Modern technology allows parents to find out the baby's sex prior to birth. A baby's sex is defined as the 'biological and physiological characteristics' that define a girl or boy, according to the World Health Organization. Most commonly, you can find out your baby's sex in an ultrasound that is done around 18 weeks gestation, but newer technology allows the baby's sex to show as early as 11 to 14 weeks.
Ultrasounds
Ultrasound technicians can usually tell the sex of a baby at around 18 to 20 weeks with 2D ultrasounds. However, this is dependent on the position of the baby and the skill of the technician. Even the most skilled technician can't tell the sex if the baby is in an awkward position or has its legs closed.
Traditional ultrasounds that visually detect the baby's sex are 95 to 100 percent accurate. Modern 3D ultrasounds can now be done between 11 and 14 weeks. According to an article published in the "British Journal of Radiology," 3D ultrasounds are 85.3 percent accurate in determining a baby's sex in the first trimester.
How Ultrasounds Work
An ultrasound is done to not only to find out the baby's sex, but also to make sure your baby is developing properly. Ultrasounds use high-frequency sound waves that create a picture of the fetus. Around week 18, this picture is able to help the technician accurately indicate if the baby is a boy or girl based on his or her genitalia. This method is not 100 percent accurate, so you should find out from your technician how clearly he can see the baby's genitals on the monitor.
Amniocentesis
Amniocentesis can be done in order to check your baby's chromosomes around 16 weeks. However, this test is usually conducted on on mothers who are over 35 years old or when it is necessary to identify possible genetic abnormalities. Amniocentesis involves removing a small amount of amniotic fluid by inserting a needle into the uterus. This test isn't generally prescribed to only find out the baby's sex.
Chorionic Villus Sampling (CVS)
Chorionic villus sampling is a diagnostic test that is typically performed between 8 and 11 weeks gestation. This diagnostic test checks your baby's chromosomes, but is only used when there is a high risk of genetic abnormalities. CVS is infrequently done and would never been done simply to determine the baby's sex. There is a miscarriage rate of 4 percent from CVS and there is a small chance that the sex the technician determines would be wrong.
Decisions
The reasons you have for finding out or not finding out the sex of your baby may be different from other parents. Some people want to pick the baby's name before birth or bond with the baby. And yet others may want to be surprised or just keep the secret to themselves. Despite any of these reasons, some mothers need to have the sex determined as early as possible to predict the baby's risk for sex chromosome abnormalities that may cause infertility, growth problems or behavioral and learning difficulties.
References
- Obstetric Ultrasound: Special FAQ on the gender of the fetus
- "Parents": Q&A: How Soon Can You Find Out Baby's Sex?
- British Journal of Radiology: The use of three-dimensional ultrasound for fetal gender determination in the first trimester
- Childbirth: Finding Out the Sex of Your Baby
- Family Friendly Fun: Chromosomal Abnormality
