***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE Our purpose was to measure the agreement , reliability , construct validity , and feasibility of a measurement tool to assess  systematic review s ( AMSTAR ) . STUDY DESIGN AND SETTING We r and omly selected 30 systematic review s from a data base . Each was assessed by two review ers using : ( 1 ) the enhanced quality assessment question naire ( Overview of Quality Assessment Question naire [ OQAQ ] ) ; ( 2 ) Sacks ' instrument ; and ( 3 ) our newly developed measurement tool ( AMSTAR ) . We report on reliability ( interobserver kappas of the 11 AMSTAR items ) , intraclass correlation coefficients ( ICCs ) of the sum scores , construct validity ( ICCs of the sum scores of AMSTAR compared with those of other instruments ) , and completion times . RESULTS The interrater agreement of the individual items of AMSTAR was substantial with a mean kappa of 0.70 ( 95 % confidence interval [ CI ] : 0.57 , 0.83 ) ( range : 0.38 - 1.0 ) . Kappas recorded for the other instruments were 0.63 ( 95 % CI : 0.38 , 0.78 ) for enhanced OQAQ and 0.40 ( 95 % CI : 0.29 , 0.50 ) for the Sacks ' instrument . The ICC of the total score for AMSTAR was 0.84 ( 95 % CI : 0.65 , 0.92 ) compared with 0.91 ( 95 % CI : 0.82 , 0.96 ) for OQAQ and 0.86 ( 95 % CI : 0.71 , 0.94 ) for the Sacks ' instrument . AMSTAR proved easy to apply , each review taking about 15 minutes to complete . CONCLUSIONS AMSTAR has good agreement , reliability , construct validity , and feasibility . These findings need confirmation by a broader range of assessors and a more diverse range of review In ninety-four Dutch nulliparous women the effects of a  low-Na diet  in pregnancy on blood pressure , energy and nutrient intake , Ca metabolism , Zn and Mg status and body composition were studied longitudinally . The women were r and omly divided into an intervention group ( n 41 ) , which used a low-Na diet ( mean urinary Na excretion 61 mmol/24 h ) from week 14 of pregnancy until delivery and a control group ( n 53 ; mean urinary Na excretion 142 mmol/24 h ) . No effect of the diet on blood pressure was observed . The use of a low-Na diet result ed in significantly reduced intakes of energy , protein , carbohydrates , fat , Ca , Zn , Mg , Fe and cholesterol . However , the women on the low-Na diet appeared to be able to adapt quite well to the reduced intake since Ca , Zn and Mg homeostasis was maintained . In the case of Ca and Mg this was probably due to the observed reduced urinary excretions of these nutrients . Non-significant reductions in weight gain ( 1.5 kg ) and fat-mass gain ( 0.9 kg ) over pregnancy were found in the women on the low-Na diet . No significant effects of the diet on birth weight or placental weight were observed OBJECTIVE To investigate the relation between gestational weight gain in women of normal prepregnant weight and complications during pregnancy and delivery in a population with high gestational weight gain and birth weight . METHODS Healthy women ( n = 615 ) of normal weight before pregnancy ( body mass index 19.5–25.5 kg/m2 ) were r and omly selected . Maternity records gave information on age , height , prepregnant weight , gestational weight gain , parity , smoking , gestational hypertension and diabetes , preeclampsia , delivery complications , and infants ' birth size and health . RESULTS The mean weight gain in pregnancy was 16.8 ± 4.9 kg ( mean ± st and ard deviation ) . A total of 26.4 % of the women had complications , either in pregnancy ( 9.1 % ) or delivery ( 17.3 % ) . Women gaining weight according to the recommendation of the Institute of Medicine ( 11.5–16.0 kg ) had lower frequency of pregnancy‐delivery complications than women gaining more than 20.0 kg ( P = .017 ) , but did not differ significantly from those gaining 16–20 kg ( P > .05 ) . When dividing weight gain in pregnancy into quintiles , a relative risk of 2.69 ( 95 % confidence interval 1.01 , 7.18 , P = .048 ) was found for complications in pregnancy in the fourth quintile ( 17.9–20.8 kg ) , using the second quintile as reference ( 12.5–15.5 kg ) . The mean birth weight was 3778 ± 496 g. A low weight gain in pregnancy ( less than 11.5 kg ) was associated with an increased frequency of infants weighing