. Carcinoma in-situ of the undescended testis. Urol Clin NorthAm 1982;9:377-85.","journal-title":"Urol Clin NorthAm"},{"key":"ref_5","first-page":"1683","article-title":"Screening for carciom n situ ofthe ontralateral testis in patients with germinal testicular cancer","volume":"285","author":"Bertlsen, J.G.; Skakkebsek, N.E.; von der Maase, H.; Sorensen, B.L.; Mogensen, P.","year":"1982","unstructured":"Bertlsen JG, Skakkebsek NE, von der Maase H, Sorensen BL, Mogensen P. Screening for carciom n situ ofthe ontralateral testis in patients with germinal testicular cancer. BrMedJ 1982;285: 1683-6.","journal-title":"BrMedJ"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"239","DOI":"10.3109\/02841868409136019","article-title":"Testicular germ cell tumnours in Denmark 1976-1980pathology of 1058 consecutive cases","volume":"23","author":"Jacobsen, G.K.; Barlebo, H.; Olsen, J.","year":"1984","unstructured":"Jacobsen GK, Barlebo H, Olsen J, et al. Testicular germ cell tumnours in Denmark 1976-1980pathology of 1058 consecutive cases. Acta Radio! Oncol 1984;23:239-47.","journal-title":"Acta Radio! Oncol"},{"key":"ref_7","first-page":"249","article-title":"Tesficular carcinoma in Denmark 1976-1980-stage and selected clinical parameters at presentation","volume-title":"Acta Radio Oncol","volume":"23","author":"Schultz, H.P.; Arends, J.; Barlebo, H.","year":"1984","unstructured":"Schultz HP, Arends J, Barlebo H, et al. Tesficular carcinoma in Denmark 1976-1980-stage and selected clinical parameters at presentation. Acta Radio Oncol 1984;23:249-53."},{"key":"ref_8","first-page":"263","article-title":"Testicular seminoma in Denmark 1976-1980results of treatment","volume":"23","author":"Schultz, H.P.; von der Maase, H.; Rorth, M.","year":"1984","unstructured":"Schultz HP, von der Maase H, Rorth M, et al. Testicular seminoma in Denmark 1976-1980results of treatment. Acta Radiol Oncol 1984;23:263-70.","journal-title":"Acta Radiol Oncol"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"255","DOI":"10.3109\/02841868409136021","article-title":"Non-seminomatous testicular germ cell tumours in Denmark 1976-198-results of trespnent","volume":"23","author":"von der Maase H; SA, Engelholm; M, Rorth; etal","year":"1984","unstructured":"von der Maase H, Engelholm SA, Rorth M, etal. Non-seminomatous testicular germ cell tumours in Denmark 1976-198-results of trespnent. Acta Radiol Oncol 1984;23:255-61.","journal-title":"Acta Radiol Oncol"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"295","DOI":"10.3109\/02841868409136025","article-title":"Nonseminomatous testicular germ cell tumou rsn-prelimiary alysis of ongoing trials in the DATECA study","volume":"23","year":"1984","unstructured":"Rorth M, von der Masse -H, Sandberg Nielsen E, Schultz HP, Svennekjser IL. Nonseminomatous testicular germ cell tumou rsn-prelimiary alysis of ongoing trials in the DATECA study. Acta Radiol Oncol 1984;23:295-304.","journal-title":"Acta Radiol Oncol"},{"key":"ref_11","first-page":"3634","article-title":"Incidence of carcinoma in situ of germ cells in contralateral testis of men with testicular tumours","volume":"ii:","author":"Berthelsen, J.G.; Skakkebek, N.E.; Mogensen, P.; Sorensen, B.L.","year":"1979","unstructured":"Berthelsen JG, Skakkebek NE, Mogensen P, Sorensen BL. Incidence of carcinoma in situ of germ cells in contralateral testis of men with testicular tumours. BrMedJ 1979;ii:3634.","journal-title":"BrMedJ"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1111\/j.1365-2559.1978.tb01706.x","article-title":"Carcinoma in situ of the testis: frequency and relationship to invasive germ cell tumours in infertile men","volume":"2","author":"Skakkebek, N.E.","year":"1978","unstructured":"Skakkebek NE. Carcinoma in situ of the testis: frequency and relationship to invasive germ cell tumours in infertile men. Histopatoogy 1978;2:157-70.","journal-title":"Histopatoogy"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/bjc.1977.1","article-title":"Design and analysis of randomized clinical trials requiring prolonged observation ofeach patient","volume":"35","author":"Peto, R.; Pike, M.C.; Armitage, P.","year":"1977","unstructured":"Peto R, Pike MC, Armitage P, et al. Design and analysis of randomized clinical trials requiring prolonged observation ofeach patient. BrJ7 Cancer 1977;35: 1-39.","journal-title":"BrJ7 Cancer"},{"key":"ref_14","first-page":"127","article-title":"Atypical germ cells in the adjacent \"normal\" tissue of testicular tumours","volume":"83","author":"Skakkebsek, N.E.","year":"1975","unstructured":"Skakkebsek