Biomedical subjects

Kofi Amankwah

Publications and source records attributed to Kofi Amankwah.

11 recordsLinked to original sources

PubMed2006

The costs of planned cesarean versus planned vaginal birth in the Term Breech Trial.

BACKGROUND: The Term Breech Trial compared the safety of planned cesarean and planned vaginal birth for breech presentations at term. The combined outcome of perinatal or neonatal death and serious neonatal morbidity was found to be significantly lower among babies delivered by planned cesarean section. In this study we conducted a cost analysis of the 2 approaches to breech presentations at delivery. METHODS: We used a third-party-payer (i.e., Ministry of Health) perspective. We included all costs for physician services and all hospital-related costs incurred by both the mother and the infant. We collected health care utilization and outcomes for all study participants during the trial. We used only the utilization data from countries with low national rates of perinatal death (< or = 20/1000). Seven hospitals across Canada (4 teaching and 3 community centres) were selected for unit cost calculations. RESULTS: The estimated mean cost of a planned cesarean was significantly lower than that of a planned vaginal birth (7165 dollars v. 8042 dollars per mother and infant; mean difference -877 dollars, 95% credible interval -1286 dollars to -473 dollars). The estimated mean cost of a planned cesarean was lower than that of a planned vaginal birth for both women having a first birth (7255 dollars v. 8440 dollars) and women having had at least one prior birth (7071 dollars v. 7559 dollars). Although the treatment effect was largest in the subgroup of women having their first child, there was no statistically significant interaction between treatment and parity since the 95% credible intervals for difference in treatment effects between parity equalling zero and parity of one or greater all include zero. INTERPRETATION: Planned cesarean section was found to be less costly than planned vaginal birth for the singleton fetus in a breech presentation at term in the Term Breech Trial.

Adult↗

PubMed2005

A model-based study of passive joint properties on muscle effort during static stance.

This study examined the impact of lower extremity joint stiffnesses and simulated joint contractures on the muscle effort required to maintain static standing postures after a spinal cord injury (SCI). Static inverse computer simulations were performed with a three-dimensional 15 degree of freedom musculoskeletal model placed in 1600 different standing postures. The required lower extremity muscle forces were calculated through an optimization routine that minimized the sum of the muscle stresses squared, which was used as an index of the muscle effort required for each standing posture. Joint stiffnesses were increased and decreased by 100 percent of their nominal values, and contractures were simulated to determine their effects on the muscle effort for each posture. Nominal muscle and passive properties for an individual with a SCI determined the baseline muscle effort for comparisons. Stiffness changes for the ankle plantar flexion/dorsiflexion, hip flexion/extension, and hip abduction/adduction directions had the largest effect on reducing muscle effort by more than 5 percent, while changes in ankle inversion/eversion and knee flexion/extension had the least effect. For erect standing, muscle effort was reduced by more than 5 percent when stiffness was decreased at the ankle plantar flexion/dorsiflexion joint or hip flexion/extension joint. With simulated joint contractures, the postural workspace area decreased and muscle effort was not reduced by more than 5 percent for any posture. Using this knowledge, methods can be developed through the use of orthoses, physical therapy, surgery or other means to appropriately augment or diminish these passive moments during standing with a neuroprosthesis.

Humans↗

PubMed2005

Mothers' views of their childbirth experiences 2 years after planned Caesarean versus planned vaginal birth for breech presentation at term, in the international randomized Term Breech Trial.

OBJECTIVE: To compare mothers' views at 2 years postpartum after participation in a randomized trial of planned Caesarean and planned vaginal birth for a singleton fetus in breech presentation at term. STUDY DESIGN: In selected centres in the Term Breech Trial, mothers completed a structured questionnaire at approximately 2 years postpartum to assess their likes and dislikes about their childbirth experiences and their views about their intrapartum care and care providers. RESULTS: Of 1159 mothers from 85 centres, 917 (79.1%) completed a follow-up questionnaire at 2 years postpartum. Baseline information was similar for both the planned Caesarean and planned vaginal birth groups. Planned Caesarean was associated with less worry about the baby's health (P < 0.001). While other differences were noted in likes and dislikes about their childbirth experiences, women's evaluations of the quality of intrapartum care, the helpfulness of staff, and their involvement in decision-making did not differ in the planned Caesarean delivery and planned vaginal birth groups. CONCLUSION: Planned mode of delivery influences aspects of women's evaluations of their childbirth experiences but does not affect evaluations of the quality of intrapartum care, support from care providers, or amount of involvement in decision-making.

