摘要:

ObjectiveTo examine utilization patterns of four antepartum screening tests by office-based obstetricians.MethodsThe population surveyed was the Collaborative Ambulatory Research Network, a voluntary subset of 550 ACOG fellows from 130 practices participating in data collection regarding ambulatory practices. Responses from self-administered questionnaires concerning screening for hepatitis B, gestational diabetes, neural tube defects, and trisomy 21 were analyzed.ResultsHepatitis screening was performed by all practices with 95% (2750 of 2886) of women tested; however, only 55% (six of 11) of at-risk newborns received treatment. For gestational diabetes screening, 94% (116 of 124) administer a 50-g glucose load to all parturients, regardless of risk factors, two-thirds initiate further testing for a 1-hour post-load glucose of 140 mg/dL or greater, and 34% do so at lower glucose levels (130-135 mg/dL). For neural tube defect screening, 92% (95 of 103) offer maternal serum alphafetoprotein (MSAFP) screening although when results are elevated, further recommendations are varied. For women under 35 years of age, 84% (87 of 103) offer serum screening for trisomy 21 risk, most (68%) with double or triple (MSAFP, hCG, and estriol) markers. For women over 35 years, a majority (87%) offer serum screening, although half do so only if amniocentesis is declined for age risk alone. The relatively high initial positive rate and poor specificity of serum screening were underappreciated by a large number of respondents.ConclusionIncreased initial and continuing education of antenatal care providers is warranted if these screening tools are to perform optimally within office practices.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo examine the association between prenatal weight gain patterns and birth weight, using Institute of Medicine (IOM) guidelines.MethodsData from a prospective follow-up study of risk factors for fetal growth restriction were used to examine the impact of low weight gain on mean birth weight. A total of 415 nonobese (body mass index [BMI] less than 26) black (n= 275) and white (n= 140) women who delivered at term were included in this analysis. Linear regression analysis was used to examine the impact of low first-trimester gain (less than 2.3 kg with low BMI [less than 19.8]; less than 1.6 kg with normal BMI [19.8-26.01) and low second- and third-trimester rates of gain (less than 0.38 kg/week with low BMI; less than 0.37 kg/week with normal BMI) on mean birth weight while controlling for selected sociodemographic and reproductive variables.ResultsPatterns with low gain in the first and second or in the second and third trimesters were associated with significant decreases in mean birth weight, ranging from 206 to 265 g; low gain in only the first or third trimester was not associated with a significant decrease in mean in birth weight. The impact of low gain on mean birth weight varied by ethnic group.ConclusionThese observations suggest that inadequate patterns of prenatal weight gain, defined by IOM guidelines, are associated with decreased birth weight, particularly when the patterns involve low second-trimester gain.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo evaluate the effect of angiotensin-converting enzyme (ACE) genotypes on pregnancy outcome, the incidence of pregnancy-induced hypertension, and changes in blood pressure (BP) during pregnancy; and the relationship between plasma ACE activities and plasma and erythrocyte zinc concentrations in each genotype.MethodsThe subjects (n= 191) were selected from 580 indigent African-American pregnant women who enrolled toward the end of a trial to evaluate the effect of zinc supplementation on pregnancy outcome. This selection resulted in 93 subjects who received zinc and 98 who received placebo. Sample size was calculated with a 0.50 correlation coefficient between plasma ACE activities and zinc levels and a power of 80%. This calculation indicated that the sample size in each ACE genotype should be more than 28. Angiotensin-converting enzyme genotypes were identified using polymerase chain reaction. Blood pressure, plasma ACE activities, and plasma and erythrocyte zinc concentrations were measured at each prenatal clinical visit.ResultsPregnancy outcome, the incidence of pregnancy-induced hypertension, and BP were not different among the three ACE genotypes. There was no significant correlation between plasma ACE activities and zinc concentrations. Zinc supplementation did not have a significant effect on either plasma ACE activities or zinc concentrations, probably because of the small sample size in our study.ConclusionThere was no effect of ACE gene polymorphism on pregnancy outcome, the incidence of pregnancy-induced hypertension, or changes in BP during pregnancy. Among each ACE genotype, plasma ACE activities did not correlate significantly with plasma zinc concentrations.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo compare the 24-hour blood pressure (BP) pattern in physiologic pregnancy, pregnancy-induced hypertension, preeclampsia, and chronic hypertension.MethodsWe investigated four groups of women with singleton pregnancy: 73 controls, 48 patients with pregnancy-induced hypertension, 38 with preeclampsia, and 53 with mild to moderate chronic hypertension. The 24-hour BP monitoring was performed longitudinally in controls and in patients with chronic hypertension, and at the time of diagnosis in those with pregnancy-induced hypertension or preeclampsia.ResultsNineteen thousand eight hundred seventy-two BP measurements were analyzed. In controls, the mean values of BP indices were lower than those first reported in nonpregnant women, and the acrophase was always localized in the first part of the afternoon. In pregnancy-induced hypertension and especially in preeclampsia, besides the obvious quantitative increase in BP, circadian BP oscillations were less pronounced than in controls, and the severity of hypertension seemed to favor the loss of diurnal rhythm. Conversely, in chronic hypertension, circadian oscillations were the same as in controls.ConclusionStandardized 24-hour BP monitoring during pregnancy allows quantitative and qualitative evaluations of the hypertensive status. However, if such a technique is used routinely in every clinical setting, we should establish specific thresholds of normality for pregnancy.