The nationwide baby formula shortage that has sent parents scrambling for supplies has been building in earnest for more than two months, new data shows.
Retailers that sell baby formula have been losing ground on sales due to supply constraints, according to NielsenIQ's on-shelf availability barometer, a measure that shows how a product's revenue compares to retailer expectations.
The metric shows that nationwide baby formula availability has fallen steadily from November to April 30, the most recent week of data available. In March, restrictions were tightened after the recall of major formula brands.
The baby formula shortage is more acute in certain states, with Iowa, Kentucky, Louisiana and West Virginia showing the lowest on-shelf availability rates in the country. Colorado, New Mexico and Arkansas have the highest formula availability rates.
In February, the U.S. Food and Drug Administration began investigating baby formula after four infants contracted serious infections and one died. In March, Abbott Laboratories recalled several formula brands and shut down the company's Michigan plant. Abbott and the FDA will reopen the plant on Tuesday.
Data from the Centers for Disease Control and Prevention shows that approximately 2 in 10 newborns receive formula in their first two days of life.
FDA commissioner Robert Califf said on Thursday that parents should see supply relief in the coming days due to increased manufacturing and a bump in formula imports. President Joe Biden invoked the Defense Production Act to ease the shortage on Wednesday, which means that the federal government will compel formula production suppliers to prioritize formula manufacturers over other customers when it comes to goods and resources.