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Biomedical subjects

George A Macones

Publications and source records attributed to George A Macones.

At least 19 recordsLinked to original sources
PubMed2006

Is vaginal birth after cesarean (VBAC) or elective repeat cesarean safer in women with a prior vaginal delivery?

OBJECTIVE: This study was undertaken to determine whether vaginal birth after cesarean (VBAC) or elective repeat cesarean delivery is safer overall for a woman with a prior vaginal delivery. STUDY DESIGN: This retrospective cohort study of pregnant women from 1996 to 2000 who had a prior cesarean delivery, was conducted in 17 centers. Trained nurses extracted historical and maternal outcome data on subjects by using standardized tools. This planned secondary analysis examined the subcohort that had also previously undergone a vaginal delivery, comparing those who underwent a VBAC trial with those who elected to have a repeat cesarean delivery. Outcomes included uterine rupture, bladder injury, fever, transfusion and a composite (uterine rupture, bladder injury, and artery laceration). We performed bivariate and multivariable analyses. RESULTS: Of 6619 patients with a prior cesarean delivery who had also had a prior vaginal delivery, 5041 patients attempted a VBAC delivery and 1578 had an elective cesarean delivery. Although there was no significant difference in uterine rupture or bladder injury between the two groups, women who underwent a VBAC attempt were less likely to experience the composite adverse maternal outcome, have a fever, or require a transfusion. CONCLUSION: Among VBAC candidates who have had a prior vaginal delivery, those who attempt a VBAC trial have decreased risk for overall major maternal morbidities, as well as maternal fever and transfusion requirement compared with women who elect repeat cesarean delivery. Physicians should make this more favorable benefit-risk ratio explicit when counseling this patient subpopulation on a trial of labor.

Adult↗
PubMed2006

Evaluating the thresholds of abnormal second trimester multiple marker screening tests associated with intra-uterine growth restriction.

Our objective was to evaluate the optimal thresholds for unexplained abnormal multiple marker screening (MMS) results that are associated with intrauterine growth restriction (IUGR). This was a case-control study from our perinatal database. MMS analyte levels (multiples of median [MoM]) of cases with IUGR (birthweight < 5th percentile for gestational age) were compared with a control group without IUGR. Pregnancies with fetal anomalies were excluded. Biochemical markers evaluated include alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3). Using receiver operating characteristic curves, the optimal thresholds of MMS (OTMs) associated with IUGR were determined. We identified 255 (12.3%) cases with IUGR and complete MMS records from the database. These were compared with 1785 controls without IUGR randomly selected from our perinatal database in a 1:7 ratio. The OTMs associated with IUGR were AFP > 2.0 MoM (odds ratio [OR] = 2.3; 95% confidence interval [CI], 1.4 to 3.7), hCG > 2.5 MoM (OR = 1.8; 95% CI, 1.1 to 3.2) and uE3 < 0.9 MoM (OR = 2.7; 95% CI, 2.0 to 3.7). The sensitivity, specificity, and positive and negative predictive values for predicting IUGR in the presence of at least one abnormal MMS were 46, 66, 11, and 90%, respectively. Elevated AFP > 2.0 MoM and hCG > 2.5 MoM were the most specific markers for MMS, with specificity of 94 and 95%, respectively. When all three analytes were abnormal, the specificity for predicting IUGR increased to 99%. Abnormal MMS results are associated with IUGR. As a screening tool for IUGR, the biochemical markers were associated with poor sensitivity. Elevated AFP and hCG, however, were highly specific in predicting IUGR. The provided thresholds could be useful in designing policies regarding women who would benefit most from sonographic screening for IUGR.

Adult↗
PubMed2006

Advanced maternal age is an independent risk factor for intrauterine growth restriction.

