Conventional wisdom is, more and more, coming around to accept the fact that the single biggest risk factor for women undergoing IVF treatment is a multiple birth. Risks that are commonly associated with multiple pregnancies are: pregnancy complications like miscarriage, higher need for special neonatal care, premature babies and low birth weights, neonatal mortality (19 deaths/1000 within the first month for multiple-birth babies, as opposed to only 3 for single-birth babies), increased instance of cerebral palsy (6.2 cases/1000 live births for multiple-birth babies, as opposed to only 1.7 for single-birth babies). For mothers, multiple births can lead to pregnancy-induced high blood pressure (hypertension), pre-eclampsia, pregnancy diabetes, assisted or interventional delivery (i.e caesarean), and mortality.
As more and more numbers come out to show that decreasing multiple births can also make IVF treatment safer for patients and babies alike, the UK government has stepped in to encourage IVF clinics to use single embryo transfers and has set goals for assessing their progress. The Human Fertilisation and Embryology Authority (HFEA) published figures that show that the reduction of multiple births is, indeed, being reduced, down to 24% as of March 2010 and looking to be on target for being down to 15% by March 2012. Eventually, the hope is that multiple births will account for not more than 10% of the overall births from IVF. What is most important to note is that even while reducing the number of embryos transferred in procedures, the overall birth rate has not gone down -- so women are receiving the same success rates with less risk factors.