What causes prematurity?
There are many factors that come into play when a baby is born prematurely. 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:
- 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 and 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 isn't 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 5 pounds), and they may need help breathing, eating, fighting infection and staying warm. Very premature babies who are 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
- hyaline membrane disease/respiratory distress syndrome - a condition in which the air sacs cannot stay open due to lack of surfactant in the lung
- 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
- 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:
- 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
- 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
How can I prevent prematurity?
Because of the tremendous advances in the care of sick and premature babies, more and more babies are surviving despite being born early and being very small. But prevention of early birth is the best way of promoting good health for babies.
Prenatal care is a key factor in preventing preterm births and low birthweight babies. At prenatal visits, the health of both mother and fetus can be checked. Because maternal nutrition and weight gain are linked with fetal weight gain and birthweight, eating a healthy diet and gaining weight in pregnancy are essential. Prenatal care is also important in identifying problems and lifestyles that can increase the risks for preterm labor and birth. Some ways to help prevent prematurity and to provide the best care for premature babies may include the following:
- identifying mothers at risk for preterm labor
- prenatal education of the symptoms of preterm labor
- avoiding heavy or repetitive work or standing for long periods of time which can increase the risk of preterm labor
- early identification and treatment of preterm labor