While 37 weeks was historically considered "full term," medical guidelines now classify it as early term, recognizing that babies benefit from those extra weeks for crucial brain, lung (respiratory), and liver development, with true "full term" being 39 weeks to 40 weeks and 6 days, as babies born earlier face higher risks for issues like breathing, feeding, and temperature control. ACOG +3
That's how your doctor or midwife will most likely estimate your due date. Experts previously believed that babies born between 37 and 42 weeks were equally likely to be born healthy. For that reason, people considered pregnancies to be full term at 37 weeks.
Since some women are unsure of the date of their last menstruation (perhaps due to period irregularities), a baby is considered full term if its birth falls between 37 to 42 weeks of the estimated last menstruation date.
Until now, choosing to deliver as early as 37 weeks was considered safe for the baby. But evidence is growing that babies delivered this early are missing out on crucial benefits in development. The brain, lungs, liver and other important organs get the time they need to develop.
By the time you're 37 weeks pregnant, your baby is fully developed and considered full-term1. There is no reason to delay labour if it starts at this stage – your baby is ready for the outside world2.
Care for Infants Born at 37 Weeks
Because infants born at 37 weeks are at risk for complications due to incomplete organ development, they may require treatment in a NICU. However, their NICU admission rate is lower compared to preterm infants. This largely depends on the baby's birth weight and overall health.
At 35 to 37 weeks in your pregnancy, your baby's brain is only 75 to 80% developed and needs to grow more. They might have trouble timing their sucking, swallowing, and breathing or keeping their body temperature normal.
Week 37. Important organs, like your baby's brain, lungs and liver, are still developing. Your baby's still gaining weight. If your pregnancy is healthy, it's best to stay pregnant for at least 39 weeks.
At 36 weeks, your baby's lungs are fully formed, and by 40 weeks, your baby has about 150 million alveoli in their lungs, ready to take over the job of breathing on their own once they're born.
Most babies weigh more than 5 pounds, 13 ounces by the 37th week of pregnancy. Babies born weighing less than 5 pounds, 8 ounces are considered low birth weight.
Three key signs that labor is approaching soon are regular contractions, losing your "bloody show" (mucus plug), and your waters breaking, often accompanied by lower backache, baby dropping, or a sudden urge to clean (nesting). These signals show your body is preparing for birth, with contractions becoming stronger and closer together as labor progresses.
And if your babies are then born prematurely, they will be given two ages: an actual age and a corrected or adjusted age. Babies born before 37 weeks are classed as preterm. Twins born after 37 weeks will not usually be given a corrected age.
The "3-2-1 Rule" in pregnancy is a guideline for first-time mothers to know when to call their midwife or doctor for active labor: consistent contractions that are 3 minutes apart, lasting 2 minutes each, for 1 hour (or sometimes cited as 3-1-1, meaning 3 minutes apart, 1 minute long, for 1 hour). For subsequent pregnancies, the 5-1-1 Rule (5 minutes apart, 1 minute long, for 1 hour) is often used, indicating labor is progressing more quickly.
A premature birth is more likely to happen when a mother has a health problem — like diabetes — or does harmful things during her pregnancy, like smoke or drink. If she lives with a lot of stress, that also can make her baby be born too early. Many things can cause a baby to be born early or with health problems.
At 37 weeks, the gross motor and communication domains remained at higher odds of failing compared to 39 weeks and at 38 weeks communication fails remained significantly higher.
For full-term babies, the average male baby weight is born at 7 pounds, 6 ounces, while the average female baby weight is a bit less at 7 pounds, 2 ounces. From birth to 6 months, the typical baby will double their birth weight.
Babies born before 34 weeks go to the Neonatal Intensive Care Unit (NICU). Babies born between 34 and 37 weeks who weigh more than 1,800 grams (about 4 pounds) may be able to go to the Progressive Care Nursery (PCN). The PCN is on the same unit where you will be staying.
Almost all organs are completely formed by about 12 weeks of pregnancy. The brain and spinal cord are exceptions—they continue to form and develop throughout pregnancy. Most congenital malformations (birth defects) occur during the period when organs are forming.
Your baby may need home oxygen because their lungs are not working well enough for them to get enough oxygen from the air. The most common reason for this is a condition called chronic lung disease (CLD). This is where fragile, immature lungs become scarred because of inflammation.
Try not to tilt your pelvis forward or backward, and avoid lifting or carrying heavy or bulky items. Contractions. At 37 weeks pregnant, you could start to feel contractions that you might recognize as being similar to menstrual cramping.
The brain is only two-thirds developed before 37 weeks, and the lungs, liver and muscles will be more fully developed at 40 weeks, as well. Babies who are born at term also tend to suck and swallow more effectively, making breastfeeding easier.
During the first trimester, which you can track using a pregnancy app like Flo, the brain develops rapidly. In fact, it makes up nearly half of the fetus' weight at this point. For comparison, by the time your baby is born, the brain is only 10 percent of their body weight.
Your baby, or foetus, is around 48.6cm long from head to heel. That's approximately the length of a leek. Your baby will be trying out different facial expressions, such as frowning and smiling.
Baby: Your baby's lungs are almost fully developed. It's still building fat deposits beneath its skin to keep warm after it leaves your womb. Your child weighs about as much as a 5-pound bag of potatoes. They won't get much longer, but they will gain weight -- about 0.5 pounds a week.