The biggest declines were in November and December 2020 and January 2021, when twin birth rates fell by 10%, 14% and 7%, respectively, compared to a year earlier.
Isabel Horon and Joyce Martin wrote in the report, “The timing of monthly declines in late 2020 and early 2021 coincides with the period when the coronavirus pandemic began and (experts) recommended that reproductive medicine professionals temporarily limit the treatment of infertility to
The authors noted that the number of single births declined by only 3% from 2019 to 2020.
Overall, twin births did not increase significantly in 2021 from 2020 levels, although rates began to rise near the end of the year.
The biggest decline in the birth of twins was seen among women over the age of 40, the group most likely to have used infertility treatments. The smallest declines were among women under 30, who are less likely to have used infertility treatments, the authors said.