***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: Background Overweight and obesity is a significant health concern during pregnancy . Our aim was to investigate the effect of providing antenatal dietary and lifestyle advice to women who are overweight or obese on components of maternal diet and physical activity . Methods We conducted a r and omised controlled trial , in which pregnant women with a body mass index ≥25 kg/m2 , and singleton gestation between 10 + 0 to 20 + 0 weeks were recruited and r and omised to Lifestyle Advice ( involving a comprehensive dietary and lifestyle intervention over their pregnancy ) or St and ard Care . Within the intervention group , we conducted a nested r and omised trial in which a subgroup of women were further r and omised to receive access to supervised group walking sessions in addition to the st and ard information presented during the intervention contacts ( the Walking group ) or st and ard information only . The outcome measures were maternal dietary intake , ( including food groups , macronutrient and micronutrient intake , diet quality ( using the Healthy Eating Index ; HEI ) , dietary glycaemic load , and glycaemic index ) and maternal physical activity . Women completed the Harvard Semi-Structured Food Frequency Question naire , and the Short Question naire to Assess Health-enhancing Physical Activity ( SQUASH ) , at trial entry , 28 and 36 weeks ’ gestational age , and 4 months postpartum . Analyses were performed on an intention-to-treat basis , using linear mixed effects models with adjustment for the stratification variables . Results Women r and omised to Lifestyle Advice demonstrated a statistically significant increase in the number of servings of fruit and vegetables consumed per day , as well as increased consumption of fibre , and reduced percentage energy intake from saturated fats ( P < 0.05 for all ) . Maternal HEI was significantly improved at both 28 ( 73.35 ± 6.62 versus 71.86 ± 7.01 ; adjusted difference in means 1.58 ; 95 % CI 0.89 to 2.27 ; P < 0.0001 ) and 36 ( 72.95 ± 6.82 versus 71.17 ± 7.69 ; adjusted difference in means 1.77 ; 95 % CI 1.01 to 2.53 ; P < 0.0001 ) weeks . There were no differences in dietary glycaemic index or glycaemic load . Women r and omised to Lifestyle Advice also demonstrated greater total physical activity ( adjusted difference in means 359.76 metabolic equivalent task units ( MET ) minutes/week ; 95 % CI 74.87 to 644.65 ; P = 0.01 ) compared with women receiving St and ard Care . The supervised walking group was poorly utilised . Conclusions For women who are overweight or obese , antenatal lifestyle advice improves maternal diet and physical activity during pregnancy . Please see related articles : http://www.biomed central .com/1741 - 7015/12/163 and http://www.biomed central .com/1741 - 7015/12/201.Trial registration Australian and New Zeal and Clinical Trials Registry ( http://ACTRN12607000161426 Background Obesity is a significant global health problem , with the proportion of women entering pregnancy with a body mass index greater than or equal to 25 kg/m2 approaching 50 % . Obesity during pregnancy is associated with a well-recognised increased risk of adverse health outcomes both for the woman and her infant , however there is more limited information available regarding effective interventions to improve health outcomes .The aims of this r and omised controlled trial are to assess whether the implementation of a package of dietary and lifestyle advice to overweight and obese women during pregnancy to limit gestational weight gain is effective in improving maternal , fetal and infant health outcomes . Methods / Design Design : Multicentred r and omised , controlled trial . Inclusion Criteria : Women with a singleton , live gestation between 10 + 0 - 20 + 0 weeks who are obese or overweight ( defined as body mass index greater than or equal to 25 kg/m2 ) , at the first antenatal visit . Trial Entry & R and omisation : Eligible , consenting women will be r and omised between 10 + 0 and 20 + 0 weeks gestation using a central telephone r and omisation service , and r and omisation schedule prepared by non- clinical research staff with balanced variable blocks . Stratification will be according to maternal BMI at trial entry , parity , and centre where planned to give birth . Treatment Schedules : Women r and omised to the Dietary and Lifestyle Advice Group will receive a series of inputs from research assistants and research dietician to limit gestational weight gain , and will include a combination of dietary , exercise and behavioural strategies .  