Pulse wave analysis: a preliminary study of a novel technique for the prediction of pre-eclampsia.

OBJECTIVE: To investigate whether first-trimester arterial pulse wave analysis (PWA) can predict pre-eclampsia. DESIGN: This was a prospective screening study. SETTING: The Homerton University Hospital, a London teaching hospital. POPULATION: Two hundred and ten low-risk women with a singleton pregnancy were analysed. METHODS: Radial artery pulse waveforms were measured between the 11(+0) and 13(+6) weeks of gestation and the aortic waveform derived by applying a generalised transfer function. Augmentation pressure (AP) and augmentation index at heart rate of 75 beats per minute (AIx-75), measures of arterial stiffness, were calculated. The multiple of the gestation-specific median in controls for AP and AIx-75 were calculated. Logistic regression models were developed and their predictive ability assessed using the area under the receiver operator curve. MAIN OUTCOME MEASURES: Prediction of pre-eclampsia by AIx-75. RESULTS: Fourteen (6.7%) women developed pre-eclampsia, and 196 remained normotensive. Eight of the 14 women developed pre-eclampsia before 34 weeks of gestation (early-onset pre-eclampsia). For a false-positive rate of 11%, AIx-75 had a detection rate of 79% for all cases of pre-eclampsia and 88% for early-onset pre-eclampsia. CONCLUSION: First-trimester arterial PWA can play a significant role in understanding the pathophysiology of pre-eclampsia and may play a role in early screening.

Internal jugular vein thrombosis after assisted conception therapy.

Superovulation therapy during assisted conception may result in a hypercoagulable state. Five cases of upper extremity venous thrombosis were identified in women who conceived after ovarian stimulation for in vitro fertilization (IVF). They presented between 7 and 10 weeks' gestation with neck pain and swelling. Three had been treated for ovarian hyperstimulation syndrome and two had evidence of inherited thrombophilia. Four patients received thromboprophylaxis before presentation. Although thrombosis is an uncommon complication of IVF, patients should be counselled before treatment. Thrombophilia screening may be considered for 'high-risk' patients, although current regimes for thromboprophylaxis remain suboptimal.

Validity of self-reported sexually transmitted diseases among African American female adolescents participating in an HIV/STD prevention intervention trial.

BACKGROUND: Studies assessing the validity attributed to self-reported measures of sexually transmitted diseases (STDs) clearly are needed, particularly those used for high-risk populations such as female adolescents, in whom STD prevention is a priority. GOAL: To determine the accuracy of self-reported STD test results in female adolescents over a relatively brief period ( approximately 28 days). STUDY DESIGN: A prospective, randomized, controlled clinical trial of STD/HIV prevention for African American females, ages 14 to 18, was conducted. Study participants were recruited from medical clinics and school health classes in low-income neighborhoods of Birmingham, Alabama, that had high rates of unemployment, substance abuse, violence, STDs, and teenage pregnancy. RESULTS: Of the 522 adolescents enrolled in the trial, 92% (n = 479) completed baseline STD testing and follow-up surveys. At baseline, 28% had positive test results for at least one disease: 4.8% for Neisseria gonorrhoeae, 17.1% for Chlamydia trachomatis, and 12.3% for Trichomonas vaginalis. Of the adolescents with negative STD test results, 98.8% were accurate in their self-report of STD status, as compared with 68.7% of the adolescents with positive results. Underreporting varied by type of STD. Adolescents who accurately reported their positive STD status were significantly more likely to report their receipt of treatment accurately (P < 0.001). CONCLUSIONS: The substantial underreporting of STD incidence in this study suggests that reliance on self-reports of STD history may introduce misclassification bias, potentially leading to false conclusions regarding the efficacy of prevention interventions. This observation highlights the importance of using biologic indicators as outcome measures.

Methods, results, and lessons learned from process evaluation of the high 5 school-based nutrition intervention.

