Preterm Labor: Meaning, Causes, Symptoms, Treatment

Written by Medicover Team and Medically Reviewed by Dr Sindhuri Gorantla , Gynecologists

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Preterm labor occurs when labor begins before 37 weeks of pregnancy. Normally, a full-term pregnancy lasts about 40 weeks, so preterm labor means the baby is born earlier than expected.

Women experiencing preterm labor may notice regular contractions, lower back pain, vaginal discharge changes or pressure in the pelvis. If not treated promptly, preterm labor can lead to preterm birth, which may increase health risks for the baby.

Signs & Symptoms of Preterm Labor

Recognizing preterm labor symptoms early is important, as it allows you to seek timely medical care, manage complications, and lower the risks of premature birth for your baby.

• Regular contractions: Feeling the uterus tighten 4-6 times or more in an hour, often experienced as mild to strong cramps that may come and go repeatedly.
• Lower back pain: Persistent dull ache or sharp lower back pain, often coming in waves and feeling very similar to strong menstrual cramps.
• Pelvic pressure: A heavy sensation of the baby pushing down into the pelvis or vagina, causing discomfort while walking, sitting or standing.
• Vaginal discharge changes: Unusual vaginal discharge that may be watery, mucus-like or mixed with blood, which can signal early labor changes.
• Abdominal cramps: Mild to strong cramping in the lower abdomen that may also be linked with diarrhea, stomach upset or nausea.
• Other signs: A general feeling of heaviness or tightening in the uterus, sometimes along with light spotting or slight vaginal bleeding.

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What causes preterm labor?

Preterm labor can occur for many reasons, and sometimes the exact cause is not clear. However, some common preterm labor causes include infections, multiple pregnancies and maternal health issues.

• Infections: Urinary tract infections, vaginal infections, or untreated maternal infections can irritate the uterus and increase the chances of triggering preterm labor.
• Multiple pregnancies: Carrying twins, triplets or more stretches the uterus, increasing the risk of contractions starting early and leading to preterm labor.
• Uterine or cervical problems: A weak or shortened cervix, uterine abnormalities or past surgeries can reduce the uterus's ability to hold the pregnancy to full term.
• Chronic health conditions: Conditions like high blood pressure, diabetes, thyroid disorders or kidney disease put extra strain on the body, raising preterm labor risks.
• Lifestyle factors: Smoking, alcohol, drug use, poor diet or high stress during pregnancy can weaken the body and raise the chance of early labor complications.
• Previous preterm birth: Women with a history of preterm labor are more likely to experience it again in later pregnancies, so closer monitoring is often needed.
• Placental problems: Issues such as placenta previa or placental abruption may cause bleeding or contractions, forcing the body into labor earlier than expected.

Understanding these causes helps doctors identify risk factors early and provide preventive care to reduce the chances of preterm birth.

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Risk Factors for Preterm Labor

Certain conditions or situations increase the likelihood of preterm labor, even if the exact cause is not clear:

• Family history increases the risk of preterm birth in women
• Short spacing between pregnancies raises early labor chances
• Very low or high maternal weight may trigger preterm delivery
• Constant high stress or anxiety can contribute to preterm labor
• Heavy physical work or strain puts mothers at higher risk
• Poor socioeconomic factors may increase preterm birth risk
• Smoking, alcohol or substance use raises preterm labor risk

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Complications of Preterm Labor

Preterm labor can lead to early delivery, which may result in multiple health challenges for both the baby and the mother. Early recognition and proper management are essential to reduce these risks.

For the Baby

• Respiratory problems: Babies born prematurely often have underdeveloped lungs, leading to breathing difficulties that may require oxygen or ventilator support.
• Low birth weight: Premature infants may weigh significantly less than full-term babies, making them more vulnerable to infections and health complications.
• Feeding and digestion issues:Premature babies may have trouble feeding, swallowing, or absorbing nutrients, sometimes needing specialized formulas or tube feeding.
• Brain and neurological problems: Early birth can increase the risk of learning disabilities, developmental delays, or conditions like cerebral palsy later in life.
• Vision and hearing problems: Preterm infants may develop eye conditions like retinopathy of prematurity or have an increased risk of hearing impairments.
• Long-term health concerns: Some premature babies may face chronic health issues, including respiratory problems, growth delays, or developmental challenges as they grow.

For the Mother

• Increased risk of cesarean section: Mothers experiencing preterm labor may require surgical delivery to ensure the safety of both baby and mother.
• Emotional stress: Early labor can cause anxiety, fear or depression due to concerns about the baby's survival and health outcomes.
• Complications in future pregnancies: Experiencing preterm labor may slightly increase the risk of preterm birth in subsequent pregnancies.
• Infections: Early rupture of membranes or prolonged labor can increase the risk of uterine or pelvic infections, requiring prompt medical care.

