Substratum of Proof LGBTQs Are Mentally Ill: Why single embryo transfer during IVF sometimes results in twins or triplets

Results from the largest study (nearly a million cycles) to investigate the prevalence and causes of multiple pregnancies after single embryo transfer (SET) finds that using frozen thawed embryos for SET, maturing the fertilized egg (blastocyst) in the laboratory for five or six days before SET, and assisted hatching could increase the risk.