TOI: The odds for natural twins are one pair per 70 natural births.

1. The country is witnessing a “ten-fold rise” in twinning rates over the past two decades owing mostly to assisted reproductive technology, hormonal drugs to boost ovulation and increased maternal age with women delaying motherhood
2. 30-50% of all twins now occur as a result of infertility treatment
3. An ICMR study of 113 couples in Mumbai revealed that 45% of pregnancies via assisted reproduction techniques resulted in twins or triplets.
4. In IVF more number of embryos are implanted simultaneously in the womb to increase chances of conception.
5. IVF also involves a procedure called ‘laser assisted hatching’ to thin the outer shell of the embryo in order to allow the embryo to hatch. That increases chances of implantation as well as twinning.
6. Advancing maternal age: Women in their mid-thirties often resort to hormonal drugs that increase ovulation, leading to a heightened chance of bearing twins or triplets.
7. Twins born out of assisted pregnancies are usually fraternal (non-identical) since they arise from separate embryos and a different egg cell.
8. Europe has strict rules on single embryo transfers now
9. Currently ICMR recommends not more than three embryo transfers and the recent advent of technology to freeze embryos is helping curb the temptation to transfer all the embryos generated in a given cycle.