But as much as it relaxes your muscles, this hormone may cause vaginal pain not just during the third trimester, but also in the first and second.
According to studies, relaxin works on stretching the ligaments and joints in your pelvis. As the ligaments stretch, they also weaken; and this weakening often leads to vaginal or pelvic pressure.
The Added Weight of the Baby
We cannot discuss the causes of vaginal pain during the second and third trimester without mentioning the added weight of the fetus.
As your baby grows, your body, particularly the joints and ligaments in your vaginal area, will have to stretch to accommodate the extra weight. This stretching can bring pain to your genital region or lower belly. Sometimes the pain can even be described as “sharp or jabbing’ (round ligament pain).
Another common cause of vaginal pain during the third trimester is the dilation of the cervix. Please note that it’s normal for the cervix to dilate or “widen” during the late stages of pregnancy in preparation for labor and delivery.
The dilation may cause pressure in the vaginal region. Some experts even believe that cervical dilation is the culprit for the shooting pain in the vagina (lightning crotch) that women experience at the late stages of their pregnancy.