Treatment of preterm labor with the beta-adrenergic agonist ritodrine.
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Female↗
Biomedical subjects
T J Benedetti
Publications and source records attributed to T J Benedetti.
Breech extraction of low-birth-weight second twins: can cesarean section be justified?
The outcomes of 54 breech-extracted second twins weighing between 750 and 2000 gm were compared with the outcomes of their siblings and of 43 sets of twins delivered by cesarean section for malpresentation. Vaginally delivered first twins had fewer days of mechanical ventilation and oxygen therapy than their breech-extracted siblings (p = 0.004). There were no significant differences in any measures of neonatal outcome when breech-extracted twins were compared with second twins delivered by cesarean section. We conclude that routine cesarean section is not justified for nonvertex second twins expected to weigh less than 2000 gm.
Breech Presentation↗
Effect of orthostatic stress on umbilical Doppler waveforms in normal and hypertensive pregnancies.
OBJECTIVE: Our study examined the effects of orthostatic stress and maternal hemodynamics on umbilical systolic/diastolic ratios in normal and hypertensive pregnancies. STUDY DESIGN: Eighteen normal and 20 hypertensive third-trimester pregnancies were examined in the left lateral recumbent, sitting, and standing positions. Measurements included umbilical systolic/diastolic ratio, maternal blood pressure, maternal cardiac output, and maternal total peripheral resistance. RESULTS: All patients demonstrated a fall in cardiac output and a rise in total peripheral resistance with standing. No change in systolic/diastolic ratio occurred with change to the upright position in patients with normotension. Patients with hypertension exhibited a significant increase in umbilical systolic/diastolic ratio with postural change. The increase was more marked in women who had hypertension with elevated peripheral resistance. CONCLUSION: Patients with hypertension are at increased risk of elevation of systolic/diastolic ratio with postural change; women with high-resistance hypertension may be at highest risk.
Diastole↗
Amyl nitrite: use as a smooth muscle relaxant in difficult preterm cesarean section.
Amyl nitrite is a smooth muscle relaxant that has been used clinically to facilitate uterine relaxation in difficult deliveries. In this retrospective study, we evaluate the safety of amyl nitrite use during preterm cesarean deliveries, and we assess possible advantageous effects on surgical incision choice. Women who received amyl nitrite cesarean section were compared to a control group matched for gestational age, fetal presentation, and mode of delivery who did not receive amyl nitrite. There were no statistical differences between the groups in the independent variables (maternal age, parity, medical or obstetric history, type of anesthesia, anesthesia or obstetric attending physician, antepartum hematocrit, or neonatal weight). Outcome (dependent) variables (estimated blood loss, Apgar scores, postpartum hematocrit, cord gases, or postpartum complications) were assessed, and there were no significant differences between the groups. Low transverse cesarean section was performed more frequently in the amyl nitrite group (58 of 64) than in the comparison group (48 of 64) (p less than 0.03). Considering the 128 women with and without amyl nitrite together, the decrease in hematocrit observed postpartum was greater after classic section (7%) than after low transverse section (4%) (p less than 0.002). We conclude that the use of amyl nitrite during preterm cesarean section poses no threat to mother or fetus and may facilitate delivery by allowing the performance of a low transverse rather than a classic cesarean section without maternal or neonatal complications.
Amyl Nitrite↗
Expectant management after sonographic diagnosis of placental abruption.
Forty cases of placental abruption were diagnosed by sonography after 20 weeks' gestation and managed expectantly. Tocolytics were used in 18 patients and were successful in delaying delivery for 34 +/- 24 days in 10. One-third of the patients delivered at term, after delays of 12.3 +/- 5.7 weeks. The majority of the patients who delivered before term (63%) had at least one other risk factor for preterm delivery, such as twins, ruptured membranes, or cervical dilation at presentation. Preterm delivery was not correlated with any of several clinical indicators of the severity of the abruption. Although the perinatal mortality rate was 22%, all perinatal deaths except one were attributable to extreme prematurity. It concluded that mild placental abruption is often a self-limited event and can safely be managed expectantly. Most of the perinatal morbidity and mortality is associated with premature delivery and, thus, in the absence of fetal distress or maternal compromise, delivery may often be delayed until fetal maturity is attained.
Abruptio Placentae↗
Prediction of infant birth weight by GDM screening tests. Importance of plasma triglyceride.