Breech Presentation↗

PubMed2004

Outcomes of children at 2 years after planned cesarean birth versus planned vaginal birth for breech presentation at term: the International Randomized Term Breech Trial.

OBJECTIVE: The purpose of this study was to determine whether planned cesarean delivery for the singleton fetus in breech presentation at term reduces the risk of death or neurodevelopmental delay at 2 years of age. STUDY DESIGN: In selected centers in the Term Breech Trial, children were screened for abnormalities at > or =2 years of age with the Ages and Stages Questionnaire, followed by a neurodevelopmental assessment if the Ages and Stages Questionnaire score was abnormal. RESULTS: A total of 923 of 1159 children (79.6%) from 85 centers were followed to 2 years of age. The risk of death or neurodevelopmental delay was no different for the planned cesarean than for the planned vaginal birth groups (14 children [3.1%] vs 13 children [2.8%]; relative risk, 1.09; 95% CI, 0.52- 2.30; P = .85; risk difference, +0.3%; 95% CI, -1.9%, +2.4%). CONCLUSION: Planned cesarean delivery is not associated with a reduction in risk of death or neurodevelopmental delay in children at 2 years of age.

Breech Presentation↗

PubMed2004

Maternal outcomes at 2 years after planned cesarean section versus planned vaginal birth for breech presentation at term: the international randomized Term Breech Trial.

OBJECTIVE: This study was undertaken to compare maternal outcomes at 2 years postpartum after planned cesarean section and planned vaginal birth for the singleton fetus in breech presentation at term. STUDY DESIGN: In selected centers in the Term Breech Trial, mothers completed a structured questionnaire at 2 or more years postpartum to determine their health in the previous 3 to 6 months. RESULTS: A total of 917 of 1159 (79.1%) mothers from 85 centers completed a follow-up questionnaire at 2 years postpartum. There were no differences between groups in breast feeding, relationship with child or partner, pain, subsequent pregnancy, incontinence, depression, urinary, menstrual or sexual problems, fatigue, or distressing memories of the birth experience. Planned cesarean section was associated with a higher risk of constipation (P = .02). CONCLUSION: Maternal outcomes at 2 years postpartum are similar after planned cesarean section and planned vaginal birth for the singleton breech fetus at term.

Adult↗

PubMed2003

External cephalic version beginning at 34 weeks' gestation versus 37 weeks' gestation: a randomized multicenter trial.

OBJECTIVE: In about 3% to 4% of all pregnancies at term, the fetal presentation will be noncephalic. External cephalic version (ECV) at term has been shown to decrease the rate of noncephalic presentation at birth and to decrease the rate of cesarean section associated with breech presentation. However, success rates for ECV are low. We did a randomized trial to compare a policy of beginning ECV early, at between 34 and 36 weeks' gestation, and beginning ECV at 37 to 38 weeks' gestation. STUDY DESIGN: At 25 centers in seven countries, 233 women with a singleton breech fetus were randomly assigned to having an ECV procedure done early (at between 34 weeks 0 days and 36 weeks 0 days), or delayed (at between 37 weeks 0 days and 38 weeks 0 days). An experienced practitioner undertook the ECV procedure, and repeat ECV procedures were allowed. Tocolytics and use of epidural analgesia were included as part of the protocol. The primary outcome was the rate of noncephalic presentation at birth. An intention-to-treat analysis was used. RESULTS: Data were received for 232 women, with 116 women in each of the early and delayed ECV groups. Of these, 86.2% in the early ECV group and 67.2% in the delayed ECV group had at least one ECV performed. The rate of noncephalic presentation at birth in the early ECV group was 66 of 116 (56.9%) and 77 of 116 (66.4%) in the delayed ECV group (relative risk [RR] [95% CI] 0.86 [0.70-1.05], P =.09). The rate of serious fetal complications and the rate of preterm birth at <37 weeks were not significantly increased in the early ECV group compared with the delayed ECV group (6.9% vs 7.8%, RR [95% CI] 0.89 [0.36-2.22], P =.69 and 8.6% vs 6.1%, RR [95% CI] 1.42 [0.56-3.59], P =.31, respectively). The rate of cesarean section in the early ECV group was 75 of 116 (64.7%) and 83 of 116 (71.6%) in the delayed ECV group (RR [95% CI] 0.90 [0.76-1.08], P =.32). Neonatal outcomes were comparable in the two groups. The rate of reversion to noncephalic was low in both groups. The majority of women in both groups indicated that they would consider having an ECV in another pregnancy. CONCLUSION: Early ECV performed at 34 to 36 weeks compared with 37 to 38 weeks may reduce the risk of noncephalic presentation at delivery. A large pragmatic trial of early ECV is now required to assess this approach further in terms of cesarean section rates and neonatal outcomes before changes in clinical practice.

