hi there...so called expert yet expectant mummy here.. there is no conclusive evidence that soya, when eaten as part of a healthy balanced diet, has any effect on fertility. If soya was really having an impact on fertility, then we would expect to see an effect in countries where soya is regularly eaten. There is no evidence that this is the case, indeed, generations of Asians have regularly consumed soya without fertility problems.
There is often confusion around the health effects of plant oestrogens , also known as Isoflavones which are clearly different from human oestrogen. Isoflavones are compounds naturally found in a great number of plants and vegetables (cereals, celery, asparagus, broccoli, Brussels sprouts, chick peas and lentils, etc.) and are particularly present in soya. They are a plant oestrogen and although they mimic human oestrogen their activity is tens of thousands times weaker than the hormone oestrogen. Recent scientific studies suggest that Isoflavones in soya may have a beneficial effect on our health particularly in relation to osteoporosis, cancer (breast cancer and prostate cancer), menopausal symptoms and cardiovascular health. There is no reason why soya foods cannot be enjoyed by pregnant women or those planning to become pregnant as part of a balanced diet so dont worry if you are currently enjoying it! Carry on...