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 The associations between homocysteine , B vitamin status , and pregnancy outcomes have not been examined prospect ively . OBJECTIVE We assessed the associations of preconception homocysteine and B vitamin status with  preterm birth and birth of low-birth-weight ( LBW ) and small-for-gestational-age ( SGA ) infants in Chinese women . DESIGN This was a case-control study of women aged 21 - 34 y. Preterm cases ( n = 29 ) delivered living infants at < 37 wk gestation ; term controls ( n = 405 ) delivered infants at > or = 37 wk . LBW cases ( n = 33 ) had infants weighing < 2500 g ; normal-birth-weight controls ( n = 390 ) had infants weighing > or = 2500 g. SGA cases ( n = 65 ) had infants below the 10th percentile of weight-for-gestational-age ; appropriate-for-gestational-age controls ( n = 358 ) had infants above this cutoff .  Nonfasting plasma concentrations of homocysteine , folate , and vitamins B-6 and B-12 were measured before conception . RESULTS Elevated homocysteine ( > or = 12.4 micro mol/L ) was associated with a nearly 4-fold higher risk of preterm birth ( OR : 3.6 ; 95 % CI : 1.3 , 10.0 ; P < 0.05 ) . The risk of preterm birth was 60 % lower among women with vitamin B-12 > or = 258 pmol/L than among vitamin B-12-deficient women ( OR : 0.4 ; 95 % CI : 0.2 , 0.9 ; P < 0.05 ) and was 50 % lower among women with vitamin B-6 > or = 30 nmol/L than among vitamin B-6-deficient women ( OR : 0.5 ; 95 % CI : 0.2 , 1.2 ; NS ) . Folate status was not associated with preterm birth , and homocysteine and B vitamin status were not associated with LBW or SGA status . CONCLUSIONS Elevated homocysteine and suboptimal vitamin B-12 and B-6 status may increase the risk of preterm birth . These results need to be confirmed in larger prospect i ve studies We examined the influence of folate intake from diet and supplements b y 28 wk of gestation and third trimester circulating concentrations of serum folate on the outcome of pregnancy in women from Camden , NJ . Mean daily folate intake by week 28 included both dietary and supplemental folate obtained prospect ively in 832 women . Circulating concentrations of serum folate as well as serum vitamin B-12 were assayed at 28 wk of gestation ( + /- 2 wk ) by radioimmunoassay . The outcomes of interest included preterm delivery ( < 37 wk ) and  infants with low birth weight ( < 2500 g ) . Mean folate intake was significantly correlated with circulating concentrations of serum folate ( r=0.17 , P<0.001 ) . Women with a low mean daily folate intake ( < /-240 microgram/d ) had an approximately twofold greater risk of preterm delivery and infant low birth weight after maternal characteristics , energy intake , and other correlated nutrients were controlled for . Lower concentrations of serum folate at week 28 were also associated with a greater risk of preterm delivery and low birth weight BACKGROUND Increased homocysteine has been associated with pregnancy complications . METHODS We investigated prospect ively the effect of maternal homocysteine on  normal pregnancy outcome .  The study included 93 women and their offspring ; 39 of the women took folic acid during the second and /or third trimesters of pregnancy . We measured homocysteine at preconception ; at weeks 8 , 20 , and 32 of pregnancy ; during labor ; and in the fetal cord ; we also recorded birth weight . RESULTS Geometric mean ( SE ) maternal total homocysteine ( tHcy ) increased between 32 weeks of pregnancy and labor [ 7.98 ( 1.05 ) micromol/L in unsupplemented women and 6.26 ( 1.07 ) micromol/L in supplemented women ; P < 0.0001 for both ] . Fetal tHcy was lower than maternal tHcy [ 6.39 ( 1.06 ) micromol/L in unsupplemented pregnancies ( P < 0.0001 ) , and 5.18 ( 1.06 ) micromol/L in supplemented pregnancies ( P < 0.05 ) ] . Maternal tHcy was correlated from preconception throughout pregnancy ( 8 weeks , r = 0.708 ; 20 weeks , r = 0.637 ; 32 weeks , r = 0.537 ; labor , r = 0.502 ; P < 0.0001 for all time points ) and with fetal tHcy [ preconception , r = 0.255 ( P < 0.05 ) ; 8 weeks , r = 0.321 ( P < 0.01 ) ; 20 weeks , r = 0.469 ; 32 weeks , r = 0.550 ; labor , r = 0.624 ( P < 0.0001 ) ] . Mothers in the highest tHcy tertile at 8 weeks of pregnancy were three times [ odds ratio , 3.26 ( 95 % confidence interval , 1.05 - 10.13 ) ; P < 0.05 ] and at labor were four times [ 3.65 ( 1.15 - 11.56 ) ; P < 0.05 ] more likely to give birth to a neonate in the lowest birth weight tertile . Neonates of mothers in the highest tHcy tertile at labor weighed , on average , 227.98 g less than those of mothers in the low and medium tertiles ( P = 0.014 ) . CONCLUSIONS Supplemented mothers had lower tHcy at labor than unsupplemented