Premature Birth: what are the causes?

Pregnancy is a period where you must have control over your actions, as your baby will be affected by many of your behaviors. One of the consequence of bad habits during pregnancy can lead to premature birth.
Premature Birth: what are the causes?

Last update: 28 December, 2018

A premature birth is one that happens before the 37th week of pregnancy. The reasons why a baby is born prematurely are varied. Some of them, you can avoid, while others are completely out of your control.

A growing number

The World Health Organization has concerns about the growing number of premature births. Between the possible causes, we can find environmental issues and the high levels of stress that come with modern society.

Along with these inherent conditions of modern society and lifestyle, the WHO also mentions cases of negligence by pregnant women and the doctors who treat them.

Thanks to medical advances, the probabilities of survival in a premature baby are increasing. Not so long ago, a newborn that arrived in the world before the 37th week had a low chance of recovery. Today, at least 80 percent of premature babies will survive.

A mom with her newborn baby

Types of premature birth

Depending on the gestation period at the time of delivery, premature births can be classified in the following way:

  • Late preterm is when the preterm baby leaves the mother’s womb during 34-36 weeks of pregnancy.
  • Moderate preterm is the category for births that happen between 32-33 weeks.
  • Very preterm is a birth that happens between 28-31 weeks.
  • Extremely preterm. A birth is considered extremely preterm when the pregnancy duration is less than 28 weeks.

Causes for a preterm birth

Experts divide the risk factors of a preterm birth into two groups. These are:

  • Maternal: reasons exclusively due to the mother’s health. During and before pregnancy.
  • Gestational: related to medical episodes and conditions that can happen during pregnancy.

These births can happen spontaneously or by being induced. In some cases, babies are delivered through natural birth, while in others, delivery is by C-section. Each situation is evaluated individually, according to the medical history of the mother and other factors.

Bad habits

This is a factor that often appears when doctors evaluate cases of premature births. Being overweight and having a deficient or unbalanced diet are two variables of negative influence.

A stressful lifestyle, that’s full of anxiety is also a part of the possible causes. Another two unfavorable concerns are not maintaining correct prenatal care or not following ob-gyn instructions and advice.

The mother’s history

Women suffering from diabetes or high blood pressure are more likely to deliver their babies before the 37th week of pregnancy. The same applies to women who already experienced a premature birth. They have a higher risk of this situation occurring again.

Age is another important factor to consider. When the mother is very young (less than 16 years old) as well as when she’s older (over 35 years old), the possibilities of premature birth are higher.

Mom and her baby smiling toghether.

Pre-eclampsia and gestational diabetes

These are two of the most feared risk factors during pregnancy. Pre-eclampsia happens from a sudden and high rise in blood pressure, this can occur in women who have never suffered from blood pressure problems before. Some symptoms are swollen legs and water retention.

With gestational diabetes, an increase in blood sugar levels occurs during pregnancy. The causes for this pathology aren’t completely clear. Even though in some cases gestational diabetes can progress to type 2 diabetes, many women recover after the delivery.

Multiple pregnancies

Statistics are very clear: At least one out of 2 twin pregnancies end before the 37th week. In the case of triplets or more babies in the womb, the rate of premature birth is practically 100% percent.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.



This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.