A premature baby, or “preemie,” is one born before 37 weeks of pregnancy, according to the March of Dimes. A normal term of pregnancy ranges from 37 to 42 weeks. As of 2010, about 12.8 percent of babies born in the United States are premature. Advances in obstetrics have enabled most premature babies to survive, but many suffer from long-term health consequences.

Cognitive Developmental Risks

Some premature babies, especially those born before 32 weeks of pregnancy, are likely to suffer from one or more serious cognitive developmental challenges, notes the March of Dimes. The risks of mental retardation, autism, learning, speech and behavioral problems significantly increase with premature birth. About 16 percent of premature births happen before 32 weeks of pregnancy; this group of infants is more likely to suffer significant cognitive developmental challenges in life, though there are no guarantees in either direction.

Physical Developmental Risks

All premature babies are usually born smaller than on-time infants, notes the March of Dimes. Again, babies born before 32 weeks of pregnancy usually suffer from the most physical risks. Their organs are much less developed than infants born later in pregnancy, and such babies are usually in additional need of specialized neonatal intensive care. Potential physical risks to premature babies include cerebral palsy, lung problems and vision and hearing loss.

Babies Born Before 26 Weeks

Survival rates are still rather high among babies born as early as 26 weeks into pregnancy, at about 80 percent, according to the March of Dimes. But these babies require months of intense medical care, including intravenous feedings; babies born at or before 26 weeks of pregnancy are not developed enough to suck and swallow simultaneously. About 25 percent of these babies will experience lasting serious medical problems.

Maternal Risks

Premature labor itself usually does not cause increased health risks to the mother, notes MayoClinic.com. But the drugs used to stall preterm labor have potential health consequences for expectant moms; fluid may build in the lungs and cause breathing problems. Other potential side effects of drugs used to stop premature uterine contractions include rapid heartbeat, blood sugar abnormalities, headache, nausea and dizziness.

Decreasing Premature Birth Incidence

Some moms are unfortunately more likely to deliver premature babies than other expectant mothers, notes the March of Dimes. The risks of premature births are highest among teenage mothers, mothers over 35, smokers, women with cervical or other reproductive abnormalities, women expecting twins, triplets or other multiples, and women with a history of premature labor. All women can decrease their chances of premature labor by practicing good self-care habits during their terms, including prenatal care and avoiding junk food, cigarettes, illegal drugs and alcohol.