The 2001 Bethesda System defines atypical glandular cells (AGC) as glandular cell abnormalities that are distinct from adenocarcinoma or adenocarcinoma in situ. 1 Before 2001, a spectrum of glandular cell abnormalities in cervical smears was grouped under atypical glandular cells of undetermined significance (AGUS) and defined as glandular cells exhibiting changes beyond reactive or reparative changes, but lacking unequivocal features of invasive adenocarcinoma. 2 The incidence and clinical significance of AGUS have been extensively reported, 3-6 however, studies reporting AGUS smears in pregnancy and postpartum period are very limited.Chhieng and colleagues 7 have reported the largest number of AGUS smears in pregnancy and postpartum period (n=35). Among the 13,361 smears performed during the 3-year study period, this group reported a 0.26% incidence rate with a mean patient age of 29. Of the 35 patients with AGUS smears, 8 patients were lost to follow up, 17 were referred for colposcopy and biopsy, and 10 had repeated smears. For those who underwent colposcopy and biopsy, five patients had histologically proven cervical intraepithelial lesions. The others had benign pathologies including squamous cell metaplasia, endocervical or endometrial polyps, Arias-Stella reactions and microglandular hyperplasia. Two of the 10 patients had persistent abnormalities on repeated smears but their outcomes were not reported. The authors reported the incidence of significant pathology in this study as 29%. However, the incidence rate of significant pathology was calculated on the basis of the 17 cases referred for colposcopy and biopsy only, and did not include the patients being followed with repeated smears which would reduce the rate of significant pathology to less than 20%.Two other studies have been reported on pregnancy related AGUS, although these involved smaller numbers of patients. Michael and colleagues 8 reported 26 cases of AGUS during pregnancy or postpartum period, most of which were followed with repeated cervical smears after 3 to 6 months. Biopsies were performed in the postpartum period only if atypia persisted on repeat smears. Eight patients had colposcopy directed biopsies and only 2 patients were diagnosed with squamous cell intraepithelial lesions. Kim and colleagues 9 reported a large study of 326 patients: 21 were diagnosed with AGUS during pregnancy or within 8 weeks postpartum. Only one of the 21 patients had significant pathology showing carcinoma in situ, though the method of follow-up was not specified. From the studies described above, the incidence of