Fetal heart rate cannot reliably reveal a baby’s sex; it mainly reflects development, activity, and overall well-being during pregnancy.

At 18 weeks, a baby in the womb is about sweet-potato sized, moving more often, and steadily maturing organs, senses, and reflexes.

At 22 weeks, a growing baby is around 28–29 cm long, weighs near 430–480 g, and shows clear movements, features, and maturing organs.

By week 37 of pregnancy, baby is usually around 48–49 cm long, weighs near 2.8–3 kg, and is classed as early term but still growing.

By around 20 weeks, a developing baby is about the size of a banana, with formed organs, active movement and growing senses inside the uterus.

Prenatal screening uses blood tests and ultrasound during pregnancy to estimate the chance of certain chromosomal or structural conditions in a baby.

During the third trimester, your baby rapidly gains weight, matures organs, and gets ready for birth.

During the last trimester, a baby gains weight steadily, finishes organ growth, and prepares for life outside the womb.

A prenatal DNA test compares cell-free fetal DNA in the mother’s blood with a potential father’s sample to confirm biological relationship.

From fertilization to birth, a baby’s body forms organs, senses, and systems in a steady sequence across roughly forty weeks.