← All notes

Signs of Jaundice in Newborns: What to Look For, When to Call Your Pediatrician, and What Happened to Us

2026-04-19 · Warren, founder of Hey Susan · 8 min

Not medical advice — please consult your pediatrician. Hey Susan is an AI assistant, not a doctor. In an emergency, call 911 or your local emergency number.

This post is not medical advice. We are parents, not doctors. If you are reading this because something feels off with your baby, please stop reading and call your pediatrician or nurse hotline now. They would much rather take a "false alarm" call at 2 a.m. than miss a real one. When in doubt, go in.

The short version (structured summary)

What is newborn jaundice? Jaundice is a yellow tint to a baby's skin and the whites of their eyes caused by bilirubin, a pigment that builds up when a newborn's liver is still learning to clear it. About 60% of full-term and 80% of preterm babies develop some jaundice in the first week of life.

The signs most pediatricians say to watch for in the first 7 days:

Call your pediatrician (or the after-hours nurse line) the same day if:

  1. Your baby looks yellow below the chest, especially on the legs or palms.
  2. Your baby is "too good" — sleeping through feedings, not crying to eat.
  3. Your baby has had fewer wet or dirty diapers than expected for their age in days.
  4. Jaundice appears in the first 24 hours of life, or gets worse after day 3.
  5. Anything feels off and you cannot shake the feeling.

Call 911 (or your local emergency number) immediately if your baby is limp, hard to wake, not breathing normally, having a seizure, or has a fever over 100.4°F (38°C) and is under 3 months old. Do not wait for the pediatrician to call you back.

Keep reading for the longer version, the founder story that made us build Hey Susan, and a simple printable checklist you can stick on the fridge.

Why I'm writing this post

My name is Warren. I'm not a pediatrician. I'm a dad. The reason Hey Susan exists is that in our son's first week of life, my partner and I nearly missed the signs of his jaundice.

We were exhausted. He was a "good baby" — he slept a lot. He nursed, but not for long. He had fewer diapers than our books suggested, but he had some, and we told ourselves it was the normal first-week dip. Our pediatrician had told us at discharge to "watch for yellow." We were watching. In the yellow light of a nursery at 3 a.m., with a baby wrapped in a yellow swaddle, everything looked a little yellow and a little fine.

At 3 a.m. on day 4, not sure who to call, we ended up describing what we were seeing to ChatGPT. It actually helped — it suggested the pattern lined up with jaundice and that we should get him checked. We booked the earliest appointment. At his 5-day well-check, his bilirubin came back high enough that we were sent straight to the hospital for phototherapy. He was okay. The nurses were not dramatic about it. They had seen this a thousand times. But I sat in that hospital chair and thought: nobody had told us to count the diapers. Nobody had told us that "too sleepy to eat" was a sign. Nobody had told us to strip him down and look at him in real daylight, not nursery-light. And the only reason we'd gone in was because, at 3 a.m., we'd remembered to open a chatbot and ask — a chatbot that had no memory of our baby between sessions, and no way to check in on us on its own.

So I built the assistant I wish we'd had. Hey Susan is a text-message nanny for new parents — she tracks feeds and diapers, is there when you're too tired to check in with yourself, and flags patterns that your pediatrician would want to know about. She is not a doctor. She is not a medical device. She is the assistant who is always up at 3 a.m. and remembers what day it is when you don't.

Join the Hey Susan waitlist →

What jaundice actually is, in plain English

Before a baby is born, they get oxygen from mom via the placenta using a form of red blood cell that is efficient in the womb but not as useful in open air. In the first days of life, those red blood cells get broken down and replaced. The leftover pigment from that breakdown is called bilirubin. The liver is supposed to process it and pass it out through stool. A newborn's liver is still ramping up. So bilirubin builds up in the blood and stains the skin and eyes yellow.

For most babies, this is mild, peaks around day 3 to day 5, and resolves on its own as the baby eats, poops, and grows. For some babies, bilirubin climbs higher than the liver can keep up with. If it climbs very high and stays there, it can cross into the brain and cause permanent damage — a rare but serious condition called kernicterus. This is the reason every modern hospital screens for jaundice before discharge and at the first pediatric check.

