Odds of Having a Boy or Girl

You may have heard that if a couple have two children, both of the same gender, say girls, their chances of conceiving a third female baby are higher than conceiving a male. This idea has lived on for centuries but it’s simply a myth.  Another myth related to gender are that men are more “manly” if they produce a line of boys and that women are more “feminine” if they produce all girls.  

With each pregnancy, a couple has a 50% chance of conceiving either a boy or a girl.  It’s no different than flipping a coin two times in a row and getting tails each time; the third time, the likelihood of getting tails is still 50%.  The previous two coin flips won’t influence the outcome of the third. With each pregnancy, a couple has the same 50% chance of conceiving a girl.

It’s human nature to believe that somehow a cause underlies such events, but not true in the game of chance or in gender selection.

Although numerous people can attest to examples of families with only girls or only boys — sometimes six or 10!— semen samples from the fathers in these cases reveal a 50:50 ratio of male to female sperm. Remember, all semen contains approximately 50% of female-carrying (X) sperm cells and 50% male-carrying (Y) sperm cells.