While exact figures are difficult to nail down, it is estimated that 15 million premature births occur worldwide each year. Premature birth (or preterm birth) is defined as any live birth that takes place prior to 37 weeks of gestation. In developed countries like the United States — where one out of every eight newborns is at least slightly premature — over 90 percent of premature babies survive. In the Third World, however, the mortality rate is much higher; only 10 percent of prematurely born infants survive in some of the poorer parts of the globe.
Classification of Premature Birth
The World Health Organization categorizes preterm birth according to gestational age. Moderate to Late preterm births are those that occur between the 32nd and 37th weeks of pregnancy. Babies born 28 to 32 weeks early are considered Very Preterm. Premature birth that occurs before the 28th week of pregnancy are considered Extremely Preterm. These children face serious health complications, and many of them do not survive. Those who do survive may suffer severe disabilities for their entire lives. The 24th week of pregnancy is considered the “Limit of Viability,” i.e., the earliest point in gestation at which an infant has at least a 50 percent chance of surviving (although the survival record belongs to James Elgin Gill, who was born in 1987 after only 21 weeks and five days of gestation).
Health Problems Associated with Premature Birth
Premature birth is a frequent cause of low birth weight, and preterm babies often require neonatal intensive care due to incomplete development of their organs. Other problems that can be caused by premature birth include:
- Small body and disproportionately large head
- Thin skin, with a slightly transparent appearance
- Difficulty breathing—many preterm babies lack surfactant, a protein that prevents air sacs in the lungs from collapsing
- Difficulty feeding due to underdeveloped swallowing reflexes
- Heart problems
- Cerebral palsy
- Anemia
- Hypoglycemia
- Jaundice (yellow complexion due to poor liver function)
- Underdeveloped immune system, which makes the baby susceptible to infections
- Psychological problems
- Intellectual disabilities
Brain bleeding, also known as intraventricular hemorrhage, is one of the more serious potential complications of preterm birth, and it can lead to hydrocephalus—necessitating surgery to drain the accumulated fluid—and severe brain damage. In addition to intellectual disability, this can cause psychological problems later in life, including anxiety, depression, and difficulty interacting with peers. Brain bleeding is more common in infants born before 24 weeks.
Premature babies also lack the body fat that a full-term baby has, so they have difficulty regulating their body temperature. Because of this, they are at risk for hypothermia, and their growth may be stunted if their bodies use all the calories they consume just to keep warm, rather than to grow larger.
Causes of Premature Birth
Many preterm births occur spontaneously, with no apparent cause. For some reason, preterm birth occurs more often to women of African descent, and no one has yet determined why this is the case. In some cases the premature birth may be associated with pregnancy involving twins or multiples, or a chronic condition such as high blood pressure or diabetes. Two other important risk factors are poor nutrition and intervals of less than six months between pregnancies; this is one of the reasons premature birth is so common in underdeveloped countries.
Other risk factors for preterm birth include:
- Previous premature birth
- In vitro fertilization
- Infections affecting the genital area or amniotic sac
- Being underweight or overweight during pregnancy
- Trauma or injury
- History of miscarriages
- Multiple abortions
Prevention of Premature Birth
- The risk of preterm birth can be mitigated with healthful behavior. See your doctor regularly throughout your pregnancy, and take care of yourself and your baby by:
- Eating a healthful diet
- Quitting smoking
- Not drinking alcohol
- Taking prenatal vitamins (especially folic acid)
- Talking to your doctor about managing any chronic conditions you may have, such as diabetes or high blood pressure
What to Expect From a Premature Birth
Even if you are not in a high-risk population group, and even if you take the best possible care of yourself, you may still experience a premature birth—it can happen to anyone. If you feel that you are going into labor prematurely, get to an emergency room immediately. The outcome of your preterm labor will depend greatly on how far along your pregnancy is, but the sooner you seek medical attention, the better your chances of delivering a healthy baby.
After your baby is born, the doctors will most likely want to place him or her in an incubator so that he or she can be kept warm (remember, premature babies are very susceptible to loss of body heat). Your baby will receive intensive neo-natal care until his or her condition stabilizes. If all goes well, you will be allowed to take your baby home when he or she:
- Weighs at least four pounds
- Can maintain his or her body temperature without the aid of an incubator
- Can breathe normally
- Exhibits steady weight gain
- Can breastfeed or bottle feed
Questions to Ask Your Doctor About Premature Birth
- Is there any reason to believe that my baby will be born prematurely?
- What changes to habits do you recommend in order to ensure that my baby will not be born prematurely?
- In the event that I go into preterm labor, will you come to the hospital to assist with my care?
- Are there any environmental factors that may be putting me at greater risk for a premature birth?
- If I were to go into preterm labor at this stage of my pregnancy, what would my baby’s prognosis be?