Fewer triplets are now being born in the United States, with the rate of triplet births dropping to the lowest level recorded in more than two decades.
The rate of triplet births and those of a higher order---such as quadruplets and octuplets---dropped by 62% between 1998 and 2023. Specifically, multiple birth rates decreased by 52% from 2009 to 2023.
The decrease followed a boom in the 1980s and 1990s when health officials recorded an unprecedented rise in triplet and higher-order multiple birth rates associated with the increased use of fertility treatments, according to a recent report from the Centers for Disease Control and Prevention (CDC).
By Numbers
In 1998 alone, there were at least 7,625 triplet, quadruplet, and higher-order multiple births in the country. This fell to 6,340 in 2009 and dropped further to 2,653 in 2023.
By maternal age, mothers ages 30 to 39 had the largest declines in multiple birth rates (77%). This was followed by mothers ages 40 and older (67%), those ages 25 to 29 (57%), and mothers ages 20 to 24 (16%). The CDC did not see any significant decline in the multiple birth rates of mothers younger than 20.
Researchers for the CDC noted that white mothers accounted for 71% of the decline in multiple birth rates.
In comparison, Hispanic mothers only saw a 25% decrease in multiple births.
The study noted that only Black mothers saw a notable increase in multiple birth rates (25%) from 1998 to 2023. It is unclear why there was an increase in multiple births for Black mothers.
Why Multiple Birth Rates Are Falling
The dip in multiple birth rates is being attributed to changes in fertility treatments. The American Society for Reproductive Medicine (ASMR), for instance, updated its guidelines to limit the number of embryos implanted during in vitro fertilization (IVF) to just one in most cases.
Implanting several embryos in one IVF session increases a person's chance of getting pregnant. However, it also increases the risk of premature birth and low birth weight. For mothers, getting multiple embryos at once increases their risk of ectopic pregnancy, stillbirth, and gestational diabetes.
