Histologic and colposcopic correlates of ASCUS pap smears in pregnancy

A historic cohort analysis was performed to assess the colposcopic and histologic correlates of atypical squamous cells of undetermined significance (ASCUS) Pap smears in pregnant and nonpregnant women.

A chart review of all gynecologic and obstetric patients seen in the outpatient clinic at the Maimonides Medical Center between January 1996 and December 1999 was undertaken. All of the charts of patients with ASCUS Pap smears were reviewed to confirm the diagnosis and to obtain medical and demographic information. To be eligible for inclusion, patients needed to have a documented colposcopic exam within 6 months of the ASCUS Pap smear and be between the ages of 14 and 45 years old. The records from the colposcopic examination including histologic data were subsequently reviewed. The generalized Fisher exact test was utilized to determine the exact probability.

Over a 4-year period from January of 1996 to December of 1999, 198 women were diagnosed with ASCUS on their Pap smears. A total of 122 patients met the inclusion criteria. Of those included in the study, 58 were pregnant at the time of diagnosis and 64 were nonpregnant. The mean age of the obstetric and gynecologic patients was 26.9 (range = 18-37) and 31.0 (range = 18-44) years, respectively (p = NS). Thirty-two (50%) nonpregnant patients had histologic findings of cervical intraepithelial neoplasia (CIN) compared with 15 of the 45 (33.3%) (p = .019) obstetric patients who had biopsies within the first 6 months postpartum. CIN 1 was detected in 12 of the 45 (26.7%) biopsies of the postpartum patients and 26 of the 64 (40.6%) (p = .16) gynecologic patients. CIN 2,3 was found in 2 of the 45 (4.4%) postpartum patients versus 6 of the 64 (9.4%) (p = .12) gynecologic patients. One pregnant woman with ASCUS was found to have cervical cancer (2.2%). Overall, a biopsy proven neoplastic lesion was found in 15 of 45 (33.3%) postpartum women compared with 32 of the 64 (50%) (p = .019) nonpregnant women.

A cytologic diagnosis of ASCUS in pregnancy is associated with a significantly lower rate of neoplasia than the rate of neoplasia found among nonpregnant women with an ASCUS smear. A risk of cervical cancer following an ASCUS Pap smear was 2.2% in our pregnant population. Therefore, ASCUS diagnosed on the Pap smear in both pregnant and nonpregnant women warrants colposcopy and close follow-up.