摘要:

ObjectiveTo test the null hypothesis of no association between ultrasound exposure in early fetal life and impaired neurologic development in childhood.MethodsStudy of children age 8–9 years whose mothers participated in a randomized controlled trial of ultrasound screening during pregnancy in Sweden during 1985–1987. Of 4637 eligible singletons, 3265 (70%) were studied through a questionnaire to their mothers. Assessment of neurologic development was based on parents' report of their child's speech and motor development. Behavioral disorders were assessed by a ten-item parent scale. Analyses were performed according to both assignment and ultrasound expo sure. With a sample size of 1600 children in each group, a two-sided α of .05 and β of .10, a risk ratio of less than 1.4 for the studied variables could not be detected.ResultsDelayed speech development was reported by 2.9% in the screening group compared with 2.4% in the nonscreening group (odds ratio [OR] 1.21; 95% confidence interval [CI] 0.79, 1.88). Similar prevalences were found when analysis was according to ultrasound exposure (OR 1.19, 95% CI 0.78, 1.83). Delayed motor development was reported by 7.6% in the screening group compared with 7.2% in the nonscreening group (OR 1.05; 95% CI 0.81, 1.37). Corresponding figures for ultrasound-exposed and -unexposed were 7.7% and 7.2%, respectively (OR 1.08; 95% CI 0.83, 1.40). There also were no significant differences in behavioral disorders between screened and unscreened children or between exposed and unexposed children, respectively, according to parents' ratings.ConclusionNo significant difference in impaired neurologic development between ultrasound-exposed and -unexposed children was found in this study.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo compare resistance to blood flow between two umbilical arteries at the same cord site during the second half of pregnancy.MethodsWe evaluated 80 patients with singleton pregnancies cross-sectionally at gestational ages ranging from 20–40 weeks' gestation. Resistance to blood flow was measured separately by means of systolic-diastolic ratio (S/D) for both umbilical arteries of each subject at the same site of transverse cord section. The higher mean value of the one umbilical artery was designated S/Dmax, whereas the lower mean value of the other paired umbilical artery was designated S/Dmin. The percent difference between the two values was calculated for each pair of measurements. Then these data were stratified by gestational age.ResultsThe overall mean (± standard deviation [SD]) S/Dmaxwas significantly different from S/Dmin(2.62 ± 0.58 versus 2.27 ± 0.40, respectivelyP< .001). The mean (± SD) calculated percent difference of 14.9 ± 10.4% ranged in a downward trend over the course of late pregnancy from 29.2 ± 17.1% in the 20–28 weeks' gestational age group to 10.4 ± 6.1% among those at term (37–40 weeks); the slope of this trend was −1.32 ± 8.55% per week, a statistically significant trend (P< .001). There was a more than 20% difference in more than one quarter (29%) of the 80 pairs of umbilical arteries we studied. Cases with these large differences were concentrated mostly among those with earlier gestational ages: At term, only 8.6% showed this difference in flow resistance measurements.ConclusionThe resistance to blood flow in one umbilical artery often differs considerably from that in the other. The difference, which equalizes gradually as pregnancy advances, perhaps as a result of functional maturation of the Hyrtl anastomosis between the vessels, may have clinical importance for identification and evaluation of the potentially jeopardized fetuses, either as an early marker of fetal hypoxia or in interpretating fetal status.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo evaluate whether the vasorelaxant molecule nitric oxide (NO) and its second messenger cyclic guanosine monophosphate (cGMP) modulate the reduction in resistance within the fetoplacental circulation that occurs during the first trimester of pregnancy.MethodsWe studied 27 women undergoing termination of pregnancy for psychosocial indications between 9 and 15 weeks' gestation. Each had ultrasound dating of the fetus and Doppler umbilical artery (UA) flow investigation immediately before the operation. Placental tissue was assayed for nitric oxide synthase (NOS) activity and cGMP content.ResultsBoth UA pulsatility index (PI) and placental endothelial NOS activity decreased significantly with advancing gestation (r= −.52 and −.41, respectively). Umbilical PI correlated positively with endothelial NOS activity and cGMP level. Multiple linear regression analysis indicated that cGMP contributed most strongly to UA PI (P< .001).ConclusionOur findings suggest somewhat paradoxically that NOS activity and cGMP levels are highest in the early gestations, when umbilical PI is also high, and decrease as umbilical PI decreases. Further studies are required to determine whether the predominant effect of NO is that of a vascular relaxant or a modulator of new villous vessel formation.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo describe postdelivery mortality rates among residents of Tennessee from 1989 through 1991 and to compare these rates with those of women who had not delivered a live or stillborn infant in the previous year.MethodsPostdelivery deaths (those occurring within a year of delivery of a live or stillborn infant) were identified using a computerized linkage of birth and fetal death certificates to death certificates of female decedents aged 15–44 years. Each identified postdelivery death was reviewed and categorized as either pregnancy-related (temporally and causally related to pregnancy) or pregnancy-associated-but-not-related (temporally but not causally related to pregnancy). Cause-specific mortality rates were compared for women who died postdelivery with women who died but had not delivered in the previous year.ResultsWe identified 129 postdelivery deaths, one quarter of which were classified as pregnancy-related. The