An older neighbor used to delight our children with the story of her birth. A premature baby born at home, she didn’t begin to breathe after birth, and the doctor considered her too small to survive. Nevertheless, he wrapped the tiny infant in a receiving blanket, put her in a shoe box and placed her in the wood burning oven that was still warm from the day’s use. About 15 minutes later, there was a cry from the oven and to everyone’s amazement the little girl survived. She became a highly respected woman in the community and the mother of seven children.

A premature baby born today has an enormous advantage over a pre-term baby born 80 years ago, as Ruth was. Babies now survive at much earlier delivery dates thanks to sophisticated neonatal intensive care units (NICUs) equipped with humidicribs and specialized staff armed with the latest drugs and procedures to help babies breathe and to protect the developing eyes, ears and brain.

Our concept of what constitutes prematurity has also changed. Normal gestation is around 40 weeks. Degrees of prematurity are classified as low birth weight (2500 grams or less, about five and one-half pounds), very low birth weight (1500 grams or less, three and one-half pounds) and extremely low birth weight (800 grams or less, about one and thre-quarter pounds).

Babies who would have had virtually no hope of survival even 20 years ago can now be saved. In the United States seven percent of babies born each year are classified as low birth weight.

What Are the Costs?
While it’s now possible to save very tiny infants, this advance comes at a cost of developmental and neurological problems, repeat hospitalizations, educational problems and family stress.

Every week of pregnancy is associated with specific stages of infant development relating to the heart, lungs, eyes, ears and brain. When a child is born prematurely, that development is interrupted and has to be continued outside the uterus.

Extremely pre-term infants, born at around 23 weeks gestation, face difficult odds. A study conducted in The Netherlands found that 66 percent of infants born this early died. Of those who survived, half had severe mental or physical handicaps at age two.

Every week an infant spends in utero increases its chances of survival and the likelihood that the child will be free of major disability.

An Australian study of infants born between 23 and 27 weeks found that by age five the survival rate was 56 percent. Although half of the children who survived had disabilities of varying degrees, almost half of the survivors had no negative indications and researchers concluded that their outcome did not differ significantly from the normal birth weight babies who served as controls in this study.

One study of full-term (40 weeks), close-to-term (37 weeks) and pre-term (34 weeks) infants found that the close-to-term and full-term infants were more similar on a number of measured tests of motor skills, attention, interaction and overall behavior than they were to the pre-term group. Although the study found that even the last three weeks of gestation made a difference behaviorally, the differences were most pronounced between those born at 34 weeks and the other two groups.

Handle With Special Care
Although many pre-term infants may be medically stable to go home in the weeks after birth, they’re not as robust as their full-term peers and tend to be more sensitive to external stimuli.

As a group they have more difficulty calming themselves and are more fragile. These babies benefit from calm, slowed feeding times and do better with fewer caregivers who are able to provide a soothing, close relationship. They respond better to a supportive, calm, nurturing daily routine. Parents should be aware that healthy, pre-term infants are generally not as well-organized, energetic and robust as full-term children.

Infants weighing 3.5 pounds or less at birth now represent 1.5 percent of all live births in the United States. At this stage of development, survival rates are around 85 percent. The risk of a major neurological or developmental handicap among those who survive is between 12 and 32 percent. About half of this group of premature children will require special assistance in school and about one in five will repeat a grade by age eight.

Studies show that infants born at this stage average about 15 points below the population mean on standard IQ scores, although most still fall within the normal range. On a more positive note, one study found that 93 percent of a group of pre-term children born before 33 weeks gestation were attending a normal school in a classroom appropriate for their age. One third of the children had problems with reading, spelling or math, about double the number of normal birth weight children showing such difficulties.

A U.S. study of a group of extremely premature infants (23 to 28 weeks gestation) identified three factors that predict the need for special education at kindergarten entry: low socioeconomic status, nonwhite race and male gender.

Researchers suggest that pre-term children benefit from structured programs in kindergarten and smaller groups that assure social interaction and individual attention.

Identifying reading and math difficulties early makes it possible to get specialized help before a child becomes frustrated and falls behind.

It is ironic that while medical science has developed highly sophisticated technology for saving infants at increasingly early gestational stages, we haven’t managed to reduce the incidence of pre-term births. The best place for an infant prior to its expected delivery date is in the mother’s uterus. No external support system can replicate the myriad complexity of the womb.

Pre-term births can occur for countless reasons, many of which can never be identified. There are risk factors that we do know about, however, and avoiding them is a first step for pregnant women.

Prenatal care from early in the pregnancy increases the chance for having a healthy, full-term infant. Regular checkups to identify and treat problems early, taking folate and vitamin supplements as recommended by your doctor, following a healthy diet with adequate weight gain and avoiding harmful substances such as drugs, alcohol and smoking are all steps that help protect the developing fetus.

Smoking is especially harmful to the fetus, robbing it of oxygen and slowing development. Studies show that premature delivery and birth defects occur twice as often in women who smoke and also have asthma compared with nonsmokers.

Medical science has much to offer premature infants. Pregnant women can strive for a healthy, full-term pregnancy and take comfort in the knowledge that should labor begin early, there is a wealth of knowledge and expertise to help the baby survive and get the best start in life it can.

REFERENCES:
Lex Doyle, “Outcome at 5 Years of Age of Children 23 to 27 Weeks’ Gestation: Refining the Prognosis,” Pediatrics, July 2001.
David Field et al, “Measuring Later Health Status of High Risk Infants,” British Medical Journal, December 1, 2001.
“The Grim Facts on Extremely Pre-Term Birth,” Contemporary OB/GYN, November 2000.
Cecilia McCarton et al, “Results at Age 8 Years of Early Intervention for Low-Birth-Weight Premature Infants,” JAMA, January 8, 1997.
Laurie Mouradian et al, “Neurobehavioral Functioning of Healthy Preterm Infants of Varying Gestational Ages,” Journal of Developmental and Behavioral Pediatrics, December 2000.
Paivi Olsen et al, “Psychological Findings in Preterm Children Related to Neurologic Status and Magnetic Resonance Imaging,” Pediatrics, August 1998.
Bradley Peterson et al, “Regional Brain Volume Abnormalities and Long-Term Cognitive Outcome in Preterm Infants,” JAMA, October 18, 2000.
“Pregnant Asthmatic Smokers At Greater Risk for Pregnancy Complications,” Women’s Health Weekly, April 26, 2001.
“Preterm Birth Changes Normal Development of Lung Function,” Immunotherapy Weekly, January 30, 2002.
“Providing Information to Parents of Extremely Premature Newborns,” JAMA, January 2, 2002.
Tony Sheldon, “Dutch Doctors Change Policy on Treating Preterm Babies,” British Medical Journal, June 9, 2001.
Lise Stevens, “Low Birth Weight,” JAMA, January 9, 2002.
D.K. Stevenson, “Sex Differences in Outcomes of Very Low Birthweight Infants: the Newborn Male Disadvantage,” JAMA, December 27, 2000.
David L. Streiner et al, “Attitudes of Parents and Health Care Professionals Toward Active Treatment of Extremely Premature Infants,” Pediatrics, July 2001.