PREMATURE BABIES

Most people think that a typical pregnancy lasts 9 months. That's not exactly the case. A pregnant woman's "due date" is generally considered to be 40 weeks from the first day of her last menstrual period, with conception usually occurring about 14 days later.


A baby born more than 2 weeks before its due date is considered premature. Because premature babies have not had time to fully develop and build strength in the womb, they are at increased risk for medical and developmental problems.
If a woman goes into labor before 36 weeks, her doctor will usually try to delay the birth, to give the baby more time to mature. However, this is not always possible, and some women give birth many weeks before their due date. Many advances have been made in caring for premature infants, and today even babies born at 25 weeks have a good chance of surviving.

We interviewed neonatologist Robert V. Johnson, M.D., about caring for premature babies.

We: What are the survival odds of premature babies, based on the week they are born?

Dr. Johnson: Babies born before or at 23 weeks probably have less than a 30 percent to 50 percent chance of surviving. Survival rates increase dramatically after 23 weeks. Babies born at 24 weeks have between 60 percent and 90 percent survival odds, depending upon how healthy they are at birth and how well they respond to initial medical care. Survival odds continue to increase the later a baby is born. A baby born at 25 to 26 weeks has between 80 percent and 90 percent survival odds, while a baby born between 33 and 36 weeks has a 98 percent chance of surviving. These are U.S. statistics.

We: What are the most serious medical or developmental problems for premature babies who survive their newborn hospital stay?

Dr. Johnson: The likelihood that a premature baby will develop chronic medical or developmental problems varies widely with their age at birth. I'll focus on the most important complications and the likelihood of their occurrence in babies born in the highest risk group, those born around 23 to 26 weeks.

One condition that very premature babies are at risk for is intracranial hemorrhage, or bleeding in the brain. The likelihood of the most serious intracranial hemorrhage ranges somewhere between 10 percent to 20 percent, with the higher numbers in the youngest babies. If brain bleeding occurs, it usually takes place within the first week to 10 days of life. The most severe bleeds, referred to as Grade 3 or Grade 4, carry the greatest likelihood that the child will develop serious problems, including developmental delays, seizures, learning disabilities, intellectual impairment and hydrocephalus (fluid accumulation in the brain). Mild cases of intracranial hemorrhage may require only observation, while severe cases may require operations to relieve excess fluid accumulation in the brain.

Another problem seen in the youngest and smallest premature babies is called retinopathy of prematurity, or ROP, a problem affecting the light-sensitive inner lining of the eye. This problem is seen most frequently in babies born at 24 to 26 weeks. The sicker a baby is, the greater the likelihood of serious problems with the developing retina. Many cases of ROP resolve on their own, while severe cases may be treated with cryotherapy, in which an extremely cold instrument is used to prevent retinal detachment.

There is also a risk of a potentially severe problem with the intestines referred to as necrotizing enterocolitis, or NEC. In the most serious cases, this condition can be life-threatening. At the very least, it can delay feedings and require intravenous nutrition and antibiotics for a week or two. This condition is seen in 5 percent to 7 percent of babies born before 28 to 30 weeks.

Perhaps a third of babies who survive after birth at 23 to 25 weeks may have serious, lasting neurologic problems, developmental delays, or significant cerebral palsy, hydrocephalus or seizures. About a third of these babies will have some chronic problems that are not considered major, such as mild cerebral palsy, the need to wear glasses and have ongoing eye care, or slight developmental delays.

Another third of these babies born at 23 to 25 weeks will do very well at first, showing no overt signs of any problems when they're sent home from the hospital. This group of babies is fortunate enough to have had no significant brain bleeding, no significant eye problems, and no other major difficulties that would seem to affect their long-term development. Yet, we know that as these children reach school age, most of them are not going to perform as well in school as their peers or as their siblings. The consequences of extreme prematurity still leave them with some problems.

We: Do all premature babies experience medical or developmental problems?

Dr. Johnson: It depends mostly on the gestational age of the baby and complications encountered during their newborn hospitalization. The highest risk of problems is in the youngest preemies. Even by 28 to 30 weeks, the risks of these complications is lower. The good news is that by 32 to 35 weeks the medical problems are usually short-term and resolved or nearly so by the time of hospital dismissal.

We: What specific care do most hospitals provide for premature babies? What can parents expect from the neonatal (newborn) intensive care unit (NICU)?

Dr. Johnson: The NICU is designed to provide care for premature babies and full-term babies who develop problems after birth. Doctors and nurses specially trained to care for newborns with medical problems will provide round-the-clock, intensive care for your baby. Your baby will probably be kept in an isolette, an enclosed plastic box that is kept warm so your baby will be able to maintain normal body temperature. There will probably be various tubes inserted and wires taped to your baby, which serve to deliver fluids, nutrition, and medication, and also to monitor blood pressure, heart rate, breathing and temperature. Caregivers may also use equipment, like ventilators, to help your baby breathe. All of the high-tech equipment may overwhelm you at first, but it's all designed to help your baby.

We: What can parents do to stay involved in their baby's care while he or she is in the NICU?

Dr. Johnson: While it may seem like the care of your premature baby is out of your hands, parents actually play a very significant role while their baby is in the NICU. Your baby's caregivers will help you learn how to touch and eventually hold your baby in ways that are reassuring, and not over-stimulating. Talking or singing softly to your baby at times, and just providing quiet company at other times, will provide great support and comfort. Eventually, when your baby is ready, the nurses will help you learn to feed your child.

We: What factors determine when preemies are ready to go home?

Dr. Johnson: Babies are ready to go home when they no longer have medical problems that require continuous hospital care, when their body temperature is stable without needing the isolette, and when they can nurse well enough to gain weight. There's no specific weight or age that a baby must reach before going home.

We: What should a parent expect in terms of follow-up care for their preemie? How often will they need to return for medical check-ups, etc.?

Dr. Johnson: Before you take your preemie home, your doctor will provide guidelines for caring for your baby at home. You should feel free to ask a lot of questions before going home with your baby. A follow-up visit will be scheduled for the near future, so your doctor can examine your baby, answer your questions, and talk with you about how things are going at home. Immunizations usually begin after the baby is 2 months old. Premature babies generally have more frequent trips to the doctor until we're confident that they are growing well and tolerating illnesses successfully.

Labels: Premature baby, Tips for parents