Preterm birth is a major cause of newborn complications and death.

Emobileclinic Trending Topic: Preterm Labour

The gestation age of a normal pregnancy lasts 37 to 42 weeks, beginning from the first day of the last menstrual period. A pregnancy that continues beyond 37 weeks is called a term pregnancy. Preterm labor is defined as labor that begins before 37 weeks of pregnancy.

It is instructive to note that not all women who have preterm labor will deliver their baby early, if preterm labor leads to an early delivery, the premature newborn is at risk for problems related to incomplete development of his/her organ systems. These problems include difficulty with breathing, staying warm, feeding, as well as injury to the eyes, intestines, and nervous system. Preterm birth is a major cause of newborn complications and death.

Risk Factors

It is difficult to predict who will develop preterm labor. Certain obstetrical conditions and other factors are known to increase a woman’s risk. However, most preterm births occur in women who have no known risk factors.

The major risk factor for preterm birth is a previous preterm birth, although most women who have had a preterm birth will have a term pregnancy in the future.

The risk of preterm delivery is also higher in women under 18 to 20 years of age. Older maternal age alone (over 35 to 40) is not associated with an increased risk of preterm labor. However, older women are more likely to have other conditions (such as hypertension and diabetes) that can cause complications requiring preterm delivery.

Causes

Uterine bleeding: conditions like placenta previa and placental abruption can cause the fetal membranes to rupture prematurely and can trigger preterm labor.

Stretching of the uterus: with multiple births or having polyhydramnios (an excessive amount of amniotic fluid around the baby) causes stretching of the uterus, which can lead to uterine contractions and preterm labor.

Bacteria or inflammation: an infection in the uterus can stimulate the production of substances that trigger uterine contractions.

Physical or psychological stress: severe stress can lead to the release of hormones that cause uterine contractions and preterm labor.

Signs and Symptoms of Preterm Labour

The signs of preterm labor are similar to the signs of labor at the end of pregnancy:

Braxton Hicks contractions: are uterine contractions (tightening of the uterus) that occur less than eight times in an hour or four times every twenty minutes.

Cramping that is relatively mild and occurs irregularly.

Excessive mucus discharge from the vagina.

Light bleeding or spotting is also common.

Rupture of the fetal membranes

A woman should contact her healthcare provider immediately if she is concerned she could be in preterm labor or has other concerning symptoms. Particularly, a woman should call if she has more than six contractions in an hour that continue despite lying down, if she has leakage of amniotic fluid, or has any vaginal bleeding.

The healthcare provider will perform a pelvic examination to determine if the membranes have ruptured and if the cervix is effacing (thinning) or dilating (beginning to open), and may also perform an ultrasound examination. He or she may also place a monitor on the uterus that electronically records uterine contractions and the fetal heart rate.

Available Treatment Options for Preterm Labor

The major goal of treatment is to delay delivery long enough that steroids, which promote development of the baby’s lungs, can be given. Delaying preterm delivery also allows the woman to be transferred, if necessary, to a facility that can provide specialized care to a premature infant.

Treatment to delay delivery is typically recommended if the woman is less than 34 weeks pregnant because infants born before 34 weeks are at particularly high risk for complications of premature birth. However, if the mother or infant’s health are at risk, labor may be allowed to proceed. Labor may also be allowed to proceed if the mother is more than 34 weeks pregnant or if tests show that the baby’s lungs are fully developed.

A woman in preterm labor will be admitted to the hospital for close monitoring while medications to stop labor are administered. An intravenous line will be inserted to give medications and fluids, and a fetal monitor will be used to measure uterine contractions and the baby’s heart rate.

Treatments to stop labor — if the mother and baby are healthy, medications are often used to try to relax the uterine muscle and stop contractions. Medications used to stop or slow labor are called “tocolytic” agents. They include terbutaline, magnesium sulfate,

nifedipine, and indomethacin. Some of these drugs are given intravenously or by injection while others can be taken orally.

Treatments to help the infant — Steroids (glucocorticoids) can speed the development of a preterm infant’s lungs, and are often administered during preterm labor. Steroids help the lungs mature and may promote the production of surfactant, a substance that prevents the collapse of alveoli (small sacs in the lungs where air is exchanged). Steroids also decrease the infant’s risk for intraventricular hemorrhage (bleeding into the brain) and other complications affecting the bowels and circulatory system.

Prevention of Preterm Labour 

One of the most important things a pregnant woman can do to prevent preterm labor is to stop habits that can be harmful, such as smoking and use of illegal drugs.

Women with a history of a previous preterm birth at less than 37 weeks of pregnancy may be offered a progesterone supplement, either as an injection or a vaginal gel, to prevent recurrent preterm labor. Progesterone supplementation is begun between 16 and 26 weeks of pregnancy and continued until 36 weeks. There is no evidence that this drug is effective in women with no previous history of preterm labor. In addition, it has not been effective in women with multiple gestations (eg, twins).