Fetal and pregnancy dates are not the same—when a woman is 24
weeks pregnant, her growing baby (fetus) is about 22 weeks old. This is because
the start of the pregnancy is counted from the first day of her last menstrual
period (LMP), but the embryo doesn't start growing until about 2 weeks
Sarah Marshall, MD - Family Medicine & Kirtly Jones, MD - Obstetrics and Gynecology
How this information was developed to help you make better health decisions.