Chances for Survival
What are the chances that my baby will survive?
Many factors determine an individual baby's chances of survival. The most important of these are:
- The baby's gestational age (number of completed weeks of pregnancy) at the time of birth
- The baby's weight
- The presence or absence of breathing problems
- The presence or absence of congenital abnormalities or malformations
- The presence or absence of other severe diseases, especially infection
In the smallest infants, gestational age is usually most important because it determines if the infant's organs, particularly the lungs, have developed enough to allow the baby to live within the limits of our current technology. Your baby's doctor will be able to give you the best estimate of your infant's chances since he/she can take into consideration many of the above factors. But, no estimate is perfect. Some babies suddenly get sick and die unexpectedly; others defy all odds. General estimates of survival for live born infants who receive neonatal intensive care in the USA in the late 1990's are:
|Completed Weeks of Gestation at Birth|
(Using last menstrual period)
|21 weeks and less||0%|
*Most babies at 22 weeks are not recuscitated because survival without major disability is so rare.
A baby's chances for survival increases 3-4% per day between 23 and 24 weeks of gestation and about 2-3% per day between 24 and 26 weeks of gestation. After 26 weeks the rate of survival increases at a much slower rate because survival is high already.
What other factors influence survival?
Other factors may influence survival by altering the rate of organ maturation or by changing the supply of oxygen to the developing fetus.
- Rupture of the fetal membranes before 24 weeks of gestation with loss of amniotic fluid markedly decreases the baby's chances of survival even if the baby is delivered much later.
- Male infants are slightly less mature and have a slightly higher risk of dying than female infants.
- For a given weight, African-American babies have a slightly better survival than Caucasian; most other races are intermediate between the two.
- Diabetes in the mother, if not well controlled, slows organ maturation and these infants have a higher mortality.
- Severe high blood pressure before the 8th month of pregnancy may cause changes in the placenta, decreasing the delivery of nutrients and/or oxygen to the developing fetus and leading to problems before and after delivery.
Can my obstetrician do anything to improve my baby's chances of survival?
Yes, there are things s/he can try if there is enough time and if you are the appropriate candidate for therapy. Sometimes women are too near delivery for treatments to be effective. Other women have complications such as infection, fetal distress or bleeding which make a more rapid delivery the best option.
- You may be placed on bedrest.
- Your obstetrician may try to stop your labor using labor-inhibiting drugs.
- Your obstetrician may give you a steroid medication such as Betamethasone or Dexamethasone to try to speed up the baby's lung development. This is most effective if it is given more than 24 hours before delivery.
Chances for Disabilty
What are the chances that my baby will have a significant disability or handicap?For any infant, IT IS IMPOSSIBLE TO PREDICT AHEAD OF TIME THE LIKELIHOOD OF A SIGNIFICANT HANDICAP (moderate or severe mental retardation, inability to walk without assistance, blindness or deafness). However, some factors increase the RISK of these handicaps:
- Extreme prematurity, especially infants of 23-24 weeks of gestation at birth. At these gestations the risk is about 50%. As gestational age increases, the chances of being normal or nearly normal increases dramatically and is similar to the chances for survival. This means if survival is 80%, then about 80% of those who survive are free of major disability. Thus, with a 80% survival, 20% will die, about 64% will be healthy and 16% will have major disabilities.
- Identifiable brain abnormalities. These may occur before birth or in the nursery. These include large intraventricular hemorrhages and/or periventricular leukomalacia.
- Babies who have been the sickest and/or remained sick for long periods of time (several weeks).
What are the chances that my baby will have a minor disability?Minor disabilities occur in about 15% of children born on time. They occur more often in premature infants, about half of infants weighing less than 3 1/2 pounds at birth. Many of these are not appreciated until school age. Common minor disabilities include short attention span; specific learning problems in school such as difficulty with math or reading; poorer than average coordination, especially for games requiring eye-hand coordination like hitting a ball; and needing glasses at an early age. Children with minor disabilities usually lead normal lives. Early identification of these problems helps make learning easier.
As you can see, these odds are not as bad as you would think. Every year, advances in medical practice become more and more sophisticated which means that more and more babies are living and thriving desptite their very early arrival. While I certainly can't know or predict if your preemie will fit into the average statistics, I can tell you that I have spoken to hundreds of preemie mothers and I have seen some very sick little babies live and lead productive lives. I myself had two micro preemies who both have come a very long way. I hope and pray that you too will have a similar outcome.