#442 - [Journal Club] - 📌 Is a low Apgar score more concerning than a low umbilical pH in preemies?

Ben kicks things off with a major career update before we dive into a critical study from JAMA Network Open. We explore the predictive value of the five minute Apgar score when combined with umbilical artery pH in very preterm infants. While the Apgar score was originally designed for term babies, this analysis of the EPICE cohort reveals its enduring utility even in the smallest patients. We discuss how these two measures interact, which one "wins" when they conflict, and why the clinician assessment remains a powerful predictor of mortality and severe morbidity in the NICU.

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Apgar Score Plus Umbilical Artery pH and Adverse Neonatal Outcomes in Very Preterm Infants. Ehrhardt H, Behboodi S, Maier RF, Aubert AM, Ådén U, Staude B, Draper ES, Gudmundsdottir A, Siljehav V, Varendi H, Weber T, Zemlin M, Zeitlin J; EPICE/SHIPS Research Group.JAMA Netw Open. 2026 Feb 2;9(2):e2557913.

Transcript

Ben Courchia (00:00.598) Hello everybody, welcome back to the Incubator Podcast. We're back today for another episode of Journal Club.

Ben Courchia (00:00.598) Daphna, good morning. What is going on?

Daphna Yasova Barbeau (00:07.286) You tell me what's going on. I've had a very prolific week of Journal Club episodes.

Ben Courchia (00:14.518) It's been a prolific week of everything. Lots of things going on. Interestingly enough, I want to mention this because at this point it's going to be public news anyway. We both co-chair the pediatric division at Nova and I've officially resigned from my post, leaving you in charge.

Daphna Yasova Barbeau (00:19.086) I guess that's true. But tell us why. Are you allowed to tell us why?

Ben Courchia (00:44.756) Lots of new opportunities presented themselves and I wanted to pursue those. Most notably, I have been recently elected as the representative of District 10 for the AAP. I'm very excited about that. By the way, if you're in District 10—Georgia, Alabama, Florida, Puerto Rico—reach out to me. Use whatever contact information you see, go to the podcast email, and our administrator will forward those to me.

Ben Courchia (01:14.694) I'm hoping that this medium allows me to tell people that I am available and accessible. Let's see if we can have a good representation at the national level. There was a great Harvard Business Review article about how to sunset a project, and I feel like at some point there is a need to understand when you no longer should be doing something. Adding one more plate to juggle is not the right thing to do.

Ben Courchia (01:43.998) The nice thing to do for the university, for you, and for the team is to say, "I am no longer as available as I thought I was going to be, and it is time for me to close this chapter."

Daphna Yasova Barbeau (01:52.248) I think people would rather you do that than not be able to give it everything that is expected.

Ben Courchia (02:04.758) True, but then you think, "Oh my god, what if this other thing doesn't work out and I regret leaving?" But if you do this the right way, opportunity...

Daphna Yasova Barbeau (02:11.116) I could probably share it with you again if needed, if you had to come back.

Ben Courchia (02:17.332) If the decision was solely yours. But this is career evolution. Just do the things that you're interested in, and if you're no longer available for a group of people, do them the justice and the service of saying, "I'm no longer available."

Daphna Yasova Barbeau (02:37.624) Definitely agree with that. Well, congratulations, buddy. It's good news for us here in the district to have you at the helm.

Ben Courchia (02:45.93) I'm following in the footsteps of a giant here. On every front, a literal giant and a giant of our field. We'll see. Ravi Patel is going to probably move on to even greater things. The only reason I believe he is moving on is because you can only run for president so many times. He's been doing a great job. If he could have continued, he would have continued to do a good job.

Ben Courchia (03:15.062) So, that is what is up for today. Before we wrap up, let me just bring up quickly a paper. This is a paper found in JAMA Network Open. It is called, "Apgar Score plus umbilical artery pH and adverse neonatal outcome in very preterm infants." I am very interested just by the title alone.