Breech Presentation↗

PubMed2002

Outcomes at 3 months after planned cesarean vs planned vaginal delivery for breech presentation at term: the international randomized Term Breech Trial.

CONTEXT: The Term Breech Trial found a significant reduction in adverse perinatal outcomes without an increased risk of immediate maternal morbidity with planned cesarean delivery compared with planned vaginal birth. No randomized controlled trial of planned cesarean delivery has measured benefits and risks of postpartum outcomes months after the birth. OBJECTIVE: To compare maternal outcomes of planned cesarean delivery and planned vaginal birth at 3 months post partum. DESIGN: Follow-up study to the Term Breech Trial, a randomized controlled trial conducted between January 9, 1997, and April 21, 2000. SETTING AND PARTICIPANTS: A total of 1596 of 1940 women from 110 centers worldwide who had a singleton fetus in breech presentation at term responded to a follow-up questionnaire at 3 months post partum. MAIN OUTCOME MEASURES: Breastfeeding; infant health; ease of caring for infant and adjusting to being a new mother; sexual relations and relationship with husband/partner; pain; urinary, flatal, and fecal incontinence; depression; and views regarding childbirth experience and study participation. RESULTS: Baseline information was similar for both the cesarean and vaginal delivery groups. Women in the planned cesarean delivery group were less likely to report urinary incontinence than those in the planned vaginal birth group (36/798 [4.5%] vs 58/797 [7.3%]; relative risk, 0.62; 95% confidence interval, 0.41-0.93). Incontinence of flatus was not different between groups but was less of a problem in the planned cesarean delivery group when it occurred (P =.006). There were no differences between groups in other outcomes. CONCLUSIONS: Planned cesarean delivery for pregnancies with breech presentation at term may result in a lower risk of incontinence and is not associated with an increased risk of other problems for women at 3 months post partum, although the effect on longer-term outcomes is uncertain.

Breast Feeding↗

PubMed2002

Multiple versus single courses of antenatal corticosteroids for preterm birth: a pilot study.

OBJECTIVES: (1) To determine the feasibility of a multicentre, randomized, double-masked, placebo-controlled trial to investigate the effects of multiple courses of antenatal corticosteroids (ACS), more than 7 days following the initial course of ACS therapy, on perinatal or neonatal mortality or neonatal morbidity. (2) To determine the risk of complications that would require discontinuation of ACS therapy. (3) To determine if multiple courses of ACS have an effect on the concentrations of plasma cortisol and adrenocorticotropin hormone (ACTH) in cord blood and in maternal blood immediately following delivery, compared to a single course of ACS. METHODS: Women at 24 to 30 weeks' gestation, at continued increased risk of preterm birth 7 or more days following a single course of ACS, were randomized to receive weekly courses of betamethasone or placebo until 33 weeks' gestation or delivery. RESULTS: Women were recruited at two hospitals in Toronto from 01 September 1999 to 31 August 2000. Of the 78 women who were approached and were eligible for the study, 12 (15%) were recruited and 66 (85%) refused to participate. Of the 66 refusals, 38 (58%) did not feel their physicians were supportive of the study, 10 (15%) did not want to be randomized, and 4 (6%) had other personal reasons for refusing to enter the trial. Fourteen women (21%) had physicians who did not allow them to join the study. The lack of physician support was due to concerns related to the potential adverse effects of multiple courses of ACS. There were no complications requiring discontinuation of ACS. Plasma cortisol and ACTH concentrations in cord and maternal blood taken after delivery were not significantly different between ACS and placebo groups. CONCLUSION: A multicentre randomized controlled trial is required to determine the benefits and risks of multiple versus a single course of ACS. If the study protocols are supported by physicians and their patients, a multicentre randomized controlled trial is feasible.

Adrenocorticotropic Hormone↗

PubMed2002

Repeated doses of antenatal corticosteroids in animals: a systematic review.