Women r and omised to the St and ard Care Group will continue to receive their pregnancy care according to local hospital guidelines , which does not currently include routine provision of dietary , lifestyle and behavioural advice . Outcome assessors will be blinded to the allocated treatment group . Primary Study Outcome : infant large for gestational age ( defined as infant birth weight ≥ 90th centile for gestational age ) . Sample Size : 2,180 women to detect a 30 % reduction in large for gestational age infants from 14.40 % ( p = 0.05 , 80 % power , two-tailed ) . Discussion This is a protocol for a r and omised trial . The findings will contribute to the development of evidence based clinical practice guidelines .Trial Registration Australian and New Zeal and Clinical Trials Registry BACKGROUND Women diagnosed with gestational diabetes mellitus ( GDM ) are at substantially increased risk of developing type 2 diabetes and obesity , currently at epidemic rates in the United States . GDM , therefore , identifies a population of women at high risk of developing type 2 diabetes and provides an opportunity to intervene before the development of this disorder . It is well recognized that acute as well as chronic physical activity improves glucose tolerance in type 2 diabetes . To date , however , primary prevention trials have not been conducted to test whether an increase in physical activity reduces risk of developing GDM among women at high risk of this disorder . METHODS The aims of this study are to investigate the effects of a motivationally targeted , individually tailored 12-week physical activity intervention on ( 1 ) development of GDM , ( 2 ) serum biomarkers associated with insulin resistance , and ( 3 ) the adoption and maintenance of exercise during pregnancy .  Women at high risk of GDM are recruited in early pregnancy and r and omized to either an individually tailored exercise intervention or a comparison health and wellness intervention . RESULTS The overall goal of the exercise intervention is to encourage pregnant women to achieve the American College of Obstetricians and Gynecologists guidelines for physical activity during pregnancy through increasing walking and developing a more active lifestyle . CONCLUSIONS The intervention takes into account the specific social , cultural , economic , and physical environmental challenges faced by pregnant women of diverse socioeconomic and ethnic background BACKGROUND Yoga may be well suited for depressed and anxious pregnant women , given reported benefits of meditation and physical activity and pregnant women 's preference for nonpharmacological treatments . METHODS We r and omly assigned 46 pregnant women with symptoms of depression and anxiety to an 8-week yoga intervention or treatment-as-usual ( TAU ) in order to examine feasibility and preliminary outcomes . RESULTS Yoga was associated with high levels of credibility and satisfaction as an intervention for depression and anxiety during pregnancy . Participants in both conditions reported significant improvement in symptoms of depression and anxiety over time ; and yoga was associated with significantly greater reduction in negative affect as compared to TAU ( β = -0.53 , SE = 0.20 , p = .011 ) . CONCLUSION Prenatal yoga was found to be a feasible and acceptable intervention and was associated with reductions in symptoms of anxiety and depression ; however , prenatal yoga only significantly outperformed TAU on reduction of negative affect Background Many women try to stop smoking in pregnancy but fail . One difficulty is that there is insufficient evidence that medications for smoking cessation are effective and safe in pregnancy and thus many women prefer to avoid these . Physical activity ( PA ) interventions may assist cessation ; however , trials examining these interventions have been too small to detect or exclude plausible beneficial effects . The London Exercise And Pregnant smokers ( LEAP ) trial is investigating whether a PA intervention is effective and cost-effective when used for smoking cessation by pregnant women , and will be the largest study of its kind to date . Methods / design The LEAP study is a pragmatic , multi-center , two-arm , r and omized , controlled trial that will target pregnant women who smoke at least one cigarette a day ( and at least five cigarettes a day before pregnancy ) , and are between 10 and 24 weeks pregnant . Eligible patients are individually r and omized to either usual care ( that is , behavioral support for smoking cessation ) or usual care plus a intervention ( entailing supervised exercise on a treadmill plus PA consultations ) . The primary outcome of