Week 38 of Pregnancy: Your Baby Is the Size of a Leek

TL;DR

• Your baby is about 49.8 cm long — roughly the length of a leek
• All of your baby's organs are ready for life outside the womb
• You may be experiencing false labor, nesting, and an intense desire to just be done
• Rest as much as you can and trust that your body knows what to do

Your Baby This Week

Your baby is ready. Every major organ system — heart, lungs, liver, kidneys, brain — is functional and prepared for life outside the womb. The lungs are producing ample surfactant, the digestive system can process milk, and the brain is directing all the reflexes your baby needs to breathe, feed, and regulate their temperature.

At about 49.8 cm and 6.8 pounds, your baby has filled nearly every available inch of space in your uterus. They're curled up tightly, knees to chest, and their movements are more like slow rolls and firm pushes than the acrobatics of earlier weeks. You might feel a foot wedged under your ribs or a head pressing firmly against your cervix.

Your baby's brain continues to develop at a remarkable pace. New neural connections are forming every second, and the brain is getting better at controlling body functions like breathing, digestion, and circulation. This brain development will continue long after birth — in fact, the brain won't reach its full size until your child is about 25 years old.

Your baby may have a full head of hair or just a bit of fuzz — it varies widely and doesn't predict what their hair will look like later. They've shed most of the lanugo (the fine body hair that kept them warm earlier) and much of the vernix coating, swallowing both along with amniotic fluid. All of this is accumulating as meconium, waiting for that first diaper change.

Your Body This Week

The waiting game is real, and it can be harder than anyone prepared you for. Every twinge, every cramp, every unusual sensation has you wondering: "Is this it?" Prodromal labor — contractions that feel real but don't progress into active labor — can be particularly frustrating. They might come for hours and then stop entirely, leaving you exhausted and disappointed.

Your cervix may continue to change. Effacement (thinning) and dilation (opening) can happen gradually over weeks or rapidly when labor begins. If your provider says you're 2 cm dilated and 50% effaced, that's a sign your body is preparing — but it's not a reliable indicator of when labor will actually start.

Physical discomfort is at its peak. Your pelvis aches, your back hurts, your bladder holds approximately three tablespoons, and getting out of a chair requires actual planning. Sleeping is a challenge, eating large meals is impossible because your stomach is compressed, and you might be experiencing swelling, heartburn, and hemorrhoids simultaneously. This is the hardest part of the physical journey — and it will end soon.

Emotionally, you might be cycling through excitement, anxiety, impatience, and deep tenderness. You might find yourself staring at your belly, trying to imagine the face you'll soon see for the first time. You might cry at commercials or feel an overwhelming urge to nest. All of this is normal. Your body and mind are preparing for one of the most profound transitions of your life.

Common Questions at Week 38

How will I know when labor really starts?

True labor contractions are regular, get closer together over time, and increase in intensity. They don't stop when you change positions or drink water. Time your contractions from the start of one to the start of the next. The general guideline is to head to the hospital when they're 5 minutes apart, lasting 1 minute each, for at least 1 hour (the 5-1-1 rule). Also go if your water breaks or if you have any bleeding.

What if I go past my due date?

About 50% of babies arrive after their due date, so going past 40 weeks is very common. Your provider will discuss monitoring options — typically including non-stress tests and ultrasounds to check amniotic fluid levels — and will talk about induction if you haven't delivered by 41-42 weeks. Every provider and situation is different, so this is a good conversation to have now.

Should I try to induce labor naturally?

The evidence on natural induction methods (walking, spicy food, evening primrose oil, etc.) is mixed at best. Walking and gentle movement can help your baby settle into the pelvis and may encourage contractions, but there's no proven way to kick-start labor before your body is ready. Talk to your provider before trying any induction methods, including herbal supplements.

What should I do with these last few days?

Rest. Sleep. Spend quiet time with your partner. Watch a movie. Take a walk. Eat at a restaurant that would be hard to visit with a newborn. Enjoy the stillness, because life is about to change in the most beautiful way. And yes — double-check that the car seat is installed.

This Week's Tip

Rest as much as you can and trust that your body knows what to do. You've spent nine months growing a human being, and your body has handled every stage with remarkable wisdom — even when it didn't feel like it. The same body that built a placenta, grew a brain, and supported a heartbeat will know how to bring your baby into the world. Rest now, breathe deeply, and trust the process. You are more ready than you think.

Sources

• American College of Obstetricians and Gynecologists (ACOG) — Third Trimester
• Mayo Clinic — Fetal Development: The Third Trimester

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