human
***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 To evaluate the effectiveness and safety of water aerobics during pregnancy . Methods A r and omized controlled trial carried out in 71 low-risk sedentary pregnant women , r and omly allocated to water aerobics or no physical exercise .  Maternal body composition and perinatal outcomes were evaluated . For statistical analysis Chi-square , Fisher 's or Student 's t-tests were applied . Risk ratios and their 95 % CI were estimated for main outcomes . Body composition was evaluated across time using MANOVA or Friedman multiple analysis . Results There were no significant differences between the groups regarding maternal weight gain , BMI or percentage of body fat during pregnancy . Incidence of preterm births ( RR = 0.84 ; 95%CI:0.28–2.53 ) , vaginal births ( RR = 1.24 ; 95%CI:0.73–2.09 ) , low birthweight ( RR = 1.30 ; 95%CI:0.61–2.79 ) and adequate weight for gestational age ( RR = 1.50 ; 95%CI:0.65–3.48 ) were also not significantly different between groups . There were no significant differences in systolic and diastolic blood pressure and heart rate between before and immediately after the water aerobics session . Conclusion Water aerobics for sedentary pregnant women proved to be safe and was not associated with any alteration in maternal body composition , type of delivery , preterm birth rate , neonatal well-being or weight The histomorphometry of term placentae from women who exercised regularly throughout either the first half or all of pregnancy was compared to that of placentae from matched controls to determine if regular exercise during pregnancy produced histomorphometric evidence of altered development and transport capacity . Conventional stereological techniques were used to estimate placental volumetric composition , surface areas , and villous and vascular configurations in the three groups . Exercise confined to early pregnancy increased the parenchymal component of the placenta , total vascular volume and site-specific capillary volume and surface area .  Exercise throughout pregnancy increased these and multiple other histomorphometric parameters associated with the rate of placental perfusion and transfer function . However , significant changes were confined to villi > 80 microns in diameter . The localization of both the timing of the stimulus and the anatomical sites affected indicates that regular , sustained exercise modifies placental development primarily in early and mid-pregnancy . We speculate that the lack of significant changes in the structure and configuration of the smaller villi indicates that other adaptive mechanisms , such as increased rates of placental blood flow , must be well developed by the latter portion of the mid-trimester and adequately maintain fetal oxygenation and substrate delivery throughout the third trimester Background Increasingly , women of reproductive age participate in recreational running , but its impact on pregnancy outcome is unknown . We investigated whether running affects gestational age at delivery and birth weight as indicators of cervical integrity and placental function , respectively . Methods 1293 female participants were recruited from parkrun , which organises weekly runs involving 1.25 million runners across 450 parks worldwide . Those under 16 or unable to provide outcome data were excluded . Women were categorised according to whether they continued to run during pregnancy or not . Those who continued were further stratified dependent on average weekly kilometres , and which trimester they ran until . Retrospectively collected primary outcomes were gestational age at delivery and birthweight centile . Other outcomes included assisted vaginal delivery rate and prematurity at clinical ly important gestations . Results There was no significant difference in gestational age at delivery : 279.0 vs 279.6 days ( mean difference 0.6 days , CI −1.3 to 2.4 days ; P=0.55 ) or birthweight centile : 46.9%vs 44.9 % ( mean difference 2.0 % , CI −1.3 % to −5.3 % ; P=0.22 ) in women who stopped running and those who continued , respectively . Assisted vaginal delivery rate was increased in women who ran : 195/714 ( 27 % ) vs 128/579 ( 22 % ) ( OR 1.32 ; CI 1.02 to 1.71 ; P=0.03 ) . Conclusion Continuing to run during pregnancy does not appear to affect gestational age or birthweight centile , regardless of mean weekly distance or stage of pregnancy . Assisted vaginal delivery rates were higher in women who ran , possibly due to increased pelvic floor muscle tone . R and omised prospect i ve analysis is necessary to further explore these findings OBJECTIVE To evaluate the influence of exercise on maternal and perinatal outcome in a low‐risk healthy obstetric population . METHODS We conducted a prospect i ve observational study of low‐risk healthy women exercising during their