Prematurity - (info from Children's Hospital, Boston, USA) http://www.childrenshospital.org/cfapps/A2Z.cfm
What is prematurity?
A baby born before 37 weeks of pregnancy is considered premature, that is, born before complete maturity. Slightly fewer than 12 percent of all babies are premature. Overall, the rate of premature births is rising, mainly due to the large numbers of multiple births in recent years. Twins and other multiples are about six times more likely to be premature than single birth babies. The rate of premature single births is slightly increasing each year.
Other terms often used for prematurity are preterm and preemie. Preterm generally refers to the pregnancy (as in preterm labor), while premature is more often used to describe the baby. Many premature babies also weigh less than 2,500 grams (5 .5 pounds) and may be referred to as low birthweight (LBW).
What causes prematurity?
There are many factors linked to premature birth. Some directly cause early labor and birth, while others can make the mother or baby sick and require early delivery.
The following factors may contribute to a premature birth:
Maternal factors:
preeclampsia (also known as toxemia or high blood pressure of pregnancy)
chronic medical illness (such as heart or kidney disease)
infection (such as group B streptococcus, urinary tract infections, vaginal infections, infections of the fetal/placental tissues)
drug use (such as cocaine)
abnormal structure of the uterus
cervical incompetence (inability of the cervix to stay closed during pregnancy)
previous preterm birth
Factors involving the pregnancy:
abnormal or decreased function of the placenta
placenta previa (low lying position of the placenta)
placental abruption (early detachment from the uterus)
premature rupture of membranes (amniotic sac)
polyhydramnios (too much amniotic fluid)
Factors involving the fetus:
when fetal behavior indicates the intrauterine environment is not healthy
multiple gestation (twins, triplets or more)
Why is prematurity a concern?
Premature babies are born before their bodies and organ systems have completely matured. These babies are often small, with low birthweight (less than 2,500 grams or 5 = pounds), and they may need help breathing, eating, fighting infection, and staying warm.
Very premature babies, those born before 28 weeks, are especially vulnerable. Many of their organs may not be ready for life outside the mother's uterus and may be too immature to function well.
Some of the problems premature babies may experience include:
temperature instability - inability to stay warm due to low body fat.
respiratory problems:
hyaline membrane disease/respiratory distress syndrome - a condition in which the air sacs cannot stay open due to lack of surfactant in the lungs.
chronic lung disease/bronchopulmonary dysplasia - long-term respiratory problems caused by injury to the lung tissue.
air leaking out of the normal lung spaces into other tissues
incomplete lung development
apnea (stopping breathing) - occurs in about half of babies born at or before 30 weeks
cardiovascular
patent ductus arteriosus (PDA) - a heart condition that causes blood to divert away from the lungs.
too low or too high blood pressure
low heart rate - often occurs with apnea
blood and metabolic:
anemia - may require blood transfusion
jaundice - due to immaturity of liver and gastrointestinal function
too low or too high levels of minerals and other substances in the blood such as calcium and glucose (sugar)
immature kidney function
gastrointestinal:
difficulty feeding - many are unable to coordinate suck and swallow before 35 weeks gestation
poor digestion
necrotizing enterocolitis (NEC) - a serious disease of the intestine common in premature babies.
neurological:
intraventricular hemorrhage - bleeding in the brain.
periventricular leukomalacia - softening of tissues of the brain around the ventricles (the spaces in the brain containing cerebrospinal fluid).
poor muscle tone
seizures - may be due to bleeding in the brain
retinopathy of prematurity - abnormal growth of the blood vessels in a baby's eye.
infections - premature infants are more susceptible to infection and may require antibiotics
Premature babies can have long-term health problems as well. Generally, the more premature the baby, the more serious and long lasting are the health problems.
Copyright © 2001, Children's Hospital Boston. All rights reserved.
The information on this website should not be taken as medical advice,
which can only be given to you by your personal health care professional.
UK Statistics on Premature Births (info from Bliss http://www.bliss.org.uk/)
The UK has the highest rate of low birthweight babies in Western Europe
Babies born at 23 weeks have a 17 per cent chance of survival
Babies born at 24 weeks have a 39 per cent chance of survival
Babies born at 25 weeks have a 50 per cent chance of survival
Twenty years ago, approx 20% of babies weighing less than 1,000gms (2lb 2oz) at birth survived. Nowadays, about 80% survive.
Twelve percent of all babies born need some level of special care at birth (about 80,000) and 2.5% of all babies born need some level of neonatal intensive care (about 17,000).
Premature baby: Born before 37 weeks
Moderately premature baby: Born between 35 and 37 weeks
Very premature baby: Born between 29 and 34 weeks
Extremely premature baby: Born between 24 and 28 weeks
Low birthweight baby: Weighs less than 2,500g (5.5 lbs)
Very low birthweight baby: Weighs less than 1,500gms (3.0 lbs)
About 8% of all deliveries in the UK, are preterm. Premature labor is responsible for about 75% of stillbirths and deaths of babies in the first 7 days of life.
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