the trial is self-reported and biochemically vali date d continuous abstinence from smoking between a specified quit date and the end of pregnancy . The secondary outcomes , measured at 1 and 4 weeks after the quit date , and at the end of pregnancy and 6 months after childbirth , are PA levels , depression , self-confidence , and cigarette withdrawal symptoms . Smoking status will also be self-reported at 6 months after childbirth . In addition , perinatal measures will be collected , including antenatal complications , duration of labor , mode of delivery , and birth and placental weight . Outcomes will be analyzed on an intention-to-treat basis , and logistic regression models used to compare treatment effects on the primary outcome . Discussion This trial will assess whether a PA intervention is effective when used for smoking cessation during pregnancy . Trial registration IS RCT Background Physical activity ( PA ) interventions design ed to prevent prenatal complications have focused on increasing moderate PA yielding conflicting results . Minimal attention has focused on the evaluation of sleep , sedentary behavior ( SB ) , light activity or total daily PA during pregnancy . The purpose of this prospect i ve , longitudinal study was to 1 ) objective ly quantify and compare habitual PA and SB during the 2nd and 3rd trimester ; and 2 ) evaluate differences in activity patterns for women meeting prenatal PA guidelines versus those that did not . Methods Forty-six participants wore 2 PA monitors ( SenseWear ® Mini and activPAL ™ ) during week 18 and week 35 of pregnancy . We compared differences in sleep duration , postural allocation , daily steps , and PA between the 2nd and 3rd trimester and for women who met and did not meet PA guidelines . Results During the 2nd trimester , 30 % of the women ’s day ( 24-hours ) was total sleep ; 52 % SB ; 13 % light ; 3 % moderate ; and 0 % vigorous PA . Light ( P = 0.05 ) , vigorous ( P = 0.02 ) , and moderate-vigorous PA ( MET-minutes ; P = 0.02 ) , decreased with a trend in increased SB ( P = 0.07 ) . Activity of other intensities and sleep duration did not significantly change . Only 39 % and 37 % of participants slept between 7–9 hours/night at week 18 and 35 , respectively . Forty-six percent ( n = 21 ) and 28 % ( n = 13 ) of participants met prenatal PA guidelines during the 2nd and 3rd trimester , respectively . At week 18 , no differences in total sleep , SB , or light PA existed for women who met PA guidelines versus those who did not ; total PA was significantly greater for women who met guidelines . At week 35 , women that met PA guidelines had significantly less SB ( P < 0.005 ) than women who did not . Conclusions This study demonstrates that pregnant women spend the majority of their day in SB . Significant reductions in total activity across pregnancy may be attributed , in part to shifts in light PA and increased SB . Based on the lifestyle of our sample , regardless of meeting PA guidelines in mid-pregnancy , no significant difference exists in time spent in SB , however meeting PA recommendations in late pregnancy may reduce SB . Future interventions should target reducing SB by increasing light and moderate PA beyond volitional exercise INTRODUCTION Walking may be a strategy for increasing moderate-intensity physical activity ( MPA )  during pregnancy . PURPOSE This study aim ed to promote MPA among overweight and obese pregnant women , via walking , and to evaluate the effect of the intervention on maternal and birth outcomes . METHODS Thirty-seven overweight or obese pregnant women were r and omly assigned to a walking intervention or control group . Anthropometric and objective PA ( StepWatch ™ Activity Monitor ) data were collected for four 1-wk periods : weeks 10 - 14 ( V1 ) , weeks 17 - 19 ( V2 ) , weeks 27 - 29 ( V3 ) , and weeks 34 - 36 ( V4 ) of gestation . Participants provided information about maternal and birth outcomes . A cadence of ≥ 80 steps per minute was defined as MPA , and " meaningful walking " was defined as moderate walking in ≥ 8-min bouts . ANOVA was used to determine the differences in walking amount and meaningful walks , the Kolmogorov-Smirnov test was used for walking intensity distribution analysis , and Fisher 's exact test was used for maternal and infant outcomes analyses . Pearson correlation was used to examine 
    Output:
    
This review highlights the under-reporting of issues of context ual factors in studies of physical activity during pregnancy .
TWEETABLE ABSTRACT The systematic review highlights the under-reporting of context ual factors in studies of physical activity during pregnancy