pregnancy . An extensive question naire collected antepartum , intrapartum , and postpartum patient information on 750 women . The women were divided into four groups based on exercise level during pregnancy . RESULTS There were no differences among groups for maternal demographic characteristics , antenatal illnesses , stress , social support , or smoking . Heavily exercising women were older ( P = .042 ) , had higher incomes ( P = .001 ) , and were exercising more at conception ( P = .001 ) . Women who did more exercise were more likely to need an induction of labor ( P = .033 , relative risk 1.84 , 95 % confidence interval 1.05 , 3.20 ) , induction or augmentation with oxytocin ( P = .015 , relative risk 1.53 , 95 % confidence interval 1.19 , 1.97 ) , and had longer first‐stage labors ( P = .032 ) result ing in longer total labors ( P = .011 ) . The difference in the length of first‐stage labor was even greater if the no‐exercise group was compared with the strongly exercising group ( P = .009 , relative risk 1.38 , 95 % confidence interval 0.16 , 2.60 ) . Fewer umbilical cord abnormalities ( P = .034 ) were observed with exercise , but exercising women had more colds and flu ( P = .008 ) . Heavily exercising women had smaller infants ( mean difference 86.5 g ) compared with sedentary women . CONCLUSION Exercise  in working women is associated with smaller babies , increased number of inductions and augmentations of labor , and longer labors . Colds and flu are more frequent in exercising women EDITORIAL COMMENT : When this paper was review ed the question was raised that the period of gestation is an obvious factor which can determine birth‐weight and the authors were asked how this may have affected their results The authors response was as follows Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more PURPOSE This study aim ed to evaluate the effect of an exercise program of two different intensities , with nutritional control , on gestational weight gain ( GWG ) , infant birth weight , and maternal weight retention at 2 months postpartum ( 2 mopp ) . METHODS Pregnant women ( prepregnancy body mass index = 18.5 - 24.9 kg·m ) were r and omized at study entry ( 16 - 20 wk of gestation ) to a low-intensity ( LI , 30 % HR reserve ( HRR ) , n = 23 ) or moderate-intensity ( MI , 70 % HRR , n = 26 ) exercise program , with nutritional control . The exercise program consisted of walking sessions three to four times per week , gradually increasing exercise time from 25 to 40 min per session . Forty-five normal-weight women who did not participate in any structured exercise program during pregnancy and had singleton births were used as a historical control group .  RESULTS Total GWG was higher in the control group ( 18.3 ± 5.3 kg ) compared with the LI ( 15.3 ± 2.9 kg , P = 0.01 ) and MI ( 14.9 ± 3.8 kg , P = 0.003 ) groups . During the intervention , GWG was similar in both intervention groups , with weekly rates of weight gain of 0.49 ± 0.1 and 0.47 ± 0.1 kg·wk in the LI and MI groups , respectively . Excessive GWG during the intervention was prevented in 70 % of the women in the LI group and 77 % of those in the MI group . Excessive GWG occurred before the intervention began . At 2 mopp , 18 % and 28 % of the women in the LI and MI groups , respectively , retained ≤2.0 kg compared with only 7 % of those in the control group . Infant birth weight was not different between the groups . CONCLUSIONS Results suggest that a prenatal nutrition and exercise program regardless of exercise intensity , reduced excessive GWG and decreased weight retention at 2 mopp in women of normal weight before pregnancy BACKGROUND : Obesity and being overweight are becoming epidemic , and indeed , the proportion of such women of reproductive age has increased in recent times . Being overweight or obese prior to pregnancy is a risk factor for gestational diabetes mellitus , and increases the risk of adverse pregnancy outcome for both mothers and their offspring . Furthermore , the combination of gestational diabetes mellitus with obesity/overweight status may increase the risk of adverse pregnancy outcome attributable to either factor alone . Regular exercise has the potential to reduce the risk of developing gestational diabetes mellitus and can be used during pregnancy ; however , its efficacy remain controversial . At present , most exercise training interventions are implemented on Caucasian women and in the second trimester , and there is a paucity of studies focusing on overweight/obese pregnant women . OBJECTIVE : We sought to test the efficacy of regular exercise in early pregnancy to prevent gestational diabetes mellitus in Chinese overweight/obese pregnant women . STUDY DESIGN : This was a prospect i ve r and omized clinical trial in which nonsmoking women age > 18 years with a singleton pregnancy who met the criteria for