Physicians and other medical providers counsel patients to provide them with most important information and available medical service options. How to provide the most effective antenatal counseling is an important focus among experts. Our study focuses on the influence of the partner's involvement during antenatal genetic group counseling (AGGC). This study aimed to compare the ratio of pregnant individuals who have knowledge score improvement after AGGC, with a focus on pregnant individuals who attend counseling with/without their partner and to identify other possible factors that could influence the knowledge improvement. A prospective cohort study was conducted. Pregnant individuals were assessed for their knowledge by using a self-questionnaire prior to and immediately after AGGC. A total of 553 pregnant women were enrolled; 310 and 243 participants attended the AGGC without and with their partner, respectively. The ratio of the participants who increased their overall knowledge score was significantly higher after the AGGC for those who were with partner compared with those without. The medians (Q1-Q3) of the overall knowledge scores before and after the AGGC were 32 (29-36) and 36 (31-39) in the AGGC with their partner, respectively, and 33 (30-36) and 35 (32-39) in the AGGC without their partner, respectively. Knowledge of trisomy-21 screening of all participants got the lowest score and less improvement when compared with other topics. Partner's involvement in the AGGC was associated with a higher ratio of the participants who increased their overall knowledge score when comparing the scores prior to and immediately after the AGGC.