Reports on the association between advanced maternal age (AMA) and intrauterine growth restriction (IUGR) are conflicting. Our objective was to determine if AMA is an independent risk factor for IUGR. Our case-control study compared cases with IUGR (birthweight<10th percentile for gestational age) and a control group without IUGR. Gestational ages were all confirmed by ultrasound. The study included only singletons and fetal anomalies were excluded. Both groups were evaluated for maternal demographics and clinical risk factors. AMA was defined as maternal age>35 years. Univariate and multivariate analyses were used to examine associations. During the study period, there were 824 cases with IUGR meeting the inclusion criteria; these were compared with 1648 controls (no IUGR) randomly selected from the same population during the same study period. The significant factors associated with IUGR multivariate analyses were black race (odds ratio [OR], 22.4; 95% confidence interval [CI], 17.8 to 28); chronic hypertension (OR, 2.2; 95% CI, 1.5 to 3.2); pregestational diabetes (OR, 3.3; 95% CI, 1.6 to 7) illicit drug use (OR, 3.3; 95% CI, 2.2 to 5.2), and AMA (OR, 1.4; 95% CI, 1.1 to 1.8). There was a positive dose-response association between increasing maternal age and increasing risk for IUGR. At maternal age of 40 years or older, the OR and 95% CI for IUGR was 3.2 and 1.9 to 5.4, respectively. AMA is an independent risk factor for IUGR. Our findings suggest that screening for IUGR is indicated in women age 35 years or older.

Adolescent↗
PubMed2006

Safety and success of vaginal birth after cesarean delivery in patients with preeclampsia.

The objective of this study was to determine if preeclampsia (PRE) or gestational hypertension (GH) affects the rate of success of vaginal birth after cesarean delivery (VBAC), VBAC-related complications, or patient election to attempt VBAC. We performed a retrospective cohort study of all women who were offered VBAC from 1996 to 2000 in 17 community and university hospitals. Demographic, medical, and obstetric history, complications, treatment, and index pregnancy outcome information was collected on all patients in the database. Bivariate analysis and multivariable logistic regression were used to assess the independent association between GH and PRE and the rate of success of VBAC, VBAC-related complications, or patient election to attempt VBAC. A total of 25,005 patients were registered in the database. 13,706 (54.81%) attempted VBAC and 11,299 (45.19%) elected repeat cesarean delivery. After adjusting for confounding variables using multivariable logistic regression, patients with PRE were more likely to fail VBAC (relative risk [RR], 1.56; 95% CI, 1.22 to 2.00). Patients with GH were less likely to attempt VBAC (RR, 0.39; 95% CI, 0.34 to 0.46). A total of 304 (1.46%) patients had a uterine rupture. The VBAC group had a rupture rate of 0.93% and the elective cesarean group had a rupture rate of 0.04%. There was no difference in uterine rupture rates between the cohorts. Patients with gestational hypertension were less likely to attempt a VBAC. Patients with PRE, if they attempted a VBAC trial, had a higher VBAC failure rate. Patients with PRE or GH do not have increased uterine rupture rates. These findings can be used to improve mode of delivery counseling for VBAC candidate patients with preeclampsia.

Adult↗
PubMed2006

Should all pregnant diabetic women undergo a fetal echocardiography? A cost-effectiveness analysis comparing four screening strategies.

OBJECTIVE: To determine if a policy of universal fetal echocardiography for all pregnant diabetic women is cost-effective as a screening tool for congenital heart defects. STUDY DESIGN: Using a decision-analysis model, we compared the cost-effectiveness of four screening strategies: (1) none--no ultrasound is performed; (2) selective fetal echocardiography after abnormal detailed anatomic survey; (3) fetal echocardiography for only high hemoglobin A1C, and (4) universal fetal echocardiography for all diabetics. The sensitivity and specificity for each strategy were derived by literature search. The analysis was from a societal perspective using a willingness-to-pay threshold (50,000 dollars) and a theoretic cohort of 40,000 pregnant diabetics. Costs included costs of tests and the costs of complications and of raising a child with a cardiac defect. Outcomes were reported as cost per quality-adjusted life years (QALY) gained for each congenital heart defect prevented by each strategy and the number of congenital heart defects detected. One-way, multiway and probabilistic sensitivity analyses were performed. RESULTS: Compared with the other strategies, selective fetal echocardiography after abnormal detailed anatomic survey costs less per QALY gained for cardiac defect screening. Although universal fetal echocardiography was associated with a higher detection rate for cardiac defects, it was more costly. The sensitivity analyses revealed a robust model over a wide range of values. CONCLUSION: Under the baseline assumptions, selective fetal echocardiography after an abnormal detailed anatomic survey is more cost-effective compared with universal fetal echocardiography as a screening strategy for cardiac defects in pregnant diabetics.

