A baby's gender is determined at conception, but the visible development of the sex organs occurs later in pregnancy.
When is Gender Determined?
The sex of a baby is determined at the moment of conception when the sperm fertilizes the egg. The sperm carries either an X or a Y chromosome. An X chromosome from the sperm results in a female (XX), while a Y chromosome results in a male (XY). Source: Boy or girl? The difficulties of early gender prediction | Your ...
When do Sex Organs Develop?
While the genetic sex is determined at conception, the visible development of the external sex organs begins between weeks 7 and 12 of pregnancy. Source: When a Baby's Gender Is Determined and How The external genitals initially appear as several small bulges, later differentiating into distinct male or female characteristics. Source: When do your baby's sex organs develop in the womb? | BabyCenter By the end of the third month, the baby's reproductive organs are fully formed. Source: 1 to 3 Months Pregnant - 1st Trimester Baby Growth & Development The development allows for sex determination via ultrasound from around 12 weeks. [Source: Although fetal sex is formed from the moment the egg and sperm meet, however, it is not until the 9th week of pregnancy that the fetus's sex organs develop differently, helping to detect by ultrasound at 12 weeks onwards.]
Key Timeline:
- Conception: Genetic sex (XX or XY) is determined.
- Weeks 7-12: External sex organs begin to develop.
- 12 weeks onwards: Ultrasound can typically detect the baby's sex.
