As you reach weeks 36 to 40 of pregnancy, you’re entering the final phase. After months of waiting, your baby is now considered full term and can arrive at any time. While you might be focused on your due date, remember that it’s only an estimated guess-most babies don’t arrive exactly on that day. These last few weeks are important because your baby is finishing important growth needed for life outside the womb. In this guide, you’ll learn what “full term” really means, what development is happening, what changes you might notice in your body, key details about labor and delivery, and tips to help you get ready for your newborn.
What does it mean when your baby is full term?
Doctors now know more about when babies are truly ready for birth. The definition of “full term” has changed to help give babies the best start.
What counts as a full-term pregnancy?
Your pregnancy is called full term when you reach 39 weeks. Experts like the American College of Obstetricians and Gynecologists (ACOG) use this definition because babies keep growing and getting stronger until then. Babies born at 37 or 38 weeks might look ready, but research shows that those born at 39 or 40 weeks usually feed better, breathe more easily, keep a more stable temperature, and have stronger immune systems.
Pregnancy week categories
To be clear about the last stages of pregnancy, doctors use these categories:
- Preterm: Less than 37 weeks. Babies may have trouble with breathing, eating, and staying warm, and often need extra care.
- Early term: 37 weeks to 38 weeks and 6 days. Babies born in these weeks usually do well but can have slightly more issues with breathing and jaundice compared to those born later.
- Full term: 39 weeks to 40 weeks and 6 days. This is the healthiest time for most babies to be born.
- Late term: 41 weeks to 41 weeks and 6 days.
- Postterm: 42 weeks and beyond. Longer pregnancies can bring small increases in risks, like a larger baby or problems with the placenta.
Doctors often count the pregnancy down to the day (for example, 38 weeks and 6 days) to watch carefully for problems and guide care decisions.
What about full term for twins and multiples?
If you’re having twins or more, “full term” can mean something slightly different. Twins are often born earlier, and many doctors suggest delivery around 38 weeks if everything is going well, since the placenta might not keep up with both babies after that. Each situation is different, so doctors watch twins and other multiples closely to pick the best and safest time for birth.
Are babies born at 36, 37, 38, 39, or 40 weeks considered full term?
Understanding the difference in timing helps you know what to expect. Even though 39 weeks is now the line for “full term,” each earlier week carries different risks and benefits.
Is it safe to deliver at 36 or 37 weeks?
While some babies born at 36 or 37 weeks are healthy, these aren’t preferred delivery times unless medically needed. At 36 weeks, a baby is “late preterm.” At 37 weeks, a baby is “early term.” Both groups may face higher risks than those born at 39 to 40 weeks, including breathing or feeding problems, so doctors aim to let pregnancy reach 39 weeks if possible.
Risks for babies born early
Babies born before 37 weeks face higher chances of health issues such as:
- Breathing trouble (Respiratory Distress Syndrome)
- Infections (like sepsis)
- Heart issues (like patent ductus arteriosus)
- Yellow skin or eyes (jaundice)
- Low birth weight
- Problems with body temperature
- Feeding problems
The risk of very serious problems, including death, goes down each week a baby stays in the womb, but some challenges can still happen at 36 and 37 weeks.
Does the week of birth affect health and survival?
Yes, each week helps your baby’s organs, especially the brain and lungs, become more mature and ready for life. Babies born in the “late preterm” window (34-36 weeks) might seem healthy but can have health and learning difficulties that show up even years later. That’s why babies should stay in the womb until at least 39 weeks, unless an early delivery is truly needed.
Do babies at 36-38 weeks need special care?
Some babies born at 36-38 weeks may need care in the Neonatal Intensive Care Unit (NICU), especially if they have problems with breathing, feeding, or keeping warm. For example, about 30% of babies born at 36 weeks have some breathing trouble, and about 5% need NICU care. This is also possible with twins born at these weeks. Doctors will watch these babies closely to decide what care is needed.
Weeks 36-40: What’s happening for you and your baby
These last weeks bring big changes for both you and your baby as the time for birth gets closer.
