Recovery of Fetal Testes
Human fetal testes were obtained following termination of pregnancy during the first trimester (7.7-9.2 wk [54-65 days], n =10) and second trimester (14-19 wk, n = 15). Women gave consent according to national guidelines, and the present study was approved by the Lothian Pediatrics/Reproductive Medicine Research Ethics subcommittee. Termination of pregnancy was induced by treatment with mifepristone (200 mg orally) followed by misoprostol (800 mg every 3 h per vaginam; Phar-macia, Milton Keynes, U.K.).
None of the terminations were for reasons of fetal abnormality, and all fetuses appeared to be morphologically normal. Gestational age was determined by ultrasound and confirmed by subsequent measurement of foot length for the second-trimester samples. Testes were fixed in Bouin fluid for 5 h followed by transfer to 70% ethanol and processed into paraffin wax using standard methods. Sections from all testes were stained with hematoxylin-and-eosin using standard methods to check for tissue integrity and to provide an overall assessment of morphological development before analysis by immunohistochemistry.