Aim The objective of this study was to assess the changes in female sexual function during pregnancy and to identify associated factors among Turkish population using a validated questionnaire. Furthermore, we aimed to examine Turkish pregnant women's beliefs regarding sexual activity and describe their source of information about sexuality during pregnancy. Material and Methods In this cross-sectional study, healthy heterosexual pregnant women who had been living with their partners within the last four weeks were asked to complete two self-administered questionnaires, one of which was Female Sexual Function Index (FSFI). Results A significant association was found between the decrease in intercourse frequency and trimesters, as a decline in frequency was reported by 58.3%, 66.1% and 76.5% of women in each trimester, respectively (P=0.01). Only the trimester of gestation and employment status were independent factors associated with the decline in sexual intercourse frequency during pregnancy. When the overall FSFI score were compared according to each trimester of pregnancy, there were no statistical significant differences between the first and second trimesters (P=0.71). The overall FSFI score in the third trimester was found to be significantly lower than the overall scores in the first two trimesters (P<0.001 for both). In linear regression analysis, overall FSFI scores were adversely affected by only being in the last trimester. 38.7% of women and 36.2% of male partners worried that sexual intercourse may harm the pregnancy. Among the total sample, only 23.8% of women discussed sexuality with the medical staff. Conclusion The third trimester is the independent variable for both decreased sexual activity frequency and sexual function scores in pregnancy. Counseling about sexuality during pregnancy is not frequent in the clinical setting, but conversations about this topic should happen on a regular basis during prenatal care visits.