The normal gestation period for a fetus is about 39 weeks. Any child born before the 37^th week of gestation is considered premature, according to the March of Dimes Birth Defects Foundation. This date is calculated based on the first day of the woman’s last menstrual period and confirmed by ultrasound. Accurate dating of a pregnancy is essential to diagnosing a premature birth. Without the additional time in the mother’s uterus to develop and mature, the baby is at a higher risk of medical and developmental complications.

The most common complication of premature delivery is underdeveloped lungs, which is often referred to as respiratory distress syndrome (RDS). This occurs because the substance surfactant is not adequately produced and the lungs cannot remain expanded. In addition, premature birth is the leading cause of neonatal death during the first month of life.

There are more than 480,000 babies born prematurely each year in the United States, according to the U.S. Centers for Disease Control and Prevention (CDC). In about half of all premature births, physicians are unable to determine what causes a woman to go into labor early. However, certain known risk factors can cause an early delivery. Some of these include:

• Little or no prenatal care
• Carrying multiples (e.g., twins, triplets)
• Maternal age (less than 18 or over 40 years)
• A history of preterm deliveries
• Smoking or other forms of tobacco use
• Certain abnormalities of the uterus or cervix

Although most women carry their babies to full term, pregnant women (especially those in high-risk categories) should be aware of the symptoms of premature labor. These include contractions that are 10 minutes apart or less, menstrual-like cramps, dull back pain, pressure in the pelvic area, stomach cramps, watery fluid leaking from the vagina or other vaginal discharge. Any woman who suspects she is entering premature labor should contact her obstetrician-gynecologist (ObGyn) immediately.

Although some ObGyns may recommend bed rest or other therapies, these recommendations have shown inconsistent results in preventing preterm births. In fact, according to the American College of Obstetricians and Gynecologists, no reliable preventive therapies have proven to be effective in reducing preterm birth rates.

The normal gestation period for a fetus is approximately 39 weeks. Any child born before the 37^th week of gestation is considered premature, according to the March of Dimes Birth Defects Foundation. This date is calculated based on the first day of the woman’s last menstrual period and confirmed by ultrasound. It is essential to establish an accurate date of a pregnancy to diagnose a premature birth. Without the additional time in the mother’s womb to develop and mature, the baby is at a higher risk of medical and developmental complications.

The most common complication of premature birth is underdeveloped lungs, which is typically referred to as respiratory distress syndrome (RDS). In addition, premature birth is the leading cause of neonatal death during the first month of life. There are several factors that greatly impact the premature baby’s chances of survival and potential developmental challenges. These factors include:

• The baby’s gestational age (the number of weeks of pregnancy that have been completed)
• The baby’s weight
• Whether the baby has respiratory difficulties
• Whether the baby has any birth defects
• Whether the baby has any severe illnesses or infections

Although there have been many advances in obstetrics, the rate of premature births in the United States has not dropped in more than 40 years, but has increased somewhat, according to the American College of Obstetricians and Gynecologists (ACOG).

In 2004, just over 4 million births were recorded by the Centers for Disease Control and Prevention (CDC). Over ½ million infants were born prematurely during that year – the highest number reported since 1981. The preterm birth rate rose two percent than the previous year to 12.5 percent, or one out of every eight live births. Although overall preterm birth rates increased for the non-Hispanic white and Hispanic populations, the highest rate of premature deliveries was found among the non-Hispanic black population at 17.8 percent.

In a baby’s first month of life, prematurity is the leading cause of death and disability, according to the March of Dimes. Premature birth results in one-third of all infant deaths in the United States, according to the CDC. In addition, the organization reports that deliveries of premature babies (or “preemies”) cost nearly 15 times more than deliveries of full-term babies. A primary reason is the length of hospitalization required for preemies. These babies are often hospitalized for days or weeks, compared to the average two to three days for a healthy, full-term infant.

Most full-term babies weigh an average of about 7 pounds at birth. This is a sharp contrast to preemies, who can weigh 5 pounds or even less. Premature babies exhibit certain physical characteristics. The more premature a baby is, the smaller the baby will be and the larger the head will appear in relation to the rest of the body.

Preemies also have less fat, which results in their skin appearing thinner and more transparent, making it possible to see the underlying blood vessels. The reduced fat means that the baby has less protection from cold or even normal temperatures. For this reason, most premature babies are placed in an incubator, which is an enclosed, climate-controlled bed that helps keep the baby warm.

Preemies are at risk for health problems, many of which are serious. However, those born between 32 and 36 weeks (84 percent of preemies) may have few or no complications, according to the March of Dimes. Those born earliest experience the greatest risk of complications, long-term disabilities and death. For extremely premature babies, the risk of mental retardation, cerebral palsy, lung and gastrointestinal problems and vision or hearing loss is much higher. Advances in the treatment of these tiny newborns during the past decade have improved the chances for survival, and helped to reduce some of the complications that may accompany early arrival.