NE. Atypical germ cells in the adjacent \"normal\" tissue of testicular tumours. Acta Patho&gica etMrobiologicaScandisviia 1975;83:A127-30.","journal-title":"Acta Patho&gica etMrobiologicaScandisviia"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2660","DOI":"10.1002\/1097-0142(19810601)47:11<2660::AID-CNCR2820471123>3.0.CO;2-6","article-title":"Carcinoma in situ of testicular tissue adjacent to malignant germ-cell tumors: a study of 105 cases","volume":"47","author":"Jacobsen, G.K.; Henrks, O.B.; von der Mase, H.","year":"1981","unstructured":"Jacobsen GK, Henrks OB, von der Mase H. Carcinoma in situ of testicular tissue adjacent to malignant germ-cell tumors: a study of 105 cases. Cancer 1981;47:2660-2.","journal-title":"Cancer"},{"key":"ref_16","first-page":"421","article-title":"Sequential bilateral germ cell tumors of the testis despite interval chemotherapy","volume":"122","author":"JE, Jr, Fowler; D, Vugrin; E, Cvitkovic; WF, Jr, WVhitmore","year":"1979","unstructured":"Fowler JE Jr, Vugrin D, Cvitkovic E, WVhitmore WF Jr. Sequential bilateral germ cell tumors of the testis despite interval chemotherapy. Lhn! 1979;122:421-5.","journal-title":"Lhn!"},{"key":"ref_17","first-page":"624","article-title":"Radiation treatment of carcinoma-in-situ of testis","volume":"i:","author":"von der Maase H; A, Givercman; NE, Skaikebek","year":"1986","unstructured":"von der Maase H, Givercman A, Skaikebek NE. Radiation treatment of carcinoma-in-situ of testis. Lancet 1986;i:624-5.","journal-title":"Lancet"},{"key":"ref_18","article-title":"Accepted","year":"1986","unstructured":"(Accepted 17 September 1986)"},{"key":"ref_19","article-title":"Cryptorchidism: an apparent substantial increase since 1960","unstructured":"Cryptorchidism: an apparent substantial increase since 1960"},{"key":"ref_20","article-title":"A total of 1849 boys born to mothers resident in a defined area around Oxford were examined for cryptorchidism. Those born in hospital were examined at birth and again after three months John Radcliffe Hospital Cryptorchidism Study Group","unstructured":"A total of 1849 boys born to mothers resident in a defined area around Oxford were examined for cryptorchidism. Those born in hospital were examined at birth and again after three months John Radcliffe Hospital Cryptorchidism Study Group"},{"key":"ref_21","article-title":"if cryptorchid at the earlier examination. The incidence of cryptorchidism at three months adjusted to the birthweight distribution of England and Wales was 1'58%h. By comparison, in a very similar study conducted around 1960 the incidence was 0-96%\/e. Hence the cryptorchidism rate had apparently increased by 65% over the two decades, which contrasted with the twofold increase in the national orchidopexy rate. The proportion ofboys undergoing orchidopexy appeared consistently to be roughly twice the proportion of boys with an undescended testis at 3 months of age","unstructured":"if cryptorchid at the earlier examination. The incidence of cryptorchidism at three months adjusted to the birthweight distribution of England and Wales was 1'58%h. By comparison, in a very similar study conducted around 1960 the incidence was 0-96%\/e. Hence the cryptorchidism rate had apparently increased by 65% over the two decades, which contrasted with the twofold increase in the national orchidopexy rate. The proportion ofboys undergoing orchidopexy appeared consistently to be roughly twice the proportion of boys with an undescended testis at 3 months of age."},{"key":"ref_22","article-title":"In a study in the late 1950s of over 3000 babies delivered in a hospital in west London and followed up to 1 year of age, Scorer found that the incidence of undescended testis was about 0-8%.2 More recently, using data on orchidopexy rates from the Hospital In-Patient Enquiry, Chilvers et al suggested that the incidence may have doubled over the past two decades.3 This may be due to a true increase in the incidence of cryptorchidism (with important consequences in terms of fertility and the incidence of testicular cancer') or it may be that boys with retractile rather than truly cryptorchid testes are undergoing orchidopexy, possibly unnecessarily. We examined a cohort of babies born between November 1984 and October 1985 in order to discover whether the true incidence of undescended testis has changed since the late 1950s","unstructured":"In a study in the late 1950s of over 3000 babies delivered in a hospital in west London and followed up to 1 year of age, Scorer found