Can You Choose the Sex of Your Twin Babies?

Gender Selection Techniques for Twins or Multiples

Family playing with newborn twins in bed
Jade Brookbank/Digital Vision/Getty Images

Do you dream of having a set of boy and girl twins? If your multiples are the result of an in vitro fertilization (IVF), you may have an opportunity to select the gender. Two procedures are currently available. While neither one is completely foolproof, they do greatly increase your odds of obtaining the desired outcome.

Sperm Sorting for IVF

The first is called sperm sorting. A sample of sperm from the father is put through a flow cytometer to identify and separate cells bearing an X (male) or a Y (female) chromosome.

The sorted sperm are used for artificial insemination or in vitro fertilization. The success rate is estimated at about 80 percent. Your odds are slightly better if you want to conceive a girl.

Preimplantation Genetic Screening for IVF

Alternatively, preimplantation genetic diagnosis (also called preimplantation genetic haplotyping or PGH) offers a better than 95 percent chance of success. Originally developed as a way to test embryos for genetic disorders, it is performed after the egg and sperm are joined, but before the embryo is transferred to the mother's uterus. A single cell is removed and its chromosomes analyzed to determine the gender of the embryo. But reliable results don't come cheap. The cost of the process adds thousands of dollars to the already expensive experience of in vitro fertilization.

Gender Selection and Unassisted Conception

Not all twins and multiples are the result of reproductive technology.

But unassisted conceptions don't offer as much opportunity for infallible results. While many parents claim success using the Shettles method of timing intercourse to coincide with a predetermined ovulation schedule, this coordinated conception model has no impact on twinning.

If you are predisposed to having twins anyway, the method might achieve the desired results, as long as you're after same-sex twins.

There are two types of same-sex twins. Monozygotic twins are always two children of the same gender (with very rare exceptions), as they develop from a single fertilized egg. On the other hand, two-thirds of dizygotic, or fraternal, twins will be either girl/girl or boy/boy sets. These multiples develop from two separate fertilized eggs. In either case, timing intercourse to promote the prevalence of male- or female-producing sperm only increases your chances of having more than one baby of the preferred gender.

Should You Choose the Sex of Your Babies?

The issue of gender selection is fraught with ethical implications. Gender selection for reasons other than allowed medical reasons, such as avoiding sex-linked genetic disorders, is not allowed in some countries, such as Canada, the European Union, and the United Kingdom. It is allowed in the United States.

Should medical technology leave well enough alone? Does the practice of gender selection promote sexual discrimination? Or does it offer an opportunity for parents to create the ideal family, especially when they may only have a single shot at conceiving a baby? These are issues that parents should consider, and only they can determine the right answer for their family based on their own personal circumstances.


Sex (Gender) Selection. La Jolla IVF.

Sex Selection. Human Fertilisation & Embryology Authority.