Women in the United States are having fewer babies than ever before — and much later in life, according to data released by National Center for Health Statistics.
Researchers found that the total number of births per 1,000 women between the ages of 15 and 44 dropped from 62.5 per 1,000 in the first quarter of 2016 to 61.5 per 1,000 in the first quatert of 2017.
That drop by one percentage point is too big of a decline to happen by chance, Brady Hamilton, an expert on fertility data, said to CNN.
But while birth rates for teenagers and those under the age of 30 declined to record lows, there was actually an increase in birth rates among women 30 or older.
The birth rate for women ages 35 to 39 rose by two percentage points, hitting the highest level for that age group since 1962.
Overall, the decrease in birth rates technically puts the United States population below replacement level, Hamilton said — “but not dramatically so.”
“We have a high level of influx of immigrants that compensates for it,” he said.
The study was conducted with birth certificates, which means that researchers do not know the reasons behind the declining birth rates.
But they have a few ideas: women placing more emphasis on their careers or economic struggles.
Much of the decline seems to come voluntarily, Dr. Alan Copperman, director of the division of reproductive endocrinology and infertility at Mount Sinai Medical Center, told CNN.
“We see more and more women entering the workforce and delaying childbearing,” he said. “They're having a lower birth rate electively.”
But because women are having children later in life, Copperman said it is important to focus on educating women about family planning options.
That would help fight “reproductive challenges that are facing women as they try to conceive,” especially among older women, he said.
The unprecedented drop in birth rates comes after another study found that sperm count in Western men is quickly dropping with no sign of “leveling off.”
Researchers tracked sperm count in men from North America, Europe, Australia and New Zealand, finding that sperm concentration had dropped by 52.4 percent during that time period.