overweight/obese status ( body mass index 24≤28 kg/m2 ) and had an uncomplicated pregnancy at < 12 + 6 weeks of gestation were r and omly allocated to either exercise or a control group . Patients did not have contraindications to physical activity . Patients allocated to the exercise group were assigned to exercise 3 times per week ( at least 30 min/session with a rating of perceived exertion between 12‐14 ) via a cycling program begun within 3 days of r and omization until 37 weeks of gestation . Those in the control group continued their usual daily activities . Both groups received st and ard prenatal care , albeit without special dietary recommendations . The primary outcome was incidence of gestational diabetes mellitus . RESULTS : From December 2014 through July 2016 , 300 singleton women at 10 weeks ’ gestational age and with a mean prepregnancy body mass index of 26.78 ± 2.75 kg/m2 were recruited . They were r and omized into an exercise group ( n = 150 ) or a control group ( n = 150 ) . In all , 39 ( 26.0 % ) and 38 ( 25.3 % ) participants were obese in each group , respectively . Women r and omized to the exercise group had a significantly lower incidence of gestational diabetes mellitus ( 22.0 % vs 40.6 % ; P < .001 ) . These women also had significantly less gestational weight gain by 25 gestational weeks ( 4.08 ± 3.02 vs 5.92 ± 2.58 kg ; P < .001 ) and at the end of pregnancy ( 8.38 ± 3.65 vs 10.47 ± 3.33 kg ; P < .001 ) , and reduced insulin resistance levels ( 2.92 ± 1.27 vs 3.38 ± 2.00 ; P = .033 ) at 25 gestational weeks . Other secondary outcomes , including gestational weight gain between 25‐36 gestational weeks ( 4.55 ± 2.06 vs 4.59 ± 2.31 kg ; P = .9 ) , insulin resistance levels at 36 gestational weeks ( 3.56 ± 1.89 vs 4.07 ± 2.33 ; P = .1 ) , hypertensive disorders of pregnancy ( 17.0 % vs 19.3 % ; odds ratio , 0.854 ; 95 % confidence interval , 0.434–2.683 ; P = .6 ) , cesarean delivery ( except for scar uterus ) ( 29.5 % vs 32.5 % ; odds ratio , 0.869 ; 95 % confidence interval , 0.494–1.529 ; P = .6 ) , mean gestational age at birth ( 39.02 ± 1.29 vs 38.89 ± 1.37 weeks ’ gestation ; P = .5 ) ; preterm birth ( 2.7 % vs 4.4 % , odds ratio , 0.600 ; 95 % confidence interval , 0.140–2.573 ; P = .5 ) , macrosomia ( defined as birthweight > 4000 g ) ( 6.3 % vs 9.6 % ; odds ratio , 0.624 ; 95 % confidence interval , 0.233–1.673 ; P = .3 ) , and large 
    Output:
    
agent
***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 To evaluate the effectiveness and safety of water aerobics during pregnancy . Methods A r and omized controlled trial carried out in 71 low-risk sedentary pregnant women , r and omly allocated to water aerobics or no physical exercise .  Maternal body composition and perinatal outcomes were evaluated . For statistical analysis Chi-square , Fisher 's or Student 's t-tests were applied . Risk ratios and their 95 % CI were estimated for main outcomes . Body composition was evaluated across time using MANOVA or Friedman multiple analysis . Results There were no significant differences between the groups regarding maternal weight gain , BMI or percentage of body fat during pregnancy . Incidence of preterm births ( RR = 0.84 ; 95%CI:0.28–2.53 ) , vaginal births ( RR = 1.24 ; 95%CI:0.73–2.09 ) , low birthweight ( RR = 1.30 ; 95%CI:0.61–2.79 ) and adequate weight for gestational age ( RR = 1.50 ; 95%CI:0.65–3.48 ) were also not significantly different between groups . There were no significant differences in systolic and diastolic blood pressure and heart rate between before and immediately after the water aerobics session . Conclusion Water aerobics for sedentary pregnant women proved to be safe and was not associated with any alteration in maternal body composition , type of delivery , preterm birth rate , neonatal well-being or weight The histomorphometry of term placentae from women who exercised regularly throughout either the first half or all of pregnancy was compared to that of placentae from matched controls to determine if regular exercise during pregnancy produced histomorphometric evidence of altered development and transport capacity . Conventional stereological techniques were used to estimate placental volumetric composition , surface areas , and villous and vascular configurations in the three groups . Exercise confined to early pregnancy increased the parenchymal component of the placenta , total vascular volume and site-specific capillary volume and surface area .  