John P. Minogue

Cocaine use during pregnancy: Adverse perinatal outcome

Cocaine use has increased dramatically in the United States during the past decade. The life-threatening cardiovascular and central nervous system complications of cocaine have been well documented; however, few studies have examined the risks of cocaine use during pregnancy. In this report the perinatal outcome data of 70 women receiving care at the Perinatal Center for Chemical Dependence of Northwestern University, whose pregnancies were complicated by cocaine abuse, were compared with those of matched control subjects. The use of cocaine during pregnancy was associated with lower gestational age at delivery, an increase in preterm labor and delivery, lower birth weights, and delivery of small for gestational age infants.

The association between occupational factors and preterm birth: A United States nurses' study☆

OBJECTIVE Our purpose was to evaluate factors associated with preterm birth among a national sample of U.S. nurses. STUDY DESIGN We conducted a case-control study of 210 nurses whose infants were delivered prematurely (< 37 weeks) (cases) and 1260 nurses whose infants were delivered at term (> or = 37 weeks) (controls). An occupational fatigue score was constructed from four sources and varied from 0 to 4. The relation between occupational activity (including hours working and fatigue score) and preterm birth was analyzed with the use of Pearson chi 2 tests, estimates of odds ratios with 95% confidence intervals, and multivariate logistic regression; we controlled for confounding factors. RESULTS Factors significantly associated with preterm birth included hours worked per week (p < 0.002), per shift (p < 0.001), and while standing (p < 0.001); noise (p = 0.005); physical exertion (p = 0.01); and occupational fatigue score (p < 0.002). The adjusted odds ratios were 1.6 (p = 0.006) for hours worked per week (< or = 36 vs > 36) and 1.4 (p = 0.02) for fatigue score < 3 vs > or = 3. CONCLUSIONS Preterm birth among working women may be related to hours worked per day or week and to adverse working conditions.

Severe acidosis and subsequent neurologic status

To examine the relationship between severe acidosis at birth and evidence of subsequent neurologic dysfunction, a 4-year review was performed encompassing 15,528 neonates. One hundred forty-two (0.91%) of these neonates had an umbilical cord arterial pH less than or equal to 7.05 with a base deficit greater than or equal to mEq/L. Neurologic assessments found 101 of 110 term neonates (91.8%) and 17 of 32 preterm neonates (53.1%) with severe acidosis to be free of neurologic deficits at the time of hospital discharge. Follow-up developmental evaluation data were available for 7 of 9 term neonates and 8 of 15 preterm neonates with abnormal examinations. Although 5 term and 6 preterm infants demonstrated mild developmental delays or mild tone abnormalities in the first year of life, none exhibited a major motor or cognitive abnormality at 12 to 24 months of age. Consequently, acidosis in umbilical cord blood, even when severe, is a poor predictor of subsequent neurologic dysfunction.

Factors contributing to the increased cesarean birth rate in older parturient women.

OBJECTIVE Our purpose was to determine factors contributing to the increased use of cesarean section in patients > or = 35 years old. STUDY DESIGN Data were collected prospectively on nulliparous patients in spontaneous labor with term, singleton pregnancies and vertex presentations. Criteria for the diagnosis of labor were standardized: regular, painful uterine contractions at least once every 5 minutes in the presence of either complete cervical effacement or spontaneous rupture of membranes. The labors of women > or = 35 years old (n = 74) were compared with those of women 20 to 29 years old (n = 275). RESULTS The cesarean section rate was significantly greater for patients > or = 35 years old (21.6% vs 10.2%, odds ratio 2.4, 95% confidence interval 1.2 to 5.1). Mean birth weights were similar in the two groups, but when birth weight was > or = 3600 gm patients > or = 35 years old were more likely to be delivered by cesarean section (36.7% vs 12.2%, odds ratio 4.0, 95% confidence interval 1.4 to 11.9). There were no differences between the two age groups in physician factors that could explain the disparate rates of cesarean delivery. Indeed, of patients delivered vaginally the older parturients received oxytocin for longer duration (6.4 +/- 2.6 vs 5.0 +/- 3.1 hours, p < 0.05) and at higher maximum doses (12.4 +/- 6.1 vs 9.8 +/- 6.2 mU, p < 0.05). After controlling for potentially confounding variables with multiple logistic regression analysis, maternal age (R = 0.125, p < 0.005), birth weight (R = 0.196, p < 0.001), the need for oxytocin (R = 0.210, p < 0.001), and epidural anesthesia (R = 0.195, p < 0.001) were found to be independently associated with the increased rate of cesarean section. CONCLUSION We could not identify any controllable physician factors affecting the rate of cesarean section in patients > or = 35 years old. The increased oxytocin requirements and the incidence of dystocia with birth weight > or = 3600 gm suggest that maternal and fetal characteristics contribute to the increased frequency of cesarean section in older parturients.

