Sonographic visualization of normal-size ovaries during pregnancy

Objective To assess the ability, of ultrasound to detect ovaries of normal size during pregnancy Methods A prospective study, of 329 women with a normal pregnancy course wa s undertaken; 68 were excluded front analysis because of an enlarged cystic ovary. Of the remainder, 60 pregnancies were examined in the first trimest er and 201 in the second or third trimester. The first group underwent tran svaginal (TVS) and transabdomminal (TAS) scanning. The second group underwe nt TAS examination only. Results In the first-trimester group, TI'S identified both ovaries in 57 pa tients (95%) and transabdominal ultrasound in 20 (33.3%). In the second- an d third-trimester patients, TAS visualized both ovaries in 33 patients (16. 4%), and neither ovary in 120 (59.7%). Both ovaries were less risible with advancing gestational age. The right ovary showed a significant change in p osition during pregnancy, from about 1 cm (nt 15-24 weeks) to 2.5 cm (at 30 -41 weeks) cranial to the iliac spine. The left ovary was found 1 cm above the iliac spine throughout pregnancy. Conclusions Transvaginal sonography is adequate for the visualization of bo th ovaries in the first trimester of pregnancy? With advanced gestational a ge, the ovaries were significantly less visible by TAS. Sonographic scannin g of the ovaries ill second and third trimester should be concentrated main ly at the level of the iliac spine. Poor sonographic visualization of both ovaries in late gestation may mandate the use of other imaging modalities.