It's getting awfully snug in there! Your baby weighs almost 4 pounds and is almost 17 inches long. You're gaining a pound a week now, and roughly half of that goes right to your baby. In fact, she'll gain a third to half of her birth weight during the next seven weeks as she fattens up for survival outside the womb. A side effect of your growing belly may be low back pain and possibly some pain in your buttocks and thighs. Be sure to tell your caregiver if the pain is severe or you feel numbness or tingling in your legs.
How your baby's growing
By now, your baby probably weighs almost 4 pounds and is almost 17 inches long, taking up a lot of space in your uterus. She has tiny toenails now, and her fingernails have grown in, too. Some babies have a head of hair already; others have only peach fuzz.
How your life's changing
Your blood volume (the plasma plus red blood cells) is now about 40 to 50 percent greater than before you became pregnant to accommodate the needs of you and your baby. (This extra amount also helps make up for any blood you'll lose when giving birth.) You're also gaining a pound a week now, and roughly half of that goes right to your baby. With your uterus pushing up near your diaphragm and adding pressure on your abdomen, you may be dealing with heartburn more often or feeling a little short of breath. To help with shortness of breath, try eating smaller quantities more often (rather than three daily feasts) and sleeping propped up. Those smaller meals should help with the heartburn, too.
As your baby grows, the increasing concentration of weight in your growing belly causes a change in your posture and a shift in your center of gravity. Plus, your abdominal muscles are stretching, hormones are making your ligaments more lax, and your growing uterus may even press on some nerves. All of this can contribute to low back pain and possibly to some pain in your buttocks and thighs as well. Let your caregiver know if you have severe pain or feel numbness or tingling in your legs.