If you have occasionally noticed a sharp pain in your groin when you exercise, you're not imagining things. Chances are you've encountered a fairly common problem for pregnant women: spasm of the round ligament.
The round ligament is the ligament that holds the uterus in place by attaching it to the hipbone. In the second and third trimesters, when your uterus has expanded, hormones cause the ligaments to stretch, grow, and thicken to support the weight of the baby. In fact, the ligaments can grow from 2 to 12 inches over 9 months, as the uterus grows from about 3.5 inches long and 2.25 inches wide to almost 14 by 9 inches.
These changes can be the underlying cause of twinges felt in the groin, usually occurring on one side. The pain runs along the underwear line from the hip to the groin, and can occur with quick movements, getting out of a bed or a chair, or when you cough or just roll over. The pain is typically sharp in nature and subsides with a short period of rest.
On the other hand, if the pain continues longer or is accompanied with other symptoms such as bleeding, cramping, fever, vomiting, or chills, call your health care provider. And if the pain occurs early in the first trimester, when uterus weight shouldn't be a factor, or continues even when you're at rest, be cautious-- call your doctor or midwife to rule out other factors.