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.