Causes of premature birth: Common reasons and triggers

Infections are the most common cause of premature birth

In more than 50 percent of cases, an infection is the cause of premature birth. The following types of infections in particular can endanger the successful course of a pregnancy.

• Vaginal infections in particular can cause premature birth. If the mother’s vagina is colonized with certain germs (eg Gardnerella vaginalis, group B streptococci), these germs migrate up the birth canal. They produce prostaglandins as a kind of metabolic product. However, prostaglandins are also substances that the mother’s body produces to induce childbirth. This means that normally prostaglandins are not formed until after 40 weeks of pregnancy when the time of birth has come and labor is to be induced. In the event of an infection, the mother’s body is “played” with a completed pregnancy. Many infections can be counteracted in good time by preventive measures .
• Urinary tract infections are not uncommon during pregnancy and are particularly noticeable through burning when urinating and a frequent and strong urge to urinate. But even infections without symptoms already increase the risk of a premature birth. For this reason, urine tests are regularly carried out as part of preventive medical check -ups. If symptoms (pain when urinating, blood in the urine) indicate a urinary tract infection, you should have an examination carried out immediately.
• Some of the mother’s infectious diseases, such as rubella , measles or  toxoplasmosis , can be transmitted from her to the child . Depending on the progress of the pregnancy, such infections can lead to damage to the child or to a miscarriage or premature birth.

Other causes of premature birth

smoking during pregnancy

Statistically, smokers are more likely to give birth prematurely than women whose bodies don’t have to fight the pollutants. Smoking narrows all blood vessels, including those in the placenta, so that less blood reaches the child. The blood vessels are not only temporarily constricted, but they can be permanently damaged over time, for example in the placenta, similar to what is known as “hardening of the arteries”. This can mean that the child can no longer be supplied with sufficient blood and thus with oxygen and nutrients. This is then called placental insufficiency. If the placental insufficiency is pronounced, labor often has to be induced prematurely. Therefore, to protect the child, every mother-to-be who has smoked up to now should definitely stop smoking during pregnancy !

Stimuli and drugs during pregnancy

• Alcohol consumption during pregnancy leads less to premature births and more to harming the child (especially short stature, malformations and mental impairments) and should therefore be avoided.
• Excessive consumption of coffee or liquorice can also increase the risk of premature birth. Coffee and liquorice should therefore only be consumed in moderation.
• It goes without saying that the consumption of illegal drugs (especially marijuana, cocaine and ecstasy) can lead to premature birth and should therefore be avoided.

Heavy physical and mental stress

In more than 50 percent of women who go into labor far too early, doctors suspect psychosocial reasons. By that they mean stress, being overwhelmed and fear of the future. Since pregnancy not only demands a lot from the soul, but also from the mother’s body, physically demanding work and mental overload should be avoided. Excessive mental and physical stress can increase the risk of premature birth. By weakening the immune system, which in turn increases the susceptibility to vaginal or other infections, there is a risk of premature birth. However, certain hormones that are released during stress can also promote or trigger premature births.

Diabetes mellitus (diabetes)

With well-controlled diabetes, the risk of premature birth or miscarriage is hardly increased nowadays. However, poorly treated diabetes mellitus can lead to miscarriages , premature births, damage to the child and complications for both mother and child. Women with diabetes mellitus should therefore ensure that their blood sugar is particularly well controlled before and during pregnancy and be treated by a specialist doctor who also has experience with diabetes during pregnancy.

EPH gestosis and HELLP syndrome

Severe forms of EPH gestosis/pre-eclampsia, formerly also known as “pregnancy poisoning”, and the HELLP syndrome are common reasons why a pregnancy has to be terminated prematurely or ends with a premature birth. In gestosis/pre-eclampsia , there is fluid retention in the legs and arms (edema), protein in the urine (proteinuria) and high blood pressure (hypertension). If the case is particularly severe, it can develop into eclampsia, which results in seizures that can be life-threatening for both the mother and the child.

Two pregnancies in a row

If the pregnant woman has already had a premature birth or a stillbirth, the risk of a premature birth also increases during the existing pregnancy. This is because the cervix is ​​dilated. Even in the case of an immediate re-pregnancy, its holding function can decrease. The uterus then responds to the opening of the cervix with labour.

multiple birth

If more than one baby grows in the womb, the uterus has to stretch further early on than with a child. The muscle receptors therefore report an advanced stage of pregnancy and the body responds with the labor hormone oxytocin.

Age and body weight of the pregnant woman

Statistically, women who become pregnant before the age of 18 and after the age of 35 have an increased risk of preterm birth. Unfortunately, this also applies to women who are very overweight or underweight. Even if the woman gains a disproportionate amount of weight during pregnancy and possibly even  develops gestational diabetes , a premature birth can occur.

Premature detachment of the placenta

Bleeding from the uterus can occur if the placenta detaches prematurely. The so-called placenta previa , the present placenta, can also lead to bleeding. The placenta lies directly in front of the cervix and seals it completely or partially. Violent movements or lifting heavy objects can tear the placenta, resulting in a large loss of blood. If left untreated, the woman can bleed to death. These causes can cause premature labor or premature rupture of membranes .

You cannot always influence the duration of the pregnancy, but it is certainly good if you keep an eye on the causes of a premature birth in order to avoid them. If you are unsure and have concerns and worries, you can find help from your gynaecologist.