Exercise throughout pregnancy increased these and multiple other histomorphometric parameters associated with the rate of placental perfusion and transfer function . However , significant changes were confined to villi > 80 microns in diameter . The localization of both the timing of the stimulus and the anatomical sites affected indicates that regular , sustained exercise modifies placental development primarily in early and mid-pregnancy . We speculate that the lack of significant changes in the structure and configuration of the smaller villi indicates that other adaptive mechanisms , such as increased rates of placental blood flow , must be well developed by the latter portion of the mid-trimester and adequately maintain fetal oxygenation and substrate delivery throughout the third trimester Background Increasingly , women of reproductive age participate in recreational running , but its impact on pregnancy outcome is unknown . We investigated whether running affects gestational age at delivery and birth weight as indicators of cervical integrity and placental function , respectively . Methods 1293 female participants were recruited from parkrun , which organises weekly runs involving 1.25 million runners across 450 parks worldwide . Those under 16 or unable to provide outcome data were excluded . Women were categorised according to whether they continued to run during pregnancy or not . Those who continued were further stratified dependent on average weekly kilometres , and which trimester they ran until . Retrospectively collected primary outcomes were gestational age at delivery and birthweight centile . Other outcomes included assisted vaginal delivery rate and prematurity at clinical ly important gestations . Results There was no significant difference in gestational age at delivery : 279.0 vs 279.6 days ( mean difference 0.6 days , CI −1.3 to 2.4 days ; P=0.55 ) or birthweight centile : 46.9%vs 44.9 % ( mean difference 2.0 % , CI −1.3 % to −5.3 % ; P=0.22 ) in women who stopped running and those who continued , respectively . Assisted vaginal delivery rate was increased in women who ran : 195/714 ( 27 % ) vs 128/579 ( 22 % ) ( OR 1.32 ; CI 1.02 to 1.71 ; P=0.03 ) . Conclusion Continuing to run during pregnancy does not appear to affect gestational age or birthweight centile , regardless of mean weekly distance or stage of pregnancy . Assisted vaginal delivery rates were higher in women who ran , possibly due to increased pelvic floor muscle tone . R and omised prospect i ve analysis is necessary to further explore these findings OBJECTIVE To evaluate the influence of exercise on maternal and perinatal outcome in a low‐risk healthy obstetric population . METHODS We conducted a prospect i ve observational study of low‐risk healthy women exercising during their pregnancy . An extensive question naire collected antepartum , intrapartum , and postpartum patient information on 750 women . The women were divided into four groups based on exercise level during pregnancy . RESULTS There were no differences among groups for maternal demographic characteristics , antenatal illnesses , stress , social support , or smoking . Heavily exercising women were older ( P = .042 ) , had higher incomes ( P = .001 ) , and were exercising more at conception ( P = .001 ) . Women who did more exercise were more likely to need an induction of labor ( P = .033 , relative risk 1.84 , 95 % confidence interval 1.05 , 3.20 ) , induction or augmentation with oxytocin ( P = .015 , relative risk 1.53 , 95 % confidence interval 1.19 , 1.97 ) , and had longer first‐stage labors ( P = .032 ) result ing in longer total labors ( P = .011 ) . The difference in the length of first‐stage labor was even greater if the no‐exercise group was compared with the strongly exercising group ( P = .009 , relative risk 1.38 , 95 % confidence interval 0.16 , 2.60 ) . Fewer umbilical cord abnormalities ( P = .034 ) were observed with exercise , but exercising women had more colds and flu ( P = .008 ) . Heavily exercising women had smaller infants ( mean difference 86.5 g ) compared with sedentary women . CONCLUSION Exercise  in working women is associated with smaller babies , increased number of inductions and augmentations of labor , and longer labors . Colds and flu are more frequent in exercising women EDITORIAL COMMENT : When this paper was review ed the question was raised that the period of gestation is an obvious factor which can determine birth‐weight and the authors were asked how this may have affected their results The authors response was as follows Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more PURPOSE This study aim ed to evaluate the effect of an exercise program of two different intensities , with nutritional control , on gestational weight gain ( GWG ) , infant birth weight , and maternal weight retention at 2 months postpartum ( 2 mopp ) . METHODS Pregnant women ( prepregnancy body mass index = 18.5 - 24.9 kg·m ) were r and omized at study entry ( 16 - 20 wk of gestation ) to a low-intensity ( LI , 30 % HR reserve ( HRR ) , n = 23 ) or moderate-intensity ( MI , 70 % HRR , n = 26 ) exercise program , with nutritional control . The exercise program consisted of walking sessions three to four times per week , gradually increasing exercise time from 25 to 40 min per session . Forty-five normal-weight women who did not participate in any structured exercise program during pregnancy and had singleton births were used as a historical control group .  