Your Baby at 21 Weeks Pregnant
Your baby's heartbeat is now loud enough to be heard through a simple stethoscope that you can buy at a drugstore. Your little one's beat can be difficult to distinguish from your own. Listen for the faster rhythm — a baby's heartbeat is 120 to 160 beats per minute, about twice as fast as your own. Many women think it sounds like galloping horses.
Snooze news. Your baby is already starting to sleep and wake in subtle cycles. Ultrasounds show that unborn babies may even settle into a favorite sleeping position.
Measuring up. Your baby weighs between 10 and 13 ounces and is around 9 inches long, the length and weight of a banana.
Your Pregnancy at 21 Weeks
Backaches, especially in the lower back, are quite common during pregnancy. Your growing uterus is shifting your center of gravity and pulling your lower back forward. Meanwhile, the hormone relaxin is loosening every joint and ligament in your body, which will allow your pelvis to expand to accommodate your baby's head.
Whenever you sit, whether you're watching television or working, use a footrest to elevate your feet slightly. If you need to stand to do a task, put one foot on a small step stool to take some pressure off your lower back. You can also soak in a warm bath. If your backache won't go away, give your healthcare provider a call.