mothers , as did their neonates . Maternal and fetal tHcy was significantly correlated throughout the study . Neonates of mothers in the highest tertile of homocysteine weighed less OBJECTIVE The purpose of this study was to determine whether second-trimester plasma homocysteine levels are elevated among women whose pregnancies are subsequently complicated by pregnancy-induced hypertension , preeclampsia , or intrauterine growth restriction . STUDY DESIGN Women with normal but relatively low plasma zinc levels were r and omly assigned to receive zinc supplementation or placebo from 19 weeks ' gestation until delivery . Plasma homocysteine concentration and plasma and erythrocyte folate levels were determined for all available stored sample s ( zinc group , 231/294 ; placebo group , 206/286 ) at 26 and 37 weeks ' gestation . Among all women with available sample s , pregnancy-induced hypertension ( n = 12 ) or preeclampsia ( n = 4 ) developed in 16 women , and 22 pregnancies were complicated by intrauterine growth restriction . RESULTS Mean homocysteine levels in women with pregnancy-induced hypertension and preeclampsia  were similar to those of control subjects at 26 weeks ' gestation but were significantly higher at 37 weeks ' gestation . Homocysteine levels were similar between women with pregnancies complicated by intrauterine growth restriction and control subjects at both time points . CONCLUSION Second-trimester plasma homocysteine concentrations do not predict the subsequent development of pregnancy-induced hypertension , preeclampsia , and intrauterine growth restriction OBJECTIVE Our purpose was to assess the incidence of hyperhomocysteinemia in patients with a history of preeclampsia or fetal growth restriction , to evaluate the effects of vitamin supplementation on the methionine loading test , and to study the course of subsequent pregnancies in women with hyperhomocysteinemia and a history of preeclampsia or fetal growth restriction . STUDY DESIGN A total of 207 consecutive patients with a history of preeclampsia or fetal growth restriction was tested for hyperhomocysteinemia . Thirty-seven were found to be positive and were treated with folic acid and vitamin B6 , and 27 had a second methionine loading test after vitamin supplementation . Fourteen patients became pregnant again while receiving vitamins and aspirin . RESULTS All patients who underwent a methionine loading test after vitamin supplementation had a completely normalized methionine loading test . Of the 14 pregnancies in women receiving vitamins and aspirin , 7 were complicated by preeclampsia . Birth weights were 2867 + /- 648 g compared with 1088 + /- 570 g in the previous pregnancies . CONCLUSIONS Vitamin B6 and folic acid correct the methionine loading test in patients with hyperhomocysteinemia . Perinatal outcome in patients with a history of preeclampsia or fetal growth restriction and hyperhomocysteinemia appears to be favorable BACKGROUND Increased total homocysteine ( tHcy ) may be associated with placental-mediated adverse pregnancy outcomes , but few prospect i ve studies have measured tHcy before pregnancy outcome . This study was undertaken to determine whether increased tHcy measured in early pregnancy is associated with  pregnancy loss , gestational hypertension ( GH ) , preeclampsia  , or small for gestational age ( SGA ) infants . METHODS We conducted a prospect i ve cohort study between 2002 and 2005 . We measured  tHcy and serum folate  in  blood sample s from pregnant women ( < 20 weeks ' gestation ) and collected detailed pregnancy information through a question naire and medical record review . RESULTS Of the 2119 women included in the study , 103 had a pregnancy loss , 115 had gestational hypertension , 65 had preeclampsia , and 129 had an SGA infant . Subjects with increased tHcy concentrations were at increased risk of pregnancy loss [ relative risk ( RR ) 2.1 , 95 % CI 1.2 - 3.6 ] or preeclampsia ( RR 2.7 , 95 % CI 1.4 - 5.0 ) than subjects with lower tHcy concentrations , but increased tHcy concentration was not associated with increased risk of developing GH or having an SGA infant . CONCLUSION The finding of high tHcy in early pregnancy as a risk factor for pregnancy loss and preeclampsia is consistent with a hypothesis that increased tHcy results in abnormalities of the placental vasculature Background Inadequate folate status has been associated with many negative reproductive outcomes , such as neural tube defects ( NTD ) , low birth weight and placental abruption . Aim of the study The objectives of this study were to evaluate the levels of dietary folate intake  during pregnancy in Japanese women and the subsequent birth weight of their babies . Methods A longitudinal prospect i ve study was conducted with 197 women with a singleton pregnancy in 2005 .  