Preventing preterm birth

Prematurity is a serious public health problem throughout the world affecting approximately 10% of all births. It is a prime cause of infant mortality with an annual rate of one million attributed to it. Moreover, it leaves indelible imprints of ill health in the survivors, who suffer a variety of handicaps, some adult diseases, and mortality at an earlier age than the unaffected population.

Medicine, as a healing profession, has addressed this issue in its customary manner. With enormous effort, ingenuity, and clinical progress, it advanced care of premature infants to a point that has saved many who would have died in the more distant past, but now remain alive. Moreover those who survive are well, or have a substantially limited range of handicaps and diseases. This is an example of medicine’s best efforts as it acts in an anti-evolutionary direction by allowing not only the fittest to survive, but also those who might be considered less fit. The drama of this is played out daily in the best perinatal health services.

Public health, on the other hand, is far less dramatic. It requires substantial introspection to be comprehended, because its successes are measured in problems that did not happen. Just as a burning house that is saved by a dramatic rescue by firemen is more impressive than a house that does not burn, because it was made fireproof, so infants who are delivered at term, present normally in contrast to premature infants, who are seen in incubators, intubated, catheterized, and otherwise mechanically managed. Although that strikes us as a crescendo of success, it is the undramatic normality that we must continue to seek.

In order for us to attempt to prevent preterm birth, we must consider what is known about term birth. There is of course a lot of information. We now can determine the gestational age with ever growing precision, and assess physiological maturity of the infant emerging from the uterus into the wholly unfamiliar environment. Yet, with much of this knowledge instinctively accepted, we lack the key message. We do not know what prompts all this.

It seems logical, although not absolutely so, that understanding all the antecedents of term birth would allow us to understand those aberrations that lead to the abnormal early start of labor. Of course, we must exercise some caution in maintaining this concept and be prepared for the possibility that early labor has pathological antecedents that may differ from term labor. However, at the current level of our knowledge we are not ready to approach this and heuristically need to focus on the probability that stimuli to early labor parallel those of normal labor, except for its timing.

These considerations must define what we mean by antecedents. We need to determine with ever deepening exploration what the ultimate start of labor actually is, or what is the proverbial ultimate straw. Many such straws have been considered, as for example, bacterial vaginosis that leads to an inflammatory reaction and then labor; hormonal fluctuations; physiological maturity of the organs – or a particular organ – size of the head of the fetus in its relation to the pelvic outlet, and many others. Although each of these is important, each still represents a collection of straws and we definitely need to dig deeper.

Reports included in this issue, in a sense, represent a microcosm of the large effort to find a solution to this important health care problem. Four papers reflect the more traditional interests, i.e. the consequences of prematurity. There is a study of vertical transmission of cytomegalovirus through breast milk and the means for preventing it [1]. Another offers us an algorithm helpful in early detection of an infection in premature infants, and an effort to prevent its progression [2]. The third describes a drug treatment of emerging retinopathy of prematurity [3]. The last of these is a brief note offering a suggestion for determining lung maturity in premature infants [4]. The other four address the question of antecedents of preterm labor. One is an epidemiological study of the change in the incidence of spontaneous versus iatrogenic preterm births [5]; another of reducing preterm labor following natural disasters [6]; another of an early prediction of preterm labor in asymptomatic pregnant women [7]; and the last about funisitis as a cause of cervical insufficiency and consequent preterm delivery [8].

Reports of the continuing stream of studies directed at the improvements in the care and fate of the premature infants are clearly important. However, reports on the efforts to understand the causes of preterm labor are essential if we are to render the former unnecessary.