The role of ultrasonography in the detection and management of adnexal masses during the second and third trimesters of pregnancy.

OBJECTIVE

Our purpose was to determine the effect of routine second-trimester and third-trimester ultrasonographic examinations on the prevalence of detectable and operable adnexal disease.

STUDY DESIGN

The study group consisted of 7996 pregnant women between 13.0 and 42.8 weeks' gestation. The size and architectural pattern of any detectable adnexal masses were noted.

RESULTS

A total of 328 of the 7996 (4.1%) women in the study group had 335 ultrasonographically detectable adnexal masses; 309 of the masses were unilocular or had a single thin septation and 26 were architecturally complex. Of the ovarian cysts 252 of 309 (81.6%) had a mean diameter < 3.0 cm; 60% of the 252 patients in this subgroup had serial ultrasonographic examinations; 43 of the unilocular cysts resolved, and 17 have persisted for up to 2 years. There is a statistically significant trend toward decreasing frequency of ovarian cysts with increasing gestational age (chi2 for linear trend; P < .00001). Eighteen of the 7996 had an exploratory laparotomy (1 operation per 444 deliveries) during pregnancy or in the postpartum period. In addition, 1 patient had a paratubal cyst excised at the time of postpartum bilateral tubal ligation. Pathologically confirmed lesions included 8 benign cystic teratomas, 3 mucinous cyst adenomas, 2 paratubal cysts, 2 corpus lutea, 1 serous cystadenoma, 1 follicular cyst, 1 endometrioma, and 1 ovarian fibroma.

CONCLUSION

Ovarian cysts are found in 4.1% of second-trimester and third-trimester obstetric ultrasonographic examinations. Most ultrasonographically detectable cysts are < 3.0 cm in diameter and usually resolve. The frequency of exploratory laparotomy for adnexal disease is not significantly different from that in reports before the widespread use of obstetric ultrasonography.