Are There Risks With Giving Birth at 37 Weeks?

What mom isn’t curious to meet her baby? It seems that this desire gets even bigger at the end of pregnancy, and the urge for labor to start comes on strong. The problem is when early labor is forced by the mom and, most of the time, by the doctor.

Is childbirth at 37 weeks considered premature?

In theory, giving birth at 37 weeks is not considered premature¹. However, did you know it can bring as many risks as giving birth at 34 or 35 weeks? The issue is how moms count their weeks. All doctors say that the 9th month starts from the 37th week of pregnancy, so women think that by 37 weeks their baby will be fully developed and have lungs ready for birth. But that’s not always the case…

As a mother of 3, I always had this information: from 37 weeks of pregnancy on, labor can happen at any moment. This sounds like an alarm going off in the head of an anxious and uncomfortable pregnant woman. So, it’s very important to clarify a few points! First, let’s recall how pregnancy is counted. We use as a starting point the first day of the last menstrual period. The LMP, as doctors call it, is the first basis for counting pregnancy².

The doctor will start the calculations based on this and, later, confirm with an ultrasound. The problem happens when the date of the last period doesn’t match the actual pregnancy date.

Margin of error in the EDD calculation

Usually, a difference of up to 7 days is considered irrelevant by doctors. But, beyond this period, it can be considered a difference between conception and implantation. That’s because, typically, the fertile period is counted as an average of 14 days before the expected date of the next period, which is the fixed luteal phase.

The doctor will calculate the gestational age using the date of the last menstrual period (LMP) or the earliest possible ultrasound. In other words, the first ultrasound in which the embryo’s heartbeat was seen. This way, the doctor will decide which date is more reliable to use as the basis for estimating the due date.

Risks of giving birth at 37 weeks

Usually, the type of birth with the highest occurrence of problems for the baby is an elective cesarean section, since it is a date pre-scheduled by the doctor to remove the baby from the uterus. Even though it’s not considered premature anymore (at 37 weeks the baby has already reached fetal maturity), by not going into labor naturally, the baby may still have some breathing difficulties at birth.

Lung maturity

This lung maturaton is crucial for a successful delivery without major problems for the baby outside the womb. The baby’s lungs can fully mature even before 37 weeks of pregnancy in some cases. In others, the lungs still aren’t fully developed even at 39 weeks. The body is able to detect when the lungs are completely formed and ready to take in oxygen independently.

Birth with immature lungs

When the birth happens without any sign that the organ is ready to function, the baby is at risk of having breathing problems right after birth because of insufficient lung maturity. The baby may be born “tired,” have to work hard to breathe and, in some cases, need oxygen therapy and an oxygen bag³. Giving birth at 37 weeks, even though it’s considered the 9th month of pregnancy, doesn’t guarantee this lung maturity.

Methods to speed up lung maturity

There are ways to prevent this kind of problem. When labor threatens to occur before nine months are up, the doctor may advise the mother to take medication to speed up lung development.

Celestone Soluspam, or simply Celestone, acts like the hormones released by the placenta and helps with premature maturation. The woman should receive about 2 doses, which can be increased as needed.

Test for verification

There is also a test to check the baby’s lung maturity. Its purpose is to measure the amount of lamellar bodies in the amniotic fluid. If the amount is above 70%, it means the baby should be able to come into the world without immediate problems after birth.

It’s a quick and simple test requested by the doctor, but it’s not available at all medical centers in every city. It costs around R$500 at specialized clinics. This kind of test is necessary when the pregnancy is at risk of being interrupted too early. It’s also available to term pregnancies (over 37 weeks).

So, my friend, it’s important to remember that the risk of giving birth at 37 weeks is not necessarily for the mother, but for the baby. What my obstetrician said during my last pregnancy made me realize the trouble many women get into when they are too eager to give birth.

The ideal week for your baby to be born

The ideal is to let your baby show when they are ready to be born. Or, if you choose an elective cesarean, try to schedule it for as close as possible to 39 or 40 weeks of pregnancy. By then, it’s much more likely that your baby’s lungs are mature enough for birth.

The author’s story

When I was pregnant with Eduardo, the date of my last period was almost four weeks off from the actual fetal age. The pregnancy happened in the second half of January, but my last period was at the beginning of December.

At 37 weeks of pregnancy as counted by LMP, the doctor, seeing a slight increase in my blood pressure, decided to do a “necessary” delivery. I was shocked, because as a doctor he should have known I wasn’t really 37 weeks, but more like almost 34—which would have resulted in a very premature birth.

As I was very concerned, I decided to get a second opinion, and the female doctor advised me to wait a few more days. In the end, I ran away from the “crazy” doctor being overly cautious (my blood pressure was 13X9) and I had my baby at almost 41 weeks of actual pregnancy as counted from conception, from the first ultrasound, with an exceptional doctor.

I’m sure that if I’d given birth at 37 weeks, Eduardo would have been born with low lung maturity and problems, as happened with Joana. Moms, please, be very careful!

See also: Amniotic Fluid – Can Low or Excess Levels Cause Problems?