Why is rate of triplet births declining in US?

A recent report by the Centres for Disease Control and Prevention (CDC) revealed that the rate of triplet births and births of a higher order, like quadruplets and sextuplets, in the United States decreased by 62% in 2023 from 1998.

The decline is particularly significant among white mothers, who saw a 71% drop, while Hispanic mothers experienced a 25% decrease, the New York Post reported citing information from the report.

In contrast, the birth rate for black mothers increased by 25%. 

The CDC report attributes this dramatic decline in numbers to the trend of implanting multiple multiple embryos during in vitro fertilisation (IVF), a method that increases the likelihood of pregnancy and is often more cost-effective.

However, it carries heightened risks for mothers and infants, including premature births, low birth weight, and other serious health complications like ectopic pregnancy, stillbirth, high blood pressure and gestational diabetes.

"This decline in triplet and higher-order births over the last 25 years has been associated with changes to guidance related to the number of embryos transferred during assisted reproductive technology use," the report read.

Previously, women under the age of 35 were limited to three embryo transfers, while those over 40 or with multiple failed IVF cycles could implant up to five, according to the guidelines issued by the American Society for Reproductive Medicine (ASMR) and the Society for Assisted Reproductive Technology in the 1990s.

However, ASRM now advises transferring primarily one embryo for most cases. For women over 40, recommendation is to implant a maximum of four untested early-stage embryos at once.

"These guidelines have evolved as the technology has evolved," Dr Micah Hill — president of the Society for Assisted Reproductive Technology, who was not involved in the new report — told CNN.

"I think it's been successful in making fertility treatments safer, which is really what we care about when we’re talking about reducing these higher-order multiples," Hill added.

The decision is ultimately left to the physician and patient.