Compared to singleton (one embryo) pregnancies, multiple pregnancies present significantly higher health risks to both the mother and the embryos. Twin pregnancies carry twice the risks of singleton pregnancies, and the risks become much greater for pregnancies with high order mulitples (HOMs - triplets or more). The greatest risks as a result of multiples include:
- total pregnancy loss
- long-term health problems
- cerebral palsy
- preterm birth (prematurity)
Multiple pregnancies are a concern for doctors in the U.S. as well as around the world. One of the most well-known, progressive perinatal specialists in the States believes that "the goal is a healthy mother and baby," (Evans). And the European Society for Human Reproduction and Embryology (ESHRE) has stated that "since the goal of infertility therapy is a healthy child, and multiple gestation puts that goal at risk, multiple pregnancy must be regarded as a serious complication of assisted reproductive treatment cycles."
Total Pregnancy Loss
The scariest aspect of pregnancy for most women is the risk of losing the entire pregnancy. While the average risk of losing a pregnancy is just 3% for a singleton pregnancy, the risk increases significantly with each additional fetus. For twins, the risk of total pregnancy loss is at 15%, and this risk jumps up to a sobering 25% with triplets (see Figure 1).
|Figure 1: The risk of total pregnancy loss increases significantly with each additional embryo.|
Multiples are far more likely to have long-term health problems after delivery than singleton babies. These problems are related to several factors including (but not limited to) low birthweight, intrauterine growth restriction (IUGR), premature labor & delivery and precipitous labor & delivery. The long-term health complications for multiples that can arise from these (and other) factors include learning disabilities, vision and hearing problems, respiratory difficulties, feeding and growth problems and cerebral palsy (see Figure 2 for a breakdown of risks by number of babies).
|Figure 2: The risk of at least one baby with long-term health problems becomes significantly higher as the number of babies increases. |
Twin pregnancies are the least likely of all multiple pregnancies to have at least one baby with long-term health problems. For triplets, however, the number is much higher. It is estimated that between 15% and 40% of triplet (and higher) pregnancies result in at least one baby who will have long-term health problems. (Sources: Evans; Sher)
|NEXT ... As the number of babies increases so does the chance for cerebral palsy, with symptoms ranging from severe to barely noticeable.|