OBJECTIVE: We measured plasma glucose, GHb, GPro, IRI and TG at 24-28-wk gestation to determine the extent of elevations in GDM and relationships to glucose intolerance and infant macrosomia. RESEARCH DESIGN AND METHODS: Plasma samples were obtained 1 h after ingestion of 50 g glucose after an overnight fast in 521 randomly selected negative screenees, 264 positive screenees with GTT-, and 96 positive screenees with GTT+ (GDM). RESULTS: Screening test values in GDM subjects exceeded the GTT- group, whose values exceeded those of negative screenees: glucose, 9.6*, 8.7*, 6.3 mM; GHb, 5.2*, 4.9*, 4.7%; GPro, 3.1*, 3.0*, 2.8%; IRI, 791*, 662*, 410 pM; and TG, 2.3*, 1.9, 1.9 mM, (*P < 0.005 vs. negative screenees). TG was the only test elevated in the GDM but not in the GTT- groups. Screening test values correlated with GTT values in the following order (strongest to weakest): glucose* > TG* > GHb* > IRI > GPro (*statistical significance). Plasma TG was the only screening test significantly associated with birth weight corrected for gestational age (birth-weight ratio) (r = 0.09-0.16) (P < 0.05 to < 0.01) and was of the same order as 1- and 2-h GTT associations with birth weight (r = 0.13 and 0.14, respectively) (P < 0.05 to < 0.01). Plots of TG/birth-weight ratio increased linearly to the 80-90th TG percentile in negative screenees and GTT- subjects. GDM subjects followed this trend but with more variation. Above the 90th percentile for TGs, birth-weight ratio trended lower, significantly so when the groups were combined (P < 0.05). In multivariate analysis, TG was associated with birth-weight ratio even when maternal prepregnancy weight and pregnancy weight gain associations with TG and birth-weight ratio were controlled (P < 0.019). CONCLUSIONS: Of the five screening tests evaluated, all were elevated in GDM, but TG is the best discriminator of GDM from the GTT- group, and it is the only test significantly related to birth-weight ratio--and to glucose intolerance besides glucose itself. The TG association with birth weight is not explained fully by maternal weight. The results suggest that plasma TG may be a physiological contributor to infant birth weight. Further evaluation of plasma TG in GDM screening is justified, but GHb, GPro, and IRI appear to hold less promise.
Analysis of Variance↗
Clinical evaluation of the NBD-PC fluorescence polarization assay for prediction of fetal lung maturity.
OBJECTIVES: 1) To examine a fluorescence polarization (FP) assay with an independent set of data that contained more cases of respiratory distress syndrome (RDS) than a previous study, 2) to determine whether the same reference ranges are applicable to infants born to diabetic women, and 3) to evaluate whether adding the lecithin-sphingomyelin ratio (L/S) would substantially improve the prediction of RDS among women with an intermediate FP value (between 0.26-0.289). METHODS: We identified 389 women who had FP analysis performed at the University of Washington Medical Center from February 1986 to October 1988 and who delivered within 3 days of amniocentesis. We reviewed the medical records of these women and their infants to extract information for our study. RESULTS: For FP values of 0.26 or greater, the sensitivity and specificity for prediction of RDS were 90.2 and 84.6%, respectively, compared with 100 and 82.0% in the previous study. For FP values of 0.29 or greater, the sensitivity and specificity were 62.8 and 94.2%, respectively (80.8 and 96.2% in the previous study). Among diabetics, an FP result below 0.26 was associated with the same low risk of RDS as among non-diabetics. Among the patients with FP between 0.26-0.289, the addition of L/S did not provide a clinically useful improvement in the prediction of fetal lung maturity. CONCLUSION: The NBD-PC FP assay can be used as the sole test of fetal lung maturity in most clinical circumstances.
Amniotic Fluid↗
Risks associated with pregnancy in spinal cord-injured women.
We reviewed the experience with pregnancy in spinal cord-injured women at the University of Washington over the past 10 years. During that time, 11 women with spinal cord injury had 13 pregnancies. Infant outcome was uniformly good. No major obstetric complication occurred. The mothers experienced medical problems including urinary tract infection in ten and pyelonephritis in three. Autonomic hyperreflexia occurred in three of five subjects with lesions at or above the sixth thoracic vertebra. Pregnancy in the spinal cord-injured patient involves medical risk for the mother, but with careful management, an excellent outcome for both mother and infant may be anticipated.
