MISCARRIAGE AND PREMATURITY
Every year an unknown number of babies miscarry and several thousand are born prematurely. A miscarriage occurs at or before twenty-eight weeks and prematurity refers to a birth between twenty-eight and thirty-seven weeks. Miscarriages are almost always fatal, whereas a premature baby may stand a good chance of surviving. Miscarriage and prematurity can both be caused by such things as serious illness, shock or foetal abnormality. A miscarriage can also be encouraged by drugs and other environmental factors.
The oldest treatment for all threatened miscarriages or prematurity is bed rest. The value of this has been widely questioned. There has never been a properly controlled trial and, as a result, the evidence for and against it remains inconclusive. But the evidence that is available suggests that it is certainly no worse, and probably better, than many of the more complicated and potentially hazardous treatments.
Two causes of miscarriage and prematurity are thought by the medical profession to be treatable. The first is known as 'cervical incompetence' and means that the muscles and tissues of the cervix are unable to hold the foetus for the full duration of pregnancy. Treatment for cervical incompetence entails putting a stitch around the cervix to keep it closed (sometimes known as cervical cerclage). This is done in hospital at about thirteen to fourteen weeks and is removed at around thirty-eight weeks.
The premature onset of labour (or uterine contractions) has been treated for a number of years with a variety of drugs, all of which are intended to stop contractions. But the number of pregnancies that are likely to benefit from this is probably very small. Furthermore all the drugs appear to carry risks. Before accepting a course of drug treatment to stop labour, it is important to be sure that it is both necessary and wise. The British Medical Journal has twice dismissed drug treatment for premature labour with the phrase 'usually unnecessary, frequently ineffective and occasionally harmful'. Few drugs have been adequately researched to know whether or not they are harmful.
Nevertheless if it is still thought a good idea to stop labour in your case, then the range of drugs that may be prescribed for you is bewilderingly large. Probably the most common ones in Britain are the betamimetic agents which go under such names as Ritodrine, Salbutamol, Terbutaline and Fenoteral. But you may also be offered ethanol or prostaglandin synthetase inhibitors or even, though it's unlikely today, hormone treatment. All drugs have three question-marks hanging over them. Firsdy, do they significandy improve the baby's chances? The evidence so far is doubtful. While some pregnancies are prolonged, the gain may be only a week or so and it is uncertain whether this outweighs the potential disadvantages associated with drugs. Secondly, do they harm the foetus? Since the foetus is very sensitive to drugs there is serious doubt as to whether these drugs are safe. There is clear evidence that some of them can damage the foetus. Too little is known about others, but that doesn't mean they can automatically be regarded as harmless to the baby. It is an international scandal that the side effects of these drugs have not been systematically studied. We have already discussed diethylstilboestrol (DES). Hormones other than DES such as ethisterone and other progestogens, which were once very popular, are now believed to be associated with congenital abnormalities. Prostaglandin synthetase inhibitors, so-called because they inhibit the body from making a chemical called prostaglandin which causes uterine contractions, enjoyed a brief vogue during the second half of the 1970s, but they are now associated with respiratory problems in newborn babies and have gone out of favour.
As the British Medical Journal reported:
The lack of information on the long-term outcome of the child after treatment of premature labour is serious; preventing the morbidity of prematurity may be just as important as reducing mortality and this aspect should be given more attention in future investigations.
Thirdly, do these drugs harm the mother? Again, many of them have potent side effects and some should never be used in certain circumstances. Ethanol produces headaches and sickness. Betamimetics are known to have serious side effects in mothers suffering from diabetes, cardiac disease and hypertension. Whether these effects are serious in a normally healthy woman is unknown.
Although there is no evidence to prove its value, an accepted practice is to inject a woman with corticosteroids over a two-day period to speed up the development of a baby's lungs, at the same time as giving her betamimetics. Several studies have suggested that this combination can cause severe problems of fluid on the lungs. One correspondent in the British Medical Journal wrote:
Because of the lingering doubts concerning the wisdom of beta [mimetic] drugs in premature labour and because their use is limited by the significant incidence of unpleasant side effects, the search must continue for therapeutic alternatives
Neither is it known whether or not the powerful corticosteroids will interfere with the developing brain, or with the establishment of immune mechanisms, or of sexual rhythms at puberty. Whether you decide to take the gamble and accept drugs will depend on your situation. If you have already lost a baby because of prematurity, the uncertainties of drug treatment may be outweighed by the desire to avoid a repetition. Only you can make this very difficult decision.
ArticlesUnexpected labor events: cesarean