The changing pattern of infant mortality in the US: The role of prenatal factors and their obstetrical implications

Infant mortality is one of the leading public health problems in the United States today. During the first half of this century the decline in infant mortality resulted largely from a reduction in postneonatal deaths (2–11 months after birth). Since 1950, two‐thirds of all infant deaths have occurred in the neonatal period (1st month after birth). Since 1981, the rate of decline in the infant mortality rate has slowed due to a deterioration in the distribution of birthweights and a slowed improvement in birthweight‐specific mortality rates. The role of birthweight is central to this issue, because low birthweight (LBW, < 2500 g) is a major determinant of death in the first year of life, particularly during the neonatal period. Stated another way, less than 0.5% of infants with birthweights > 2500 g die during the first year of life compared to 10.2% of infants with birthweights <2500 g and 45.3% with birthweights < 1500 g (very low birthweight, VLBW). These effects are magnified when evaluated on a race‐specific basis: the rate of LBW is twice as high and the rate of VLBW is three times as high for black infants compared to white infants. Reducing the rates of VLBW and LBW, particularly among blacks, holds the greatest potential for future reductions in infant mortality in the United States. The important role of maternal factors in the antecedents of infant mortality (VLBW, LBW, intrauterine growth retardation, preterm birth) have been clearly and repeatedly demonstrated. Some of these factors, such as maternal race, adverse obstetrical history and low level of education, are not amenable to change during pregnancy. Other factors, such as cessation of smoking, higher maternal weight gain and the initiation of early prenatal care have been shown to improve the course and outcome of pregnancy and subsequently result in reduced infant mortality.

Factors that influence route of delivery—Active versus traditional labor management

OBJECTIVE Our purpose was to compare maternal and fetal factors that influence the route of delivery with active management of labor and a traditional labor management protocol. STUDY DESIGN Data were collected prospectively on 346 consecutive patients receiving active management of labor and 354 patients who were managed traditionally. Within each group demographic and labor characteristics of patients undergoing cesarean section were compared with those of patients having vaginal deliveries by means of the Student t test, chi 2 analysis, and stepwise logistic regression. RESULTS With both active management of labor and traditional labor management success in achieving vaginal delivery was related to the station of the fetal vertex at admission, the need for oxytocin augmentation of labor, the uterine response to oxytocin, the use of epidural anesthesia, and the development of chorioamnionitis. By means of multiple logistic regression analysis maternal age, height, payor status, and birth weight were also identified as risk factors for cesarean section with traditional labor management but not with active management of labor. CONCLUSIONS Differences were identified in risk factors for cesarean section between active management and traditional labor management. Active management of labor may diminish or eliminate some patient characteristics as risk factors for cesarean birth.