This article describes the process evaluation of High 5, a school-based intervention targeting fruit and vegetable consumption among fourth graders and their families. The outcome evaluation involved 28 schools randomized to intervention or control conditions. The intervention included classroom, family, and cafeteria components. Process evaluation was completed on each of these components by using observations, self-report checklists, surveys, and other measures. Results indicated high implementation rates on the classroom activities. Moderate family involvement was attained, perhaps diminishing intervention effects on parent consumption. Cafeterias provided environmental cues, and fruit and vegetable offerings as directed by the program. A lower dose of the intervention was delivered to schools with larger African American enrollments and lower-income families. This article provides insights into the effective elements of a school-based dietary intervention and provides suggestions for process evaluation in similar studies.

Increasing the fruit and vegetable consumption of fourth-graders: results from the high 5 project.

BACKGROUND: This study evaluated the effects of a school-based dietary intervention program to increase fruit and vegetable consumption among fourth-graders. METHODS: Twenty-eight elementary schools were randomized to an immediate intervention condition or to a delayed intervention control condition. Measures of diet and psychosocial variables were collected at base line and 1 and 2 years post-baseline. The intervention included classroom, parent, and cafeteria components. RESULTS: Mean daily consumption of fruit and vegetables was higher for the intervention children compared with controls at Follow-up 1 (X(t) = 3.96, X(c) = 2.28) and at Follow-up 2 (X(t) = 3.20, X(c) = 2.21). Macro- and micronutrient changes favoring the intervention children were also observed at both Follow-up 1 and Follow-up 2. Mean daily consumption of fruit and vegetables was higher for intervention parents compared with controls at Follow-up 1 (X(t) = 4.23,X(c) = 3.94) but not at Follow-up 2. CONCLUSIONS: Strong effects were found for the High 5 intervention on fruit and vegetable consumption, on macro- and micro-nutrients, and on psychosocial variables. Future work is needed to enhance the intervention effects on parents' consumption and to test the effectiveness of the intervention when delivered by classroom teachers.

Design of "High 5": a school-based study to promote fruit and vegetable consumption for reduction of cancer risk.

BACKGROUND: This paper describes the methods used in "High 5," a school-based study to increase fruit and vegetable consumption for cancer risk reduction. METHODS: Twenty-eight elementary schools were matched and randomized to intervention or control conditions. All students were assessed based on diet and psychosocial variables at baseline and one and two years post-baseline. The intervention included classroom, parent, and environmental components. RESULTS: The study recruited 1,698 families and retained 85%. The two conditions were equivalent at baseline; 50% female students, 81% to 84% European-American students, and 2.9 servings of fruit and vegetables per day. Good completion was achieved across the intervention components (e.g., 90% of lessons taught, 72% of parent materials read, 3.6 servings of fruit and vegetables offered in cafeterias). CONCLUSIONS: The use of school-based programs, with strong evaluation designs, will enhance knowledge about the modification of nutrition behavior and cancer risk in children. Lessons learned from the study are reported.

A cross-sectional study of platelet volume in healthy normotensive women with bilateral uterine artery notches.

High uterine artery resistance characterized by bilateral notches seen on Doppler ultrasound in the second half of pregnancy is associated with an increased risk of adverse outcome related to pre-eclampsia and intrauterine growth retardation. We sought to establish whether there was a difference in platelet volume in healthy, normotensive women with high-resistance uterine artery Doppler findings compared to those with normal uterine artery Doppler findings. Forty-seven women were allocated prospectively into 'bilateral notch' and 'no notch' groups at color Doppler imaging of the uterine arteries carried out at a mean of 26 weeks' gestation. The difference in platelet volume between the two groups and the relationship of adverse outcome with raised platelet volume and high-resistance uterine artery Doppler findings was investigated. Twenty-three women had no evidence of uterine artery notches and 24 had bilateral uterine artery notches. Platelet volume in the women with bilateral notches was greater than in those with no notches (8.28 fl vs. 7.46 fl; p = 0.01). However, unlike high-resistance uterine artery Doppler findings, increased platelet volume was not associated with adverse outcome. Uterine artery Doppler flow abnormalities have not previously been studied in combination with hematological or biochemical markers. Our findings show, for the first time, that women with bilateral uterine artery notches have an increased platelet volume compared to those with normal uterine artery Doppler findings many weeks before clinical signs of pre-eclampsia or fetal growth retardation are evident. Women with abnormal uterine artery flow at this gestation may have other cardiovascular and hematological differences compared to those with normal flow.