In about half of all premature births, physicians are unable to determine what caused a woman to go into labor early. For the rest of the more than 480,000 babies born prematurely each year in the United States, there are many factors that can cause an early delivery. These include:

• Little or no prenatal care.
  
  
• Multiples. With an increasing number of women using in vitro fertilization (IVF) to become pregnant, physicians are delivering more and more sets of twins and triplets or higher multiples. The rate of twins and triplets being born prematurely is higher than for single births, with some studies showing as much as half of all twins being born prematurely.
  
  
• Previous premature birth. Women who have had a premature delivery previously have an increased risk of having another early delivery.
  
  
• Short time period between pregnancies. A period of less than six to nine months between the birth of one baby and the beginning of the next pregnancy increases the risk of premature delivery.
  
  
• Preeclampsia. Characterized by high blood pressure during pregnancy, this condition can lead to potentially serious complications for the mother and fetus including premature birth.
  
  
• Smoking. There are many well-known risks associated with smoking during pregnancy, including low birth weight babies and premature deliveries.
  
  
• Uterine or cervical abnormalities. This includes stretching or abnormally shaped uterus or cervix, as well as fibroids or even having too much (polyhydramnios) or too little (oligohydramnios) amniotic fluid (liquid that surrounds the fetus during pregnancy). Women diagnosed with an incompetent cervix may require a procedure known as a cerclage. Performed at about 12 weeks gestation, this procedure involves placing a stitch in the cervix to prevent it from opening up too soon. The stitch is then removed when the baby is closer to full term.
  
  
• Recurring infections of the urinary tract, bladder, kidney and/or vagina.
  
  
• Infection with a high fever of more than 101 degrees Fahrenheit (38 degrees Celsius) during pregnancy.
  
  
• Unexplained vaginal bleeding after the 20^th week of pregnancy.
  
  
• Chronic illnesses, such as high blood pressure, diabetes, inflammatory bowel disease (IBS), kidney disease or lupus).
  
  
• History of second-trimester abortion or more than two first-trimester abortions. The cervix may be damaged during these procedures.
  
  
• Mother’s age is younger than 18 or older than 40 years.
  
  
• Mother is underweight or overweight before pregnancy.
  
  
• Taking certain antidepressant medications (e.g., selective serotonin reuptake inhibitors) slightly increases the risk of premature birth.
  
  
• Clotting disorder (thrombophilia).
  
  
• Alcohol and drug abuse.
  
  
• Domestic violence (physical, sexual or emotional abuse).
  
  
• Low socioeconomic status, which may be accompanied by high levels of stress or poor social support.
  
  
• Trichomoniasis. Each year, more than 5 million new cases of trichomoniasis are diagnosed, making it the most common nonviral sexually transmitted disease (STD) in the United States. According to the National Institutes of Health (NIH), a woman with untreated trichomoniasis is 40 percent more likely to deliver prematurely or deliver a low birth weight child than those without the STD.
  
  
• Bacterial vaginosis (BV). This form of vaginitis involves a bacterial imbalance in the vagina that leads to an overgrowth of harmful bacteria. BV is of particular concern for women who are pregnant as this condition can lead to delivering babes who are premature or have a low birth weight.

Heredity also may play a role in the risk of premature birth, according to new research. African-American babies are more likely than babies of European descent to have a variation of the SERPINH1 gene that can lead to a reduced amount of the protein collagen. Lack of collagen can cause the fetal membranes to become weak and rupture (premature rupture of membranes), resulting in preterm delivery.

Most women carry their babies to full term (approximately 39 weeks). However, all pregnant women – especially those in high-risk categories – should be aware of the symptoms of a premature labor. These include:

• Contractions (tightening and hardening of the uterus) that are 10 minutes apart (or less)
  
  
• Watery fluid that leaks from the vagina, indicating that the woman’s water may have broken
  
  
• Menstrual-like cramps in the lower abdomen, which could be intermittent or constant
  
  
• A low, dull pain in the back (below the waistline), which could be intermittent or constant
  
  
• Pressure in the pelvic area that feels as if the baby is pushing down
  
  
• Stomach cramps that may sometimes be accompanied by diarrhea or gas
  
  
• Vaginal discharge that changes or becomes heavier, especially a sudden flow or leak of fluid, and includes spotting or bleeding

It is recommended that any woman who suspects she is entering premature labor contact her obstetrician-gynecologist (ObGyn) immediately. Some ways that have been suggested to reduce symptoms associated with preterm labor include emptying the bladder, lying on the side (lying on the back can sometimes increase contractions) and drinking several glasses of water because dehydration can lead to contractions.

Although these efforts to prevent preterm delivery have been widely reported, many, including bed rest, home monitoring of uterine activity, hydration and sedation, have little supportive evidence that they are effective, according to the American College of Obstetricians and Gynecologists (ACOG).