Week-by-week changes for your baby
- 36 weeks: About 20.7 inches tall and 6 pounds. The brain develops quickly, sleep cycles start, and lungs are almost ready. The baby can suck and swallow well.
- 37 weeks: About 21 inches and nearly 6.5 pounds. Rounding out, stronger bones and muscles, hands able to grip. Feels tight in the womb, but still moves and kicks.
- 38 weeks: Hair and protective skin coating (lanugo and vernix) are mostly gone. The baby gets antibodies from you and builds up more fat for warmth. Growth slows, but the baby is nearly ready to be born.
- 39 weeks: Muscles are strong, fingernails and toenails are fully formed, lungs are mature. The baby’s head usually drops into your pelvis, making breathing a bit easier for you.
- 40 weeks: About 7.25 pounds, as big as a small watermelon. Most protective hair is gone. Ready to eat, cry, and breathe easily after birth.
What does your baby look like from weeks 36 to 40?
During these weeks, your baby becomes chubbier and loses the wrinkled, skinny look. The skin gets pinker and fills out with fat-important for warmth. Most lanugo and vernix disappear. Fingernails and toenails are complete by week 39. At birth, your baby may have slightly puffy eyes and some dry skin, but this is normal and goes away soon.
What’s happening in your body?
Your uterus grows to its full size, crowding your organs and making you uncomfortable. By week 39, it’s likely under your ribs. Weight gain slows and you may notice bursts of energy (“nesting” urge), along with more tiredness and possible clumsiness. Your cervix starts to thin and open, which you won’t feel, but it’s part of getting ready for labor. Nipple changes prepare you for breastfeeding. At this stage, most people see their doctor weekly for checks.
Common symptoms near the end of pregnancy
You may notice:
- More frequent urination and possible urine leaking with laughter or coughing
- Braxton Hicks (practice contractions)-painless tightening
- Sore back and achy joints
- Pelvic heaviness or discomfort
- Numbness in fingers, hands, or feet from nerve pressure
- Trouble sleeping
- Indigestion or heartburn
- Swollen hands and feet from fluid retention
- Ups and downs in mood
- Shortness of breath (until the baby drops lower)
Signs of labor and when to go to the hospital
As your due date approaches, you’ll want to know what’s normal and what means labor has started.
False labor or real labor?
Braxton Hicks contractions are often irregular and go away with rest, food, or water. They’re usually mild and only in the front of your belly. Real labor contractions are regular, get stronger, and don’t go away with movement or rest. They may start in your lower back and move around your belly. A “bloody show” (mucus with some blood) can also mean labor is near.
Cervix changes as labor gets closer
During checkups, your provider might check for:
- Effacement: Thinning of your cervix, described by percentage (e.g., 50% or 100%)
- Dilation: Opening of your cervix, measured in centimeters (up to 10 cm)
- Station: How far down the baby’s head is in the pelvis (from -3 high up, to +3 ready to be born)
When to call your doctor or go to the hospital
- Contractions every 5 minutes for at least an hour and growing stronger
- Your water breaks (big gush or slow leak)
- Heavy bleeding (more than spotting)
- Much less fetal movement than usual
- Bad headache, vision changes, or swelling (could mean preeclampsia)
How babies are born: your delivery options
Birth can happen in a few different ways. Knowing the basics can help you feel less nervous.
Vaginal birth and the stages of labor
About 60% of births happen vaginally. There are three main stages:
- Dilation and Effacement: The cervix opens and thins. Contractions grow stronger and closer together. This stage lasts 6-12 hours or more, especially for first babies.
- Pushing and Birth: You’ll feel pressure to push when fully dilated. This stage can take up to 3 hours for first babies. With each push, your baby moves down and is born.
- Placenta Delivery: After the baby, your womb contracts again to push out the placenta. This usually happens in 30 minutes or less.
Pain relief options include breathing, massage, medicine, and epidurals. Sometimes, tools like suction cups or forceps are needed, along with extra numbing medicine.