Cost-Benefit Analysis↗
PubMed2006

Co-dispensing of contraindicated medications in patients using cisapride in Italy.

PURPOSE: To investigate the co-dispensing of contraindicated medications in patients using cisapride in an Italian population. METHODS: The study included patients who had at least one cisapride prescription dispensed between 1 April 1997 and 30 September 2000. The proportion of cisapride users with concomitant medications, the proportion of prescriptions of cisapride with an overlapping dispensing of a contraindicated medication and the proportion of person-days of cisapride use concomitant with contraindicated medications, were calculated. RESULTS: In the 4-year study period, 249,740 total cisapride prescriptions, which corresponded to 382,835 packages, were dispensed to 91,204 users (52,442 female, 57.5%). Concomitant use of contraindicated drugs was identified in 4403 cisapride users (4.83%). Throughout the study period, there was an increase in the proportion of cisapride users with contraindicated co-prescriptions: 4.29% in 1997, 4.99% in 1998, 5.15% in 1999, but a decline to 3.34% in 2000. In each year, this figure was higher in males, with the highest proportion reported in 1999 (5.50%). A total of 7215 cisapride prescriptions (2.85%) were concomitant with contraindicated drugs, ranging from 2.27% in September 1998 to 3.55% in January 1999. Cisapride prescriptions were most frequently associated with macrolide antibiotics (1.14%) and class III antiarrhythmics (1.03%). CONCLUSIONS: In the period 1997-2000, a substantial proportion of cisapride prescriptions were concomitant with contraindicated medications. In Italy in 1998, the National Health Authority issued a bulletin warning about the risk of serious arrhythmias after concomitant use of contraindicated drugs. Despite this warning, there was no reduction in contraindicated drug uses.

Adolescent↗
PubMed2006

Can uterine rupture in patients attempting vaginal birth after cesarean delivery be predicted?

OBJECTIVE: This study was undertaken to use multivariable methods to develop clinical predictive models for the occurrence of uterine rupture by using both antepartum and early intrapartum factors. STUDY DESIGN: This was a planned secondary analysis from a multicenter case-control study of uterine rupture among women attempting vaginal birth after cesarean (VBAC) delivery. Multivariable methods were used to develop 2 separate clinical predictive indices--one that used only prelabor factors and the other that used both prelabor and early labor factors. These indices were also assessed with the use of Receiver operating characteristic curves. RESULTS: We identified 134 cases of uterine rupture and 665 noncases. No single individual factor is sufficiently sensitive or specific for clinical prediction of uterine rupture. Likewise, the 2 clinical predictive indices were neither sufficiently sensitive nor specific for clinical use (receiver operating characteristic curve [area under the curve] 0.67 and 0.70, respectively). CONCLUSION: Uterine rupture cannot be predicted with either individual or combinations of clinical factors. This has important clinical and medical-legal implications.

Adult↗
PubMed2006

17alpha-hydroxyprogesterone caproate for the prevention of preterm delivery: A cost-effectiveness analysis.

OBJECTIVE: To evaluate whether the use of 17alpha-hydroxyprogesterone caproate for the prevention of recurrent preterm deliveries is cost-effective. METHODS: Using decision-analysis modeling, we compared the cost-effectiveness of using 17alpha-hydroxyprogesterone caproate in four subgroups: 1) Prior preterm deliveries less than 32 weeks; 2) prior preterm deliveries 32-37 weeks; 3) prior term delivery; and 4) no prior delivery. Each subgroup was compared with a "no treatment" group. Costs included those for 17alpha-hydroxyprogesterone caproate, hospital admissions, and complications from preterm deliveries. The main outcome measures include cost per quality-adjusted life-year gained and the number of preterm deliveries prevented. Secondary outcomes include neonatal complications prevented. One-way and multiway sensitivity analyses were performed. RESULTS: The use of 17alpha-hydroxyprogesterone caproate for the prevention of preterm deliveries result in cost-savings in women with prior preterm deliveries less than 32 weeks and 32-37 weeks. The sensitivity analyses revealed the model to be robust over a wide range of values for evaluated variables. CONCLUSION: Within our baseline assumptions, 17alpha-hydroxyprogesterone caproate was associated with cost-savings when used for the prevention of preterm deliveries in women with prior preterm deliveries.