less than 3500 g at birth ( P < .01 ) . CONCLUSION A gestational weight gain of 11.5–16.0 kg ( Institute of Medicine recommendation ) for women of normal prepregnant weight is related to the lowest risk for pregnancy‐delivery complications . In the population studied , the upper limit might be higher ( up to 18 kg ) , and low weight gain should be avoided to optimize birth outcome BACKGROUND : The Institute of Medicine ( IOM ) recommends that normal‐weight women ( BMI ( body mass index ) of 19.8–26.0 ) gain 25–35 lb ( 11.4–15.9 kg ) during pregnancy , and that overweight women ( BMI of 26.1–29.0 ) gain 15–25 lbs ( 6.8–11.4 kg ) . A significant number of normal‐weight women and an even greater proportion of overweight women exceed these guidelines , which increases postpartum weight retention and may contribute to the development of obesity . OBJECTIVE : To determine whether a stepped care , behavioral intervention will decrease the percentage of women who gain more than the IOM recommendation . DESIGN : R and omized controlled trial comparing a stepped-care behavioral intervention with usual care .  Women ( n=120 ) who had a BMI > 19.8 , age>18 and < 20 weeks gestation were recruited from a hospital-based clinic serving low-income women and r and omized by race and BMI category to the intervention or control group . The intervention group received education about weight gain , healthy eating , and exercise and individual graphs of their weight gain . Those exceeding weight gain goals were given more intensive intervention . Women were followed through pregnancy to their first postpartum clinic visit . The main outcome measure was weight gain during pregnancy categorized as above the IOM recommendations vs below or within the IOM recommendations . RESULTS : The intervention significantly decreased the percentage of normal-weight women who exceeded the IOM recommendations ( 33 vs 58 % , P<0.05 ) . There was a non-significant ( P=0.09 ) effect in the opposite direction among overweight women ( 59 % of intervention and 32 % of control gained more than recommended ) . Postpartum weight retention was strongly related to weight gain during pregnancy ( r=0.89 ) . CONCLUSIONS : The intervention reduced excessive weight gain during pregnancy among normal weight women Summary : A r and omised controlled trial was design ed to determine the effect of moderate 30 % maternal dietary energy restriction on the requirement for maternal insulin therapy  and the incidence of macrosomia in gestational diabetes .  Although the control group restricted their intake to a level similar to that of the intervention group ( 6845 kiloJoules ( kJ ) versus 6579 kJ ) , the result ing cohort could not identify any adverse effect of energy restriction in pregnancy . Energy restriction did not alter the frequency of insulin therapy ( 17.5 % in the intervention group and 16.9 % in the control group ) . Mean birth weight  ( 3461 g in the intervention group and 3267 g in the control group ) was not affected . There was a trend in the intervention group towards later gestational age at commencement of insulin therapy ( 33 weeks versus 31 weeks ) and lower maximum daily insulin dose ( 23 units versus 60 units ) which did not reach statistical significance . Energy restriction did not cause an increase in ketonemia BACKGROUND A high prevalence of gestational diabetes mellitus and type 2 diabetes has been observed among the Cree of James Bay , Quebec . To address this problem , a diet and activity intervention during pregnancy , which was based on social learning theory , was initiated in 4 Cree communities . METHODS A prospect i ve intervention compared dietary , weight and glycemic indicators for 107 control subjects and for 112 women who received the intervention during the course of their pregnancy . A control period in 4 communities ( July 1995-March 1996 ) was followed by an intervention period ( April 1996-January 1997 ) when subjects were offered regular , individual diet counselling , physical activity sessions and other activities related to nutrition . RESULTS The intervention and control groups did not differ at baseline regarding their mean age ( 24.3 years [ SD 6.29 ] v. 23.8 years [ SD 5.86 ] ) , mean prepregnancy weight ( 81.0 kg [ SD 19.46 ] v. 78.9 kg [ SD 17.54 ] ) and mean gestational age at recruitment ( 17.1 weeks [ SD 7.06 ] v. 18.5 weeks [ SD 6.92 ] ) . The intervention did not result in differences in diet measured at 24 - 30 weeks ' gestation , rate of weight gain over the second half of pregnancy ( 0.53 kg per week [ SD 0.32 ] v. 0.53 kg per week [ SD 0.27 ] ) or plasma glucose level ( 50 g oral glucose screen ) between 24 and 30 weeks ( 7.21 mmol/L [ SD 2.09 ] v. 7.43 mmol/L [ SD 2.10 ] ) . Mean birth weights were similar ( 3741 g [ SD 523 ] v. 3686 g [ SD 686 ] ) , as was maternal weight at 6 weeks post partum ( 88.1 kg [ SD 16.8 ] v. 86.4 kg [ SD 19.0 ] ) . The only changes in dietary intake were a reduction in caffeine ( pregnancy ) and an increase in folate ( post partum ) . INTERPRETATION This intervention had only a minor impact on diet ; finding ways of encouraging appropriate body weight and activity levels remains a challenge OBJECTIVE The research addresses two questions : Are potentially modifiable psychosocial and behavioral factors related to gestational weight gain ? Do the same factors relate to both excessive and insufficient weight gain ? DESIGN Prospect i ve cohort study that followed women from early pregnancy until two years postpartum . Data were collected through mailed question naires and an audit of the medical record . Subjects/ setting The sample included 622 healthy adult women who gave birth to live singleton infants . Subjects were recruited from all women who registered for prenatal care in a hospital and primary care clinic system serving a 10-county area of Upstate New York . Statistical analyses performed Multiple linear and logistic regression with adjustment for timing of measurements and length of gestation were performed . RESULTS Only 38 % of women gained an amount of weight in pregnancy that was within the range recommended by the Institute of Medicine . Valid and easily implemented measures of change in food intake and physical activity from prepregnancy and cigarette smoking during pregnancy were each significantly ( P<.05 ) and independently related to gestational weight gain . Along with other variables in a biopsychosocial regression model , these variables accounted for 27 % of the variance in gestational weight gain and were also significantly related to risk of inadequate and excessive gain . APPLICATIONS/ CONCLUSIONS The findings facilitate the design of more effective nutrition interventions to promote appropriate gestational weight gain and the long-term health of women and their infants Objective To determine whether the risk of maternal overweight associated with an excessive rate of gestational gain needs to be balanced against the risks of impaired fetal growth associated with a low rate of gain . Methods  Rate of gestational weight gain  was measured prospect ively in a sample of 274 young , low-income , and primarily minority women ( 12–29 years old ) with pregravid body mass indices ( BMI ) in the normal range ( 19.8–26.0 ) . We defined an excessive rate of gain between 20–36 weeks ' gestation as one greater than 0.68 kg/week , and a low rate of gain as one less than 0.34 kg/week . Women were followed-up at 4–6 weeks and 6 months postpartum . Results Rate of measured gestational gain between 20–36 weeks ' gestation was associated with total weight gain based on pregravid weight , with infant birth weight and gestation duration , and with maternal overweight ( BMI greater than 26 ) and weight retention postpartum . Infant birth weight and gestation duration were significantly reduced for women with low rates of gain , and there was no significant difference between women with excessive and moderate gains . Despite little difference in pregravid BMI , women with excessive rates of gain retained more weight overall , attained a greater postpartum BMI , and had higher levels of subcutaneous fat and overweight . Maternal anthropometric status showed little change between 4–6 weeks and 6 months postpartum . Conclusion Weight gained at an excessive rate by women with a pregravid BMI in the 
    Output:
    
The results of published intervention trials are of insufficient quality to enable evidence -based recommendations to be developed for clinical practice in antenatal care