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When to See a Doctor for Preterm Labor?

It's crucial to get medical attention immediately if you notice any signs of preterm labor. Contact your doctor or go to the hospital if you experience:

• Regular uterine contractions (tightening 4-6 times per hour or more) before 37 weeks
• Lower back pain that doesn't go away with rest
• Pelvic pressure or heaviness
• Watery fluid, mucus or blood-tinged vaginal discharge
• Abdominal cramps or persistent stomach discomfort
• Any other unusual symptoms during pregnancy that feel concerning

Early medical attention can help delay labor and improve outcomes for both mother and baby.

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Diagnosis of Preterm Labor

Diagnosis of preterm labor involves reviewing medical history, checking physical signs and using tests like ultrasound, fetal fibronectin, and lab work. These help doctors detect risks early, monitor contractions, and decide the best steps to protect mother and baby.

Medical History

Doctors review your past pregnancies, history of preterm labor, and current symptoms like contractions, pain, or unusual discharge to check risks early.

• Contractions, pelvic pressure or back pain
• Vaginal discharge or fluid leakage
• Previous preterm labor or high-risk pregnancy conditions

Physical Examination

Doctors check cervical changes, uterine contractions, and the baby's position to assess preterm labor symptoms and overall pregnancy health.

• Checking the cervix for dilation or effacement (thinning)
• Assessing uterine contractions
• Measuring baby's position and overall health

Test to determine preterm labor:

• Ultrasound: Used to measure cervical length, monitor baby's growth, and detect early signs that may suggest a risk of preterm labor.
• Fetal fibronectin test: Helps detect a protein released near delivery time; its presence may show higher risk of early labor starting soon.
• Urine and blood tests: Check for infections, anemia or other health issues that could increase the chance of preterm labor.

Monitoring

Continuous or frequent monitoring of contractions and the baby's heart rate helps assess the ongoing risk of preterm labor. Accurate diagnosis allows doctors to decide whether treatment or hospitalization is needed, helping delay labor and protect the baby's health.

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Preterm Labor Treatment and Management

The goal of preterm labor management is to delay delivery, giving the baby more time to grow and reducing risks of complications linked to early birth. Treatment choices depend on the mother's health, symptoms, and how far along the pregnancy is.

Medications to Stop Contractions (Tocolytics)

Tocolytic drugs are used to slow down or temporarily stop uterine contractions. This delay gives time for other treatments, like steroid injections, to work. While they do not cure preterm labor, they help buy crucial hours or days for the baby's development.

Corticosteroids

Steroid injections are given when preterm delivery looks likely. They help speed up the baby's lung development, lowering the chances of breathing problems, bleeding in the brain, and other newborn complications.

Antibiotics

If the amniotic sac ruptures early or an infection is suspected, antibiotics are prescribed. They protect both mother and baby by reducing the risk of infections that can worsen preterm labor or harm the baby's health.

Bed Rest and Monitoring

Doctors may suggest reducing physical activity or complete bed rest to ease pressure on the uterus. At the same time, close monitoring of contractions, the baby's growth and heart rate helps track any changes and guide timely treatment.

Hospitalization

In severe cases, the mother may need hospital care for round-the-clock monitoring. Hospitals provide immediate access to medicines, intravenous fluids, and emergency care if labor progresses rapidly.

Addressing Underlying Causes

Managing health issues like infections, high blood pressure, or diabetes is essential. Treating these conditions lowers the risk of complications and helps prevent preterm labor from happening again in future pregnancies.

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How To Prevent Preterm Labor?

While preterm labor cannot always be fully prevented, following healthy habits, attending regular checkups, managing medical conditions, and treating infections early can reduce risks.

• Attend all prenatal checkups to monitor mother and baby's health.
• Eat a balanced diet, stay hydrated, and avoid smoking or alcohol.
• Control blood pressure, diabetes, and other health issues carefully.
• Practice relaxation and limit strenuous activity to reduce risks.
• Wait 6-12 months between pregnancies for full recovery.
• Treat urinary, vaginal, or other infections promptly during pregnancy.
• Follow doctor's advice on supplements, medications, or interventions.

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Conclusion

Preterm labor occurs when labor begins before 37 weeks of pregnancy, which can lead to early birth and possible health risks for the baby. Recognizing symptoms early, understanding the risk factors and seeking timely medical care are essential.

With proper preterm labor management, including medications, monitoring, and supportive care, many mothers can delay labor, improve the baby's chances of healthy development and have a safer delivery experience.

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