PREMATURITY: IT’S CAUSE & PREVENTION
Although, for the most part, the cause is unknown, there are a few obvious reasons for prematurity.
Cervical incompetence: This probably is the only condition which is avoidable. But, until it has occurred once, there is no way of predicting and preventing it.
In this, the cervix is too weak to stay closed for the duration, generally giving way in the last weeks of the second trimester. The incidence is higher in women who have had abortions.
Multiple pregnancies: Women who are carrying two or more babies are predisposed to premature birth, commonly occurring between 30 and 34 weeks.
Foetal abnormality: If an abnormality is detected by screening methods, such as ultrasound or amniocentesis, it may alert your doctor to the possibility of pre-term labour.
Induction and Caesarean section: Certain conditions, including pre-eclampsia and antepartum haemorrhage (both manifest in high blood pressure), sometimes call for induction or Caesarean to save the lives of the mother and/or baby. Likewise, pre-existing maternal conditions, such as diabetes, epilepsy and kidney disease, or severe illness, may indicate intervention in the pregnancy.
Hydration: This rare condition, in which there is an excess of amniotic fluid, is most likely to occur where the uterus is carrying identical twins, although occasionally, it is associated with diabetes.
Uterine abnormalities: Huge fibroids—muscle tumours in the uterine wall—are another rare cause of pre-term labour. A congenital abnormality in the size or shape of the uterus may prevent it from carrying a foetus for the entire term.
Maternal age: Mothers under the age of 20 may have a predisposition to premature labour.
Hereditary factors: If your mother delivered her babies prematurely, there is a slight chance that you will have inherited this trait.
PREVENTION OF PRE-TERM BIRTH
Where the reason is unknown, generally, nothing can be done to prevent the start of premature labour. However, sometimes it can be halted if the baby is considered too young to survive.
• If cervical incompetence caused a pre-term birth previously, a second may be avoided by the insertion of a cervical stitch at about 14 weeks gestation, to be removed a couple of weeks before the expected delivery date or when labour starts, whichever happens first.
• Drugs can be given to lower blood pressure, obviating the need for induction. However, once labour has started, intervention is usually not undertaken.
• If premature labour begins for no apparent reason, a woman will be admitted to a hospital where drugs may be administered to stop contractions temporarily. During this respite, the mother will be treated with a drug that will cross the placenta and work on developing the baby’s lungs.
• Where a woman has had a previous pre-term labour, she may be advised to abstain from intercourse for the final two months. This is because prostaglandins in semen are believed to trigger contractions.
• Some doctors suggest that patients expecting multiple births take to their beds as a safeguard from 30 to 34 weeks or for the rest of their pregnancy.
SOME FACTS
Pre-term birth occurs when a foetus is born after 20 weeks and before 37 weeks gestation.
• The incidence of premature births is five or six per cent.
• A foetus is considered ‘viable’—that is, capable of ex-uterine survival—at 28 weeks. Babies three or four weeks younger than this have survived only after long-term intensive care.
• According to the Royal Hospital for Women in Sydney, under optimum conditions, a 26 weeks foetus has a 65 per cent chance of survival. By 28 weeks, the figure has risen to 85 per cent.
• Birthweight used to be the factor in determining prematurity: today, it is the duration of pregnancy. Less than 2500 g is considered low birth weight, and this usually applies to pre-term babies.
• Australia’s youngest surviving twins, born in Tasmania in 1986, weighed just over 600 g and 700 g at birth.
• Forceps are often used during delivery in an effort to protect the baby’s soft skull.
• Although by no means a certain occurrence, subsequent births can also be premature.
• If there is reason to suspect you may deliver prematurely, you should be booked into a hospital with a neonatal intensive care unit.
• In the best scenario, a pre-term baby could be ready to go home by the time she reaches her expected date of delivery. However, some, especially if they are oxygen-dependent or have digestive troubles, may be hospitalised for as long as five or six months.
• Research has shown that the milk of women whose baby was born prematurely is perfectly balanced for the needs of a pre-term infant, as it will provide antibodies you usually would have passed on to the baby in the uterus.
IF YOUR BABY IS PREMATURE
The premature baby’s appearance—
Parents generally are shocked at the strange appearance of their premature baby.
As most fat cells are laid down in the last six weeks of pregnancy (the baby’s weight almost doubles during this period), the premature infant appears to be nothing but red, wrinkly skin and bone. Compared with full-term infants, her length is disproportionate to her weight and her head, in turn, seems unnaturally large. Her ears may appear misshapen as cartilage has not yet formed.
Before 28 weeks, the baby probably will have fine hair (lanugo) on her body. Her eyes will be closed.
Tiny babies often have jerky movements, but these are pretty normal at this stage.
Suppose she goes into level 3 intensive care. In that case, some 50 per cent of her subtle body will be covered with suction cups and sticking plaster, attached tubes and wires linked to a buzzing, flashing bank of equipment that would not look out of place on board the Millenium Falcon.
In itself, the sight of their elfin newborn overwhelmed by such high technology is enough to distress many parents. One of life’s most heart-rending sights is of a human atom, barely larger than a kitten, crying soundlessly in her plastic cocoon.
After a couple of days, the baby may look like the victim of a car smash. Her skin is so delicate that whenever one of the plasters is removed, or she is attached to an intravenous drip, she will be left with a bruise or raw patch. Do not worry about this.
RESPONSE
Full-term newborns cannot focus appropriately for some weeks; a premature baby cannot see at all. However, it is believed that she can hear and, especially if she is reasonably mature, will respond to auditory stimuli.
Nursery staff, whose working life is devoted to monitoring premature infants, are convinced they know when their parents are present.
Pre-term babies tend to sleep virtually all the time when they are not feeding.
PROBLEMS AND CARE
Most of their difficulties are associated with the maturity of their organs. Trouble breathing and regulating body heat are the two most common problems, even at 34 weeks. For this reason, they are placed in an incubator which is actually an artificial extension of the mother’s womb.
Breathing difficulties may be manifest in apnoea (interrupted breathing) or respiratory distress caused by a lack of surfactant, which reduces surface tension in the lungs, preventing them from total deflation with each breath.
Hypoglycaemia, or low blood sugar, is not uncommon in these babies. Treatment is by intravenous drip containing glucose.
Due to the immaturity of the liver, jaundice, which makes the baby look like she has just returned from a tropical holiday, is common.
Compared with full-term infants, premature babies make giant leaps forward
When the baby is being treated with ultraviolet light, she will wear a bonnet, and her eyes will be well covered to protect her.
Low birth weight, whether associated with prematurity or not, predispose a newborn to illness and infection.
The sucking reflex doesn’t come into its own until about 36 weeks, sometimes later. In the first days or weeks, in the case of a really tiny baby—she will be fed intravenously, first with glucose, then with a unique mixture. After that, she progresses to a catheter which leads through a nostril to her stomach.