In general, an obstetrician-gynecologist (ObGyn) will be more aggressive in attempts to delay labor when the patient is less than 32 weeks pregnant. If a physician orders the patient to the hospital, an examination of the cervix will help determine if the cervix is opening (dilating), which could indicate labor has begun. The physician will also check to see if fetal membranes have ruptured. Monitors are typically placed on the patient’s abdomen to measure the baby’s heart rate, and observe possible uterine contractions.

Some ObGyns may order a fetal fibronectin test (fibronectin is a protein that attaches the sac that holds the fetus to the uterus). This test requires that a sample be taken of the cervical and vaginal secretions. Most women consider it about as uncomfortable as a Pap smear. Though the results will not definitively determine if a woman has begun premature labor, it will clearly indicate if she has not begun labor. A negative test result means that it is highly unlikely that the woman will give birth within the next seven to 14 days, and can help the physician decide whether to delay giving medications to stall preterm labor.

Other tests might include a urine test, to exclude a urinary tract infection as a cause of preterm labor, or an amniocentesis, which can offer information about the baby’s lung development. Additional samples from the cervix may be tested for infection, which is a major cause of premature labor. If preterm labor is determined, initial treatment will most often include hydration with or without administration of terbutaline.  If this is unsuccessful in stopping labor, further treatment may include the intravenous administration of magnesium sulfate. An initial large dose, which may cause nausea, is followed by lower dose continuous intravenous administration over a period of 12 to 24 hours or more.

If labor continues to progress, and the patient is between 24 and 34 weeks gestation, a corticosteroid may be given to the woman by injection 24 hours before birth in order to increase the baby’s lung and brain development. Hospitals that have neonatal intensive care units (NICUs) offer premature babies the best chance for optimal health and survival. If premature labor continues and a premature delivery is expected, the patient may be transferred to a hospital with an NICU. Depending on how premature the labor is, the ObGyn may call in a neonatologist, a physician who specializes in premature intensive care. The neonatologist can help determine if any additional treatments are necessary for the premature infant.

Many infants born before 37 weeks of gestation will have respiratory distress syndrome (RDS). RDS is one of the most common complications associated with premature delivery. If left untreated, severe cases can lead to multiple organ failure and even death.

Treatment of RDS includes placing the baby on a respirator, which is a machine that helps the baby to breathe. In addition, the neonatologist may order oxygen treatments or treatments that include nitric oxide to improve breathing. In many cases, RDS usually resolves within four or five days. Additional treatment of a pulmonary surfactant, which keeps small air sacs in the lungs from collapsing, can help to speed recovery. In some cases, RDS can be avoided if labor can be delayed by 24 to 48 hours and specific medications (e.g., steroids) are administered to the mother to allow an accelerated development of the lungs.

Another common complication of premature infants and a serious concern for parents and physicians is bleeding in the brain (intracranial hemorrhage). This happens more often in very premature babies (before 34 weeks gestation), who are at higher risk of serious complications and conditions.

In addition to RDS and intracranial hemorrhage, other common complications that impact premature babies more often than full-term babies include:

• Low birth weight (less than 2,500 grams or about 5 pounds, 8 ounces)
  
  
• Very low birth weight (less than 1,500 grams or about 3 pounds, 5 ounces)
  
  
• Eye problems (retinopathy of prematurity)
  
  
• Intestinal problems
  
  
• Breathing problems (apnea)
  
  
• Jaundice (a yellow skin color due to an immature liver)
  
  
• Anemia (lack of red blood cells)
  
  
• Infections
  
  
• Sudden infant death syndrome (SIDS)

Although there are identifiable risk factors that indicate a woman is more likely to deliver prematurely, there are no known methods of prevention. Perhaps the most important way to lower the risk of a premature birth is to get early and adequate prenatal care.

Another way for women to prevent many pregnancy complications is to maintain a healthy weight and lifestyle. In addition, consuming the recommended amount of prenatal vitamins, including folic acid, may reduce the risk of premature birth, as well as birth defects and other complications.

Although bed rest, fluids and labor-inhibiting medications including steroids may be prescribed, these attempts often merely offer a short delay in the delivery to allow physicians to speed the development of the baby’s lungs and, if necessary, transfer the mother to a hospital that is better equipped for premature babies, such as one with a neonatal intensive care unit (NICU).

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about premature birth:

1. Am I at risk for having a premature baby?
   
   
2. What are the signs that I may be going into early labor?
   
   
3. At what point should I contact you?
   
   
4. If I do go into premature labor, are there any preventative measures I can use?
   
   
5. Once I go into premature labor, what are my treatment options?
   
   
6. Are there any lifestyle changes that could reduce my risk of a premature baby?
   
   
7. If I’m pregnant with multiple babies, are my chances increased for premature delivery?
   
   
8. Which hospital should I consider if I’m at risk for premature delivery?
   
   
9. Will I need a neonatologist? If so, can you recommend a doctor?
   
   
10. What will be done for my premature baby once he or she is delivered?