Exploring the interaction of knee and ankle component use on mobility test performance in people with unilateral transfemoral amputation.

BACKGROUND: Ankle-foot and knee components are important determinants of mobility for individuals with transfemoral amputation. Individually, advanced ankle-foot and knee components have been shown to benefit mobility in this group of people. However, it is not clear what effect a variety of combinations of ankle-foot and knee components have on mobility test performance. OBJECTIVES: To assess whether outcomes from mobility tests in people with unilateral transfemoral amputation are influenced by varying combinations of ankle-foot and knee components. STUDY DESIGNS: Repeated measures. METHODS: Nine adults with unilateral transfemoral amputation completed the two-minute walk test, the timed up-and-go test, the L-test, and a custom locomotion course in four randomized prosthetic conditions. These conditions were each a combination of an ankle-foot component (rigid, nonarticulating [RIG] or hydraulically articulating [HYD]) and a knee component (non-microprocessor-controlled [NMPK] or microprocessor-controlled [MPK]). The test-retest reliability and concurrent validity of the custom locomotion course were also established. RESULTS: The best performance in all mobility tests was associated with the MPK + HYD combination, followed by the MPK + RIG, NMPK + HYD, and NMPK + RIG combinations. This effect was statistically significant for the two-minute walk test (P = 0.01, = 0.36) and on threshold for the L-test (P = 0.05, = 0.36), but not statistically significant for the locomotion course (P = 0.07, = 0.38) or the timed up-and-go test (P = 0.12, = 0.22). Locomotion course performance had good to excellent test-retest reliability and strong concurrent validity. CONCLUSION: Using a combination of a HYD ankle-foot and a MPK knee resulted in the highest performance in mobility tests. This was observed in contrast to combinations of prosthetic components that included a rigid ankle-foot component and/or a NMPK knee component.

The aryl hydrocarbon receptor nuclear translocator gene polymorphism in patients with recurrent miscarriage.

OBJECTIVE: The human aryl hydrocarbon receptor nuclear translocator gene (ARNT) is crucial for embryonic development. Knockout of ARNT is embryonic lethal. We thus hypothesized that some cases of recurrent miscarriage (RM) may be due to a polymorphism in the ARNT gene. METHODS: Polymerase chain reaction was used to compare the gene frequencies of a polymorphism in codon 511 of the ARNT gene in 170 women with idiopathic RM and 105 controls. RESULTS: Using the Hardy-Weinberg equilibrium calculation, the predicted ARNT genotype frequencies for the N511/N511, N511/D511, and D511/D511 genotypes were 0, 2, and 167 respectively. The observed frequencies were 0, 2, and 168 (NS). The N/511/D511 genotype was detected in 1.2% of cases and 2.8% of controls, and the D511/D511genotype was detected in 98.8% of cases and 97.2% of controls (NS). CONCLUSIONS: In our cohort of patients, the polymorphism in codon 511 of the ARNT gene is not associated with RM.

The factor V Leiden and the G20210A prothrombin gene mutations are rare in women with fetal death.

PROBLEM: To determine if there is an association between two commonly inherited thrombophilias, the factor V Leiden and the G20210A prothrombin mutations, and fetal death. METHOD OF STUDY: We used a case-control study design to compare the frequencies of these mutations in women with fetal death and controls. Fetal death was the intrauterine death of the conceptus > or =10 weeks gestation. Controls had one live birth, no miscarriages, and no fetal death. Results were compared using chi square analysis. RESULTS: One hundred and seventy-five cases and controls were identified. There were 4.6% of cases and 3.8% of controls heterozygous for the factor V Leiden mutation (NS), and 1.3% of cases and 1.7% of controls heterozygous for the prothrombin mutation (NS). CONCLUSION: In our population, neither the factor V Leiden nor the G20210A prothrombin mutations are associated with fetal death. Further evidence is required before routine screening for these mutations can be recommended.

Recurrent fetal aneuploidy and recurrent miscarriage.

OBJECTIVE: Some investigators have found a high frequency of abortus aneuploidy in women with recurrent miscarriage, suggesting the possibility of recurrent aneuploidy as a cause of recurrent miscarriage. Others contend that aneuploidy is not a cause of recurrent miscarriage. The purpose of this study was to investigate the relationship between fetal aneuploidy and recurrent miscarriage by estimating whether fetal aneuploidy is more common in patients with recurrent miscarriage than in patients with sporadic miscarriage METHODS: Recurrent miscarriage cases (n = 135) included women who had a subsequent miscarriage in which an abortus karyotype was obtained. Controls (n = 150) were patients experiencing a sporadic miscarriage who had fetal karyotypes performed as part of a study to assess the utility of abortus tissue for transplantation. Karyotype analysis was performed using standard G-banding techniques. RESULTS: Abortuses from 122 cases and 133 controls were successfully karyotyped. Thirty-one (25.4%) abortuses from cases and 56 (42.1%) from controls were aneuploid (odds ratio 0.47, 95% confidence interval 0.27-0.80). Aneuploid abortuses occurred in 20% of cases and 25% of controls, aged 20-29 years, 19% of cases and 24% of controls, aged 30-34 years, 35% of cases and 47% of controls, aged 35-39 years, and 50% of both cases and controls, aged 40 years or older (not significant). Of 30 cases in whom 2 or more miscarriages were karyotyped, 3 (10%) had aneuploidy in each abortus. CONCLUSION: In our population of recurrent miscarriage patients, abortus aneuploidy occurred significantly less often than in sporadic miscarriages. The rate of aneuploidy in this study was considerably lower than reported in other studies. If recurrent aneuploidy contributes to recurrent miscarriage, it does so in only a small number of patients. LEVEL OF EVIDENCE: II-2

Poor obstetric outcome in subsequent pregnancies in women with prior fetal death.