OBJECTIVE: The purpose of this review was to assess the effects of repeated doses of antenatal corticosteroids on lung and brain function and on growth restriction in animals. STUDY DESIGN: MEDLINE and EMBASE were searched for randomized controlled trials that compared repeated doses of antenatal corticosteroids versus a single dose, with or without placebo, in pregnant animals. RESULTS: Nineteen studies were included. The animals that were studied included sheep, monkeys, rabbits, and mice. There were 8 studies that assessed the effects of repeated doses of antenatal corticosteroids on lung function. All the studies reported improvement in lung function after repeated doses of antenatal corticosteroids. Seven studies investigated the effects of repeated doses of antenatal corticosteroids on brain or nervous system function or growth; all the studies found adverse effects with repeated doses of antenatal corticosteroids. Eleven studies looked at the effect of repeated doses of antenatal corticosteroids on fetal growth. Nine studies found evidence of fetal growth restriction with repeated doses of antenatal corticosteroids. One study assessed long-term behavioral outcomes in mice and found no effect. CONCLUSION: Evidence from randomized controlled trials in animals suggests that repeated doses of antenatal corticosteroids may have beneficial effects in terms of lung function but may have adverse effects on brain function and fetal growth. Because of the differences between animals and humans, it is difficult to extrapolate directly the results of these studies to humans. Therefore, randomized controlled trials in humans are needed to assess the effects of repeated courses of antenatal corticosteroids for pregnant women who are at increased risk of preterm birth in terms of important perinatal, neonatal, and maternal outcomes.

Adrenal Cortex Hormones↗

PubMed2002

Abdominal versus vaginal cerclage after a failed transvaginal cerclage: a systematic review.

OBJECTIVE: The purpose of this study was to compare the outcomes of pregnancy after transabdominal cerclage versus after transvaginal cerclage in patients with a failed transvaginal cerclage during a previous pregnancy. STUDY DESIGN: MEDLINE and EMBASE were searched in English. We included studies that reported perinatal and/or maternal outcomes in women who had a transabdominal cerclage or a transvaginal cerclage placed at or before 20 weeks of gestation, after having had a failed nonemergent transvaginal cerclage in a previous pregnancy. Data were included for individual patients if they met the inclusion criteria, and their outcomes were reported separately. We excluded patients with cervical amputation because transvaginal cerclage is not an option for these women because of technical difficulty. RESULTS: Fourteen studies met the inclusion criteria. Thirteen of the studies were case series (12 retrospective and 1 prospective), and one study was a retrospective cohort study. In total, 157 women in the studies had a failed vaginal cerclage in a previous pregnancy; 117 women had a subsequent transabdominal cerclage; 40 women had a subsequent transvaginal cerclage. The likelihood of perinatal death or delivery at <24 weeks was 6.0% (95% CI, 3.8%-8.2%) after transabdominal cerclage and 12.5% (95% CI, 2.7%-22.7%) after transvaginal cerclage. The likelihood of serious operative complications after transabdominal cerclage was 3.4% (95% CI, 0.01%, 6.8%). There were no serious operative complications after transvaginal cerclage. CONCLUSION: Transabdominal cerclage may be associated with a lower risk of perinatal death or delivery at <24 weeks of gestation, but it may be associated with a higher risk of serious operative complications. A multicenter randomized controlled trial should be conducted to address this question.

Abdomen↗

PubMedDate not supplied

Effects of spinal cord injury on lower-limb passive joint moments revealed through a nonlinear viscoelastic model.

We developed a mathematical model to describe the lower-limb passive joint moments to investigate and compare these moments in a small sample of able-bodied volunteers and individuals with long-standing motor complete paraplegia. Isokinetic tests, which were performed on a sample of four subjects with spinal cord injuries (SCIs) and five uninjured individuals, measured the passive moments at the ankle, knee, and hip joints throughout their ranges of motion in the sagittal and coronal planes. We fitted an 11-parameter nonlinear viscoelastic model to the acquired passive moment data (mean square error ranging from 0.020 to 5.1 Nm2) to compare subject populations and to determine the influences of joint velocity and passive coupling between adjacent joints. Although the passive moment curves of the SCI and able-bodied groups exhibited many similarities in shape, a repeated measures analysis of variance (ANOVA) that compared the passive moment curves of the two groups indicated a statistically significant (p < 0.01) difference for every joint except the knee. This new model for passive joint moments should prove to be useful in examining how changes in passive properties affect bipedal function and movement.

Adult↗