How to Determine the Sex of a Baby in the Womb

As nice as it would be, nature doesn't include an abdominal window so you can see your baby's sex before birth. Several medical techniques and procedures, however, do provide either an indirect look into the uterus or the ability to test the unborn baby's genetic makeup to determine not only sex but a number of genetic issues. The way you carry, pregnancy symptoms and other folk methods are not accurate ways to determine the sex of your baby.


Many obstetricians recommend an ultrasound to make sure your baby is developing normally during the second trimester of pregnancy. Although fetal ultrasound can often detect fetal sex at around week 11 of pregnancy, the accuracy of the results increase with gestational age. The authors of a study presented in the April-June 2012 issue of the "Nigerian Medical Journal" reported a sex determination accuracy rate of 99 percent for fetuses beyond week 17 of pregnancy. At this point, an experienced ultrasonographer or other medical professional can easily tell if you're having a boy or girl -- as long as your baby cooperates and turns in the right direction and doesn't cover his private parts.

Chorionic Villus Sampling

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Often abbreviated to CVS, chorionic villus sampling provides a way to examine the genetic material of a growing fetus early in pregnancy. CVS testing is done between weeks 9 to 12, depending on your practitioner's preferences, explains the nursing text "Maternity Nursing Care." The doctor removes cells from the placental site to test for the baby's sex and also for serious genetic abnormalities. Most doctors will not do CVS strictly to determine the sex of a fetus. Doing CVS before week 9 of pregnancy carries a risk of limb reduction defect, in which part of a limb doesn't develop properly, the text "Fetal Medicine" cautions. The procedure also carries a 1 to 3 percent risk of miscarriage, the authors report.


Before CVS became an accepted technique for evaluating chromosomes, parents-to-be anxious to know if their child was genetically normal had to wait until between weeks 15 and 16 of pregnancy to undergo amniocentesis -- and then wait several more weeks for the results. In this procedure, the doctor removes a small amount of amniotic fluid from the amniotic sac. The fluid contains cells shed by the developing fetus. By looking at the chromosomes under the microscope, the doctor can identify not only the sex of your baby but also the presence of a number of genetic abnormalities. As with other invasive techniques, amniocentesis is not performed solely to determine the sex of a fetus. The procedure also carries a small risk of miscarriage.

Preimplantation Genetic Diagnosis

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If you're undergoing in vitro fertilization procedures, you can determine the sex of your baby even before an embryo is placed into the womb. Preimplantation genetic diagnosis, better known as PGD, scrutinizes chromosomes from an embryonic cell in the laboratory. Parents who are carriers for inherited genetic disorders or who are at high risk for chromosomal disorders such as Down syndrome may prefer to undergo artificial reproductive technology rather than abort an abnormal fetus. The Ethics Committee of the American Society of Reproductive Medicine discourages -- but doesn't wish to legally ban -- the use of PGD for nonmedical purposes, such as sex selection, unless there is also a medical reason to choose one sex over the other. For example, some genetic diseases are carried only by male children.