rates of postdelivery pregnancy-related and of pregnancy associated-but-not-related death were 14.6 and 58.7, respectively, per 100,000 women who had delivered. Nonwhite women were 6.9 times more likely to experience postdelivery pregnancy-related death and 2.0 times more likely to experience postdelivery pregnancy-associated-but-not related death than were white women. The leading cause of death among both women who had delivered and women who had not delivered a live or stillborn infant in the previous year was injury, although the risk of death the year after delivery was lower than for women who had delivered.ConclusionWomen were less likely to die in the year after delivery than were women who had not delivered a live or stillborn infant in the previous year. However, regardless of their delivery status, injuries were the leading cause of death among women. Postdelivery mortality was statistically significantly higher in nonwhite than white women, especially for pregnancy-related deaths.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo evaluate the maternal serum dehydroepiandrosterone (DHEA) sulfate level as a factor associated with the outcome of labor induction.MethodsVenous blood was collected from 161 women at the initiation of labor induction. Pregnancies complicated by maternal corticosteroid use, antepartum chorioamnionitis, or cesarean delivery for indications other than arrest disorders were excluded from analysis. In 155 women meeting inclusion criteria, induction followed established protocols. Serum DHEA sulfate levels were measured by radioimmunoassay and correlated with the outcome of each induction attempt. A success was defined as progression to active labor. The Welch approximatettest, Mann-Whitney test, Fisher exact test, simple regression, and multiple regression were used for statistical analysis, withP< .05 considered significant.ResultsThe mean (± standard error) DHEA sulfate level was higher in women who progressed to active labor (n= 147) than in those with unsuccessful attempts (n= 8), (109.01 ± 5.19 μ/dL versus 58.78 ± 15.83 μ/dL, respectively;P= .02). Compared with women with DHEA sulfate levels above 70 μ/dL, women with lower levels had an unsuccessful induction odds ratio (OR) of 4.46 (95% confidence interval, 1.12, 17.67;P= .04). The OR increased as DHEA sulfate levels decreased.ConclusionDehydroepiandrosterone sulfate may be an important factor in successful labor induction.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo compare the cesarean rates in women undergoing induction of labor with unfavorable cervices who receive either misoprostol or extra-amniotic saline infusion.MethodsWe assigned 250 women undergoing indicated induction of labor randomly to misoprostol (50 μg every 4 hours for three doses with or without oxytocin) or extra-amniotic saline infusion and oxytocin. Each eligible subject had a singleton gestation, vertex presentation, intact membranes, cervical dilation no more than 2 cm, and effacement no more than 50%.ResultsTwo hundred forty-eight women were studied after two exclusions; 120 were assigned to misoprostol, and 128 to extra-amniotic saline infusion. This sample size ensured an 80% chance of detecting an intergroup difference in cesarean rates of at least two-fold. The groups were similar in age, race, parity, indication for induction, and gestational age. The extra-amniotic saline infusion group had a significantly lower median initial dilation; however, at 12 hours, this group was significantly more dilated. The groups also were similar in epidural use, chorioamnionitis rates, endometritis rates, birth weights, and neonatal outcomes. Overall, 23% of women underwent cesarean deliveries, 18% and 27% for the misoprostol and extra-amniotic saline infusion groups, respectively (P= .12). There were no significant differences in the median time to either vaginal or cesarean delivery between the two groups. Eighty-one percent of women were delivered in less than 24 hours from initiation of induction; 78% in the misoprostol group, and 84% in the extra-amniotic saline infusion group (P= .19).ConclusionBoth methods of labor induction appear to be equally effective in this group of women at high risk for cesarean delivery and prolonged induction of labor.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo provide the obstetrician-gynecologist with the recent advances in mechanisms of chemotherapy resistance in ovarian cancer.Data SourcesA computerized search of articles published through September 1997 was performed on the MEDLINE Ovid and Cancerlit databases. Additional references were identified from the reference section of all selected papers.Methods of Study SelectionAll identified references were evaluated as to their relevant contribution to our understanding of the basic mechanisms underlying the response to chemotherapy, the development of chemotherapy resistance in ovarian cancer, and possible strategies for therapy.Tabulation, Integration, and ResultsOne hundred sixteen references were reviewed. A brief summary of the classic concepts on resistance to cisplatin and paclitaxel is provided, followed by a description of the basic mechanisms governing apoptosis and cell cycle arrest as well as their involvement in cell response to chemotherapy and the development of chemoresistance. Finally, a brief summary of the molecular alterations described in ovarian cancer, together with hypothetic strategies for gene-targeted therapy, are reported.ConclusionCisplatin or paclitaxel chemotherapy induces arrest of the cell cycle or apoptosis in ovarian cancer cells. Tumor suppressor genes such as p53 play a paramount role in mediating this response and p21WAF1/CIP1is a major mediator of p53-induced arrest of the cell cycle. Molecular alterations involving these tumor suppressor genes are related to the development of resistance to chemotherapy and represent possible targets for gene therapy in ovarian cancer.

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0029-7844    

出版商:OVID    

年代:1998

数据来源: OVID