Warren M. Crosby

Fetal survival following impact: Improvement with shoulder harness restraint

Abstract A series of 22 pregnant baboons were subjected to impact under similar conditions. The only major variable was the difference in maternal restraint. The fetal death rate of 8.34 per cent (1/12) among animals impacted with 3 point restraint was significantly lower than that of 5 fetal deaths among 10 maternal animals impacted with lap belt restraint alone (p =

IMPACT INJURIES IN PREGNANCY. I: EXPERIMENTAL STUDIES,

Abstract Eleven pregnant baboons were subjected to 12 experimental impacts. At the 20 g level of decelerative force, maternal injuries were minimal. Fetal death occurred in association with traumatic head injury, placental separation, and maternal shock. Although prevention of body flexion during impact did not prevent elevation of intrauterine pressure, fetal injury, or placental separation, the number of animals is too small to draw conclusions regarding the superiority of one restraint system over another. The lap belt should be worn by pregnant women, and it should be snugly placed across the pelvis and not over the fundus.

Fetal malnutrition: An appraisal of correlated factors

Fetal malnutrition has emerged as a significant health problem over the past decade. Present evidence suggests that maternal environment plays the major etiologic role in fetal malnutrition. The association of fetal malnutrition in mothers with chronic hypertension is well known, but fetal malnutrition is associated with maternal hypertension in less than 25 per cent of cases. Among a group of 182 pregnant women studied at midpregnancy for blood levels of vitamins, trace metals, proteins, amino acids, and parameters of maternal leukocyte energy metabolism, it was found that the concentration of 10 amino acids, alpha-1-globulin, zinc, and total carotenes had a statistically significant relationship to fetal growth. Similarly significant correlations were found for maternal leukocyte adenosine disphosphate, phosphofructokinase activity, ribonucleic acid (RNA) synthesis, and cell size. Maternal cigarette smoking was correlated with reduced fetal growth. Analysis showed that there was a significant reduction in leukocyte RNA synthesis and phosphokinase activity and in the plasma levels of 14 amino acids, and carotene in smoking mothers. This information lends support to the hypothesis that factors which affect the growth of fetal cells also will affect maternal leukocytes in a definable way.

Hyperthyroidism during pregnancy

Abstract Obstetrics services which have had experience with both the medical and surgical treatment of the hyperthyroid pregnant woman should be in the best position to evaluate the success of each form of management. The experience in managing this problem during the last 12 years at the University of Oklahoma Health Sciences Center has been reviewed. Nineteen women with 20 pregnancies satisfied the criteria for inclusion in the study. Women managed with antithyroid therapy had a successful pregnancy outcome 70 per cent of the time. Twenty-eight per cent of the surgically treated patients had a successful pregnancy outcome and were free of surgical complications. We believe these results show a clear advantage for the nonsurgical management of the pregnant woman with hyperthyroidism.

Impact injury to the pregnant female and fetus in lap belt restraint.

Although it has been well-established that the lap (seat) belt offers considerable protection against injury or death in crash environments, there has long been controversy over the injury potential to the pregnant female. This question is of importance in consideration of restraint and seat protective environments for both aircraft and automotive vehicles. Most of the four million pregnant women per year in the United States travel by automobile, with a large number traveling by commercial civil aircraft or the Military Air Transport Service. Thus, a sizable population is involved. This combined study by the Civil Aeromedical Institute, FAA, 6571st Aeromedical Research Laboratory, Holloman AFB, and the University of Oklahoma School of Medicine has been concerned with the clinical, experimental, and applied aspects. Tests utilizing pregnant baboons (Papio doguera) have been run on the Holloman AFB Daisy Decelerator, and clinical case histories have been obtained in automotive accidents involving late-term pregnant women through cooperation of the California and Oklahoma Highway Patrol and individual obstetricians. This paper outlines the medical evidence for concern and notes the experimental findings to date. THE LAP (SEAT) BELT offers considerable protection against injury in impact accidents, although little is known of its effects on the pregnant mother and her fetus (Ref. 1). In the United States, most women travel by automobile at one time or another during their pregnancy (Refs. 2, 8). A large number also travel as passengers in commercial or private aircraft and, as dependents, on planes of the Military Air Transport Service (Refs. 3, 4, 9). The present study was initiated to determine the effects of abrupt deceleration

Spectrophotometric analysis of amniotic fluid: Direct assessment of fetal status in the isoimmunized pregnancy

Abstract Forty-two pregnancies with various types of isoimmunization have been evaluated by direct spectrophotometry of amniotic fluid. The 450 mμ peak was plotted against the week of gestation in which the fluid was obtained. The resultant graph was arbitrarily divided into three zones. A high degree of correlation exists between the zone of the 450 mμ peak and the severity of the fetal hemolytic process. The results of this study indicate that amniotic fluid analysis is a safe procedure, and provides a reliable guide to fetal status in utero and the need for premature delivery in the isoimmunized pregnancy. A plan of management for the isoimmunized pregnancy is presented.

