These amazing 4D ultrasound images show you how babies move in the womb. Fetal Development view text These amazing 4D ultrasound images show you how babies move in the womb. Pregnancy lasts about 40 weeks and is divided into three trimesters. It starts at week 28 of your pregnancy, and ends with the birth of your baby.
Fetus in Utero Click Image to Enlarge Amniotic sac - a thin-walled sac that surrounds the fetus during pregnancy. The sac is filled with amniotic fluid liquid made by the fetus and the amnion the membrane that covers the fetal side of the placenta , which protects the fetus from injury and helps to regulate the temperature of the fetus. Anus - the opening at the end of the anal canal. Cervix - the lower part of the uterus that projects into the vagina. Made up of mostly fibrous tissue and muscle, the cervix is circular in shape. Fetus - an unborn baby from the eighth week after fertilization until birth. Placenta - an organ, shaped like a flat cake, that only grows during pregnancy and provides a metabolic interchange between the fetus and mother.
Your Body at 28 Weeks of Pregnancy At this point in pregnancy, the top of your uterus is about one-third of the distance between the bellybutton and the xiphoid cartilage at the lower end of your breastbone. Between the growth of your uterus and general weight gain, you may be feeling fatigued. Some women also experience heartburn as your uterus presses against your stomach. Your breasts are also changing to get ready for breastfeeding.