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo examine the risk of placental abruption, placenta previa, and uterine bleeding of unknown etiology in relation to advanced maternal age and parity in a large, population-based study.MethodsData for this study were derived from the Nova Scotia Atlee perinatal provincial data base, Canada, an ongoing project on human reproduction. Women who delivered between 1980 and 1993 (n= 123,941) in the province of Nova Scotia were included in the study, with the exception of pregnancies resulting in multiple births (n= 2859) and those missing data on maternal age or parity (n= 14). Multivariable logistic regression models based on the method of generalized estimating equations were used to generate odds ratios after adjustment for multiple confounders.ResultsThe frequency of abruption was increased slightly among younger women (relative risk [RR] 1.3, 95% confidence interval [CI] 1.0-1.7), compared with women ages 25-29 years, but there was no increase with advancing maternal age. In contrast, the risk of placenta previa increased dramatically with advancing maternal age, with women older than 40 years having a nearly ninefold greater risk than women under the age of 20, after adjustment for potential confounders, including parity. Uterine bleeding of unknown etiology was not associated with advanced maternal age, except for a slight increase among women over 40 (RR 1.3, 95% CI 1.0-1.6). The risk of placenta previa and placental abruption was increased with higher parity among younger women only, but uterine bleeding of unknown etiology was more weakly associated with higher parity. In addition, an analysis of the joint effects of age and parity on placental abruption indicated a strong parity effect for women under 30 years, whereas the risk of placenta previa increased with increasing parity up to age 35 years. Uterine bleeding of unknown etiology also indicated a parity effect that was restricted to women under 25 years.ConclusionMultiparity is associated with the risk of placenta previa and, to a lesser extent, placental abruption, but not with other uterine bleeding. Increasing maternal age is associated independently with the risk of placenta previa, but not with either of the other two conditions. Finally, the increased risks of uteroplacental bleeding disorders with advanced parity among the younger women (ie, 20-25 years, parity 3+) may reflect effects of close pregnancy spacing, or confounding by unmeasured factors that characterize women who have many pregnancies at a relatively young age. Overall, the findings suggest that the three uteroplacental bleeding disorders do not share a common etiology in relation to maternal age and parity, and that placenta previa is linked to aging of the uterus and the effects of repeated pregnancies.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo compare oxytocin infusion alone and with intravenous (IV) propranolol in the management of dysfunctional labor.MethodsNinety-six parturients with abnormalities of the active phase of labor were randomly assigned to either propranolol 2 mg IV or an identical placebo, in addition to continuous infusion of oxytocin. Administration of propranolol or placebo was repeated in 1 hour if there was no change in cervical dilation. Patients not responding to this second administration of propranolol or placebo were delivered by cesarean.ResultsAmong 96 subjects enrolled, 49 were allocated to the propranolol group and 47 to the placebo group; 13 (26.5%) of the former were delivered by cesarean, compared with 24 (51.1%) of the latter (relative risk 0.58, 95% confidence interval 0.35-0.93;P= .02). Between the two groups, no differences were observed in low Apgar scores, cord arterial pH, or incidence of admissions to the neonatal intensive care nursery. Maternal morbidity was similar in both groups. After logistic regression analysis controlling for nulliparity, birth weight, and epidural anesthetic use, the significant reduction in the cesarean rate associated with use of propranolol persisted. Propranolol administration was associated with a markedly reduced cesarean rate among patients with inadequate uterine contractility.ConclusionLow-dose administration of IV propranolol in patients with dysfunctional labor augmented with oxytocin safely reduced the need for cesarean delivery, particularly among patients with inadequate uterine contractility.