Where Did All the Triplets Go? Mystery Explained: ScienceAlert

The rise and fall of triplet births in the United States is a dangerous rollercoaster that has thankfully stabilized.

In the 1980s, the number of triplets born in the country suddenly exploded, increasing fivefold in just two decades.

However, since this peak, the rate of multiple births from a single pregnancy has fallen dramatically.

The number of triplet and higher-order births decreased by nearly 65 percent between 1998 and 2023, according to a new report from the Centers for Disease Control and Prevention (CDC).

At the same time, births of quadruplets and higher were reduced by 80 percent.

Unlike America’s overall birth rate 30 years of rapid declineThis coincidental decline in multiple births is considered a positive turn of events.

This is a response to rapid advances in fertility treatments and the increasing age at which people choose to have children.

The first ‘test tube baby’ was born through in vitro fertilization (IVF) in 1978 and was introduced in the 80s and 90s when success rates were low. routine application In many countries, transferring more than one fertilized egg is used to increase the likelihood of pregnancy.

Thus began a dramatic increase in the rate of multiple pregnancies. greater risks Risk of death and morbidity for both mother and child, including preeclampsia, pregnancy diabetespostpartum hemorrhage and low birth weight. triplets almost certain born prematurely.

A 1997 study found that the risk of having a triplet due to the transfer of three embryos during IVF was approximately 7.5 percent.unacceptably high“.

Transferring just one or two embryos avoids such negative outcomes, so early 2000sThe American Society for Reproductive Medicine (ASRM) has recommended that no more than two embryos be transferred to patients under 35 years of age. Their goal was to eliminate quadruplets and limit triplets. below 2 percent IVF cases.

There is no national law in the U.S. limiting the number of embryos that can be transferred in a single IVF cycle, but assisted reproductive technology (ART) is one of the most heavily regulated of all medical practices in the country, and most providers appear to comply with federal and state guidelines.

Data from the UK predicts average IVF pregnancy rate The use of frozen embryos has increased from 7 percent in the 1990s to 36 percent in 2021, affecting the risk-benefit equation for multiple transfers.

Between 1998 and 2011, studies It shows a 70 percent reduction in the transfer of three or more embryos during IVF in the US.

The new CDC report reveals a 52 percent decline in multiple births of triplets or more in the U.S. from 2009. Among white women with the most access to IVF in the United States, the rate of births of triplets or higher dropped by 62 percent during the same period.

“If you look at the CDC’s numbers, you can see these declines occurring every year or two following these guideline updates,” said Micah Hill, president of the Association for Assisted Reproductive Technologies. said CNN.

“These guidelines have evolved as technology has evolved,” adds Hill, who was not involved in the CDC report. “I think it’s been successful in making fertility treatments safer, which is what we really care about when we talk about reducing high-order multiples.”

As of 2020 more than 80 percent 50% of embryo transfers in the US involve only one embryo.

To increase this number even further, researchers at ASRM recommend: expansion of insurance coverage Addressing fertility issues in the USA.

IIf someone cannot afford multiple IVF procedures, patients, and providers They may face a greater desire to transfer more than one embryo to increase their chances of pregnancy, even though it increases the risks involved.

CDC report can be read Here.