PubMed HealthSearch

Biomedical subjects

I Morrison

Publications and source records attributed to I Morrison.

9 recordsLinked to original sources

Must macrosomic fetuses be delivered by a caesarean section? A review of outcome for 786 babies greater than or equal to 4,500 g.

Because difficult vaginal delivery is more frequent with macrosomic fetuses, some writers recommend routine Caesarean section for the delivery of fetuses greater than or equal to 4,500 g. The purpose of this study was to evaluate the appropriateness of this recommendation. A retrospective review was undertaken to determine how many fetuses born in our hospital weighing greater than or equal to 4,500 g died or were permanently damaged as a consequence of mechanical difficulties at delivery. During a 10-year period, 590 (75%) of 786 cephalic babies weighing greater than or equal to 4,500 g and alive at the start of labour were born vaginally. No baby died or was permanently damaged as a consequence of mechanical difficulties at delivery. Routine Caesarean section for macrosomic fetuses to prevent death or damage from difficult delivery is not warranted by our results.

Birth Weight

Assessment of fetal well-being with ultrasound.

The practice of medicine is undergoing marked changes fueled by the infusion of vast amounts of new information concerning the etiology, the progressive pathophysiology, and the complexity of host response to disease states. It is only recently that we have begun to examine the present extent of fetal disease and to determine the characteristics of its advancements. This information now permits new and rational approaches to the management of fetal disease. Clinical significance, both real and potential, of this new wealth of information in reducing perinatal mortality and morbidity is difficult to overestimate. Cumulative experience with fetal biophysical scoring as a method for antepartum fetal risk assessment is now extensive. The cumulative data indicate that the method is sensitive for recognizing both the normal and the compromised fetus. Moreover, the method appears to offer the advantage of grading various degrees of fetal compromise. The additional information gained by real-time ultrasound scanning (gestational age determination, fetal morphometrics, and fetal anomaly screening), although not an integral part of the fetal biophysical profile score, nevertheless remains a critical aspect of antepartum fetal assessment. These data are collected simultaneously with fetal biophysical profile scoring. It is impossible to separate cleanly the advantage of fetal biophysical profile scoring in isolation of this additional information. It would, however, seem that such attempt at separation is artificial because the data in combination provide the key information that the physician needs to guide fetal management. It seems more reasonable to expect that continued modification and improvement of the existing fetal biophysical profile scoring method with inclusion of new testing techniques will be the steps that will occur to improve testing accuracy (Fig. 3). In medical schools in the 1960s, it was generally taught that the concept of "irreducible" perinatal mortality existed and that this figure was usually set at a perinatal mortality of around 8 per 1000. Now in the 1990s that perinatal mortality has already fallen below this irreducible level and continues to fall. We now observe perinatal mortality among tested fetuses of less than 7 per 1000 and corrected perinatal mortalities of less than 2 per 1000. These remarkable results strongly underscore the advantages obtained by ultrasound assessment of the fetus.

Amniotic Fluid

Perinatal mortality and antepartum risk scoring.

A simplified, numerical form for antepartum risk scoring was introduced as a component of the prenatal record for use in all pregancies in a large geographic area under a variety of collection practices. In a population of approximately 1,000,000 with 16,733 deliveries, 19% of the pregnant population scored greater than or equal to 3 and were designated as high risk on the basis of previous pilot studies. This group with high-risk scores had a perinatal mortality rate of 69/1000 compared to the low-risk group with a perinatal mortality of 7/1000 (P = less than 0.0001). The high-risk group accounted for almost 70% of the total perinatal deaths. The implications of being able to predict the statistical likelihood of perinatal deaths are discussed. It is suggested that the risk scoring system has its greatest potential as a screening process and as a method of recording regional statistical trends rather than in dictating the final management of the pregnancy.

Birth Weight

The elderly primigravida.

A five-year review of 127 elderly patients (35 years of age and over), in their first pregnancies, defines the risk to the fetus in terms of perinatal death and neonatal morbidity. With the equivalent of a perinatal mortality rate of 94/1,000, an 11 per cent incidence of small-for-dates infants, and a neonatal morbidity rate of 18 per cent, there would still appear to be a need for an increased awareness of the fetal risks in this group and an increased emphasia on their prevention. Areas of management in prenatal care and labor which might reduce these figures are defined.

Adult

Maximum possible impact of tocolytics in preventing preterm birth: a retrospective assessment.

Although tocolytic drugs are widely used to try to stop preterm labor, their actual contribution to preventing preterm deliveries is unknown. Since tocolytic drugs are not used at the University of Manitoba, it was possible to estimate the proportion of preterm deliveries that might have been eligible for tocolytic drug therapy. Of 364 consecutive preterm deliveries between 24 and 35 weeks, only 9% would have been eligible for, let alone prevented by, tocolytic drug therapy, and even a smaller percentage of babies would actually have benefitted from their use. The use of tocolytic drugs can, at best, benefit only a very small percentage of babies born preterm. Whether the risks of treatment justify this small benefit is arguable.

Female