After the tenth week of pregnancy, baby is now considered a “fetus”, entering into the fetal stage halfway between 10 and 11 weeks gestation, and will stay in this stage until birth.
During week 11, baby will grow to be an inch and a half long. Fingers and toes lose their webbing during this week and structures such as hair follicles, tooth buds and nail beds are beginning to form. Amniotic fluid is also beginning to develop. This fluid helps cushion the baby inside the womb to protect against injury from normal life activities of the mother. Genital organs will begin to take on gender characteristics, but it will be another few weeks before an ultrasound can pick up the correct sex of the baby.
Week 12 is the transitional week between the first trimester and the second trimester. By the end of this week almost all of baby’s systems are fully formed and begin to properly function the way they will in life outside of the womb. The biggest advance this week is the development of reflexes, when the baby will be able to open and close her hands, curl toes and begin the sucking movements that will help in feeding. Synapses are energetically taking place inside the brain and nerve cells are being produced at lightning-like speed. By the end of the week, baby will be roughly two inches from crown-to-rump length and the second trimester will begin.
Published in: Family