that the incidence of undescended testis was about 0-8%.2 More recently, using data on orchidopexy rates from the Hospital In-Patient Enquiry, Chilvers et al suggested that the incidence may have doubled over the past two decades.3 This may be due to a true increase in the incidence of cryptorchidism (with important consequences in terms of fertility and the incidence of testicular cancer') or it may be that boys with retractile rather than truly cryptorchid testes are undergoing orchidopexy, possibly unnecessarily. We examined a cohort of babies born between November 1984 and October 1985 in order to discover whether the true incidence of undescended testis has changed since the late 1950s."},{"key":"ref_23","article-title":"A total of 1879 eligible boys were born alive in the 12 months of the study; 1837 (97-8%) were born in the John Radcliffe Hospital, and we examined 1803 (98 1%) of them soon after birth (\"at birth\" examination). Sixteen mothers refused permission for their babies to be examined, seven babies died, and 11 left the hospital before being examined","unstructured":"A total of 1879 eligible boys were born alive in the 12 months of the study; 1837 (97-8%) were born in the John Radcliffe Hospital, and we examined 1803 (98 1%) of them soon after birth (\"at birth\" examination). Sixteen mothers refused permission for their babies to be examined, seven babies died, and 11 left the hospital before being examined."},{"issue":"6","key":"ref_24","first-page":"7","article-title":"Of the 1803 boys examined at","volume":"120","unstructured":"Of the 1803 boys examined at birth, 120 (6 7%) were found to have one or both testes undescended. Table I shows the results of this examination separately for babies weighing over and under 2500 g. Ninety five (5 5%) of the 1716 babies weighing 2500 g or more were cryptorchid, as were 25 (28-7%) of the 87 babies weighing less than 2500 g.","journal-title":"birth; were found to have one or both testes undescended. Table I shows the results of this examination separately for babies weighing over and under 2500 g. Ninety five (5 5%) of the 1716 babies weighing 2500 g or more were cryptorchid, as were 25 (28-7%) of the 87 babies weighing less than 2500 g"},{"key":"ref_25","article-title":"Subjects and methods Birth records for the Oxfordshire Health Authority for 1982 and 1983 were scrutinised to identify parishes where at least 85% of babies were born in the John Radcliffe Hospital","volume-title":"and 31 October 1985 to mothers resident in these parishes (study area) were included in the study","year":"1984","unstructured":"Subjects and methods Birth records for the Oxfordshire Health Authority for 1982 and 1983 were scrutinised to identify parishes where at least 85% of babies were born in the John Radcliffe Hospital, Oxford. All babies born between 1 November 1984 and 31 October 1985 to mothers resident in these parishes (study area) were included in the study."},{"key":"ref_26","article-title":"Differences in binomial proportions (two by two tables) were tested for statistical significance (p values) by Fisher's exact test.' The method of Mantel and Haenszel was used for testing the joint statistical significance of differences in proportions in two two by two tables.4 Quoted p values are one sided, as the question posed before the study was whether the rate of TABLE I-Results of screening for neonatal undescended tests, John Radcliffe Hospital, November 1984 to October 1985","unstructured":"Differences in binomial proportions (two by two tables) were tested for statistical significance (p values) by Fisher's exact test.' The method of Mantel and Haenszel was used for testing the joint statistical significance of differences in proportions in two two by two tables.4 Quoted p values are one sided, as the question posed before the study was whether the rate of TABLE I-Results of screening for neonatal undescended tests, John Radcliffe Hospital, November 1984 to October 1985"},{"key":"ref_27","first-page":"691","article-title":"Undescended testis: the effect of treatment on subsequent risk of subfertility and ralnmcy.y","volume-title":"JPediatrSwrg","volume":"21","author":"Chilvers, C.; Dudley, N.E.; Gough, M.H.; Jacksn, M.B.; Pike, M.C.","year":"1986","unstructured":"(95-2) 87 (4-8)"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1136\/adc.39.208.605","article-title":"The descent of the testis","volume":"39","author":"Scorer, C.G.","year":"1964","unstructured":"Chilvers C, Dudley NE, Gough MH, Jacksn MB, Pike MC. Undescended testis: