Catching a Rare Liver Condition in the First Weeks of Life

What a large review of newborn screening studies and a hospital's new step-by-step pathway mean for babies with biliary atresia and the families who care for them

Biliary atresia is a rare liver condition in newborns in which the tubes that carry bile out of the liver become blocked. Surgery works best when it happens in the first six weeks of life, but most babies are still diagnosed later than that. Two recent studies suggest that a simple blood test already collected in the newborn nursery — followed, in one hospital's approach, by a short ultrasound — could find these babies weeks earlier.

Why a few weeks make such a difference

Bile is a fluid the liver makes to help digest fat. It normally travels out of the liver through small tubes called bile ducts and into the intestine. In biliary atresia, those tubes outside the liver do not stay open. Bile backs up, and over months it scars the liver. Roughly four out of five children with this condition eventually need a liver transplant [1].

There is an operation that helps. It is called the Kasai portoenterostomy, and it connects the liver directly to the intestine so bile has a route out. The catch is timing. A large study from France found that when the operation was done within the first 46 days of life, about 65 out of every 100 children were still living with their own liver at two years of age [2]. Done later, the odds get worse. That is an unusually sharp deadline in medicine, and it is the reason so much effort has gone into finding these babies sooner.

The problem is that a newborn with early biliary atresia looks like a lot of other newborns. Jaundice — a yellow tint to the skin and the whites of the eyes — is extremely common in the first weeks, and in most babies it is completely harmless [3]. There is no way to tell by looking. Biliary atresia is also rare — fewer than 10 babies in every 100,000 born in the United States, according to national figures [4] — so a doctor in general practice may see one case in an entire career.

What families used to face

For decades, the way biliary atresia was found was simply that someone eventually noticed. A parent kept mentioning the yellow colour. A stool looked oddly pale. A visit got moved up. Because that process depends on chance and persistence, it was slow. A study of children across several United States centres found that, on average, babies were referred to a specialist at 53 days of life and had surgery at 61 days [5] — after the window in which the operation works best had already begun to close.

The first organised attempt to change this came from Taiwan and Japan in the 2000s. Parents were given a printed card showing photographs of normal and abnormal stool colours, and asked to compare their baby's nappies against it in the first weeks. Nationwide, this worked: babies were diagnosed earlier and more of them kept their own livers [6][7]. But the stool card has a built-in delay. Stools only turn pale once the blockage has been building for a while — in one analysis, only about three-quarters of affected babies had pale stools by 30 days of life [8]. When the American Academy of Pediatrics reviewed the whole question in 2015, it concluded that there was not yet enough evidence to recommend screening every newborn [9].

The clue hiding in a routine blood test

What changed the conversation was a discovery about a specific blood measurement. Bilirubin is the yellow pigment behind jaundice, and it comes in two forms. Most newborn jaundice involves the "unconjugated" form, which is normal and temporary. The other form — called direct or conjugated bilirubin — rises when bile is not draining properly. Researchers found that babies with biliary atresia already have elevated direct bilirubin in their first 24 to 48 hours of life, long before anyone could tell by looking [10].

That matters practically, because most newborns already have blood drawn in the first two days for the standard newborn screen and, in many hospitals, for a bilirubin check before going home. The direct bilirubin can often be measured on that same sample, with no extra heel prick [11].

What the large review of screening studies found

In 2024, a research team based at Baylor College of Medicine and Texas Children's Hospital, working with colleagues at the University of Pennsylvania and the University of Birmingham in the United Kingdom, pulled together every population-wide study of newborn screening for biliary atresia they could find [12]. This kind of study is called a systematic review with meta-analysis: rather than running a new experiment, the researchers combine results from many existing studies to get a clearer overall picture.

They ended up with 15 studies covering more than 1.8 million babies, testing five different screening approaches. The direct bilirubin blood test came out strongest. Across five studies and about 662,000 babies, it identified every case of biliary atresia that was present — a sensitivity of 100% — and correctly gave a normal result for about 98.8% of babies who did not have it. The researchers rated the quality of that evidence as "high," the top of the scale they used. Stool colour cards, tested in seven studies covering nearly a million babies, found about 80% of cases. Three other approaches had been tried in only one study each, so there was not enough evidence to judge them [12].

There is an important caveat in those numbers, and the researchers spelled it out honestly. Because biliary atresia is so rare, even a very accurate test produces a lot of false alarms. In an imaginary group of 100,000 newborns, they calculated that the blood test would miss no babies with the condition but would flag roughly 2,000 babies who turn out not to have it [12]. Their view was that for a condition this serious and this time-sensitive, missing no one is worth the extra follow-up testing — but it does mean a screening programme has to be built to handle those follow-ups well.

What a hospital pathway built on that finding looks like

That is the gap the second paper addresses. In 2026, a team at Texas Children's Hospital in Houston — a large children's hospital, working with colleagues at Baylor College of Medicine and Stanford University — published the step-by-step approach they had developed [13].

