The intervention group ( group @ ; n = @ ) received intravenous infusion of @ mL @ % calcium gluconate in @ mL @ % saline solution on the day of ovum pick-up ( OPU ) and days @ , @ , and @ after , and the placebo group ( group @ ; n = @ ) received @ mL @ % saline solution on the day of OPU and days @ , @ , and @ after .