Adult↗
Saltatory fetal heart rate pattern.
A retrospective descriptive study reviewed 433 consecutive intrapartum fetal heart tracings. The saltatory fetal heart rate pattern was defined as fetal heart amplitude changes of greater than 25 beats per minute with an oscillatory frequency of greater than 6 per minute for a minimum duration of 1 minute. Data were analyzed for each mother-infant pair over the time of labor and birth. The saltatory pattern was demonstrated in 10 of the 433 tracings reviewed for an overall incidence of 2.3%. All 10 fetuses demonstrating the saltatory pattern were term (38 to 42 weeks' gestation). None of the 147 preterm fetuses demonstrated the saltatory pattern (P less than .02). In 6 patients the saltatory pattern was observed after parenteral ephedrine administration, in 3 patients with uterine hyperstimulation, and in 1 patient during cervical examination. When the saltatory pattern was seen with ephedrine administration, it was present only at total doses of greater than or equal to 30 mg (P less than .001). In all patients the saltatory pattern occurred during active phase or second stage of labor. Short-term and long-term variability recorded by the fetal-scalp electrode were present both before and after the episode of saltatory pattern. At birth, all 10 infants were vigorous, with Apgar scores of 8/9 or 9/9. In the absence of abnormal periodic fetal heart rate changes and with the presence of short-term and long-term variability, the saltatory fetal heart rate pattern appears benign.
Adult↗
The maternal hemodynamic effect of indomethacin in normal pregnancy.
The vasodilation of pregnancy is thought by many to be due to increased endothelial production of prostacyclin, a vasodilatory prostanoid. Indomethacin, a potent inhibitor of prostaglandin synthesis, is known to increase the maternal blood pressure response to angiotensin II infusion. We sought to measure directly the hemodynamic effects of a short course of indomethacin. Twenty-three healthy pregnant women with uncomplicated pregnancies between 26-32 weeks' gestation completed the study. Using Doppler technology, we determined cardiac output, stroke volume, and total peripheral resistance before and after three 25-mg doses of indomethacin. Although blood pressure did not change, peripheral resistance rose and stroke volume fell following indomethacin administration. Our findings support the hypothesis that indomethacin interferes with tonic prostaglandin-induced vasodilation in pregnancy. However, the increase in vascular resistance was very slight, suggesting that other vasodilators are also at work in pregnancy. We recommend that indomethacin be used judiciously in hypertensive pregnant patients until more information concerning possible adverse hemodynamic effects becomes available.
Blood Pressure↗
Antiepileptics and the development of congenital anomalies.
We are conducting a prospective cohort study of epilepsy and pregnancy to determine the nature and extent of adverse pregnancy outcomes in infants of mothers with epilepsy (IME). Women with epilepsy were enrolled no later than the first trimester and were matched with controls; their infants were examined at 8 weeks by pediatricians blinded to maternal status. A number of variables were compared between case and control infants: birth weight, length, gestational age, head circumference, Apgar scores, feeding difficulties, neonatal irritability, and presence of major malformations and minor anomalies. The number of minor anomalies per infant was greater for IME than for controls (mean, 5.05 and 3.65, p less than 0.0001 per infant, respectively). Prominent occiput was the only anomaly seen significantly more often in IME than in controls (p less than 0.05).
Abnormalities, Drug-Induced↗
Cesarean section before the onset of labor and subsequent motor function in infants with meningomyelocele diagnosed antenatally.
Background. Meningomyelocele can now be detected before birth. Few data are available on its natural history, however, and optimal management at the time of delivery is controversial, although it has been suggested that labor and vaginal delivery may cause pressure on exposed nerve roots, resulting in additional loss of neural function. Methods. To assess the effect of labor and the type of delivery on the level of motor function in fetuses with uncomplicated meningomyelocele, we identified 200 cases of this disorder, accounting for 95 percent of the cases that occurred in the state of Washington during our 10-year study period. We compared the outcomes of 47 infants delivered by cesarean section before labor began, 35 delivered by cesarean section after a period of labor, and 78 who were delivered vaginally (another 40 were ineligible for the study). In cases of meningomyelocele detected prenatally, cesarean section was performed before the onset of labor if isolated meningomyelocele without severe hydrocephalus was present. The infants delivered in this manner were compared with those who were delivered either vaginally or by cesarean section after labor began. Results. At two years of age, the infants who had been exposed to labor were 2.2 times more likely to have severe paralysis than those delivered by cesarean section without labor (95 percent confidence interval, 1.7 to 2.8). Infants delivered by cesarean section before the beginning of labor had a mean (+/- SD) level of paralysis 3.3 +/- 3.0 segments below the anatomical level of the spinal lesion at two years of age, as compared with 1.1 +/- 2.3 for infants delivered vaginally and 0.9 +/- 4.1 for infants delivered by cesarean section after the beginning of labor (P less than 0.001 for both comparisons). Exposure to labor did not affect the frequency of neonatal complications or later intellectual performance. Conclusions. For the fetus with uncomplicated meningomyelocele, delivery by cesarean section before the onset of labor may result in better subsequent motor function than vaginal delivery or delivery by cesarean section after a period of labor.
