During the last weeks of the first trimester of gestation, the muscles of the future baby will form, including the diaphragm. The kidneys will begin to function and expel fetal urine, the main component of amniotic fluid. From the 11th week of pregnancy, the fetus will also produce its own red blood cells.
Fetal development at 11 weeks
By Zaira Salvador B.Sc., M.Sc. (embryologist) and Cristina Algarra Goosman B.Sc., M.Sc. (psychologist).
Last Update: 03/30/2022