This is why the poops and pees matter so much. Bilirubin leaves the body in stool and, to a lesser extent, urine. A baby who isn't eating isn't pooping. A baby who isn't pooping is recirculating bilirubin back through their gut. Feeding and output are the intervention. This is the part I wish we had understood in week one.

The signs of jaundice in the first 7 days

These are the signs most pediatricians, lactation consultants, and NICU nurses list. I am reproducing them here because I could not find a single plain-language list when I needed one at 3 a.m. Please still ask your own pediatrician what to watch for — babies vary, and this list is a starting point, not a substitute.

1. Yellow skin, starting at the face and moving down

Jaundice typically appears first on the face, then the chest, then the belly, and finally the arms and legs. A rough rule many nurses teach: if the yellow has reached below the chest, it's time to call. If it's reached the palms of the hands or the soles of the feet, it's time to be seen today. Check your baby in natural daylight, not under the warm bulbs of a nursery. Press lightly on the forehead, nose, or sternum — if the skin blanches yellow instead of white, that's worth noting.

2. Yellow in the whites of the eyes

Easier to spot than skin color, especially on babies with darker skin tones where skin jaundice can be missed. The whites (sclera) should be white. If they're tinted yellow, write it down and mention it at the next check.

3. "Too good" — sleepy, hard to wake, not demanding

A jaundiced baby is often a sleepy baby. If you are saying things like "I wish she'd wake up to eat" or "He's such an easy baby, he just sleeps" in the first week, take that seriously. Newborns are supposed to wake to eat every 2 to 3 hours, including through the night. A baby who sleeps through feedings in week one is not "a good sleeper." That baby may need to be woken, undressed, and fed.

4. Poor feeding

Weak latch, short nursing sessions, falling asleep at the breast or bottle, taking less than expected. Bottle-fed babies on day 3 are typically eating around 1.5 to 2 ounces per feed every 2 to 3 hours. Breastfed babies should be having audible swallows and should seem satisfied afterward. If you are feeding and feeding and the baby still seems unsatisfied or is too tired to finish — call.

5. Too few wet and dirty diapers

This is the one we missed. Rough expectation for the first week, counted from the day of birth:

Fewer diapers than this is a reason to call. You do not need to wait until the next well-check. Count them. Write them down. A running tally on your phone is enough. This is exactly the kind of pattern Hey Susan watches for you — but even a scrap of paper on the changing table will do.

6. High-pitched cry, arched back, limpness, or fever

These are late, urgent signs. If you see them, call your pediatrician or go to the emergency room immediately. A newborn under 3 months with a fever over 100.4°F (38°C) is always an ER trip, jaundice or no jaundice.

When to call the pediatrician, and what to say

Pediatric offices are used to this call. You are not wasting their time. When you call, they will ask you roughly:

Write these down before you call. You will forget if you try to hold them in your head. If your office is closed, most health plans have a 24/7 nurse advice line, and many hospitals have a postpartum or lactation line that will take the call.

If you cannot get through and something feels wrong, go to the emergency room. Bilirubin tests are quick. Reassurance is free. A missed high-bilirubin case is not.

What the treatment looks like

For most babies with elevated bilirubin, treatment is phototherapy — blue-spectrum light that helps the body break down bilirubin through the skin. This usually happens in the hospital for 24 to 48 hours, sometimes with a wearable "bili-blanket" at home. The baby lies under the lights in a diaper and tiny eye protectors. Feeding continues. It is not painful. It is not scary in the way it looks on first encounter.

For a small minority of babies with very high bilirubin, an exchange transfusion is used. This is rare, and the reason every hospital screens aggressively before discharge is specifically to avoid ever needing one.

A printable first-week diaper and feeding checklist

Copy this into your notes app or print it and stick it on the fridge.

Day ____ — Date ____

  • Wet diapers so far: ____ (target: at least equal to day number, minimum 6 from day 5)
  • Dirty diapers so far: ____ (target: at least 3 from day 3)
  • Stool color today: black / green / yellow / other: ____
  • Feeds in last 24h: ____ (target: 8–12 for newborns)
  • Baby wakes on own to eat: yes / no
  • Skin color in daylight: normal / yellow on face only / yellow below chest / yellow on legs or palms
  • Whites of eyes: white / yellow
  • Anything that felt "off" today:

If any row looks wrong for your baby's age in days, call.

