摘要:

ObjectiveTo determine the effect of third-trimester calcium supplementation on maternal hemodynamic function.MethodsPregnant women were randomized to receive either 1.5 g of elemental calcium or placebo for 6 weeks during the third trimester. Using Doppler technique, maternal hemodynamic characteristics were measured at baseline, at 2 hours after the first dose of study drug, and at the completion of 6 weeks. Serum, dietary, and urinary calcium levels were also assessed. Power calculation indicated the need to study ten subjects in each group to detect a 1.2 L (20%) difference in cardiac output between groups, assuming a mean of 6.2 ± 1.0 L/minute. Data were analyzed by analysis of variance for repeated measures, Student t test, Mann-Whitney U test, and Fisher exact test.ResultsTwenty-three women enrolled, and 18 completed the study. There were no statistically significant differences in demographic characteristics or in serum, dietary, or urinary calcium levels between the two groups. There were also no statistically significant differences in hemodynamic function over time within the calcium supplementation or placebo group (P> .05; analysis of variance for repeated measures). After 6 weeks, there were no significant differences between the calcium- and placebo-treated subjects in any hemodynamic measurement. Specifically, there was not a statistically significant difference in cardiac output (7.3 ± 1.2 L/minute versus 8.0 ± 0.9 L/minute;P= .09) between the calcium- and placebo-treated groups.ConclusionsThese findings suggest that third-trimester calcium supplementation does not significantly alter cardiac output. The mechanism by which calcium supplementation lowers blood pressure remains to be elucidated.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine whether increased calcium intake (2 g/day) in pregnancy is effective in reducing the risk of preeclampsia in pregnant teenagers.MethodsThe present study was a prospective, randomized, double-blind, controlled clinical trial. Two hundred sixty teenaged pregnant girls attending the Hospital Gíneco-Obstétrico Isidro Ayora in Quito, Ecuador, were included. Selection criteria were age less than 17.5 years, nulliparity, first prenatal visit before 20 weeks' gestation, and residency in Quito (2800-m altitude). We used a table of random numbers to assign 125 girls to receive 2000 mg of elemental calcium daily, beginning at 20 weeks of gestation and continuing until delivery; 135 women in the control group received a placebo. Blood pressure (BP) was measured twice every 4 weeks until delivery and at 48 hours after delivery. The diagnosis of preeclampsia was defined as BP greater than 140/90 mmHg on at least two occasions more than 6 hours apart and proteinuria greater than 30 mg/dL (over one cross by dipstick on two occasions 4-24 hours apart).ResultsThe average daily calcium intake in this population was approximately 51% of the Recommended Dietary Allowance. Calcium supplementation was associated with a significantly decreased risk of preeclampsia (risk reduction 12.35%;P< .001), with 3.2% (n= 4) developing preeclampsia in the treatment group versus 15.5% (n= 21) in the placebo group. Moreover, calcium supplementation led to a reduction in systolic BP of 9.1 mmHg and in diastolic BP of 6.0 mmHg.ConclusionThese results suggest that calcium supplementation during pregnancy in populations with low calcium intake is a safe, effective, and inexpensive preventive measure that significantly reduces the risk of preeclampsia.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine whether homocyst(e)ine, a relatively new risk factor for possible endothelial cell dysfunction and premature vascular disease, is elevated in nulliparous pregnant women with preeclampsia.MethodsWe measured plasma homocyst(e)ine, folic acid, and vitamin B12levels in 40 nulliparas, 20 with and 20 without preeclampsia at the time of their delivery.ResultsMean (± standard deviation) plasma homocyst(e)ine levels in the 20 nulliparous women with preeclampsia were significantly higher than in the 20 nulliparous women without preeclampsia (8.66 ± 3.05 versus 4.99 ± 1.11 μmol/L,P< .001). Folic acid and vitamin B12concentrations were not significantly different between the two groups.ConclusionHomocyst(e)ine levels are elevated in pregnant nulliparas with preeclampsia at the time of their delivery. Further studies are necessary to determine what role homocyst(e)ine may play in the etiology of preeclampsia.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo identify risk factors associated with complicated eclampsia.MethodsTwenty-four patients with eclampsia complicated by intracerebral hemorrhage, pulmonary edema, renal, hepatic, or respiratory failure, disseminated intravascular coagulation, abruptio placentae, pulmonary aspiration, or hemolysis, elevated liver enzymes, low platelets syndrome were compared retrospectively with 101 uncomplicated eclamptic controls. Information on maternal demographic factors, medical and obstetric histories, and maternal and perinatal outcomes was retrieved and analyzed by univariate and multivariate analysis.ResultsBy multiple logistic regression, the only risk factors associated with the development of complicated eclampsia were maternal age over 26 years (adjusted odds ratio [OR] 6.3, 95% confidence interval ICI] 2.17, 18.48), multiparity (adjusted OR 4.5, 95% CI 1.55, 13.60) and no prenatal care (adjusted OR 3.3, 95% CI 1.25, 9.60).ConclusionMaternal age above 26 years, multiparity, and no prenatal care are the maternal risk factors identified for the development of complicated eclampsia.