I was surprised when one of my more liberal friends, who has been a vegetarian for close to 10 years, started eating meat because she's pregnant.
Yesterday I asked her why, and lo-and-behold you learn something new everyday...
Soy, like yams and avocados, has progesterone and exposure to female hormone during gestation can have an adverse effect on babies’ reproductive organs. The normal level found in food is not proven to be a problem, but for most vegetarians who get their main source of protein from soy could be causing harm to their growing baby.
I had to check to see if this was true --and I found it in the National Library of Medicine (along with many other web resources). The gist was that boys born to high-volume soy eating moms could have smaller genitalia (along with more feminine features) and girls could have reproductive problems later in life... (Maybe that's why the Playgirl study said Republicans were better in bed....?) ;)
"In utero and lactational exposure to estrogenic agents has been shown to influence morphological and functional development of reproductive tissues. Thus, consumption of dietary phytoestrogens, such as isoflavones, during pregnancy and lactation could influence important periods of development, when the fetus and neonate are more sensitive to estrogen exposure."
...Crazy stuff kids!