Voutilainen R
Department of Pediatrics, University of Helsinki, Finland.
Horm Res. 1992;38 Suppl 2:66-71. doi: 10.1159/000182601.
Gonadal differentiation may be divided into four stages: pregonadal, indifferent, primary sex differentiation, and secondary sex differentiation. Sertoli cells appear at 6-7 weeks and Leydig cells differentiate at 8 weeks, but in ovaries, primary sex differentiation occurs much later. Testosterone secretion peaks at 12-16 weeks causing male secondary sex development together with the appearance of anti-Müllerian hormone. Fetal testis is able to synthesize and secrete inhibins. Lower circulating luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in male than in female fetuses at midgestation suggest that the fetal pituitary is already responsive to the gonadal hormones. Placental human chorionic gonadotrophin may regulate testosterone synthesis at midgestation, and both LH and FSH are likely to have some regulatory effect on fetal gonads during the last third of gestation.
性腺前期、未分化期、初级性别分化期和次级性别分化期。支持细胞在6 - 7周时出现，睾丸间质细胞在8周时分化，但在卵巢中，初级性别分化发生得要晚得多。睾酮分泌在12 - 16周达到峰值，导致男性次级性征发育，并出现抗苗勒管激素。胎儿睾丸能够合成和分泌抑制素。妊娠中期男性胎儿循环中的促黄体生成素（LH）和促卵泡生成素（FSH）水平低于女性胎儿，这表明胎儿垂体已经对性腺激素有反应。胎盘人绒毛膜促性腺激素可能在妊娠中期调节睾酮合成，并且LH和FSH在妊娠最后三分之一期间可能对胎儿性腺都有一定的调节作用。
