The number of multifetal gestations has grown considerably in the United States during the last several decades. Between 1980 and 2009, for example, the rate of twin births grew by 76 percent, from 18.9 to 33.3 per 1,000 births. However, after more than three decades of gains, the twin birth rate fell by 4% between 2014 and 2018, to 32.6 twins per 1,000 total births in 2018. During the 1980s and 1990s, the rate of triplet and higher-order multifetal gestations climbed by more than 400 percent, peaking at 193.5 per 100,000 births in 1998 before declining to 153.4 per 100,000 births by 2009. The rate of triplet and higher-order multiple births in 2018 was 93.0 per 100,000 births, an 8 percent decrease from 2017 and a 52 percent decrease from the peak in 1998. Long-term changes in the incidence of multifetal gestations have been attributed to two main factors: 1) an increase in maternal age at conception, when multifetal gestations are more likely to occur naturally, and 2) an increase in the use of assisted reproductive technology (ART), which is more likely to result in a multifetal gestation.
Multiple gestations increase the risk of perinatal problems such as fetal abnormalities, hypertension, and gestational diabetes. Preterm delivery and the associated infant morbidity and death are two of the most serious consequences associated with multifetal gestations. Despite the fact that several therapies have been tested in the hopes of extending these gestations and enhancing outcomes, none have had a significant effect. The goal of this publication is to discuss the difficulties and complications related with twin, triplet, and higher-order multifetal gestations and to propose an evidence-based treatment approach.