Table of Content

• What is Premature Labor?

• Signs and symptoms of Premature Labor

• Signs of Premature Labor at 32 weeks

• What triggers Premature Labor?

• What Causes Premature Labor?

• Risk Factors of Premature Labor

• Prevention of Premature Labor

• Difference between False Labor and true Labor

• Diagnosis and Treatment of Premature Labor

• Treatment of Premature Labor includes

• When to see a doctor

• Take Home Point

• FAQs on Premature Labor

Introduction

Premature labor occurs before the 37th week of pregnancy. According to recent statistics, 8 out of 100 babies are born by premature labour. Signs of premature labour are an important perspective because it allow timely diagnosis to start tocolytic treatment and achieve efficient foetal pulmonary maturity. It is also important to distinguish between true and false labor. 

Labor at term involves a normal physiological process, but premature labor is a pathological process. In this article, we will understand more on signs of premature labor, its causes, prevention, and more.

What is Premature Labor?

Labor is a physiological process involving cervical changes, uterine contraction and other processes. The duration of human pregnancy is about 40 weeks. Preterm labor occurs between after 20 weeks of gestation and before 37 weeks.

It is of two types:

• Early preterm labor: It occurs before 33 weeks gestation.

• Late preterm labor: It is between labor at 34 weeks and labor at 36 weeks.

Types of premature labor based on timing:

• Late preterm births: Labor at 34 weeks and 0 days through 36 weeks and 6 days.

• Moderately preterm births (from 32 weeks to 33 weeks and 6 days)

• Very preterm births

Signs and symptoms of Premature Labor

Pregnant women should be educated on signs and symptoms of premature labor for timely diagnosis and treatment. Contraction, discharge and discomfort are the three major signs and symptoms of premature labor. 

• Contractions of premature labor are similar to the menstrual cramps. However, the contractions can be painless, regular and highly frequent also. There may be a feeling that baby is balling up pregnant women may sense changes in the baby’s position and movement. 

• The amount of vaginal discharge increases due to the ruputuring of the membranes, the consistency of discharge is watery, mucus or bloody.

• Back pain is constantly low and dull.

• Pelvic abdominal pressure

Signs of Premature Labor at 32 weeks  

According to How et al. and Copper et al., signs of premature labor can be:

• Cervical dilatation between 0 to 1 cm

• Diarrhoea 

• discharge 

• Bleeding

• Increase in frequency of contractions

• Increase in cervical examination findings

• Backache,

• Pressure

• Cramping. 

What triggers Premature Labor?

According to recent findings following factors may trigger Preterm labor and premature birth:

• Presence of infection

• Trigger of the inflammatory response by LPS (lipopolysaccharide) in the amniotic cavity and cervico-vaginal microenvironment.

• Changes and disruption in the vaginal microbiome changes.

•  Increasing inflammation in the cervico-vaginal space.

• Bacteria from the vagina in the amniotic cavity.

• Deficiency of progesterone.

• Uterine overdistension

•  Stress on the mother and fetus.

• Stimulation of the pathway between the decidua and the fetal membranes causing membrane rupture and uterine contractility. 

• Involvement of chemokines, and inflammatory cytokines.

What Causes Premature Labor?

The causes of premature labor are:

• Medical history including previous history of abortion.

• Presence of stress

• Infection

• Placental abruption

• Placenta previa (placenta completely or partially covers cervix)

• Intra-amniotic infection

• Premature preterm rupture of membranes associated with short cervical length, second and third trimester bleeding and other factors.

Risk Factors of Premature Labor

There are many risk factors associated with premature labor. They are discussed below:

• Pregnancy risk factors for preterm labor: Biologic factors like advanced maternal age, assisted reproductive technology, history of cardiovascular disease, cervical insufficiency, depression, anxiety, mood disorders, diabetes, fetal anomalies, presence of genetic or inherited disorders, high blood pressure, short cervix, short interpregnancy interval, vaginal infection, vaginal bleeding, bacterial vaginosis, 

• Age and race risk factors for preterm labor: advanced maternal age, women over age of 35, high body mass index, underweight before pregancy, black race, 

• Lifestyle risk factors for preterm labor: chronic stress, inadequate nutrition, air and water quality, alcoholism, substance use, opioid use disorder, poor dietary habits and eating unhealthy food, history of smoking, longer working hours, prolonged periods of standing, maternal stress, sleep disturbance, tiredness, tobacco use.

• Medical risk factors for preterm labor: This includes lack of access to prenatal care provider, lack of transportation and accessible health care, lack of health insurance, history of abdominal surgery, history of preterm delivery, urinary and genital tract infection, thyroid, diabetes, sexually transmitted diseases like chlamydia, gonorrhea, trichomoniasis, shortened cervix < 25 mm.

• Other  risk factors: unsafe neighborhood, inadequate housing, level of education, low income, poverty, lack of social support.

Prevention of Premature Labor

The main goal of preventing premature labor is to address the risk factors and aim at improving the health of the mother. Education about risk factors is important so that it is important to avoid these risk factors before and after pregnancy. Some of the important strategies are given below:

• Progesterone in used in the prevention of premature labour and according to studies, it can reduce the preterm birth rate by over 30 %.

• Smoking cessation.

• To maintain a healthy weight.

• Nutritional counselling to improve maternal health and maintain nutritional health.

• To avoid a stressful work environment. To decrease the world load.

• If the work is strenuous, temporary work cessation is recommended.

• Transvaginal ultrasonography to measure cervical length.

Difference between False Labor and true Labor

Diagnosis and Treatment of Premature Labor

Following are important considerations in diagnosing premature labor, preterm labor, and birth:

History:

• This includes history of pain, vaginal bleeding, amniotic fluid leakage, cramps, lower back pain, pelvic pressure.

• Changes in vaginal discharge 

• Fever 

• psychosocial factors including intimate partner violence, substance use disorder.

• Mental health

• Assesment of cervical length. 

• Physical exam: To assess firmness, abdominal tenderness, fetal size, and position. 

• Cervical examination

• Cardiotocography

• Detection of vaginal infection

• Vaginal pH measurement

• Abdominal ultrasonography of the fetus.

• Biochemical investigations

Treatment of Premature Labor includes 

• Tocolytic drugs are given between 22 and 34 weeks of gestational age. It includes Calcium channel blockers (Nifedipine), Beta-adrenergic (terbutaline), and COX inhibitors (indomethacin). 

• Magnesium sulfate may reduce the risk of cerebral palsy in infants.

• Corticosteroid therapy decreases neonatal morbidity and mortality.

When to see a doctor

Regular appointments with a Gynecologist and regular check-ups are often recommended in pregnancy to rule out the risks involved and begin early treatment. In case of fever, abnormal vaginal discharge, discomfort, etc it is important to visit the doctor and take an opinion. 

Take Home Point

• Every pregnant woman must know the signs of premature labor, and risk factors to prevent complications.

• Women's age plays an important role in premature labor. 

• Pregnant women must make healthy lifestyle choices.

• Avoid smoking and  substance abuse during pregnancy

• Maintain good nutritional status. Consult a dietician to get a proper diet chart planned.

• Family members should prioritize social support and psychosocial factors to support maternal health.

• Routine health check up is recommened for pregnant women.