Thursday, 11 October 2007

Having an older brother may decrease Fertility

Research looking at historical data by The University of Sheffield has concluded that having boys takes more out of a mother and may reduce her lifespan. One theory is that male fetuses produce more of the sex hormone testosterone and the stress hormone cortisol. Both these hormones may make a mother’s immune system weaker, thereby making her more vulnerable to illnesses and disease.

Surprisingly, it was also found that offspring to mothers whose first child was a boy were likely to have fewer children, than those in families where the first child was a girl. This was true regardless of the gender of your second or subsequent child (i.e. whether you have a boy or girl). This may also be a result of the mother having a weaker immune after first having a boy. It may also be due to the first born boy depleting more nutrients from the mother’s stores. Consequently, younger siblings may not receive the same nutrients throughout pregnancy.

“What this suggests”, says UrBod Nutritionist Melody Mackeown, “is that optimizing your diet before and during all pregnancies is vital for a mother’s immune system (especially if you are having a boy) and then for your children for their reproductive health later in life (especially it would seem for younger siblings).

The best way to do this is to eat a good, balanced diet rich in fruit and vegetables (at least five portions a day) and protein sources such as meat, poultry and fish. Meat is a good source of animal protein and important minerals such as iron and zinc, with zinc being especially important for male fertility. Fatty fish is a very good source of essential fats, which are important in the development of the foetus.