Fewer triplets are being born in the US. Researchers have a theory as to why
Triplet births in the U.S. have reached their lowest point in 25 years.
The number of triplets born in the United States has reached a 25-year low, according to new data from the U.S. Centers for Disease Control and Prevention.
After experiencing a boom in the 1980s and 1990s, the rates of triplets born in the U.S. dropped 64% between 1998 and 2023, according to the new data published Thursday.
Other higher-order multiple births, including quadruplets, also decreased in that same period, the data shows.
In 1998, there were 7,625 triplet, quadruplet and higher-order multiple births in the U.S., a high that researchers say was the result of the growing use of fertility treatments, which were popularized in the 1980s.
The CDC described the rise in multiple births as a "public health concern" because births of more than one baby come with greater health risks for both the mother and babies.
By 2023, the number of births involving three or more babies had dropped to 2,505 in the U.S., according to the CDC.
Researchers attributed the decline in multiple births to changes in fertility treatments.
In more recent years, the American Society for Reproductive Medicine has changed its guidelines to limit the number of embryos that are transferred during in vitro fertilization, in order to try to promote singleton pregnancies.
In the IVF process, ovulation is induced and eggs are removed from a patient's ovaries. The eggs are then fertilized with sperm outside of the body, and the resulting successful embryos are either placed in the patient's uterus in the hope of pregnancy or are stored in a laboratory for future use, according to the American College of Obstetricians and Gynecologists.
Around 2% of all infants born in the U.S. are conceived through the use of assisted reproductive technology, which includes IVF, according to the Department of Health and Human Services.
While there has been an overall decline in multiple births in the U.S. over the past two decades, researchers found the decline is not equal among all races.
The rate of non-Hispanic Black mothers giving birth to three or more children increased by 25% between 1998 and 2023, the same time period where the rate among white mothers declined 71%, according to the CDC.
Researchers did not provide an explanation for the increase in multiple births for Black mothers.