Dietary folate was investigated 3 times : in the first trimester at 12 weeks , in the second trimester at 20 weeks and in third trimester at 32 weeks using a diet history question naire ( DHQ ) . Non fasting blood sample s were collected from the women for measurement of homocysteine , hemoglobin , ferritin , unbound iron-binding capacity ( UIBC ) and total iron-binding capacity ( TIBC ) . Results Energy intake increased as pregnancy advanced , but not significantly . The daily intake of folate  increased from 248.5 ± 113.1 µg/d in the first trimester to 275.4 ± 100.2 µg/d in the third trimester ( P = 0.04 ) . This was well below the recommended level of 440 µg/d and only 10 % of mothers were above the levels . In the third trimester , plasma homocysteine concentration was significantly higher in the low folate group of less than 250 µg/d ( P = 0.02 ) , but not the first and second trimesters . Dietary folate intake and plasma homocysteine concentrations were not likely to be predictors of birth weight in our subjects . Conclusions Our study shows that Japanese women ’s energy and folate intakes do not meet their energy needs during pregnancy and are at an extremely low recommended dietary allowance level throughout pregnancy OBJECTIVE The aim of this prospect i ve study was to determine the impact of thrombophilia on the recurrence of preeclampsia . STUDY DESIGN In a multicenter , observational , cohort design , 172 white patients with a previous pregnancy complicated by preeclampsia were observed in the next pregnancy . They were evaluated for heritable thrombophilia ( factor V Leiden and factor II G20210A mutations , protein S , protein C , and antithrombin deficiency ) , hyperhomocystinemia , lupus anticoagulant , and anticardiolipin antibodies . Development of preeclampsia and maternal complications and both gestational age at delivery and birthweight were recorded . RESULTS Sixty women ( 34.9 % ) showed the presence of a thrombophilic defect . They had a higher risk for the recurrence of preeclampsia ( odds ratio [ OR ] , 2.5 ; 95 % confidence interval [ CI ] , 1 
    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 The associations between homocysteine , B vitamin status , and pregnancy outcomes have not been examined prospect ively . OBJECTIVE We assessed the associations of preconception homocysteine and B vitamin status with  preterm birth and birth of low-birth-weight ( LBW ) and small-for-gestational-age ( SGA ) infants in Chinese women . DESIGN This was a case-control study of women aged 21 - 34 y. Preterm cases ( n = 29 ) delivered living infants at < 37 wk gestation ; term controls ( n = 405 ) delivered infants at > or = 37 wk . LBW cases ( n = 33 ) had infants weighing < 2500 g ; normal-birth-weight controls ( n = 390 ) had infants weighing > or = 2500 g. SGA cases ( n = 65 ) had infants below the 10th percentile of weight-for-gestational-age ; appropriate-for-gestational-age controls ( n = 358 ) had infants above this cutoff .  Nonfasting plasma concentrations of homocysteine , folate , and vitamins B-6 and B-12 were measured before conception . RESULTS Elevated homocysteine ( > or = 12.4 micro mol/L ) was associated with a nearly 4-fold higher risk of preterm birth ( OR : 3.6 ; 95 % CI : 1.3 , 10.0 ; P < 0.05 ) . The risk of preterm birth was 60 % lower among women with vitamin B-12 > or = 258 pmol/L than among vitamin B-12-deficient women ( OR : 0.4 ; 95 % CI : 0.2 , 0.9 ; P < 0.05 ) and was 50 % lower among women with vitamin B-6 > or = 30 nmol/L than among vitamin B-6-deficient women ( OR : 0.5 ; 95 % CI : 0.2 , 1.2 ; NS ) . Folate status was not associated with preterm birth , and homocysteine and B vitamin status were not associated with LBW or SGA status . CONCLUSIONS Elevated homocysteine and suboptimal vitamin B-12 and B-6 status may increase the risk of preterm birth . These results need to be confirmed in larger prospect i ve studies We examined the influence of folate intake from diet and supplements b y 28 wk of gestation and third trimester circulating concentrations of serum folate on the outcome of pregnancy in women from Camden , NJ . Mean daily folate intake by week 28 included both dietary and supplemental folate obtained prospect ively in 832 women . Circulating concentrations of serum folate as well as serum vitamin B-12 were assayed at 28 wk of gestation ( + /- 2 wk ) by radioimmunoassay . The outcomes of interest included preterm delivery ( < 37 wk ) and  infants with low birth weight ( < 2500 g ) . Mean folate intake was significantly correlated with circulating concentrations of serum folate ( r=0.17 , P<0.001 ) . Women with a low mean daily folate intake ( < /-240 microgram/d ) had an approximately twofold greater risk of preterm delivery and infant low birth weight after maternal characteristics , energy intake , and other correlated nutrients were controlled for . Lower concentrations of serum folate at week 28 were also associated with a greater risk of preterm delivery and low birth weight BACKGROUND Increased homocysteine has been associated with pregnancy complications . METHODS We investigated prospect ively the effect of maternal homocysteine on  normal pregnancy outcome .  