While it's commonly thought to be a 50/50 chance, there's actually a slight bias towards male births. The sex ratio at birth, according to the World Health Organization (WHO), is about 105 males for every 100 females. This means that there's a slightly higher chance of having a boy.
This difference can be attributed to various factors like:
- Sperm carrying the Y chromosome (for males) are slightly faster than sperm carrying the X chromosome (for females). This could lead to a higher chance of Y sperm reaching the egg first.
- More female fetuses are lost during pregnancy. This could explain why the sex ratio at birth is skewed towards males.
However, it's important to note that the chance of having a boy or a girl is still very close to 50/50. The slight bias towards male births is not a significant factor in most cases.