17 alpha-Hydroxyprogesterone Caproate↗
PubMed2006

Vaginal birth after caesarean section versus elective repeat caesarean section: assessment of maternal downstream health outcomes.

OBJECTIVE: To compare the maternal implications of strategies of vaginal birth after caesarean section (VBAC) attempt versus elective repeat caesarean section in women with one previous lower segment caesarean section. DESIGN: Decision model. POPULATION: Women with one prior low transverse caesarean section who are eligible for trial of labour. METHODS: Two decision models were built: the first one applying to women planning only one more pregnancy, the second one applying to women planning two more pregnancies. Probability estimates for VBAC success rate and risks of uterine rupture, placenta praevia, placenta accreta and hysterectomy were extracted from the available literature. MAIN OUTCOME MEASURES: Hysterectomy for uterine rupture, placenta accreta or other indications. RESULTS: In the first model VBAC attempt led to a higher hysterectomy rate (267/100,000) compared with repeat caesarean section (187/100,000). However, in the second model a policy of elective repeat caesarean section led to higher cumulative hysterectomy rate: 1465/100,000 versus 907/100,000 for VBAC. The first model was robust to all but one variable in sensitivity analyses. The second model was robust to all variables in sensitivity analyses. CONCLUSIONS: These results indicate that long term reproductive consequences of multiple caesarean sections should be considered when making policy decisions regarding the risk-benefit ratio of VBAC.

Cesarean Section, Repeat↗
PubMed2006

Evaluating the efficiency of using second-trimester nasal bone hypoplasia as a single or a combined marker for fetal aneuploidy.

OBJECTIVE: Although second-trimester nasal bone (NB) hypoplasia has been associated with fetal aneuploidy, its role as a single marker is still uncertain. Our objective was to evaluate the efficiency of NB hypoplasia as an independent marker for fetal aneuploidy. METHODS: This was a prospective cohort study of women undergoing an anatomic survey between 16 and 22 weeks' gestation. The fetal NB and other markers of fetal aneuploidy, including nuchal fold, femur and humeral lengths, choroid plexus cysts, major fetal anomalies, echogenic bowel, pyelectasis, and hypoplastic fifth digits, were evaluated. Nasal bone hypoplasia was defined either as an absent NB or by a ratio of the biparietal diameter to NB. Fetuses or infants with fetal aneuploidy were compared with those without for the presence of NB hypoplasia either as a single marker or in the presence of other markers for aneuploidy. RESULTS: Of 2885 women evaluated, NB measurements were obtained in 2465 (85%). There were 35 (1.4%) cases with fetal aneuploidy. The sensitivity and specificity of a single NB in detecting Down syndrome varied from 23% to 64% and 57% to 99%, respectively, depending on the definition of NB hypoplasia used. There was an improvement in the efficiency of using the NB when combined with other markers, with sensitivity and specificity increasing from 59% to 82% and 74% to 87%, respectively. CONCLUSIONS: Nasal bone hypoplasia is a marker for fetal aneuploidy. The combination of the NB with other makers was associated with an improvement in detection of fetal aneuploidy.

Abnormalities, Multiple↗
PubMed2005

Development of a clinical prediction rule for iron deficiency anemia in pregnancy.

