You're at the tail end of the second trimester. Things are getting real. When you look at a picture of a 23 week fetus, it isn’t just a grainy blob or a shrimp-looking thing anymore. It looks like a person. Honestly, it’s a little startling how much detail is there. If you could peek inside right now, you’d see a baby that is roughly the size of a large grapefruit or maybe a bunch of grapes, weighing in at about a pound and a person-like 11 inches from head to heel.
But the image tells a deeper story than just size.
At 23 weeks, the skin is still a bit translucent. It has a reddish or pinkish hue because the capillaries are starting to show through. It’s wrinkly, too. The baby hasn’t quite put on that "baby fat" that makes newborns look like little marshmallows, so they’re still kind of skinny and slight. They’re basically a work in progress, but the blueprint is fully visible.
The face you’re starting to recognize
The face is what usually gets people. By the time you’re looking at a 4D ultrasound or a high-resolution picture of a 23 week fetus, the features are remarkably distinct. The nostrils are forming. The lips are clearly defined. It’s not just a generic face; it’s their face.
The eyes are fully formed, though they are still fused shut. They won't pop open for a few more weeks. Even so, the baby is sensing light. If you were to shine a bright flashlight on your belly, they might actually turn away. It’s wild to think about, right? There’s a whole sensory world happening in there while you’re just trying to find a comfortable sitting position.
💡 You might also like: Foods to Eat to Prevent Gas: What Actually Works and Why You’re Doing It Wrong
And the hair? It’s there. Lanugo—that fine, downy hair—covers most of the body to keep them warm. It’s weird, but it serves a purpose. Sometimes you can see the faint outline of eyebrows or even the tiniest bit of hair on the scalp in high-quality imaging.
What’s happening under the surface
A picture doesn't show you the noise. But if it could, it would be loud. At 23 weeks, the inner ear bones have hardened. The baby can hear you. They hear your heartbeat, sure, but they also hear the dog barking or the vacuum cleaner. They might even jump if a door slams.
The lungs are the big focus for doctors at this stage. They are developing "surfactant," which is basically the lubricant that allows the air sacs to inflate once they hit the outside world. This is the "viability" window. While 23 weeks is incredibly early, modern NICUs, like those at the Mayo Clinic or Children’s Hospital of Philadelphia, have seen survival rates climb for babies born at this gestation. It’s a delicate balance, though, because those lungs are still so incredibly fragile.
Pancreas development is also hitting a stride. It’s starting to produce insulin. The brain is growing millions of neurons. It’s a literal construction site in there.
📖 Related: Magnesio: Para qué sirve y cómo se toma sin tirar el dinero
Why 23 week ultrasounds look different
If you go in for a scan now, you might notice the baby is incredibly active. They have enough room to do literal somersaults. You’ll see them sucking their thumb or grabbing the umbilical cord. It’s not just random twitching; it’s purposeful movement.
Sometimes the picture of a 23 week fetus looks a bit "skeletal" to parents. Don't freak out. That's just because the fat deposits—the subcutaneous fat—haven't filled in yet. They’re basically a tiny, lean athlete right now. The bones are also ossifying, or hardening, which is why they show up so clearly on the white parts of an ultrasound.
Real talk about viability and the 23-week mark
This is a heavy topic for some. In the medical world, 23 weeks is often cited as the lower limit of viability. According to a study published in the New England Journal of Medicine, babies born at 23 weeks have a chance, but it requires intensive, high-level neonatal care.
- Survival rates vary wildly based on the hospital's equipment.
- Long-term health outcomes are a major discussion point between parents and neonatologists at this stage.
- Every day in the womb counts for lung and brain maturation.
It’s a miracle of modern science that we can even talk about survival at this point. A few decades ago, this wasn't even a conversation.
👉 See also: Why Having Sex in Bed Naked Might Be the Best Health Hack You Aren't Using
The "practice" breathing
One of the coolest things you might see on a live ultrasound "picture" is chest movement. The baby isn't breathing air, obviously—they’re in a bag of salt water. But they are practicing the motion of breathing by inhaling and exhaling amniotic fluid. It’s like a rehearsal for opening night.
This helps the lungs develop and expand. If they get a little too much fluid, they might get the hiccups. You’ll feel those as rhythmic little taps. It’s one of those things that makes the whole experience feel less like a medical event and more like a relationship.
Navigating the emotions of the image
Seeing your baby at this stage is an emotional rollercoaster. You might feel a rush of "oh my god, that’s a human," or you might feel terrified because they look so small and vulnerable. Both are totally normal.
Experts like Dr. Catherine Spong, a specialist in maternal-fetal medicine, often point out that the second trimester is the "honeymoon phase" for a reason. You’re likely feeling more energy, and seeing that 23-week progress is a huge psychological milestone. It makes the upcoming third trimester feel manageable.
Practical steps for your 23rd week
If you’re looking at these pictures or preparing for a scan, here’s what you actually need to do. Forget the generic advice; focus on the biology.
- Boost your Iron: Your blood volume has expanded massively. You need the iron to prevent anemia, which is common right now.
- Talk to the Bump: Since the ears are functional, start that bonding. It sounds cheesy, but they’ll recognize your voice when they come out.
- Watch for Regularity: You don't need to do formal "kick counts" yet (that’s usually week 28), but get to know their patterns. Do they wake up when you eat spicy food? Do they move when you lie down?
- Plan the Big Scan: If you haven't had your anatomy scan, do it now. It's the most detailed picture of a 23 week fetus you'll get, checking the four chambers of the heart and the kidneys.
Don't get hung up on "perfect" ultrasound photos. Sometimes the baby is shy and hides behind the placenta, or they have their hands over their face. It’s not a photo shoot; it’s a check-up. The fact that they are moving, growing, and developing those tiny fingernails is the real win. Focus on the growth, stay hydrated, and try to wrap your head around the fact that in about four months, that little person in the picture is going to be keep you up all night. It’s a wild ride.