CHOLESTEROL, CAROTENE AND BIRTHWEIGHT IN SMOKING MOTHERS

It has been suspected that nutrition during pregnancy might counteract the adverse effects of smoking on birthweight (BWT). In our previous prospective studies of ∼2100 mothers, 47% were smokers who had 63% of the babies with BWT below our median (3300g). A prospective, randomized, controlled trial of a food supplement (WIC) from 19 weeks to term in 410 of these free-living mothers led to increased mean BWT +91g (p=0.039), which was greater in smokers (+115g, p=0.034), taking into account sex, gestational age, race, prenatal visits. In 288 mother/baby pairs multiple regression analysis revealed an interaction between maternal midpregnancy (19 weeks) plasma levels of cholesterol (chol), β carotene (βC) and smoking on BWT (p=0.017). Prospective data on the interactive effects of βC, chol and smoking on BWT apparently have not previously been noted. High βC (> 116 μg/dl) and low chol levels (< 150 mg/dl) were associated with significantly larger babies (+ ∼500g) in the smokers. If βC levels remained high from 19 to 36 weeks of gestation, heavy smokers delivered large babies. If βC levels decreased, the babies were small. In nonsmokers, no interaction between these nutrients on BWT was detected, but BWT was ∼300g more with higher chol, i.e., from 116 to 272 mg/dl at midpregnancy, at all levels of βC. We conclude that certain plasma levels of β carotene and cholesterol in smokers might counteract the adverse effect of smoking on fetal growth.

481 MATERNAL SMOKING MAY IMPAIR EETAL NUTRITION

Cigarette smoking by pregnant women is known to significantly reduce birth weight of their babies. The effect appears dose-related. The mechanism is uncertain. We have shown previously that maternal plasma nutrient & amino acid levels, & some polymorphonuclear leukocyte (PMNL) enzyme & metabolite levels at midpregnancy are closely related to, predictive of, & account for, about 20% of the variance in birth weight of the baby. In a prospective study of ∼600 mother/baby pairs who had complete demographic & biochemical data, 294 mothers were non-smokers, 285 smoked. Birth weight, adjusted for gestational age & sex of the baby, & for race, age, prepregnant height, weight, & parity of the mother, was significantly reduced in proportion to the number of cigarettes reportedly smoked daily. A two-tailed t test showed that smoking mothers had significantly decreased PMNL G6PDH activity, ATP & ADP levels. Hair root protein content was reduced, as were plasma total protein, albumin, β & γ globulins, & cholesterol. The levels of plasma free amino acids ALA, CYS & LYS also were significantly reduced. Analysis of variance showed significant differences between standardized scores for nonsmokers & those who smoked 1-10, 11-20, 21-30, > 30 cigarettes/d for education, hematocrits, diet calorie & protein intakes (recall), PMNL G6PDH & ATP, hair root protein & DNA, plasma total protein, α 2, β & γ globulin, & the amino acids: GLU, LYS, HIS, & ORN. We conclude that smoking during pregnancy alters maternal plasma nutrient levels, protein stores & cell PMNL metabolism. These nutritional effects might account for the reduced birth weight.

601 MID-PREGNANCY NUTRITION AS A PREDICTOR OF BIRTH WEIGHT

Among 1100 mother-baby pairs studied prospectively, certain patterns of nutrient levels in maternal plasma & bioactivities in her leukocytes at midpregnancy were associated with delivery of small or large babies some 18 to 20 weeks later. The relation of bioactivities in rapidly replicating cells, like leukocytes, to nutrient levels in the surrounding plasma was complex; e.g.: protein synthesis or activities of glycolytic enzymes may be modulated by factorial interactions between plasma levels of trace minerals & certain amino acids. Using multiple regression analysis to incorporate these data & to statistically control for non-nutritional factors which modulate fetal growth, in 215 uncomplicated pregnancies, we find that 8 maternal clinical characteristics, 6 plasma nutrient levels & the aminogram, with 5 leukocyte bioactivities, all measured once at midpregnancy, can account for 65% of the variance in birth weight; the nutrition-related variables contributing 20%. The prediction equation derived from these measures can specifically identify mothers who will not have small babies, (96%) but is somewhat less sensitive (65%) for detection at midpregnancy of those who will. The results show that maternal nutrition modulates fetal growth & contributes significantly to the prediction of birth weight in our sample of pregnant women.

200 PREDICTING HUMAN FETAL MALNUTRITION (FM)

We hypothesize that during pregnancy maternal nutrition regulates metabolism of all rapidly replicating cells, including maternal leukocytes, as well as those of fetus & placenta. Fetal malnutrition complicates about 6-8% of all pregnancies in the U.S.A. FM babies are at high risk for congenital anomalies & impaired postnatal physical & mental development. It is often unrecognized when birth wt. < 2500 g. @ 37+ weeks gestation, is used to identify FM babies, since babies are too small if their observed size (wt., length, head circumference, arm & thigh muscle area, & fat folds, etc.) is more than one SD (approx. 450 g.) below their expected size when adjusted for sex, gestational age and maternal age, ht., pre-preg. wt., race and parity. Currently, prospective data have been obtained from 584 mother-baby pairs. 294 had no detected complications during pregnancy and their data was used to adjust baby size. Operationally, maternal dietary intake, plasma levels of 11 nutrients & 19 amino acids, hair root protein & DNA, & metabolism of maternal leukocytes as an indicator of fetal cell metabolism, all measured only once at mid-pregnancy, were used as independent variables to predict deviations from expected baby size. Significant multiple correlation coefficients were found for principal components relating maternal mid-pregnancy nutrient, amino acids, & leukocyte measures to adjusted birth size of the baby These data support our hypothesis. The prediction equations require further refinement, but offer promise to predict fetal growth & identify mothers at mid-pregnancy who are carrying malnourished fetuses. Supported by USPHS NICHD-06915