RESULTS Total GWG was higher in the control group ( 18.3 ± 5.3 kg ) compared with the LI ( 15.3 ± 2.9 kg , P = 0.01 ) and MI ( 14.9 ± 3.8 kg , P = 0.003 ) groups . During the intervention , GWG was similar in both intervention groups , with weekly rates of weight gain of 0.49 ± 0.1 and 0.47 ± 0.1 kg·wk in the LI and MI groups , respectively . Excessive GWG during the intervention was prevented in 70 % of the women in the LI group and 77 % of those in the MI group . Excessive GWG occurred before the intervention began . At 2 mopp , 18 % and 28 % of the women in the LI and MI groups , respectively , retained ≤2.0 kg compared with only 7 % of those in the control group . Infant birth weight was not different between the groups . CONCLUSIONS Results suggest that a prenatal nutrition and exercise program regardless of exercise intensity , reduced excessive GWG and decreased weight retention at 2 mopp in women of normal weight before pregnancy BACKGROUND : Obesity and being overweight are becoming epidemic , and indeed , the proportion of such women of reproductive age has increased in recent times . Being overweight or obese prior to pregnancy is a risk factor for gestational diabetes mellitus , and increases the risk of adverse pregnancy outcome for both mothers and their offspring . Furthermore , the combination of gestational diabetes mellitus with obesity/overweight status may increase the risk of adverse pregnancy outcome attributable to either factor alone . Regular exercise has the potential to reduce the risk of developing gestational diabetes mellitus and can be used during pregnancy ; however , its efficacy remain controversial . At present , most exercise training interventions are implemented on Caucasian women and in the second trimester , and there is a paucity of studies focusing on overweight/obese pregnant women . OBJECTIVE : We sought to test the efficacy of regular exercise in early pregnancy to prevent gestational diabetes mellitus in Chinese overweight/obese pregnant women . STUDY DESIGN : This was a prospect i ve r and omized clinical trial in which nonsmoking women age > 18 years with a singleton pregnancy who met the criteria for overweight/obese status ( body mass index 24≤28 kg/m2 ) and had an uncomplicated pregnancy at < 12 + 6 weeks of gestation were r and omly allocated to either exercise or a control group . Patients did not have contraindications to physical activity . Patients allocated to the exercise group were assigned to exercise 3 times per week ( at least 30 min/session with a rating of perceived exertion between 12‐14 ) via a cycling program begun within 3 days of r and omization until 37 weeks of gestation . Those in the control group continued their usual daily activities . Both groups received st and ard prenatal care , albeit without special dietary recommendations . The primary outcome was incidence of gestational diabetes mellitus . RESULTS : From December 2014 through July 2016 , 300 singleton women at 10 weeks ’ gestational age and with a mean prepregnancy body mass index of 26.78 ± 2.75 kg/m2 were recruited . They were r and omized into an exercise group ( n = 150 ) or a control group ( n = 150 ) . In all , 39 ( 26.0 % ) and 38 ( 25.3 % ) participants were obese in each group , respectively . Women r and omized to the exercise group had a significantly lower incidence of gestational diabetes mellitus ( 22.0 % vs 40.6 % ; P < .001 ) . These women also had significantly less gestational weight gain by 25 gestational weeks ( 4.08 ± 3.02 vs 5.92 ± 2.58 kg ; P < .001 ) and at the end of pregnancy ( 8.38 ± 3.65 vs 10.47 ± 3.33 kg ; P < .001 ) , and reduced insulin resistance levels ( 2.92 ± 1.27 vs 3.38 ± 2.00 ; P = .033 ) at 25 gestational weeks . Other secondary outcomes , including gestational weight gain between 25‐36 gestational weeks ( 4.55 ± 2.06 vs 4.59 ± 2.31 kg ; P = .9 ) , insulin resistance levels at 36 gestational weeks ( 3.56 ± 1.89 vs 4.07 ± 2.33 ; P = .1 ) , hypertensive disorders of pregnancy ( 17.0 % vs 19.3 % ; odds ratio , 0.854 ; 95 % confidence interval , 0.434–2.683 ; P = .6 ) , cesarean delivery ( except for scar uterus ) ( 29.5 % vs 32.5 % ; odds ratio , 0.869 ; 95 % confidence interval , 0.494–1.529 ; P = .6 ) , mean gestational age at birth ( 39.02 ± 1.29 vs 38.89 ± 1.37 weeks ’ gestation ; P = .5 ) ; preterm birth ( 2.7 % vs 4.4 % , odds ratio , 0.600 ; 95 % confidence interval , 0.140–2.573 ; P = .5 ) , macrosomia ( defined as birthweight > 4000 g ) ( 6.3 % vs 9.6 % ; odds ratio , 0.624 ; 95 % confidence interval , 0.233–1.673 ; P = .3 ) , and large 
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