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine the pharmacokinetics and pharmacodynamics of thyrotropin-releasing hormone (TRH) in pregnant women.MethodsTwenty-four pregnant and eight nonpregnant women were given 400 μg TRH as either intravenous infusion or bolus. Serial venous samples were collected for TRH, TSH, thyroxine, and prolactin assay.ResultsWhen given as bolus, mean (± standard error of the mean) peak plasma concentration (50 ± 5.2 and 73 ± 5.1 ng/mL,P< .01), elimination half life (4.3 ± 0.3 and 6.3 ± 0.4 minutes,P< .001), and area under the curve (156.4 ± 14.8 and 340.1 ± 32.8 ng/mL/minute,P< .001) in pregnant subjects were reduced compared with controls, whereas plasma clearance (45.4 ± 6.5 and 23.6 ± 2.1 mL/kg/minute,P< .01) and volume of distribution (27.8 ± 1.8 and 19.0 ± 1.3% body weight,P< .01) were increased. When given by infusion, steady-state concentration (6.6 ± 0.5 and 9.8 ± 0.9 ng/mL,P< .01) and elimination half-life (4.6 ± 0.5 and 6.3 ± 0.3 minutes,P< .05) were lower in pregnant subjects than in controls. Thyrotropin-releasing hormone kinetics were independent of mode of administration. Although basal TSH and thyroid hormone concentrations were similar in patients and controls, the TSH response to TRH was blunted in pregnant subjects compared with controls (9.3 ± 0.6 and 16.4 ± 1.4 μIU/mL,P< .001). The basal (3187 ± 488 and 147 ± 16 mIU/L) and maximal prolactin response (6193 ± 426 and 1316 ± 106 mIU/L) were increased in pregnant subjects compared with controls (P< .001).ConclusionThe peak plasma concentration and elimination half-life of TRH are reduced during pregnancy because of the increased volume of distribution and rapid clearance. Mode of administration does not affect TRH pharmacokinetics, but the maternal pharmacodynamic response differs in patients receiving bolus compared with infusion.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo demonstrate the use of generalized additive logistic regression in the development of a risk-scoring system to predict cesarean delivery.MethodsWomen who delivered in the Prince of Wales Hospital, Hong Kong, from 1994 to 1995 were the subjects of our study. Cases included were term singleton pregnancies with cephalic presentation, excluding those requiring cesarean delivery before labor. The cases were divided randomly into two sets. The prediction models were developed from set A and tested on set B, and vice versa. Maternal demographic and obstetric variables were used as potential predictors. Two models were formed, one before and one after the onset of labor. The generalized additive logistic regression was used to achieve optimal dichotomization of continuous measurements, and the predictive models were then developed. The validating results were pooled, represented, and compared as areas under receiver operating characteristic (ROC) curves.ResultsThe first prediction model used maternal age, height, and weight at delivery as well as nulliparity, history of cesarean delivery, and the need for induction of labor. The second model had in addition the need for labor augmentation. The areas under the ROC curve for the models were 0.81 and 0.82, respectively, a statistically significant difference (z= 5.75,P< .001).ConclusionThe use of generalized additive logistic regression optimizes dichotomization of continuous measurements and facilitates the development of precise and reproducible prediction models. Generalized additive logistic regression appears to be a useful tool, and its use is commended.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine the utilization rate of second-trimester genetic sonogram and its role in influencing the decision for amniocentesis in women at increased risk for fetal trisomy 21.MethodsFrom November 1, 1993, to December 31, 1996, a second-trimester genetic sonogram or only genetic amniocentesis (as a first choice) were offered to pregnant women referred to our institution who were at increased risk for fetal trisomy 21.ResultsDuring the study period, 2089 women were referred to our unit for genetic prenatal diagnosis; of these, 1426 (68%) chose only genetic amniocentesis, and 663 (32%) chose a genetic sonogram as their first option. The yearly utilization rates of genetic sonogram were two of 477 or 0.4% for 1993, 82 of 495 or 16.6% for 1994, 251 of 523 or 48.0% for 1995, and 328 of 594 or 55.2% for 1996. Adjusting for potential confounders, multivariable logistic regression analysis showed that the most important factors associated with the women's decision to undergo genetic amniocentesis were three or more ultrasound markers present (relative risk [RR] 189.5, 95% confidence interval [CI] 37.1, 980.0), two ultrasound markers present (RR 47.2, 95% CI 9.8, 267.8), one ultrasound marker present (RR 12.7, 95% CI 5.5, 29.7), and abnormal serum biochemistry (RR 3.0, 95% CI 1.0, 8.9).ConclusionThe increasing utilization trend, in conjunction with the fact that an abnormal sonogram was the most influential factor in women's decision to undergo genetic amniocentesis, suggests that genetic sonogram services for detection of trisomy 21 should be added to the armamentarium of all prenatal diagnostic centers.