The Association Between Maternal Weight Gain and the Birthweight of Twins

Maternal pregravid weight, weight-for-height2 (body mass index, BMI), and gestational weight gain are acknowledged factors influencing the intrauterine growth and subsequent birthweight of singletons. The effect of these factors, singly and in combination, on the birthweight of twins is less clear. Using an historical prospective design, this study evaluated the association between maternal pregravid weight, weight gain (as early rate of gain, late rate of gain, and total weight gain), and the birthweight of twins.One hundred and sixty-three twin pregnancies of 28 weeks gestation or greater with both twins born alive were evaluated in this study. Mothers were categorized by their BMI as underweight, normal weight, or overweight. Weight gain was measured as early (before 24 weeks) rate of gain, late (after 24 weeks) rate of gain, and total gain. Based on weight gain to 24 weeks gestation, early rate of gain (before 24 weeks) and late rate of gain (after 24 weeks) was calculated. Discordancy was evaluated a...

Contribution of Gestational Age and Birth Weight to Perinatal Viability in Singletons Versus Twins

The objective of this study was to determine the effects of birth weight and gestational age on twin vs. singleton mortality. Population-based analysis of live births, fetal deaths, and infant deaths by plurality in the United States from 1983 to 1986 was conducted. Seven mortality rates and relative risks (RRs) of twin vs. singleton mortality were calculated by birth weight, gestational age, and combined birth weight and gestational age. The mortality rates included fetal, perinatal, early neonatal, late neonatal, neonatal, postneonatal, and infant. Twins had 3–4 times the RRs of mortality compared to singletons, ranging from a RR of 2.71 for postneonatal mortality to a RR of 3.73 for late neonatal mortality. Generally, for birth weights of 2,800 g or less and gestational ages of 38 weeks or less, twins had lower combined birth weight and gestational age mortality rates and lower RRs. Between 1,900 and 2,799 g, mortality rates decreased then increased with advancing gestation between 31 and 42 weeks both...

Prediction of fetoplacental blood volume in isoimmunized pregnancy

Direct intravascular fetal transfusion under ultrasound guidance allows precise evaluation of both fetal anemia and adequacy of therapy. In addition, the change in hematocrit after transfusion may be used to estimate the circulatory fetoplacental blood volume. In this study we present the estimates of fetoplacental blood volume calculated at the time of intravascular fetal transfusions. Between March 1986 and March 1988, 60 intravascular fetal transfusions were performed in 20 patients. The 56 procedures in which fetal hematocrits were obtained both before and after transfusion were analyzed. The mean fetoplacental blood volume before transfusion was 94.0 ml/kg. Furthermore, the fetoplacental blood volume per kilogram fetal weight decreased with advancing gestation. These estimates of fetoplacental blood volume and changes relative to gestational age may be useful in the treatment of the severely isoimmunized fetus. Reliance on the more recently generated fetoplacental blood volumes may allow more accurate predictions of transfusion volumes and estimation of the hematocrit after transfusion.

Maternal serum α-fetoprotein levels in pregnancies complicated by diabetes: Implications for screening programs

Maternal serum alpha-fetoprotein may be reduced in diabetic pregnancies, but the association with elevated glycosylated hemoglobin has been controversial. We tested the hypothesis that reductions in maternal serum alpha-fetoprotein may reflect the same phenomena that can also impair normal rates of embryo growth in the presence of poorly compensated maternal diabetes. If so, associations would be expected among maternal serum alpha-fetoprotein, embryo rates of growth, and levels of glycosylated hemoglobin reflective of regulation of maternal diabetes during the period of organogenesis. We found maternal serum alpha-fetoprotein levels in 93 pregnant patients with diabetes to be negatively associated with the earliest (4 to 12 weeks) glycosylated hemoglobin determinations. At glycosylated hemoglobin values greater than 9.6% (which approximates the upper quartile), all maternal serum alpha-fetoprotein values fell below the median for patients without diabetes (below 0.8 multiple of the median after weight adjustment). Moreover, there was a trend for pregnancies with lower maternal serum alpha-fetoprotein levels and higher glycosylated hemoglobin values to also demonstrate early fetal growth delay as measured by ultrasonography.