OBJECTIVE: The purpose of this study was to elucidate if anemia in pregnancy caused by iron deficiency could be predicted by simple measures obtained on a complete blood count (CBC) using ferritin as the gold standard. STUDY DESIGN: One hundred forty-one pregnant patients with anemia were recruited during their first prenatal visit. CBC and ferritin level were obtained and candidate-predictors identified. Receiver operator characteristic (ROC) curves, stratified analysis, and logistic regression analysis were used to develop a prediction rule with maximum specificity. RESULTS: A hemoglobin level < or = 9.7 and a red cell distribution width (RDW) > or = 15 (in gestational age <20 weeks) predicted iron deficiency with high specificity. Our final model correctly classified 79.43% of the patients (area under the ROC curve of 0.88 [95%CI 0.82-0.93], specificity of 95.74%). CONCLUSION: Iron deficiency anemia can be predicted in pregnancy using lower cost tests, which could be an incredibly useful tool in areas with limited resources and a high prevalence of the disease. This study was limited to a mostly African American population in an urban setting, and the results may not be generalized to other populations.

Adult↗
PubMed2005

Obstetric outcomes in women with two prior cesarean deliveries: is vaginal birth after cesarean delivery a viable option?

OBJECTIVE: This study was undertaken to compare clinical outcomes in women with 1 versus 2 prior cesarean deliveries who attempt vaginal birth after cesarean delivery (VBAC) and also to compare clinical outcomes of women with 2 prior cesarean deliveries who attempt VBAC or opt for a repeat cesarean delivery. STUDY DESIGN: We performed a secondary analysis of a retrospective cohort study, in which the medical records of more than 25,000 women with a prior cesarean delivery from 16 community and tertiary care hospitals were reviewed by trained nurse abstractors. Information on demographics, obstetric history, medical and social history, and the outcomes of the index pregnancy was obtained. Comparisons of obstetric outcomes were made between women with 1 versus 2 prior cesarean deliveries, and also between women with 2 prior cesarean deliveries who opt for VBAC attempt versus elective repeat cesarean delivery. Both bivariate and multivariate techniques were used for these comparisons. RESULTS: The records of 20,175 women with one previous cesarean section and 3,970 with 2 prior cesarean sections were reviewed. The rate of VBAC success was similar in women with a single prior cesarean delivery (75.5%) compared with those with 2 prior cesarean deliveries (74.6%), though the odds of major morbidity were higher in those with 2 prior cesarean deliveries (adjusted odd ratio[OR] = 1.61 95% CI 1.11-2.33). Among women with 2 prior cesarean deliveries, those who opt for a VBAC attempt had higher odds of major complications compared with those who opt for elective repeat cesarean delivery (adjusted OR = 2.26, 95% CI 1.17-4.37). CONCLUSION: The likelihood of major complications is higher with a VBAC attempt in women with 2 prior cesarean deliveries compared with those with a single prior cesarean delivery. In women with 2 prior cesarean deliveries, while major complications are increased in those who attempt VBAC relative to elective repeat cesarean delivery, the absolute risk of major complications remains low.

Adult↗
PubMed2005

Maternal complications with vaginal birth after cesarean delivery: a multicenter study.

OBJECTIVE: This study was undertaken to determine incidence and risk factors for uterine rupture in women attempting vaginal birth after cesarean delivery (VBAC) in a wide range of hospital settings. STUDY DESIGN: We performed a case-control study nested within a cohort of women who have had a prior cesarean to determine the incidence and risk factors for uterine rupture in women attempting VBAC. RESULTS: The incidence rate of uterine rupture in those who attempt VBAC was 9.8 per 1000. A prior vaginal delivery was associated with a lower risk of uterine rupture (adjusted odds ratio [OR] = 0.40, 95% CI 0.20-0.81). Although prostaglandins alone were not associated with uterine rupture, sequential use of prostaglandin and pitocin was associated with uterine rupture (adjusted OR = 3.07, 95% CI 0.98-9.88). CONCLUSION: Women with a prior cesarean should be offered VBAC, and women with a prior cesarean and prior vaginal delivery should be encouraged to VBAC. Although other studies have suggested that prostaglandins should be avoided, we suggest that inductions requiring sequential agents be avoided.

Adult↗
PubMed2005

Is fetal gender associated with adverse perinatal outcome in intrauterine growth restriction (IUGR)?

