It must have seemed irresistible to pillow manufacturers. There it was -- the pregnant belly resting on a bed without extra support! Yes, there are special little pillows out there designed specifically to support the growing pregnant belly as women lie on their sides. For some women, this seems like a no-brainer and they have been makeshifting with various pillows at home. For other women, it seems like yet another attempt by the "pregnancy industrial complex" to market one more thing (I am constantly amazed!).
The uterus is anchored into the pelvis but a series of ligaments (unless your Victorian doctor has diagnosed you with the dreaded floating uterus of hysteria!). These ligaments undergo tremendous stretching and strain as the pregnant uterus grows in size and becomes heavier. There are three major sets of ligaments -- the round ligaments which attach to the pubis, the broad ligaments which attach to the inside of the sides of the pelvis, and the sacrouterine ligament which connects the uterus to the anterior surface of the sacrum. These ligaments can cause all sorts of discomforts for pregnant women. The round ligament actually has some contractile tissue and can go into spasm. As the heavy uterus begins to spill forward out of the pelvic bowl, the broad and sacrouterine ligaments tug at the already loosening pelvic bones and refer all sorts of pain to the low back and back of the pelvis.
When a woman lies on her side, the uterus will shift with gravity toward the surface she is lying on. This can add further strain or stretch to some ligaments, which in turn can in turn pull on the bones of the pelvis and cause discomfort and pain. Many women find support relief by tucking pillows under the uterus. By propping their belly up with pillows, they are able to keep the center of the uterus more in line with the midline of the body and eliminate possible strain.
In my own work with pregnant women, many are often surprised at the difference made by a supportive belly pillow. It not only minimizes strain to the uterine and pelvic ligaments, but it helps keep your back and pelvic bones aligned and lets you sleep in a more neutral alignment.
Yes, belly propping makes sense. But a specialized pillow?
Believe it or not, but there's this study...Yep. Those Australians. In this study, researchers tested the effect of using a specific wedge-shaped pillow compared with a standard hospital pillow, used to support the abdomen of a pregnant woman while lying on her side, in preventing or alleviating backache and backache-related insomnia. Women used the specialized belly pillow one week and a standard hospital pillow for the their belly for one week. The weeks they used the belly pillow they reported lower scores for backache and reported better sleep (though actual sleep scores didn't corroborate this). Though some women felt both pillows were helpful, more felt that the specialized pillow was superior.I.L. Thomas’, J. Nicklinz, H. Pollock’ and K. Faulkner. "Evaluation of a Maternity Cushion (Ozzlo Pillow) for Backache and Insomnia in Late Pregnancy." Ausl NZ J Obster Gynaecol. 1989; 29: 133
Many of the pregnancy body pillows that are out there are intended to tuck under the belly and offer similar support. For those of you for whom that doesn't cut it or you are not interested in purchasing a big body pillow (or taking up that much room in bed), there are several wedge-shaped pillows on the market.