How early you can tell the gender of your baby depends on the method of detection you use. You might want to know your baby's gender so that you can choose an appropriate name, or you might need to know if your baby is at increased risk for gender-linked genetic abnormalities. Only a medical test can tell gender; you can't tell from things like how you carry your pregnancy.
Traditional Ultrasound
Most mothers-to-be have an ultrasound around 18 to 20 weeks that shows the gender of the baby, but ultrasounds are sometimes done at 16 weeks. While the position of the baby and the skill of the technician are important in determining the baby's sex, this visual method is approximately 95 percent to 100 percent accurate at detecting the gender at 20 weeks.
3D Ultrasound
The use of 3D ultrasound can detect the gender of a baby even earlier than with traditional 2D ultrasound. According to a study published in the British Journal of Radiology, among 150 women who had 3D ultrasounds in their first trimester, 128--or 85.3 percent--received correct gender predictions. These predictions were made between weeks 11 and 14 weeks, demonstrating that 3D ultrasound can be an effective way of identifying the gender of a baby in the first trimester.
How Ultrasound Works
An ultrasound scan sends high-frequency sound waves into the uterus. As these sound waves bounce around, they encounter internal surfaces, bouncing back and generating on a computer monitor as an image of the fetus. The ultrasound image can help detect fetal developmental abnormalities, the baby's size and growth, as well as the gender of the baby. Ultrasounds show the gender of the baby by showing the 3-line sign, which denotes the labia in a female fetus, or a penis for a boy.
Amniocentesis
Amniocentesis is an option if there is a medical need, such as an increased risk for genetic diseases or birth defects, or if the mother is older. Usually this procedure takes place between 18 and 20 weeks of pregnancy, so it isn't any earlier than ultrasound procedures. The procedure involves taking a sample of amniotic fluid and analyzing the cells, identifying potential genetic problems as well as the gender of your baby.
Chorionic Villus Sampling (CVS)
Chorionic villus sampling, or CVS, is another test used in pregnancies that are at high risk for genetic or chromosomal defects. CVS is usually done at around 10 to 12 weeks. It is less common than amniocentesis..
References
- "Parents": Q&A: How Soon Can You Find Out Baby's Sex?
- Obstetric Ultrasound: Special FAQ on the Gender of the Fetus
- British Journal of Radiology: The Use of Three-Dimensional Ultrasound for Fetal Gender Determination in the First Trimester
- Baby Centre: Is There a Reliable Way to Tell My Unborn Baby's Sex?
- Consumer Genetics, Inc.: Ultrasound Baby Gender Testing: Baby Boy or Girl?