OBJECTIVE: Patients with recurrent first-trimester spontaneous abortion have been the subject of intensive investigation. However, relatively little is known about second- and third-trimester pregnancy loss. Thus, it is difficult for clinicians to optimally counsel, evaluate, and manage women with previous unexplained fetal death. Our objective was to ascertain the outcome of subsequent pregnancies in patients with prior fetal death. METHODS: Subjects were identified from patients referred for evaluation of fetal death (occurring at >/= 10 weeks of gestation) and having at least one subsequent pregnancy. Patients with antiphospholipid antibodies were excluded. Logistic regression analysis was performed to determine the association of clinical variables with pregnancy outcome. RESULTS: Two hundred thirty subjects met inclusion criteria. Up through the time of their first fetal death, these women had a total of 721 pregnancies, resulting in 268 (37%) live births, 230 (32%) fetal deaths, and 200 (28%) spontaneous abortions. In total, these women had 839 subsequent pregnancies, resulting in 202 (24%) live births, 209 (25%) fetal deaths, and 372 (44%) spontaneous abortions. Univariate logistic regression analysis identified older age at pregnancy (P =.009, odds ratio 0.63, 95% confidence interval 0.42-1.03) and treatment with low-dose aspirin (P =.001, odds ratio 0.41, 95% confidence interval 0.25-0.68) to be associated with a decreased risk for subsequent pregnancy loss. CONCLUSION: Women with prior fetal death are at high risk for subsequent pregnancy loss and recurrent fetal death, with fewer than 25% of pregnancies resulting in surviving infants. These data underscore the need for additional research into the pathophysiology and prevention of recurrent fetal death.

The management of acardiac twins: a conservative approach.

OBJECTIVE: Optimal management of acardiac twin pregnancies is controversial. Data suggest a 50% mortality rate in the "pump" twin when the pregnancy is managed expectantly. Because of increased antenatal diagnosis, outcomes in expectantly managed cases may be better than reported. Our objective was to determine the outcome of expectantly managed acardiac twin pregnancies. STUDY DESIGN: All cases of antenatally diagnosed acardiac twins delivered in our community between 1994 and 2001 were ascertained. All were managed expectantly. Perinatal outcome of pump twins was the primary outcome variable. RESULTS: Ten cases were identified. Nine women were delivered of healthy pump twins. There was one neonatal death. The mean gestational age at delivery was 34.2 weeks. The mean weights of the pump and acardiac twins were 2279 g and 1372 g, respectively. CONCLUSION: Neonatal mortality of pump twins in antenatally diagnosed acardiac twin pregnancies may be considerably less than reported. Expectant management with close antepartum surveillance deserves consideration.

Pregnancy outcome in recurrent miscarriage patients with skewed X chromosome inactivation.

OBJECTIVE: To analyze X inactivation in women with recurrent miscarriage to estimate whether skewed X inactivation is associated with recurrent miscarriage and whether it predicts next pregnancy outcomes. METHODS: A multicenter study was performed. A power calculation determined that 101 patients were needed to detect a difference in skewed X inactivation between patients and controls. Patients were entered into a prospective trial of mononuclear-cell immunotherapy and subsequently tested for skewed X inactivation. Age-matched controls had one live birth and no prior miscarriages. Results from our X inactivation assay were compared with those from an independent genetics laboratory. RESULTS: Greater than 75% skewing was seen in 22.6% of patients and 26.5% controls (P =.52). Greater than 90% skewing was seen in 6.6% of patients and 3.9% of controls (P =.77). There were 19.8% of primary aborters and 32% of secondary aborters with greater than 75% skewed X inactivation (P =.38). There were 4.9% of primary aborters and 12.0% of secondary aborters with greater than 90% skewed X inactivation (P =.27) Neither greater than 75% nor greater than 90% skewed X inactivation impacted next pregnancy outcomes (odds ratios = 0.87 [95% confidence interval (CI) 0.34, 2.3] and 1.4 [95% CI 0.27, 7.5], respectively). Results of the exchange of samples with an independent laboratory were highly correlated (alpha = 0.987, P <.001, coefficient of variation = 5.5%). CONCLUSION: Skewed X chromosome inactivation is not associated with recurrent miscarriage. A patient's X chromosome inactivation status does not predict next pregnancy outcome. Our assay correlates with another experienced laboratory.