Cesarean Section↗
The effect of maternal hemodynamics on fetal growth in hypertensive pregnancies.
Seventy-six pregnancies in which hypertension complicated pregnancy before 28 weeks' gestation were studied. In 36, hemodynamics were characterized by increased cardiac output and low vascular resistance; in 32, hemodynamics were characterized by high resistance; in eight hemodynamics crossed over from high output to high resistance during pregnancy. High-resistance hypertension was associated with a mean birth weight 1058 gm less than that in the low-resistance group (p = 0.001). The reduction in birth weight was due to a 4-week difference in gestational age (p = 0.001) and lower percentile weights for gestational age, 19th versus 39th (p = 0.005). Infants in the crossover group had low percentile weights and a high rate of intrauterine fetal death.
Adult↗
Position change and central hemodynamic profile during normal third-trimester pregnancy and post partum.
Central hemodynamic response to position change was assessed in 10 normotensive primiparous patients between 36 and 38 weeks' gestation. Studies were repeated between 11 and 13 weeks post partum. Compared with the left lateral position, we observed a mean 9% fall in cardiac output in the supine position and an 18% fall when patients were standing. When standing, these patients had a 30% increase in pulse and a 21% fall in left ventricular stroke work index. The orthostatic response after pregnancy was much more labile than that during the third trimester. These findings have important descriptive implications for the understanding of the human response to orthostasis during pregnancy, as well as clinical implications for patients at risk of uteroplacental insufficiency and for working women during pregnancy.
Adult↗
Maternal hemodynamics in pregnancies complicated by hyperthyroidism.
The hemodynamics of six pregnant women with hyperthyroidism were studied before and after therapy. Cardiac output was measured by Doppler technique, and blood pressure by automated cuff. When compared with values in euthyroid pregnant women, blood pressure (83.6 mmHg, P less than .001), heart rate (89.2 beats per minute, P less than .001), cardiac output (11.2 L/minute, P less than .001), and stroke volume (123 mL, P less than .001) were significantly elevated. Total peripheral resistance was significantly reduced (609 dyne.second.cm-5, P less than .001). Despite normalization of thyroid indices after therapy, cardiac output remained markedly elevated (9.7 L/minute, P less than .001) and vascular resistance remained reduced (708 dyne.second.cm-5, P = .01). Although the hemodynamics of pregnant thyrotoxic women normalize with therapy, they remain significantly hyperdynamic.
Echocardiography, Doppler↗
Maternal hemodynamics and aortic diameter in normal and hypertensive pregnancies.
The aortic diameters of 89 normotensive pregnant women were compared with those of nine rigorously defined preeclamptic women and 59 women who required antihypertensive therapy. Over the course of normal pregnancy, the diameter increased significantly; it was larger in preeclamptic than in normotensive women throughout pregnancy. The aortic diameter in women with high-resistance hypertension was smaller than that in normotensive women and in those with high-output, low-resistance hypertension, but it was larger in women with low-resistance hypertension than in normotensive women. The aortic diameter increased after treatment of high-resistance hypertension with hydralazine, but decreased after treatment of high-output, low-resistance hypertension.
Aorta↗
Measurement of cardiac output by impedance technique.
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Cardiac Output↗
Measurement of cardiac output in pregnancy by Doppler technique.
Doppler technique of measuring cardiac output was evaluated during pregnancy. In a study of accuracy Doppler technique correlated well with thermodilution, (r = 0.95, y = 1.05x - 0.35). In a study of interoperator variability, the technique was found to be reproducible, (r = 0.92, y = 0.91x + 0.74).
Aorta↗