Pregnancy Calendar - Week 21
Your baby now weighs about 13 ounces. She is still able to move about inside the amniotic fluid, and will only settle down towards the end of this trimester, where she will turn and settle in a head-down position.
Growth is starting to slow down and the heart beat is starting to get stronger. Legs will also be reaching their relative proportions.
The amniotic fluid that has cushioned and supported your baby in the uterus now serves another purpose. The intestines have developed enough so that small amounts of sugars can be absorbed from the amniotic fluid the baby swallows. This sugar will be passed through the digestive system to the large bowel. Most of your baby’s nourishment still comes from you through the placenta, though.
Up until now your baby’s liver and spleen have been responsible for the production of blood cells (the fetal liver produces blood cells right up until the time of birth). Now, however, the bone marrow spaces are developed enough to contribute to blood cell formation as well.
Exercise can be a great way to stay in shape during pregnancy and can even keep some symptoms, such as varicose veins, excessive weight gain, and backache, at a minimum. But pregnancy is not the time to start training for a triathlon - ‘going slow’ is the name of the game. Because ligaments become more relaxed during pregnancy, you’re at higher risk for injury, so low or non-impact exercise such as yoga, swimming, and walking are your best bets. Talk to your health care provider before beginning any exercise program while you’re pregnant.
Because the second trimeter is the easiest on your body, now is a good time to do things with your partner. Perhaps going away for a weekend will give you that alone time you’ve been craving.
Revision date: June 22, 2011
Last revised: by Janet A. Staessen, MD, PhD