OBJECTIVE: The purpose of this study was to determine if there is a difference in perinatal outcome by gender among growth-restricted fetuses. STUDY DESIGN: This was a retrospective cohort study of intrauterine growth restriction (IUGR) singleton pregnancies over a 5-year period. Clinical outcomes compared by gender included preterm delivery, perinatal mortality (PNM), respiratory distress syndrome (RDS), grade 3 or 4 intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), and periventricular leukomalacia (PVL). Statistical analysis included bivariate and multivariable techniques. RESULTS: Seven hundred and twenty-seven singleton pregnancies with IUGR were identified. Three hundred and forty-six (47.6%) were males. Birth weight was similar between the groups. After adjusting for maternal demographics, medical history, gestational age, mode of delivery, and antenatal corticosteroids, adverse perinatal outcomes were similar between the groups. Severity of outcomes was also similar between males and females (P = .66). CONCLUSION: Male fetuses with IUGR have similar outcomes when compared with female IUGR fetuses. Gender does not play a role in perinatal outcome in the setting of fetal growth restriction.

Female↗
PubMed2005

Vaginal birth after cesarean (VBAC) attempt in twin pregnancies: is it safe?

OBJECTIVE: The purpose of this study was to compare the rate of vaginal birth after cesarean (VBAC) attempt, VBAC failure, and major maternal adverse outcomes in women with a previous cesarean with twin or singleton pregnancies. STUDY DESIGN: This was a multicenter retrospective cohort study between the years 1996 and 2000. Subjects were identified by ICD-9 code. Trained research nurses collected medical record data on the outcome of VBAC attempts, and clinical outcomes, including uterine rupture and major operative injuries. We used bivariate and multivariable techniques to assess the association between twins and the outcomes. RESULTS: Of 25,005 patients with at least 1 previous cesarean, there were 535 twin pregnancies and 24,307 singleton pregnancies. Compared with patients with singleton gestations, patients with twins were less likely to attempt a VBAC (adjusted odds ratio [AOR] 0.3, 95% CI 0.2-0.4), but no more likely to have a VBAC failure (AOR 1.1, 95% CI 0.8-1.6), a uterine rupture (AOR 1.2, 95% CI 0.3-4.6), or a major maternal morbidity (AOR 1.6, 95% CI 0.7-3.7). CONCLUSION: Women with twin gestations are less likely to attempt a VBAC, but they are no more likely to fail a VBAC trial or experience a major morbid event compared with women with singleton gestations.

Adult↗
PubMed2005

First trimester screening: economic implications.

The implementation of new strategies for the detection of Down syndrome will have economic implications. These economic considerations must be considered before implementation, since resources are limited and health care costs in the Unites States are soaring. Economic analyses of prenatal diagnosis have unique challenges that must be considered. Most analyses include only direct medical costs, ignoring indirect and intangible costs.

Adult↗
PubMed2005

Perinatal outcomes in growth-restricted twins compared with age-matched growth-restricted singletons.

The objective of this study was to compare the perinatal outcomes in growth-restricted (IUGR) twins with a matched group of IUGR singletons. We performed a retrospective cohort study evaluating the perinatal outcomes in IUGR twins matched for gestational age at delivery to the next four IUGR singletons (1:4) in our perinatal database. The perinatal outcomes evaluated included rates of uncorrected perinatal mortality (PMR), admission to the neonatal intensive care unit (NICU), respiratory distress syndrome, grades 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, periventricular leukomalacia, and length of NICU stay. A cohort of twins with IUGR were matched with a cohort of IUGR singletons and compared for perinatal outcomes. A p value < 0.05 was considered significant. During the study period, we identified 99 IUGR twins meeting our inclusion criteria. These were matched with 396 singletons with IUGR. The mean gestational age at delivery for the twins was 34 +/- 3.8 weeks and 35 +/- 3.5 weeks for the singletons ( p = 0.11). The PMR in twins was significantly higher than in singletons (OR, 2.2; 95% confidence interval, 1.1 to 5.7). Perinatal morbidity was similarly significantly higher in IUGR twins. Compared with age-matched singletons, twins with IUGR have higher perinatal mortality and morbidity rates.

Adult↗