Incidence at birth and natural history of cryptorchidism: a study of 10,730 consecutive male infants.
Of the 10,730 neonates born in the period 1978-1997 and examined for cryptorchidism (C) at birth, 1387 were pre-term (gestational age <37 wk), and 9343 were full-term. At birth, a total of 737 neonates (6.9%) were cryptorchid, 487 had bilateral C and 250 unilateral C. The C rate of pre-terms was 10 times higher than that of the full-terms (30.1 and 3.4%, respectively). Comparing the two studied decades, a significant decrease of C rate was found in the second decade in full-term neonates. The rates of C at birth were significantly elevated for low birth weight, babies born from mothers with an age <20 or >35 yr, newborns from mothers with A Rh positive and B Rh positive blood group. Of the 737 cryptorchid newborns at birth, 613 (83%) were re-examined after 12 months from the expected date of delivery, and those born in the period 1988-1997 were also re-evaluated at 6 months of life. Late spontaneous descent occurred in 464 cases (75.7%), while 149 (24.3%) were still cryptorchid. The incidence of C at 12 months from the expected date of delivery, after survival curve calculation, in term and pre-term infants, was 1.53 and 7.31%, respectively, in the period 1978-1987, and 1.22 and 3.13% respectively, in the 2nd decade (1988-1997). In the groups also examined at 6 months of life, spontaneous descent occurred almost completely within the first 6 months of life in term infants, but not in pre-terms. No evidence of seasonal cyclicity was found. Medical and/or surgical treatment was generally started within 2-4 yr of age earlier in the second decade of the study. In conclusion, the main risk factor for C at birth and at 12 months of life seems to be pre-term birth and low birth weight. If this is associated itself to a higher risk of infertility too, it remains to be defined.
Ghirri
P
P
Division of Neonatology, University of Pisa, S. Chiara Hospital, Italy. pghirri@med.unipi.it
Ciulli
C
C
Vuerich
M
M
Cuttano
A
A
Faraoni
M
M
Guerrini
L
L
Spinelli
C
C
Tognetti
S
S
Boldrini
A
A
D000328:Adult; D017677:Age Distribution; D000375:Aging / Q000502:physiology; D001789:Blood Group Antigens; D003456:Cryptorchidism / Q000150:complications / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D008297:Male; D008423:Maternal Age; D009035:Mothers; D036801:Parturition; D011247:Pregnancy; D011248:Pregnancy Complications; D012621:Seasons
D001789:Blood Group Antigens