Reduced access to infertility treatments early in the pandemic may have contributed to a decline in twin births, data from the US Centers for Disease Control and Prevention suggests.
The number of twin births fell 7% between 2019 and 2020 – from 120,291 to 112,437 – compared to an average decline of 2% per year from 2014 to 2019, researchers in the CDCit is National vital statistics reportsbased on data from 50 states and the District of Columbia.
The twinning rate fell by 3% between 2019 and 2020, from 32.1 to 31.1 per 1,000 births, compared to an average annual decline of 1% from 2014 to 2019, according to the researchers.
The largest declines occurred in November and December 2020 and January 2021, when twin birth rates fell 10%, 14% and 7%, respectively, from the previous year.
“The timing of the monthly declines in late 2020 and early 2021 coincides with a conception period when the coronavirus pandemic began and (experts) advised reproductive medicine professionals to temporarily limit infertility treatment,” declared Isabelle Horon and Joyce Martin written in the report.
The number of births involving a baby fell just 3% between 2019 and 2020, the authors said.
Overall, twin births did not increase significantly in 2021 from 2020 levels, although rates started to rise towards the end of the year.
The biggest drop in twin births was seen in women over 40, the group most likely to use fertility treatment. The smallest drop was seen in women younger than 30, who are least likely to use infertility treatment, the authors said.
The study cannot prove that the pandemic lockdowns led to a decline in twin births. In fact, the authors point out that Hispanic women experienced a greater decline in twinning rates than non-Hispanic white women, even though Hispanic women are less likely to receive infertility treatments.
At the start of the pandemic, the number of babies born prematurely or with dangerously low weight was lower than normal, the researchers noted.
Because twins are at higher risk for these outcomes, “the decline in twin births may have contributed, in part, to the reduction in preterm and low birth weight deliveries … between 2019 and 2020,” they said.
The number of twin births fell 7% between 2019 and 2020 – from 120,291 to 112,437 – compared to an average decline of 2% per year from 2014 to 2019, researchers in the CDCit is National vital statistics reportsbased on data from 50 states and the District of Columbia.
The twinning rate fell by 3% between 2019 and 2020, from 32.1 to 31.1 per 1,000 births, compared to an average annual decline of 1% from 2014 to 2019, according to the researchers.
The largest declines occurred in November and December 2020 and January 2021, when twin birth rates fell 10%, 14% and 7%, respectively, from the previous year.
“The timing of the monthly declines in late 2020 and early 2021 coincides with a conception period when the coronavirus pandemic began and (experts) advised reproductive medicine professionals to temporarily limit infertility treatment,” declared Isabelle Horon and Joyce Martin written in the report.
The number of births involving a baby fell just 3% between 2019 and 2020, the authors said.
Overall, twin births did not increase significantly in 2021 from 2020 levels, although rates started to rise towards the end of the year.
The biggest drop in twin births was seen in women over 40, the group most likely to use fertility treatment. The smallest drop was seen in women younger than 30, who are least likely to use infertility treatment, the authors said.
The study cannot prove that the pandemic lockdowns led to a decline in twin births. In fact, the authors point out that Hispanic women experienced a greater decline in twinning rates than non-Hispanic white women, even though Hispanic women are less likely to receive infertility treatments.
At the start of the pandemic, the number of babies born prematurely or with dangerously low weight was lower than normal, the researchers noted.
Because twins are at higher risk for these outcomes, “the decline in twin births may have contributed, in part, to the reduction in preterm and low birth weight deliveries … between 2019 and 2020,” they said.