the effect of treatment on subsequent risk of subfertility and ralnmcy.y.JPediatrSwrg 1986;21:691-6.","journal-title":"ArchDis Child"},{"key":"ref_29","first-page":"330","article-title":"Apparent doubling of frequency of undescded tis in Engand and Wales in 196241","volume":"i:","author":"Chilvers, C.; Pike, M.C.; Forman, D.; Fogemnan, K.; Wadsworth, M.E.J.","year":"1984","unstructured":"Scorer CG. The descent of the testis. ArchDis Child 1964;39:605-9.","journal-title":"Lances"},{"key":"ref_30","article-title":"The analysis of case-control studies. In: Stastcal methods iscancer research. Vol 1","author":"Breslow, N.E.; Day, N.E.","unstructured":"Chilvers C, Pike MC, Forman D, Fogemnan K, Wadsworth MEJ. Apparent doubling of frequency of undescded tis in Engand and Wales in 196241. Lances 1984;i:330-2."},{"key":"ref_31","article-title":"Birth count: statics ofpregnancy and chilbrh","author":"Macfarlane, A.; Mugford, M.","year":"1984","unstructured":"Breslow NE, Day NE. The analysis of case-control studies. In: Stastcal methods iscancer research. Vol 1. Lyon: International Agency for Research on Cancer (IARC) Scientific PubLications, 1980:32."},{"key":"ref_32","article-title":"Congenital defoni of dte tests and eddymn","author":"Scorer, C.G.; Farmngton, G.H.","year":"1971","unstructured":"Macfarlane A, Mugford M. Birth count: statics ofpregnancy and chilbrh. London: HMSO, 1984."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1093\/ije\/13.3.311","article-title":"Matenal and gestational factors affecting the risk of cryptorchidism and inguinal hernia","volume":"13","author":"Depue, R.H.","year":"1984","unstructured":"Scorer CG, Farmngton GH. Congenital defoni of dte tests and eddymn. London: Butterworth, 1971.","journal-title":"Intl Epideil"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1111\/j.1464-410X.1985.tb06315.x","article-title":"Ascent ofthe testis: fact or ficton","volume":"7","author":"Atwell, J.D.","year":"1985","unstructured":"Depue RH. Matenal and gestational factors affecting the risk of cryptorchidism and inguinal hernia. Intl Epideil 1984;13:311-8.","journal-title":"BrJ Urol"},{"key":"ref_35","first-page":"789","article-title":"Hospital Cryptchkidism Study Group. Boys with late dacnding testes: the source of cases of\"retractile\" testes undergoing orchidopezy?","volume":"293","author":"Radcliffe, John","year":"1986","unstructured":"Atwell JD. Ascent ofthe testis: fact or ficton. BrJ Urol 1985;S7:474-7.","journal-title":"BrMedJ"},{"key":"ref_36","article-title":"Accepsed9 Octoer","year":"1986","unstructured":"John Radcliffe Hospital Cryptchkidism Study Group. Boys with late dacnding testes: the source of cases of\"retractile\" testes undergoing orchidopezy? BrMedJ 1986;293:789-90."},{"key":"ref_37","article-title":"Patients and methods We began endoscopic correction of vesicoureteric reflux in March 1984 and by March 1985 had treated 61 children with primary vesicoureteric reflu. There were 52 girls and nine boys and their age range was 3 months to 13 years (mean 5-2 years). Twenty eight patients had unilateral vesicoureteric reflux and 33 bilateral reflux and so the series represented 94 refluxing ureters. Patients with refluxing duplex systems were not included. Vesicoureteric reflux was graded according to the international classification of reflux: I, ureter only; II, ureter, pelvis, and calices, no dilatation, normal caliceal fornices; III, mild or moderate dilatation or tortuosity of ureter and mild or moderate dilatation of renal pelvis but with no or slight blunting of fornices; IV, moderate dilatation or tortuosity of ureter and moderate dilatation of renal pelvis and calices, complete obliteration of sharp angle of fornices, but maintenance of papilIary impressions in most calices","unstructured":"(Accepsed9 Octoer 1986)"}],"container-title":["BMJ"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmj.293.6559.1401","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,10,3]],"date-time":"2021-10-03T19:10:46Z","timestamp":1633288246000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.bmj.com\/lookup\/doi\/10.1136\/bmj.293.6559.1401"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1986,11,29]]},"references-count":37,"journal-issue":{"issue":"6559","published-print":{"date-parts":[[1986,11,29]]}},"URL":"https:\/\/doi.org\/10.1136\/bmj.293.6559.1401","relation":{},"ISSN":["0959-8138","1468-5833"],"issn-type":[{"value":"0959-8138","type":"print"},{"value":"1468-5833","type":"electronic"}],"subject":[],"published":{"date-parts":[[1986,11,29]]}}}