Cesarean delivery (C-section)
About 30% of babies are born by C-section, a surgery to deliver the baby through the belly and womb. This may be planned (for reasons like the baby’s position, health conditions, or previous C-sections) or done in an emergency (for reasons like stress to the baby or long, slow labor). The operation takes 40-50 minutes. Recovery usually takes a few days in the hospital and several more weeks at home.
Inducing labor: when and why
Sometimes, labor is started by doctors (induced) for medical reasons like:
- Pregnancy much past the due date (41-42 weeks)
- Health problems in the mother (such as high blood pressure, diabetes)
- Concerns for the baby’s size or well-being
- Water breaking without labor starting
Labor can be started by breaking the water, by hormone gels, or medicines. Doctors do not recommend starting labor for convenience alone before 39 weeks.
Risks for overdue and postterm babies
Most pregnancies last a little past the due date, but going far past 40 weeks can bring some new risks for you and your baby.
Possible problems after 40 weeks
- Bigger babies, which can make vaginal birth harder
- Placenta works less well over time
- Lower levels of the fluid around the baby (amniotic fluid)
The mother may have a longer, more difficult labor, and sometimes more interventions like C-sections or induced labor are needed.
Watching the baby closely when you’re overdue
The doctor will usually check the baby closely after 40 weeks, using tests like:
- Nonstress Test (NST): Checks the baby’s heart rate when the baby moves
- Biophysical Profile (BPP): Look at movement, breathing, muscle tone, and amniotic fluid with an ultrasound
- Other ultrasounds: To see fluid levels and baby’s size
- Counting movements: Monitoring kicks and rolls
These checks help your doctor decide when and how to deliver if there are any signs of trouble.
Why induction might be needed if overdue
If you go past 41 or 42 weeks, the doctor may talk to you about inducing labor, especially if:
- Amniotic fluid goes down
- The baby may be getting too large
- Placenta is not working well
- There’s any risk to the baby’s health (such as a higher stillbirth risk, even if rare)
Getting ready for your baby: what you can do
Taking simple steps now can help you feel calmer and make the first days smoother.
What to pack for the hospital
Have a bag ready from week 36. It’s helpful to have one for yourself and one for your baby.
| Your Bag | Baby’s Bag |
|---|---|
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Planning for the time after birth
- Transport to hospital: Decide how you’ll get there and have a backup in case it’s needed
- Extra help: Arrange for someone to help at home, especially in the first weeks
- Meals: Make and freeze food ahead of time
- Recovery: Plan to rest, eat well, talk to your doctor about family planning and any extra appointments for your baby
- Care for other children: Organize babysitting during your hospital stay
- Mental health: Mood changes are common; talk to your doctor, family, or friends if you feel sad or stressed
Frequently asked questions about weeks 36-40 of pregnancy
Is it safe to deliver at 37 or 39 weeks?
It is usually safe at either week, but 39 weeks is best for most babies-they’re more likely to have fully developed lungs and other organs. Babies at 37 weeks (“early term”) may have more trouble with breathing or feeding.
Is 36 weeks considered premature?
Yes, 36 weeks is “late preterm.” Babies are at lower risk than earlier preemies, but can still have trouble with breathing, keeping warm, and feeding, and may need extra help in the hospital.
When can a baby be born with few problems?
Most babies born after 37 weeks do well, but the lowest risk for complications comes if the baby arrives between 39 and 40 weeks, when all vital systems are ready.
Main points to remember for weeks 36-40
As you get close to meeting your baby, keep in mind:
- The due date is a guess-most babies don’t arrive on that exact day.
- Staying pregnant until at least 39 weeks, if possible, helps your baby’s brain and lungs get ready.
- Getting support and being prepared can make things easier when the baby arrives.
- Every new twinge can be exciting or worrying, but your doctor is there to help with questions or concerns.
Take care of yourself, trust your own instincts, and lean on your support network. The last days of pregnancy can be uncomfortable but are just a short moment before a wonderful new chapter begins for you and your growing family.