Their pathway has two steps. The first is the direct bilirubin blood test in the nursery, with results interpreted using a free website called BiliScreen.org, which works much like the online tools clinicians already use to decide whether a newborn needs light therapy for ordinary jaundice. For babies who did not have a normal result recorded earlier, a 2025 American Academy of Pediatrics report asks the paediatrician to check this blood test at the one-month visit if the baby still has jaundice after two weeks, has pale stools, or had a high reading earlier [14].

The second step is what is new: a "feeding ultrasound." Ultrasound scans of the liver have traditionally required a baby to fast for about four hours, which is uncomfortable for the baby and hard to schedule. In this approach, the baby feeds just before or during the scan, which actually makes the key structure easier to see. The sonographer looks for a small duct near the liver's entrance and measures the thickness of a bright band of tissue above a nearby vein. Among 64 babies with a high bilirubin result, every one of the five with a thickened band turned out to have biliary atresia, and 49 babies had a visible duct — none of whom had the condition [13]. In other words, a short, non-invasive scan sorted most babies out of the worry group without any procedure requiring anaesthesia [15].

What a positive screen actually means for your baby

If your newborn's screening result comes back high, it is worth knowing what that number does and does not mean. Most babies with a high direct bilirubin do not have biliary atresia. Many simply need one repeat blood test a couple of weeks later that comes back normal. In one hospital's programme, out of 3,861 babies screened, 53 had a raised initial result, and after repeat testing only 12 needed to see a specialist — and biliary atresia was ruled out at an average of 28 days of life [16].

Some of the babies who do turn out to have a liver problem have a different one — conditions such as Alagille syndrome or alpha-1 antitrypsin deficiency. Finding those early is also valuable, because children with any kind of bile flow problem can become short on vitamins that need bile to be absorbed, and that is straightforward to treat once it is known about [13].

What researchers are working on next

Three questions are open. The first is proof of benefit: no study has yet randomly assigned babies to be screened or not and then followed them for years, so the case for screening still rests on the strong link between earlier surgery and better outcomes rather than on a direct trial. The second is cost. Existing estimates were made before the feeding ultrasound existed and assumed a more expensive workup than is now needed, so those calculations are being redone [17]. The third is fairness. Black and Hispanic infants have been diagnosed later on average than other children [18], and universal newborn screening is one of the few approaches that could reduce that gap — but only if every family reliably gets their result and their follow-up appointment, not just the families easiest to reach.

For now, the practical takeaway for parents is small and specific: if your baby is still yellow after two weeks of age, or if the stools look pale or chalky, ask for a direct bilirubin blood test. It is one ordinary test, and in the small number of babies for whom it matters, it can move a diagnosis forward by weeks that count.

References

  1. Fanna M, Masson G, Capito C, et al. Management of Biliary Atresia in France 1986 to 2015: Long-term Results. Journal of Pediatric Gastroenterology and Nutrition. 2019;69(4):416–424. doi:10.1097/MPG.0000000000002446 ↩
  2. Serinet MO, Wildhaber BE, Broué P, et al. Impact of age at Kasai operation on its results in late childhood and adolescence: a rational basis for biliary atresia screening. Pediatrics. 2009;123(5):1280–1286. doi:10.1542/peds.2008-1949 ↩
  3. Maisels MJ, Clune S, Coleman K, et al. The natural history of jaundice in predominantly breastfed infants. Pediatrics. 2014;134(2):e340–e345. doi:10.1542/peds.2013-4299 ↩
  4. Hopkins PC, Yazigi N, Nylund CM. Incidence of Biliary Atresia and Timing of Hepatoportoenterostomy in the United States. The Journal of Pediatrics. 2017;187:253–257. doi:10.1016/j.jpeds.2017.05.006 ↩
  5. Shneider BL, Brown MB, Haber B, et al. A multicenter study of the outcome of biliary atresia in the United States, 1997 to 2000. The Journal of Pediatrics. 2006;148(4):467–474. doi:10.1016/j.jpeds.2005.12.054 ↩
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  7. Gu YH, Yokoyama K, Mizuta K, et al. Stool color card screening for early detection of biliary atresia and long-term native liver survival: a 19-year cohort study in Japan. The Journal of Pediatrics. 2015;166(4):897–902. doi:10.1016/j.jpeds.2014.12.063 ↩
  8. Lien TH, Chang MH, Wu JF, et al. Effects of the infant stool color card screening program on 5-year outcome of biliary atresia in Taiwan. Hepatology. 2011;53(1):202–208. doi:10.1002/hep.24023 ↩
  9. Wang KS; Section on Surgery, Committee on Fetus and Newborn, Childhood Liver Disease Research Network. Newborn Screening for Biliary Atresia. Pediatrics. 2015;136(6):e1663–e1669. doi:10.1542/peds.2015-3570 ↩
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