Risk Factors for Premature Birth

A Healthier Michigan

| 3 min read

Nearly 1 in 10 women who give birth experience premature or preterm birth, defined as any birth before the 37th week of pregnancy. There are a variety of inherent health, environmental and lifestyle factors that increase the risk of premature birth. In some cases, labor may be induced early if there are health risks for the mother or baby. Other times, mothers may go into premature labor.

What are warning signs and symptoms before premature labor?

Premature births can happen without any known cause, but there are some signs and symptoms that suggest higher risk of premature labor. Signs of preterm labor include:
  • More than four contractions in an hour that are not relieved by changing positions or other relief measures
  • Vaginal bleeding
  • Cramping, similar to menstrual cramps
  • An increase or change of watery, mucus-like or bloody vaginal discharge
  • Pressure in the pelvic area, or feeling the baby push down
  • Backache, especially lower back pains
  • Preterm rupture of membranes, or water breaking
There are no definite warning signs of a premature birth that show up early in pregnancy. Get regular medical care during pregnancy to monitor your health and the health of the fetus and identify any potential risk factors for an early birth.

Health factors that increase risk of premature birth

Existing health factors can affect the risk of premature birth. Some are related to medical history, especially past pregnancies, and others are linked to existing conditions or factors. These include:
  • Having delivered preterm before
  • Being pregnant with two or more babies
  • Fewer than 6 months between pregnancies
  • Having had multiple previous pregnancies
  • Using assisted reproductive techniques, like in-vitro fertilization
  • Previously having had a Caesarean section (C-section) or having had uterine fibroids removed, which can increase the risk of uterine rupture
  • Having a short cervix or the shortening of the cervix during gestation
  • Placenta previa, in which the placenta covers the cervix completely or partially
  • Developmental anomalies in the fetus
  • Being underweight or obese prior to pregnancy
  • Malnutrition
  • Late or no health care during pregnancy
  • Ethnicity – African Americans, Native Americans and Alaska Native mothers are at higher risk of premature birth
  • Being under 18 or over 35 at the time of pregnancy
  • Urinary tract infections
  • Sexually transmitted diseases
  • Vaginal infections such as bacterial vaginosis or trichomoniasis
  • High blood pressure
  • Heart disease
  • Vaginal bleeding, spotting or bloody discharge
  • Diabetes
  • Blood clotting issues or anemia

Environmental factors that increase risk of premature birth

Environmental factors at home or work can affect the risk of premature birth. Increased stress from your environment can raise the risk of pre-term birth. Women who live in higher-polluted areas have a higher-risk of premature birth than other women. Other environmental factors include:
  • Domestic violence including physical, sexual or emotional abuse
  • Lack of social support
  • Stress
  • Long working hours with uninterrupted standing
  • Exposure to certain environmental pollutants including DDT or DDE

Lifestyle choices that increase risk of premature birth

Some lifestyle choices and substance use increase the risk of premature birth and developmental challenges for the baby. These lifestyle choices include:
  • Smoking
  • Drinking alcohol
  • Using illegal drugs
  • Eating a diet lacking in nutrients

How to reduce the risk of premature birth

Considering all the factors that contribute to an increased risk of premature birth, there are ways to reduce the risk as well. These include:

Before pregnancy:

  • Maintaining a healthy weight
  • Eating a well-balanced nutritious diet
  • Stop smoking and reduce alcohol consumption
  • Avoid illegal drug use
  • Waiting six months or longer between pregnancies

During pregnancy:

  • Seeing a doctor early in pregnancy and regularly throughout
  • Drinking plenty of fluids and maintaining good hydration
  • Eating a well-balanced nutritious diet
  • Managing chronic conditions such as diabetes, hypertension and autoimmune conditions
  • De-stressing and avoiding high stress situations

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A Healthier Michigan is sponsored by Blue Cross Blue Shield of Michigan, a nonprofit, independent licensee of the Blue Cross Blue Shield Association.
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