Objectives: Sexual life may change during pregnancy. Due to negative attitudes toward having sex, unpleasant feeling, and fear of several issues, women might avoid vaginal intercourse during pregnancy. Therefore, the present systematic review aimed to investigate the frequency of vaginal intercourse in pregnancy.

Materials and Methods: Comprehensive literature review was conducted to find the relevant articles published (from December 1990 to April 2018) on the issue including observational studies (e.g., cross-sectional and cohort studies) that certainly determined the mean frequency of vaginal sex throughout pregnancy. In this regard, online international databases such as ISI, PubMed, Scopus, Cochrane, and Google Scholar were independently explored and checked by two authors. Duplicate articles were removed by the EndNote X7 Reference Manager. The results were analyzed using RevMan 5.3 software. The P < 0.05 was considered significant.

Results: Totally, after excluding the duplicate and irrelevant articles based on having the mean frequency of vaginal intercourse during pregnancy, 13 articles were obtained. The range of vaginal intercourse frequency varied from 6.01 to 21 times every month pre-pregnancy, 3.67-9.87 times monthly in the first trimester, 2.78-7.21 times monthly in the second trimester, and 1.35-5.9 times monthly in the third trimester. Five out of the 13 selected articles reporting the mean and standard deviation were entered the current meta-analysis. The frequency of vaginal intercourse was obtained 7.75 (7.13-8.38) times monthly prior to pregnancy, 4.16 (3.86-4.46) times in the first trimester, 6.37 (5.60-7.14) times monthly in the second trimester, and 1.81 (1.49-2.13) times monthly in the third trimester.

Conclusions: Generally, the frequency of vaginal intercourse decreased in the first trimester while increasing in the second trimester. However, a sharp decline was observed between the second and third trimesters of pregnancy.