Ovarian pain during pregnancy can be a bit confusing for many women. While some women experience ovarian pain each month during ovulation, most women know that ovulation ceases during pregnancy. Regardless, there are several reasons that women might experience ovarian pain during pregnancy, some of which are common and normal, and others of which are rare and potentially indicative of trouble.
The corpus luteum is an important hormone-secreting area of tissue that forms on the ovary following ovulation each month. While a normal corpus luteum secretes hormones, including estrogen and progesterone, for about 14 days, after which it atrophies and disintegrates, the hormones of pregnancy cause the corpus luteum to remain in place for the first four months of fetal development. In his book "Anatomy and Physiology," Dr. Gary Thibodeau explains that the purpose of the corpus luteum is to maintain the lining of the uterus, which provides nourishment for the developing embryo, until the placenta forms. Occasionally, the corpus luteum becomes filled with fluid and forms a cyst during early pregnancy. This cyst may be small--the size of an olive, for instance--or may grow quite large. Cysts are generally somewhat tender and sensitive, and women with luteal cysts often experience pain upon stretching, bending, or rolling over. While some cysts rupture, leading to sharp pain, most simply resolve on their own.
A fertilized egg should implant in the uterine lining, explains Dr. Miriam Stoppard in her book "Conception, Pregnancy and Birth." Some women, however, have damage to the fallopian tubes or grow endometrial tissue outside the uterus due to a disease called endometriosis. Either of these abnormalities can result in a fertilized egg implanting in the fallopian tube, near the ovary from which it was ovulated. As the egg develops and grows, it begins to stretch and stress the fallopian tube, leading to sensations of ovarian pain and abdominal discomfort. Obstetricians check hormone levels and perform sonograms on women experiencing severe, regularly occurring ovarian pain to determine whether the pregnancy is ectopic, since such pregnancies are very dangerous to the mother.
A rare but potential source of ovarian pain during pregnancy is ovulation. While pregnancy hormones typically suppress ovulation during pregnancy, in rare cases, women can ovulate despite their pregnancies. Dr. Miriam Stoppard, in her book "Conception, Pregnancy and Birth," notes that though many women don't feel ovulation at all, some do. This is true during pregnancy as well, meaning that a very small percentage of women may feel themselves ovulate. The extra ovulation does not affect the viability of the pregnancy, nor does it lead to menstruation, as normal ovulation would. Generally, the egg simply dies, and the pregnancy proceeds as usual.