Cohen-Bendahan Celina C C, van Goozen Stephanie H M, Buitelaar Jan K, Cohen-Kettenis Peggy T
Department of Child and Adolescent Psychiatry, University Medical Center Utrecht, and the Rudolf Magnus Institute of Neuroscience, the Netherlands.
Twin Res Hum Genet. 2005 Apr;8(2):173-7. doi: 10.1375/1832427053738764.
Increased prenatal exposure to testosterone (T) in females of an opposite-sex (OS) twin pair may have an effect on the development of sex-typical cognitive and behavioral patterns. The prenatal exposure to T due to hormone transfer in OS twin females may occur in two ways, one directly via the feto-fetal transfer route within the uterus, the other indirectly through maternal-fetal transfer and based in the maternal-fetal compartment. Although some studies in singletons indeed found that women pregnant with a male fetus have higher T levels during gestation than women pregnant with a female fetus, many other studies could not find any relation between the sex of the fetus and maternal serum steroid levels. Therefore at present it is unclear whether a pregnant woman bearing a male has higher levels of T than a woman bearing a female. Up to this point, no-one has investigated this issue in twin pregnancies. We examined the relationship between maternal serum steroid levels and sex of fetus in 17 female-female, 9 male-male and 29 OS twin pregnancies. No differences were observed between the maternal serum steroid levels of women expecting single-sex and mixed-sex offspring. It is concluded that the source of prenatal T exposure in females probably comes from the fetal unit, which is the direct route of fetal hormone transfer.
在异性（OS）双胞胎中的女性胎儿产前暴露于睾酮（T）增加，可能会对典型性别认知和行为模式的发育产生影响。OS双胞胎女性由于激素转移导致的产前T暴露可能通过两种方式发生，一种是直接通过子宫内的胎儿-胎儿转移途径，另一种是间接通过母胎转移并基于母胎隔室。尽管一些针对单胎妊娠的研究确实发现，怀有男胎的女性在孕期的T水平高于怀有女胎的女性，但许多其他研究并未发现胎儿性别与母体血清类固醇水平之间存在任何关联。因此，目前尚不清楚怀有男胎的孕妇的T水平是否高于怀有女胎的孕妇。到目前为止，还没有人在双胎妊娠中研究过这个问题。我们检查了17对女性-女性、9对男性-男性和29对OS双胞胎妊娠中母体血清类固醇水平与胎儿性别的关系。在预期生育同性和异性后代的女性的母体血清类固醇水平之间未观察到差异。得出的结论是，女性产前T暴露的来源可能来自胎儿单位，这是胎儿激素转移的直接途径。
