The miscarriage rate was 18.1% (38/210) in the GnRH antagonist and 18.7% (43/229) in the PPOS group (p = 0.67). Similarly, the multiple pregnancy rate was 6.1% (13/172) and 11.3% (21/186) in the GnRH antagonist and PPOS groups, respectively (p = 0.31) (Table 2). Here, GNRH1 is linked to spontaneous abortion.