Ben Courchia (03:43.786) The paper mentions that babies born very preterm, less than 32 weeks, have a high risk of morbidity: IVH, BPD, and long-term health difficulty over the life course. An unmet challenge for clinicians and researchers is to estimate an infant's risk of developing these morbidities to target preventive care. Patient characteristics and perinatal management—like gestational age, birth weight, fetal growth restriction, infection, whether you delivered at a tertiary center, and the receipt of antenatal steroids—are all variables established in the context of neonatal morbidity.

Ben Courchia (03:43.786) However, the accurate estimation of both short and long-term outcomes based on clinical items or biomarkers soon after birth remains an unmet need. The Apgar score, evaluated at 1, 5, and 10 minutes of life, is the first clinical assessment we do after birth in the delivery room. For term infants, there is a reliable association between a low 5-minute Apgar score and adverse neonatal outcomes, which we talked about extensively these past couple of weeks with HIE. This measure is increasingly used to assess risk, despite warnings from the community about its use to specify individual risk.

Ben Courchia (03:43.786) The accuracy of the 5-minute Apgar score for estimating in-hospital mortality decreases with declining gestational age. One of the reasons for this is the uncertainty about how to score preemies. The Apgar score at 5 minutes was not designed for a 23-weeker; it was designed for full-term infants, raising questions about the measure's utility in that population.

Ben Courchia (05:39.15) No association was detected between the 5-minute Apgar score and severe brain injury, like IVH or PVL, in the iNeo research collaborative looking at babies born 24 to 28 weeks. So the authors are thinking, what about the umbilical artery pH, which reflects acidosis and possibly hypoxemia immediately after birth?

Ben Courchia (06:04.554) We know that this is also associated with clinical outcomes. A low umbilical artery pH demonstrates a much better association with HIE in term infants. Whether adding this information to the Apgar score can improve risk estimation for adverse neonatal outcomes among very preterm infants has not been investigated. That is what we are going to look at today.

Ben Courchia (06:04.554) This is an analysis using data from the EPICE cohort. It included stillbirths and live births of babies born between 22 and 31 weeks of gestation in 19 regionally diverse regions in 11 European countries over a 12-month period between 2011 and 2012. The analysis sample contains all live births from this cohort with data on both the 5-minute Apgar and umbilical artery pH.

Ben Courchia (07:03.2) In terms of exposure, the studies used the 5-minute Apgar score and the umbilical artery pH. They prefer the 5-minute over the 1-minute Apgar, as the 1-minute score is notoriously unreliable. They used an Apgar score cutoff of 7, with scores lower than 7 having an association with poor outcome. They categorized umbilical artery pH as low (less than 7.2) or normal (7.2 or higher).

Ben Courchia (07:03.2) This creates a four-category variable: a good Apgar with a low pH, a good Apgar with a high pH, a bad Apgar with a bad pH, and a bad Apgar with a good pH. The main outcome was the combined outcome of mortality and any adverse morbidity comprising IVH grade 2 or more, cystic PVL, NEC requiring surgery, ROP greater than stage 2, and moderate to severe BPD.

Ben Courchia (07:03.2) The prevalence rates of retinopathy of prematurity was 2.8% and necrotizing enterocolitis was 2.0%. Because of that, they excluded these components, as the numbers were too low to pick up on changes. Three components were selected in the end: mortality, IVH, and BPD. It is a great lesson in statistics; if your baseline risk is low, you will have a hard time seeing differences.

Ben Courchia (09:24.854) Among the 10,000 plus infants in the EPICE cohort, 4,174 infants had data on both the 5-minute Apgar and the umbilical artery pH. They had a median gestational age of 29.9 weeks and a median birth weight of 1.24 kilos. 750 infants (18%) had an Apgar below 7, while 13.5% had a low umbilical artery pH.

Ben Courchia (09:24.854) When these combined: 8.8% had an Apgar score of 7 or higher but a low pH; 13.4% had an Apgar score lower than 7 but a normal pH; and 4.7% had an Apgar score lower than 7 with a low umbilical artery pH. Infants with an Apgar lower than 7 and a low pH were more likely to be from a singleton pregnancy and in the lowest gestational age stratum, below 24 weeks.

Ben Courchia (09:24.854) Pre-eclampsia/Eclampsia/HELLP syndrome was less frequently observed in infants with an Apgar score lower than 7, regardless of the pH. Meanwhile, cases with an Apgar score of 7 or higher and a low pH had the lowest frequencies of PPROM and congenital anomalies, and the highest rate of pre-labor C-section and being small for gestational age below the third percentile.

