If you are pregnant, one of the questions you likely hear the most from friends, family or co-workers is whether your baby is a boy or a girl. In the past, you could not find out your baby's gender until birth. Today, however, there are various methods to allow you to find out your baby's gender while you are still pregnant.
Gender Determination
Geneticist Dr. Barry Starr of Stanford University explains that sperm carries the 46th chromosome that determines a baby's gender. All egg cells contain the X gender chromosome. If a sperm cell with the X chromosome fertilizes the egg, the resulting baby will be a girl; if a Y sperm fertilizes the egg, it creates a baby boy.
Physical Development
Although your baby's gender is determined at fertilization, physical signs of gender do not immediately appear. The National Institutes of Health, or NIH, reports that external sex organs are not distinguishable until weeks 11 to 14 of pregnancy, counted from the first day of your last menstrual period.
Ultrasound Images
Your doctor may use ultrasound testing at various points in your pregnancy to check your baby's development and detect problems. Ultrasound testing uses high-frequency sound waves to produce an image of your baby. Traditional ultrasounds, done during the second or third trimester of pregnancy, use an external wand applied to your abdomen. Earlier ultrasounds are transvaginal, using a wand inserted into your vagina.
The Mayo Clinic advises that a routine ultrasound, usually done between weeks 18 to 20 of pregnancy, will show your baby's physical features better than an earlier ultrasound can. At this time, you will be most likely to find out your baby's gender from the physical appearance of the genitalia in the ultrasound pictures.
Chorionic Villus Sampling
If you are over 35 years old or have a family history of certain genetic conditions, you may undergo genetic testing before your baby's gender is clear on an ultrasound. One example of this testing is chorionic villus sampling.
Chorionic villus sampling typically takes place in your first trimester of pregnancy, between weeks 10 and 12, according to the Mayo Clinic. Your doctor removes a sample of placenta through your cervix or abdomen, depending on the exact location of the placenta. Results of the chromosome testing done on this sample, including gender, may take a few days or up to two weeks. The more tests the laboratory runs on the sample, the longer the results take.
Amniocentesis
Amniocentesis is another option for genetic testing if you decline chorionic villus sampling. According to the University of Maryland Medical Center, amniocentesis generally takes place at about week 15 of your pregnancy, with results available in approximately two weeks. Amniocentesis carries less chance of miscarriage and may detect neural tube defects, such as spina bifida, that chorionic villus sampling cannot.
During an amniocentesis, your doctor withdraws a small amount of amniotic fluid with a long needle inserted through your abdomen. This fluid is tested for a number of conditions, such as spina bifida and Down's syndrome. The test also reveals your baby's gender.
