Introduction
Multifetal pregnancy is one of the greatest perinatal challenges. Changing demographics and fertility practice has resulted in the global epidemic of multifetal pregnancies which has substantially inflated the perinatal disease burden for clinicians, parents as well as society.1,2 Bergh3 attributed a third of the increase to in-vitro fertilization(IVF), a third to ovulation induction and rest to advanced maternal age. Lawlor and Nelson et al4 demonstrated that the success rate for live-borns was higher by about 7% by transferring 2 embryos in 1 cycle rather than 1 each for 2 cycles. Thus, where aggressive embryo transfers seem justifiable, mounting multiple pregnancies are to be dealt with.Evans5 reviewed trends over past 3 decades and reported that twin births have surged high and stayed relatively constant, but the curves for triplets and above show a curvilinear pattern, an incidence which skyrocketed initially, has returned to almost baseline due to Human Fertilization and Embryology Authority Code of Practice (2001), which restricted the number of embryos transferred at IVF/ICSI cycle to two.
The incidence of complications in multifetal pregnancy directly correlates with the number of fetuses. Besides the higher risk of miscarriages, infants born are at increased risk of prematurity, cerebral palsy, chronic lung disease, developmental delay, behavioral difficulties and death.6-8 Advancements in neonatal care may have reduced associated mortality though morbidity has remained unabated. Pharoah and Cooke reported cerebral palsy rates per 1,000 1st year survivor at 2.3 for singletons, 12.6 for twins, and 44.8 for triplets.9,10Complications secondary to unique placental vascular connections further escalates risks for monochorionic gestations. Maternal risks include hypertension, preeclampsia, gestational diabetes, postpartum hemorrhage.11
Sub-fertile couples may consider multiple pregnancies as a desirable outcome after trying many years but associated high rate of maternal and perinatal complications has compelled obstetricians to consider prevention options. Primary prevention has been achieved to an extent with sonographic monitoring of ovulation induction with cancellation if excessive ovulation is predicted, and the restrictions on embryo transfer. However, once twins or higher-order multiple pregnancy has occurred, the option of multifetal pregnancy reduction or selective termination (ST) needs to be considered as a secondary prevention measure. Fetal reduction not only improves medical outcomes but also significantly reduces the economic and psychological impact of caring for multiple new-borns.