Three tests will be done on your baby that nobody asked you about
A heel prick, a hearing test and an oxygen probe. In one US study, only about a third of parents whose baby needed a repeat screen knew why.
Before you leave hospital your baby will be screened three separate ways. Most parents find out when it happens. The national review of newborn screening published in 2025 says so in its own words: parents may learn about newborn screening before the birth of their child, or they may not know of its existence until a nurse comes to collect a blood spot from their newborn, or they may never know.
1. The heel prick, or dried blood spot. It covers about 3.6 million US babies a year, run by 56 separate state and territory public health programmes. The same review states: In most programs, there is no formal opt-in process, although families do have the option of opting out in most jurisdictions.
The federal recommended list holds 34 core conditions and 25 secondary ones, last updated in July 2024. One thing to know about who maintains it: the federal page carrying that list states that the advisory committee responsible for it was terminated as of March 2025
and that the page is no longer active
. What that means for how the list will be updated from here was not resolved at the time this was written, so this guide makes no claim that the panel's governance is as it was. If that matters to you, check the current federal position rather than relying on this page or any other.
What the heel prick finds. Pooled confirmed cases from 49 states and 2 territories give a birth prevalence of 20.07 per 10,000 babies for the core conditions on the list, for 2018 to 2020. That is about 1 in 500 (that conversion is arithmetic done here). The commonest were congenital hypothyroidism at 6.69 per 10,000, sickle cell disease at 4.98 per 10,000 and cystic fibrosis at 2.29 per 10,000. The paper reporting those rates gives three different annual counts of babies in three different places, so no annual count is quoted here, only the rate.
How often the heel prick raises a false alarm is not known nationally. The same analysis states plainly that more work is needed before birth prevalence and other metrics, such as positive predictive value, can be more accurately determined
. Older national figures exist but are from data collected in 1993 and 1994, before the current technology, and cannot honestly be presented as current. So: false alarms are common enough to be a recognised problem, and no current US rate for them could be verified.
2. The hearing screen. These are the national figures for babies born in 2022, the most recent year that could be verified.
| US babies born in 2022, 55 state and territory programmes | Number | Rate |
|---|---|---|
| Births reported | 3,616,776 | |
| Screened | 3,547,774 | 98.1% |
| Did not pass the final screen | 62,508 | 1.8% of those screened |
| Completed a diagnostic evaluation | 35,940 | 55.2% of those needing one |
| Of those evaluated, hearing turned out typical | 29,668 | |
| Confirmed deaf or hard of hearing | 6,272 | 1.7 per 1,000 births |
| Lost to follow-up or documentation | 22,146 | 34.0%, range 0.0% to 83.2% by jurisdiction |
So about 18 in every 1,000 screened babies are told their baby did not pass, and about 1.7 in every 1,000 births turn out to be deaf or hard of hearing. Of those who did complete a full evaluation, 29,668 of 35,940 had typical hearing (that comparison is arithmetic done here). The great majority of families given that news have a baby who hears normally. And more than a third of families never complete the follow-up at all, which is the part of this system that is genuinely not working.
3. The oxygen probe, for critical heart defects. These affect about two of every 1,000 births
. The test was added to the recommended list in 2011, and by 2018 all 50 states and DC had screening policies. Pooling 13 studies covering 229,421 babies, it detects 76.5% of critical heart defects (95% confidence interval 67.7 to 83.5) with a false alarm rate of 0.14%, which is about 14 per 10,000 babies screened (that conversion is arithmetic done here). Timing matters a lot: screened after 24 hours of age the false alarm rate was 0.05%; before 24 hours it was 0.50%, ten times higher.
Does it work? Comparing states before and after they made screening mandatory, across 26,546,503 US births, early infant deaths from critical heart defects fell by 33.4% in relative terms, which was an absolute fall of about 3.9 deaths per 100,000 births. States with voluntary policies showed no significant decrease.
Now the human cost, which is measured. A US study compared parents of 173 infants with a false-positive screening result against parents of 67 children with normal results. The false-positive group scored higher on parenting stress overall, and on the parent-child dysfunction and difficult child measures. The finding that should change how this is done: Only approximately one third of parents in the false-positive group reported knowing the correct reason for repeat screening.
Mothers who did know the correct reason had less stress than those who were misinformed, not informed, or could not remember. A review of this literature adds that raised anxiety has been found even after the infant's good health is confirmed
.
"Can the hearing screen be done after 24 hours, and can the oxygen test be too?"
"If a result is abnormal, who calls me, how soon, and what happens next?"
"How often does a repeat test on this screen turn out to be nothing?"
"Who makes sure the follow-up appointment actually happens?"