Objective: To investigate the current status of sexual function and its influencing factors among pregnant women, so as to provide the reference for improving sexual health among pregnant women. Methods: From January to July 2025, pregnant women attending regular prenatal check-ups at Shanxi Children's Hospital (Shanxi Maternal and Child Health Hospital), were selected as study participants using a convenience sampling method. Information on sociodemographic, pregnancy-related conditions, and sexual activity during pregnancy was collected through questionnaire surveys. Sexual function status over the past four weeks was assessed using the Chinese version of the Female Sexual Function Index. A multiple linear regression model was employed to analyze the influencing factors for sexual function among pregnant women. Results: A total of 424 pregnant women were surveyed, with the majority aged 30-<35 years (211 cases, 49.76%). Among them, 72 were in the first trimester (16.98%), 200 in the second trimester (47.17%), and 152 in the third trimester (35.85%). The overall sexual function score among pregnant women was (17.85±6.46) points. Scores for the six domains, desire, arousal, lubrication, orgasm, satisfaction, and pain were (3.23±0.78) (2.21±1.20) (2.76±1.63) (2.95±1.68) (4.14±1.08) (2.56±1.96) points, respectively. Multiple linear regression analysis revealed that cohabitation with a companion (β'=0.124), stage of pregnancy (third trimester, β'=-0.360), and changes in sexual practices or positions during pregnancy (β'=0.164) were statistically associated with sexual function scores among pregnant women (all P<0.05). Conclusions Sexual function declines among pregnant women, with mean scores across all domains falling below the critical threshold. Cohabitation with a companion and appropriate adjustments in sexual practices or positions according to the stage of pregnancy may improve sexual function among pregnant women.