How Hey Susan helps (and what she won't do)

Hey Susan is a messaging-app assistant — you text her on Telegram like you'd text a friend. She does three things, on purpose:

  1. She tracks what you tell her. Feeds, pees, poops, how you're feeling. No app to open, no form to fill out. You type "fed 2oz" and she logs it. At the end of the day she can show you a summary — the kind of summary we did not have when we were staring at a sleepy baby and trying to remember whether we'd seen three wet diapers or four.

  2. She checks in on you — proactive check-ins ship as a launch feature. A gentle nudge every few hours in the newborn stage, less often as things stabilize: if you haven't logged a feed in six hours, she'll ask; if the last stool was 36 hours ago, she'll ask. The idea is to be proactive the way a good postpartum doula or night nurse is proactive — never nagging. Until then, message her anytime and she's there.

  3. She nudges you toward your pediatrician when patterns look off. If your baby hasn't eaten, hasn't pooped, hasn't peed, and is hard to wake — Susan will say something, and the something will include the phrase "I am not a doctor, and you should call your pediatrician." She will never diagnose. She will never tell you it's definitely jaundice or definitely anything. She will notice when we missed it.

Hey Susan is explicitly not a medical device, not a childcare provider, and not a substitute for professional medical advice. She is an assistant. The diaper log is yours. The decision to call is yours. She just helps you see it.

Join the Hey Susan waitlist →

Frequently asked questions

Is a little bit of jaundice normal?

Yes. Most full-term babies have some degree of visible jaundice between day 2 and day 5. The question pediatricians care about is not "is there any yellow?" but "how high is the bilirubin, and is the baby feeding and pooping enough to clear it?" That's why every newborn gets a heel-stick bilirubin screen before leaving the hospital and typically another at the first well-check.

My baby was fine at discharge — can jaundice appear after?

Yes. Bilirubin typically peaks between day 3 and day 5, which is often after you've been sent home. This is exactly why the first pediatric visit happens within 48–72 hours of discharge, and why you should keep the appointment even if your baby "seems fine."

Does breastfeeding cause jaundice?

There is a specific pattern called breastfeeding jaundice that happens when the baby isn't getting enough milk in the first week — not because of breastfeeding itself, but because of under-feeding. The fix is more feeding, not less breastfeeding. A lactation consultant (your hospital usually has one on staff for free in the first month) can help. There is also a rarer, later pattern called breast-milk jaundice, which is usually benign and lasts longer but is managed differently. Your pediatrician will know the difference.

Are babies with darker skin tones at higher risk of missed jaundice?

Yes — visual skin-color assessment misses jaundice more often on darker-skinned babies, which is why the screen uses a transcutaneous bilirubinometer (a small light on the forehead) or a blood test, not just eyeballing it. If your baby has a darker complexion, check the whites of the eyes, gums, and palms, and insist on objective screening at the first well-check. Your pediatrician should already be doing this.

What's the difference between jaundice and just a tan from the sun?

Newborns should not be in direct sun. If your baby's skin looks yellow, assume jaundice and ask, rather than assuming sun exposure.

One last thing

If you are reading this at 3 a.m. on day 4 with a sleepy baby and a nagging feeling — listen to the feeling. Call. The worst that happens is the nurse says "she sounds okay, here's what to watch for tonight." The best that happens is you catch something early. Nobody regrets the call they made. We regretted the call we almost didn't make.

Take care of yourselves. You are doing better than you think.

— Warren and the Hey Susan team

Sources and further reading

Last updated: 2026-04-19. If you're a pediatrician, lactation consultant, or NICU nurse and spot something in this post that could be clearer or more accurate, please email hi@heysusan.app — this is a living document.

Where this fits in Hey Susan's safety framework. Jaundice paired with a drop in wet-diaper count is what our safety framework calls an L2 — same-day nudge pattern that can escalate quickly in the first days — so Susan names it and tells you to get same-day eyes on your baby (a pediatrician call or visit), not a wait-and-see. Because she's tracking the feeds and wet diapers alongside it, the trend is visible instead of buried in memory; she points you to a clinician and never diagnoses on her own.

This is not medical advice. If your baby's skin or eyes look increasingly yellow, or your baby is hard to wake or feeding poorly, call your pediatrician or your local emergency number today.

Remember: this post is not a substitute for a conversation with your pediatrician. If you're worried about your baby, call them. Full medical disclaimer →