Study Population

Pregnant women who received antenatal care at the Huzhou Maternal & Child Health Care Hospital in Zhejiang Province from January 2018 to January 2020 and met the following conditions were enrolled into the study: no history of cervical cancer or precancer or history of other malignant tumors; no history of cervical surgical treatment; not in the active period of autoimmune diseases or taking long-term oral immunosuppressor medication; aged between 20 and 44 years; no liquid-based thin-layer cytology (TCT) or HPV test within the past year; no pathological gestation such as placenta previa or vasa previa; and agreed to participate in this study voluntarily and signed informed consent. During this period, a total of 22 133 pregnant women received antenatal care in our hospital, of which 1774 met the above conditions and were included in the study.

Non-pregnant women who received health examinations in our hospital during the same period were selected as controls when they met the following criteria: no history of cervical cancer or precancer or history of other malignant tumors; no history of cervical surgical treatment; not in the active period of autoimmune diseases or taking long-term oral immunosuppressor medication; not pregnant; and agreed to participate in this study voluntarily. At a 1: 1 ratio, 1774 age-matched non-pregnant women were selected randomly as controls, according to a random numbers table of the clinic visiting order. Figure 1 shows the flow chart of the test.

Flow chart of the test. NILM – no intraepithelial lesion or malignancy; ASCUS – abnormal squamous cells of uncertain significance; LSIL – low-grade squamous intraepithelial lesion; ASC-H – atypical squamous cells, cannot exclude HSIL; HSIL – high-grade squamous intraepithelial lesion; SCC – squamous cell carcinoma; AGC – atypical glandular cells; VVC – vulvovaginal candidiasis; BV – bacterial vaginosis; TV – trichomonas vaginalis.