Recruitment issues in school-based research: lessons learned from the High 5 Alabama Project.

School-based research requires a multi-level recruitment process to ensure an adequate sample. This article describes the High 5 Alabama recruitment experience at four levels; district, school, classroom and individual. One hundred percent of 28 schools across three districts and 108 classroom teachers contacted agreed to participate. Moderate success (69%) at the individual level, which required active parental consent for the student and parent to participate, resulted in 1,698 student/parent participants. An examination of differences between participants and nonparticipants revealed under-representation of a subsample of the population in the project sample. Suggestions obtained from project staff and teachers intended to enhance future school-based recruitment strategies include enlistment of a district advocate; meeting with teachers to solicit support; using incentives with students and teachers; direct contact with parents; having teachers keep rosters of students returning consent forms; and tailoring recruitment strategies for specific subpopulations.

Prediction of pre-eclampsia by abnormal uterine Doppler ultrasound and modification by aspirin.

OBJECTIVE: To assess the effect of low dose aspirin on severe pre-eclampsia when given to women identified as high risk by abnormal uterine artery Doppler ultrasound. DESIGN: Women with abnormal uterine artery flow velocity waveforms were recruited to the CLASP trial at 24 weeks. Abnormal uterine artery waveforms, with a high resistance index or an early diastolic notch, were identified at the 18-22 week anomaly scan and confirmed at 24 weeks. Of those women with persistently abnormal waveforms, 63 agreed to enter the CLASP trial. Three women were lost to follow up and five did not comply. Thus, 60 were randomised: 29 to placebo and 31 to low dose aspirin (60 mg daily) and analysis by intention to treat is reported. RESULTS: There were nine cases (29%) of pre-eclampsia in the aspirin group and twelve (41%) in the placebo group (odds ratio (OR) 0-58, confidence interval (CI) 0.2-1.69, P = 0.32). Severe pre-eclampsia developed in four women in the aspirin group and eleven women in the placebo group (OR 0.24, CI 0.07-0.88, P = 0.03) and intrauterine growth retardation occurred in eight cases in the aspirin group and twelve in the placebo group (OR 0.49, CI 0.17-1.47). The mean birthweight and gestation at delivery were 2.69 kg and 38.5 weeks in the aspirin group and 2.38 kg and 37.4 weeks in the placebo group, neither of which were statistically significant using the unpaired t test; P = 0.09 and P = 0.23, respectively. CONCLUSION: In high risk pregnancy low dose aspirin commenced at 24 weeks may reduce the incidence of severe pre-eclampsia.

Doppler velocimetry studies of the uterine artery in the early prediction of pre-eclampsia and intra-uterine growth retardation.

Pre-eclampsia/proteinuric pregnancy-induced hypertension (PPIH) and intra-uterine growth retardation (IUGR) are associated with incomplete trophoblastic invasion of the uterus in the first half of pregnancy. The uteroplacental circulation can be observed using Doppler ultrasound. We have performed two mid pregnancy screening studies of our antenatal population in the last three years, to assess the use of Doppler velocimetry studies at that time in predicting the subsequent development of PPIH and IUGR. In the first study continuous wave Doppler ultrasound was used to study the uterine circulation. The Resistance Index (RI) was measured once in both uterine arteries in 925 patients between 16 and 24 weeks gestation. There was a significant association between an abnormal RI (greater than 95th centile) and the subsequent development of PPIH, IUGR and severe complications of pregnancy. However, even though the specificity (95%) was high the sensitivity was low (25%). There was no significant association with nonproteinuric hypertension. In an attempt to improve the sensitivity for the second study, colour flow imaging and the use of a diastolic notch as well as an elevated RI were introduced. 2437 patients had continuous-wave Doppler studies of the uterine circulation performed at 20 weeks gestation. 16% had abnormal waveforms, persisting in 5.4% at 24 weeks and 4.6% at 26 weeks when measured with colour/pulsed Doppler. The high sensitivity (76%) of this innovation at 20 weeks is retained at 24 and 26 weeks, while the specificity (from 86% to 97%) and positive predictive value (13% to 44%) improve progressively with gestation.(ABSTRACT TRUNCATED AT 250 WORDS)