Preterm labor (“PTL”) is defined as the dilation, or opening, of the cervix when it occurs anytime before the 37th week of pregnancy. Under normal circumstances, pregnancy lasts for approximately 40 weeks, calculated from the first day of the last menstrual period. Occasionally, environmental influences, illnesses or other forces of nature alter the plans and preterm labor becomes a reality. It is estimated that as many as 10% of pregnant women will suffer from preterm labor.
Symptoms of Preterm Labor
Any of the following symptoms occurring before the 37th week of pregnancy may be signs of preterm labor and should be reported to your health care provider immediately:
- Regular uterine contractions, occurring at a frequency of more than four per hour;
- Persistent back pain;
- Menstrual-type cramping that doesn’t subside with rest or a change in position;
- Abdominal cramps (particularly those accompanied by diarrhea, intestinal cramping or gas-type pains) and/or pain that radiates to the upper thigh area;
- Persistent pressure in the pelvic region, with or without pain;
- Loss of the mucus plug; (although this doesn’t necessarily precipitate or indicate the immediate onset of labor, it should be reported to your health care provider);
- Spotting or blood-tinged discharged, particularly if bright red in color;
- A sudden change in the consistency or amount of vaginal discharge, particularly sudden gushes or slow trickles of watery fluid
Preterm labor is most often diagnosed through ultrasound, contraction monitoring devices, a manual pelvic exam, or a combination of all three. Some practitioners discourage pelvic exams when preterm labor is suspected to avoid the risk of introducing infection into the vaginal area. Another method of diagnosing, or predicting the likelihood of, preterm labor is through a non-invasive test called the salivary estriol test. After collecting the saliva from a pregnant mother suspected to be in preterm labor, this test measures the levels of the body’s hormone, estriol, which is thought to surge between one and two weeks prior to the onset of labor and is produced as a result of hormonal changes from the fetus shortly before labor begins. Since the test is thought to be highly accurate, and because over half of women who delivery prematurely present with normal, uncomplicated pregnancies prior to the onset of PTL, some doctors have incorporated the salivary hormone test as a course of routine prenatal care.
Most recently, a new technology known as the Fetal Fibronectin Test (“fFN”) is available and designed to determine a woman’s risk of going into preterm labor by detecting the presence of the hormone, fFN, in vaginal secretions. Administered much like a pap smear, the fFN is most commonly reserved for women who are either at an increased risk for preterm labor, or who have experienced preterm contractions, as the analytical process of the test is quite costly. Unfortunately, while the fFN is thought to be highly accurate at predicting preterm labor, the implementation of it is ineffective at reducing the incidents of premature births.
Women with certain medical histories or health factors are considered to be at high risk for preterm labor and/or delivery. Among the factors that potentially increase your risk include:
- History of preterm labor and/or premature delivery;
- Structural anomalies of the uterus or cervix;
- Smoking or non-prescribed drug use during pregnancy;
- Previous repetitive elective abortions;
- Inadequate prenatal care and/or nutrition;
- Multiple pregnancies;
- A pregnancy that occurred while using the contraceptive device, IUD, particularly if the device was left intact during part or all of the pregnancy;
- A maternal mother who used diethylstilbestrol (“DES”) during her pregnancy;
- Unsanitary or poverty-level living conditions;
- Previous cervical cone biopsy surgery;
- Cervical infections such as Group B Strep, or sexually transmitted diseases such as gonorrhea, syphilis or chlamydia;
- Urinary tract infections (“UTI”) during pregnancy;
- Dangerously low weight at onset of pregnancy;
- Chronic medical conditions, such as high blood pressure, diabetes or kidney disease.
Depending on how far along you are in your pregnancy, your health care provider may or may not attempt to stop your preterm labor. Among methods to manage preterm labor include:
- Bedrest in the left side-lying position, either at home or in the hospital;
- Regular fetal evaluation, including ultrasound, non-stress tests and amniotic fluid volume index (AFI), used to evaluate safe levels of amniotic fluid;
- Efforts to hydrate the pregnant mother, including IV fluid administration;
- Medications to stop labor, such as terbutaline, brethine, or magnesium sulfate;
- Steroid medications given to the pregnant mother to expedite fetal lung development, particularly if delivery appears to be inevitable;
- Antibiotic medication is given to prevent, or clear, maternal infection, particularly if membranes have ruptured;
- Hospitalization to monitor and/or treat symptoms of preterm labor.
Because the cause of the majority of preterm labor incidents are unknown, it is sometimes difficult to prevent preterm labor altogether, although some steps you can take to lessen your risk of delivering early include the following:
- Stay well hydrated, particularly during summer months. Dehydration can cause a drastic decrease in blood volume and, in turn, can increase the levels of the hormone, oxytocin (the hormone that causes contractions), in the body.
- Obtain adequate prenatal care;
- Eat a nutritious, well-balanced diet during pregnancy;
- Avoid “risk” foods during pregnancy such as soft, unpasteurized cheeses (brie, feta, goat,) and ready-to-eat meat products (such as pate, hot dogs, deli-style luncheon meats) unless heated to steaming prior to eating; although somewhat rare, these foods have the potential of causing a bacterial infection called Listeria, which can place a pregnant mother at high risk for preterm labor and, in some cases, miscarriage. Speak with your care provider about specific foods to avoid during pregnancy or for more information on Listeria.
- Avoid strenuous labor at work or home such as heavy lifting or climbing;
- Don’t smoke;
- Don’t hesitate to call your health care provider if you notice any unusual symptoms that might indicate preterm labor.
Thankfully, with the help of advanced medical technology, many cases of preterm labor can be treated and many women who experience preterm labor go on to deliver healthy infants. Although in some cases, preterm labor cannot be stopped, maintaining good prenatal care and paying close attention to any warning signs you might experience during pregnancy can improve your chances of delivering a term baby. If you have any questions about symptoms or risk factors for preterm labor, consult your health care provider.