Should I have an ultrasound to find out the sex of my baby?


I’m having my first baby in six months. I’m resisting the urge to find out the sex of my baby during an ultrasound, but I hear there are other ways to tell. Is this true?


For centuries, pregnant women and their husbands have made guesses about whether their baby would be a boy or a girl. Some prospective parents think they can tell by things such as the shape of a woman’s pregnant belly or by her food cravings. Sometimes they’re right — in fact, they’re right about half of the time.

What I mean is that about half the time it’ll be a boy, and half the time it’ll be a girl. So if you guess right, it’s not because your method was right, it’s because you got lucky.

A baby’s sex is determined by the father. Each of the father’s millions of sperm contains either a Y chromosome or an X chromosome. If the sperm that fertilizes the mother’s egg contains an X chromosome, the baby will be female. If it contains a Y chromosome, the baby will be male. All of a mother’s eggs contain only an X chromosome, so the mother’s egg cannot influence the sex of their baby. It all depends on which of the father’s sperm penetrated and fertilized the egg. (There are rare exceptions to all this, but we’ll ignore those for now.)

There are tests that can tell whether the baby will be a boy or a girl. An ultrasound test done after about the 16th week of pregnancy is pretty accurate. Such tests are performed for medical reasons, such as determining the location of the placenta or to check the baby’s growth.

Amniocentesis is a technique in which a needle is inserted into the fluid surrounding the baby in the womb. A somewhat similar test is called chorionic villus sampling. Both tests are performed to determine whether the baby may have certain genetic defects. However, they also can tell the baby’s sex.

Amniocentesis and chorionic villus sampling both are invasive and contain risks. For that reason, they should not be performed just to tell the sex of the baby. Many doctors also raise ethical questions about using ultrasound just to determine the sex of the baby. In my view, the main question is whether insurance should pay for an ultrasound that has no purpose other than satisfying the curiosity of the parents. Since there is no medical indication, I don’t think insurance should pay in such cases.

Suppose you both want a baby that is one particular sex. Can you do anything about it? You may have heard that you can control whether you conceive a boy or girl in other ways. It’s been said that your position during intercourse or your diet can influence a baby’s sex. I’m afraid that’s not true. There is relatively little a couple can do — through naturally occurring conception — to alter the chances of conceiving a boy or a girl.

Gender tests are not required for a healthy pregnancy, yet many parents know which they’re having. Apparently, most of us just can’t stand the suspense.