They found no statistically significant difference in live birth rate when comparing cumulative single embryo versus double embryo transfer rate (38.8 % vs. 42.9 %, P = 0.3). Compared to the eSET arm, the rate of multiple births was significantly greater in the double embryo group (0.8 % vs. 33.1 %, P < 0.001).
Depending on the patient, implanting two embryos can slightly increase the chance of at least one of those embryos implanting and resulting in a successful pregnancy. Implanting two embryos can also result in those adorable twins, which is particularly appealing to parents needing IVF to get pregnant. They often think they can get two kids in one try and not have to go through IVF again.
But a pregnancy with twins can be more dangerous than adorable. Multiple pregnancy – which we call a pregnancy of twins, triplets or more – is fraught with potential health problems for the children and mother.
Multiple gestation pregnancies have higher risks for low birth weight children and premature birth, which can result in infant mortality or other problems for the children. Problems can include needing special care at birth (short or prolonged neonatal intensive unit care) and facing long-term issues such as developmental delays, ongoing lung and gastrointestinal dysfunction, cerebral palsy and other debilitating problems.
The mother carrying twins has an increased risk of Caesarean section, which prolongs recovery and can result in hemorrhage during and after delivery. Worse, one or both fetuses may not survive to term and require removal. Carrying twins can also increase mom’s morning sickness, weight gain, and risk of developing gestational diabetes and blood pressure problems including preeclampsia. Further, the sleep deprivation, fatigue, marital and family stress created from caring for more than one baby has been shown to be far higher than when caring for one at a time.
Mothers and fathers have a choice: implant a single embryo or two. While it is possible to implant more than two embryos (remember Octomom?), few doctors will do that these days.