Ben Courchia (09:24.854) The group at highest risk of mortality and adverse morbidity had both an Apgar score lower than 7 and an umbilical artery pH less than 7.2. This was 55.1% of the population, followed by infants with an Apgar score lower than 7 and a normal pH at 48.4%.

Ben Courchia (11:25.172) You have said that these preemies are a little bit more accustomed to acidosis than their full-term counterparts, so it is not surprising that the Apgar score is carrying more of the lift here than the pH. Infants with an Apgar score of 7 or higher and a low pH had a higher proportion of the primary outcome than those with a good Apgar and a normal pH.

Ben Courchia (11:56.374) After adjustment, they found no difference in the composite mortality and morbidity outcome associated with an Apgar score lower than 7 and either low or normal umbilical artery pH. Regarding mortality specifically, the association was high between mortality risk and an Apgar score lower than 7 and a low pH (adjusted risk ratio of 2.4). Cases with low pH but an Apgar of 7 or higher had no increased risk of mortality.

Ben Courchia (11:56.374) When looking at IVH risk, the association was robust in cases of babies who had a low Apgar and a low pH (adjusted risk ratio of 2.5). An association was also found in infants with an Apgar score of 7 or higher and a low pH. For BPD, there was no association.

Ben Courchia (13:24.686) I asked Claude to make me a little table to summarize this. It is quite nice. If you are a little dizzy from this review, look at this table. We look at whether the Apgar is high or low, then it's subdivided into the pH. Having a low Apgar and a low pH represents the highest risk for in-hospital mortality, severe IVH, and the primary composite outcome.

Ben Courchia (14:22.356) I was thinking about it in terms of three buckets. If the Apgar is low and the pH is low, this should be the sickest patient. I was expecting the association to be high, which is what we see except for BPD. The lowest risk is if you have a good Apgar and a good pH. The extremes behaved the way you expect.

Ben Courchia (14:51.412) What was very interesting was when the two were competing. If you have a good Apgar and a bad pH or vice versa, the Apgar score wins. If you have a competing value, the Apgar indicates whether the risk is worse. Babies with Apgars less than 7 had a higher risk of death or severe morbidity, regardless of pH.

Ben Courchia (15:49.238) The conclusion is that in very preterm infants, the accuracy of the 5-minute Apgar score could be improved by combining it with the umbilical artery pH. Risk assessment models should consider adding these items. To me, the clinician assessment through the Apgar score still matters quite a lot, even in these smaller infants.

Ben Courchia (16:18.442) I have thought many times about the significance of scoring a baby on the Apgar score when they are this small, but you can see how it correlates quite nicely.

Daphna Yasova Barbeau (16:43.661) I think it still all depends on the fact that we don't have a good consensus about scoring. If you have an intubated ELBW, do you get two points for respiration? Do you get zero points?

Ben Courchia (17:04.149) Yeah, a baby at 27 weeks on CPAP—do you give them two? Technically they are doing exactly what they are supposed to do, but they are in respiratory distress. If they are a little bit cyanotic, do you give them just one point? You will never see a preemie on CPAP get a 10. That doesn't exist.

Daphna Yasova Barbeau (17:39.737) Well, even the term baby with acrocyanosis is doing exactly what they're supposed to do.

Ben Courchia (17:44.97) We reviewed a paper called, "Nine is the new 10 of Apgar scores," in episode 220. That is how good the website is. In a few seconds, I found it by clicking on the resuscitation icons and the Journal Club tab.

Ben Courchia (18:44.086) All right, buddy, I'll see you tomorrow.

Daphna Yasova Barbeau (18:44.207) All right. I guess when they're bugging us during resuscitation for Apgar scores, we shouldn't be so annoyed. We should pay attention.

Ben Courchia (18:49.622) Pay some attention. If you're hesitating between eight and nine, you're fine. But a six versus an eight looks like an important difference. All right, everybody, I'll see you tomorrow.

Daphna Yasova Barbeau (19:03.673) Bye.