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo evaluate the effectiveness and safety of the vaginal application of misoprostol for induction of labor at term, with the interval duration from labor induction to vaginal birth as the primary outcome measure.MethodsTwo hundred twenty-two women with indications for induction of labor at term were randomized to receive either misoprostol 50 μg per vagina every 4 hours as needed or our standard approach (physician-chosen combinations of intracervical or vaginal dinoprostone every 6 hours, artificial rupture of membranes, and oxytocin infusion).ResultsMean (± standard deviation) time to vaginal delivery was 753 ± 588 minutes for misoprostol versus 941 ± 506 minutes for the physician-chosen combination (P= .018). Oxytocin infusion was used less frequently (relative risk [RR] 0.48, 95% confidence interval [CI] 0.31-0.74). There was no significant difference in cesarean rate or maternal morbidity. Neonatal outcomes, including cord-blood acidbase analysis, were not significantly different. The estimated cost per patient in Canadian dollars for prostaglandins was $0.22 with misoprostol and $70.00 with standard therapy.ConclusionVaginal misoprostol is a cost-effective alternative to current labor-induction protocols. We found no evidence of harm to mother or newborn in substantive outcomes.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo assess our ability to detect macrosomic fetuses, and to examine the relationship between prenatal diagnosis of macrosomia and the incidence of shoulder dystocia and birth trauma.MethodsWe instituted a protocol for routine detection of macrosomic fetuses, defined as weight estimated to be at least 4500 g. Fetal weight was estimated by ultrasonography when there was clinical suspicion of macrosomia. We collected data on these pregnancies as well as on deliveries of macrosomic infants, shoulder dystocia, and birth trauma.ResultsDuring the 14-month study period, there were 4480 deliveries. There were 23 macrosomic newborns (0.5%), of whom 17 were born vaginally. Six of these 17 (35%) vaginal deliveries were complicated by shoulder dystocia, and one infant sustained brachial plexus injury. The overall frequency of shoulder dystocia was 2%, the majority (93%) occurring in infants weighing less than 4500 g. Eleven newborns sustained brachial plexus injury (0.2%), and 39 had isolated clavicular fracture. Six of nine cephalic deliveries that resulted in brachial plexus injury were associated with shoulder dystocia. The sensitivity and predictive value of the study protocol were 17% (four of 23) and 36% (four of 11), respectively. Surprisingly, clinical estimation alone had a sensitivity of 43% (ten of 23) and a positive predictive value of 53% (ten of 19).ConclusionThe ability to predict macrosomia is limited. The predictive value of clinical estimation of fetal weight alone may be slightly higher than when it is combined with ultrasonography. Because most cases of shoulder dystocia and birth trauma occur in nonmacrosomic infants, these conditions are practically impossible to prevent.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo evaluate the relationship between race, age, and the risk of cesarean delivery.MethodsThis was a cohort study of 3603 nulliparous enlisted United States Navy women who were on active duty and had a singleton delivery between October 1987 and September 1989. Type of delivery and complications of pregnancy, labor, or delivery were identified through hospital discharge diagnoses codes. Demographic risk factors were obtained from military personnel files.ResultsWomen over age 30 had a significantly increased risk of cesarean delivery (odds ratio [OR] 1.4, 95% confidence interval [CI] 1.1-1.9) compared with women under age 30. Multiple logistic regression modeling adjusted for education, marital status, military rank, type of hospital, and complications of pregnancy, labor and delivery showed African-American women over age 30 to have a significantly increased risk for cesarean delivery (OR 2.2, 95% CI 1.1-4.2) compared with white women over age 30. Among women under 30, African-Americans were not at a greater risk of cesarean delivery (OR 1.1; 95% CI 0.89-1.3). Other demographic factors were not related to the risk of cesarean delivery, but complications of pregnancy, labor, and delivery were strong predictors.ConclusionWe observed an increased risk in this unique population over age 30. Active duty military women serve as a useful population to examine demographic differences because of equitable access to medical care.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo investigate the role of cytokines in normal term and preterm labor in the absence of intrauterine infection.MethodsCytokine (interleukin [IL]-1β, IL-6 and tumor necrosis factor-α [TNF-α]) release was estimated from placental and decidual cell cultures from 22 nonlaboring women at term with cesarean deliveries, 18 women with spontaneous labor at term, and 21 women with preterm labor (19-36 weeks gestation) who delivered vaginally or by cesarean, according to gestational age. Eight of 21 women delivering preterm had clinical evidence of intrauterine infection, and 13 were not infected.ResultsPlacental cell cultures obtained from women with spontaneous term labor released significantly larger amounts of cytokines (median: IL-1β 6450 pg/mL, IL-6 1821 ng/mL, and TNF-α 13,506 pg/mL) compared with placental cell cultures from nonlaboring women at term (median: IL-1β 2602 pg/mL, IL-6 993 ng/mL, TNF-α 3475 pg/mL;P< .02). Placental cells from women delivering preterm with intrauterine infection did not produce significantly different amounts of cytokines (median: IL-1β 3929 pg/mL, IL-6 1084 ng/mL, TNF-α 2847 pg/mL) when compared with those of nonlaboring women at term, whereas placental cells from uninfected women delivering preterm produced significantly larger amounts of cytokines (median: IL-1β 22,903 pg/mL, IL-6 1899 ng/mL, TNF-α 15,005 pg/mL;P< .01) than cells from nonlaboring women at term. Cytokine release from decidual cell cultures was similar in all groups tested.ConclusionIn the absence of intrauterine infection, preterm labor was associated with elevated placental cytokine release.

ISSN:0029-7844    

出版商:OVID    

年代:1996

数据来源: OVID