CSI itself does not directly cause twins, but it can increase the chances of twin pregnancies due to factors associated with IVF treatments.
Here’s why twins might occur more frequently with ICSI:
- Multiple Embryo Transfer: To improve success rates, fertility specialists often transfer more than one embryo into the uterus during ICSI cycles. This increases the likelihood of multiple pregnancies, including twins.
- Controlled Ovarian Stimulation: IVF/ICSI involves stimulating the ovaries to produce multiple eggs, resulting in multiple embryos, which naturally raises the chance of twins if more than one embryo implants.
- Monozygotic (Identical) Twins: IVF treatments, including ICSI, are associated with a slightly higher rate of identical twins due to embryo splitting after transfer.
Risks and Management:
Twin pregnancies carry higher risks of preterm birth, low birth weight, gestational diabetes, and preeclampsia compared to singleton pregnancies. To minimize these risks, fertility clinics may recommend:
- Single Embryo Transfer (SET): Transferring one embryo to reduce twin pregnancies while maintaining good success rates.
- Careful Monitoring: Close supervision of ovarian stimulation and embryo development to avoid excessive embryo numbers.
Conclusion:
While ICSI increases fertilization chances, it doesn’t directly cause twins. Multiple embryo transfers during IVF/ICSI cycles are the primary reason for twins. Discuss embryo transfer options and risks with your fertility specialist to choose the best approach for a safe pregnancy.