The earliest you can find out the sex of a baby depends on the method used:
- Non-Invasive Prenatal Testing (NIPT), a blood test that analyzes fetal DNA in the mother's blood, can determine the baby's sex as early as 10 weeks into pregnancy with over 99% accuracy. Results typically return about 8 days after the test. This is one of the earliest and most reliable methods available outside of invasive testing.
- Some at-home DNA-based blood tests claim to predict sex as early as 6 weeks with around 99% accuracy, though these are less commonly used and should be approached with caution.
- Ultrasound can suggest the baby's sex as early as 11 to 13 weeks using the "nub theory," but the most common and reliable ultrasound timing to determine sex is during the anatomy scan at around 18 to 22 weeks. At this stage, the baby's genitalia are more clearly visible, and accuracy is typically above 95%.
- More invasive diagnostic procedures like amniocentesis or chorionic villus sampling (CVS) can definitively determine the baby's sex by analyzing fetal DNA and are usually performed for medical reasons around 10-20 weeks.
In summary, the soonest generally reliable determination of a baby's sex is from NIPT blood testing at about 10 weeks, and the traditional ultrasound determination is around 18 to 22 weeks. Ultrasound earlier than 14 weeks is less accurate, and invasive testing is accurate but used primarily for health concerns.