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine the infant and early childhood developmental outcome associated with choroid plexus cysts diagnosed prenatally.MethodsBetween January 1990 and August 1995, 8270 women underwent second-trimester ultrasound examinations. All women whose fetuses were diagnosed as having choroid plexus cyst(s) underwent ultrasonographic detailed anatomy survey, were offered fetal karyotyping, and were followed with serial ultrasounds. Fetal karyotype, associated structural anomalies, maternal serum triple analyte screen, neonatal outcomes, and infant and early childhood developmental milestones were recorded. The children were followed subsequently, and developmental assessment was performed with a modified Denver II Developmental Screening Test.ResultsA diagnosis of choroid plexus cyst was made in 89 fetuses (1.1%). The mean (± standard deviation [SD]) gestational age at diagnosis was 18.2 ± 1.9 weeks (range 15–22). The cysts varied in size and laterality, with a mean (±SD) size of 5.9 ± 3.3 mm (range 1–23). Three of the 61 women who underwent testing for fetal karyotype (4.9%) had abnormal karyotypes identified. All three karyotypes were trisomy 18, and all three trisomy 18 fetuses had additional sonographic abnormalities. All 28 women who chose not to undergo fetal karyotypic analysis delivered phenotypically normal infants. Infant and childhood developmental follow-up was performed on 76 children with cysts diagnosed prenatally. The mean (±SD) length of childhood follow-up was 35.5 ± 16.2 months (range 12–82). All 76 children were found to be developmentally normal by the Denver II Developmental Screening Test.ConclusionThese observations suggest that the finding of isolated choroid plexus cysts is not associated with delayed infant and early childhood development or an increased risk of abnormal karyotype. The presence of isolated choroid plexus cysts does not warrant intensive infant and early childhood follow-up.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo identify the teratogenic risk of large doses of various drugs taken by women in attempting suicide.MethodsThis population-based, prospective, epidemiologic study involved 559 women with pregnancy verified by a serum pregnancy test who were admitted to the toxicologic inpatient clinic in Budapest responsible for providing health services to chemically poisoned individuals from a population of 3 million. Each self-poisoned woman was matched for age and gestational age with a control selected from among participants in periconceptional care.ResultsTwo of 559 self-poisoned pregnant women died. One hundred seventy-eight infants born to mothers who poisoned themselves during pregnancy either were examined personally or had appropriate medical data available. After excluding eight infants with fetal alcohol syndrome born to heavy-drinking mothers, the rate of congenital abnormalities in study infants (9.0%) did not significantly exceed the rate of control infants (6.1%). Thus, no teratogenic effect of drugs used for self-poisoning could be identified, even though large doses of drugs were used in 27 cases between the 3rd and 8th weeks of fetal development. This sample was not large enough to evaluate single drugs separately.ConclusionDrugs taken by women in attempting suicide do not seem to pose a risk for structural birth defects in the offspring.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo test the hypothesis that oxytocin labor stimulation of twin gestations is similar to that of singletons regarding dosage, time, complications, and ability to achieve vaginal delivery.MethodsThis retrospective investigation included 124 gravidas receiving oxytocin for augmentation or induction of labor. Sixty-two women with twin gestations were matched by parity, cervical dilation at initiation of oxytocin, gestational age, oxytocin dosage regimen, and indications for oxytocin to controls with singleton pregnancies. Outcome variables included maximum dosage of oxytocin, incidence of hyperstimulation and fetal heart rate (FHR) abnormalities, time from oxytocin to delivery, cesarean deliveries, and maternal and neonatal outcomes. Statistical analysis was done using McNemar test, pairedttest, and Wilcoxon signed-rank test for paired samples.ResultsWomen with twin pregnancies and those with singletons responded similarly regarding maximum oxytocin dosage (21 ± 1.5 and 18 ± 2.4 mU/minute, respectively,P= .1), time from oxytocin to delivery (7.0 ± 0.8 and 6.7 ± 0.6 hours, respectively,P= .88), and successful vaginal delivery (90% and 90%, respectively). Oxytocin stimulation of twins resulted in fewer interruptions of the infusion for FHR abnormalities (5% compared with 26%, odds ratio [OR] 0.27, 95% confidence interval [CI] 0.16, 0.47) and hyperstimulation (6% compared with 18%, OR 0.19, 95% CI 0.36, 0.99).ConclusionTwin gestation has no adverse impact on the effectiveness or efficiency of oxytocin labor stimulation. Twin pregnancy seems to be associated with fewer side effects.

ISSN:0029-7844    

出版商:OVID    

年代:1997

数据来源: OVID