When a baby is born at 37 weeks of gestation, many parents wonder whether this is considered premature and if it poses any risks to the baby’s health. Full-term pregnancy is typically 40 weeks, and babies born before 37 weeks are medically categorized as premature. However, the classification for a baby born exactly at 37 weeks has changed in recent years, leading to some confusion among expectant parents and caregivers. Understanding the nuances of gestational age and what it means for newborn development is crucial for anticipating care needs and outcomes.
Understanding Gestational Age
Gestational age is calculated from the first day of a woman’s last menstrual period, not from the date of conception. A full-term pregnancy is between 39 weeks and 40 weeks and 6 days. Babies born before 37 completed weeks of gestation are officially classified as premature. However, not all preterm births are equal in risk or developmental outcome.
Classification of Birth by Gestational Age
- Early term: 37 weeks 0 days through 38 weeks 6 days
- Full term: 39 weeks 0 days through 40 weeks 6 days
- Late term: 41 weeks 0 days through 41 weeks 6 days
- Post term: 42 weeks 0 days and beyond
According to this classification, a baby born at 37 weeks is not considered premature but is categorized as early term. This is an important distinction because while 37-week babies are generally healthy, they are still at higher risk for certain complications compared to those born at full term.
Is 37 Weeks Premature?
Medically speaking, a baby born at exactly 37 weeks is not considered premature under current guidelines. The term premature or preterm specifically applies to births that occur before 37 weeks of gestation. However, being just one day over 36 weeks doesn’t mean a baby is entirely risk-free. The organs, especially the lungs and brain, may still be in the final stages of development.
It is more accurate to say that a 37-week baby is early term rather than premature. This classification reflects the fact that while many 37-week babies do very well, they may still face mild health issues that require attention.
Developmental Status at 37 Weeks
At 37 weeks, most babies are close to full term, and many of their critical organs are well developed. However, there are still some developmental processes that continue into weeks 38 and 39. For example:
- Brain development: The brain continues to grow and develop rapidly in the final weeks of pregnancy. At 37 weeks, it’s only about 80-90% of the size it will be at full term.
- Lung maturity: Most babies born at 37 weeks can breathe on their own, but there is still a small risk of respiratory issues like transient tachypnea or respiratory distress syndrome.
- Feeding and temperature regulation: Some 37-week infants may have difficulty with sucking and swallowing, or with maintaining their body temperature.
Potential Health Risks for 37-Week Babies
While many early term babies born at 37 weeks experience no complications, studies show that they are at slightly higher risk for certain conditions compared to full-term infants. These may include:
- Jaundice
- Low blood sugar (hypoglycemia)
- Feeding difficulties
- Increased risk of infection
- Longer hospital stays or brief NICU admission
These risks are usually manageable and often temporary, but they are important for parents and medical professionals to be aware of.
Why Are Some Babies Born at 37 Weeks?
There are several reasons why labor may be induced or a baby may be delivered at 37 weeks. Some common causes include:
- Maternal health issues such as preeclampsia, high blood pressure, or diabetes
- Placental problems, such as placenta previa or placental abruption
- Fetal distress or growth restrictions
- Multiple pregnancies (twins or more)
- Preterm rupture of membranes (water breaking early)
In these cases, the benefits of early delivery may outweigh the risks of staying in the womb. However, if possible, most doctors aim to delay delivery until at least 39 weeks to maximize the baby’s development.
What to Expect with a 37-Week Baby
If your baby is born at 37 weeks, you can generally expect a positive outcome. Most 37-week infants weigh between 5.5 and 6.5 pounds (2.5 to 3 kilograms) and are able to breathe and feed on their own. Still, doctors and nurses will monitor the baby closely to ensure there are no complications.
Parents should be prepared for the possibility of a longer hospital stay if the baby shows signs of jaundice, low blood sugar, or feeding problems. In many cases, however, the baby can go home within the standard 2 to 3 days after birth, just like a full-term newborn.
Long-Term Outcomes of 37-Week Births
Research suggests that early term babies can perform slightly lower on cognitive and developmental assessments than those born at full term, although the differences are generally small. Most children born at 37 weeks go on to live healthy, normal lives. Still, the data supports the importance of those last few weeks of pregnancy for optimal brain and body development.
For this reason, many healthcare providers now recommend avoiding elective deliveries before 39 weeks unless there is a medical necessity. The wait until 39 initiative has helped reduce unnecessary early births and improve newborn outcomes.
In summary, a baby born at 37 weeks is not considered premature, but rather early term. While not classified as preterm, these infants may still face mild complications that usually resolve with proper care. Understanding the importance of those final weeks in utero helps both parents and providers make informed decisions regarding delivery. If you’re expecting and concerned about early delivery, always consult with your healthcare team to weigh the risks and benefits specific to your pregnancy.