The study included 93 women and their offspring ; 39 of the women took folic acid during the second and /or third trimesters of pregnancy . We measured homocysteine at preconception ; at weeks 8 , 20 , and 32 of pregnancy ; during labor ; and in the fetal cord ; we also recorded birth weight . RESULTS Geometric mean ( SE ) maternal total homocysteine ( tHcy ) increased between 32 weeks of pregnancy and labor [ 7.98 ( 1.05 ) micromol/L in unsupplemented women and 6.26 ( 1.07 ) micromol/L in supplemented women ; P < 0.0001 for both ] . Fetal tHcy was lower than maternal tHcy [ 6.39 ( 1.06 ) micromol/L in unsupplemented pregnancies ( P < 0.0001 ) , and 5.18 ( 1.06 ) micromol/L in supplemented pregnancies ( P < 0.05 ) ] . Maternal tHcy was correlated from preconception throughout pregnancy ( 8 weeks , r = 0.708 ; 20 weeks , r = 0.637 ; 32 weeks , r = 0.537 ; labor , r = 0.502 ; P < 0.0001 for all time points ) and with fetal tHcy [ preconception , r = 0.255 ( P < 0.05 ) ; 8 weeks , r = 0.321 ( P < 0.01 ) ; 20 weeks , r = 0.469 ; 32 weeks , r = 0.550 ; labor , r = 0.624 ( P < 0.0001 ) ] . Mothers in the highest tHcy tertile at 8 weeks of pregnancy were three times [ odds ratio , 3.26 ( 95 % confidence interval , 1.05 - 10.13 ) ; P < 0.05 ] and at labor were four times [ 3.65 ( 1.15 - 11.56 ) ; P < 0.05 ] more likely to give birth to a neonate in the lowest birth weight tertile . Neonates of mothers in the highest tHcy tertile at labor weighed , on average , 227.98 g less than those of mothers in the low and medium tertiles ( P = 0.014 ) . CONCLUSIONS Supplemented mothers had lower tHcy at labor than unsupplemented mothers , as did their neonates . Maternal and fetal tHcy was significantly correlated throughout the study . Neonates of mothers in the highest tertile of homocysteine weighed less OBJECTIVE The purpose of this study was to determine whether second-trimester plasma homocysteine levels are elevated among women whose pregnancies are subsequently complicated by pregnancy-induced hypertension , preeclampsia , or intrauterine growth restriction . STUDY DESIGN Women with normal but relatively low plasma zinc levels were r and omly assigned to receive zinc supplementation or placebo from 19 weeks ' gestation until delivery . Plasma homocysteine concentration and plasma and erythrocyte folate levels were determined for all available stored sample s ( zinc group , 231/294 ; placebo group , 206/286 ) at 26 and 37 weeks ' gestation . Among all women with available sample s , pregnancy-induced hypertension ( n = 12 ) or preeclampsia ( n = 4 ) developed in 16 women , and 22 pregnancies were complicated by intrauterine growth restriction . RESULTS Mean homocysteine levels in women with pregnancy-induced hypertension and preeclampsia  were similar to those of control subjects at 26 weeks ' gestation but were significantly higher at 37 weeks ' gestation . Homocysteine levels were similar between women with pregnancies complicated by intrauterine growth restriction and control subjects at both time points . CONCLUSION Second-trimester plasma homocysteine concentrations do not predict the subsequent development of pregnancy-induced hypertension , preeclampsia , and intrauterine growth restriction OBJECTIVE Our purpose was to assess the incidence of hyperhomocysteinemia in patients with a history of preeclampsia or fetal growth restriction , to evaluate the effects of vitamin supplementation on the methionine loading test , and to study the course of subsequent pregnancies in women with hyperhomocysteinemia and a history of preeclampsia or fetal growth restriction . STUDY DESIGN A total of 207 consecutive patients with a history of preeclampsia or fetal growth restriction was tested for hyperhomocysteinemia . Thirty-seven were found to be positive and were treated with folic acid and vitamin B6 , and 27 had a second methionine loading test after vitamin supplementation . Fourteen patients became pregnant again while receiving vitamins and aspirin . RESULTS All patients who underwent a methionine loading test after vitamin supplementation had a completely normalized methionine loading test . Of the 14 pregnancies in women receiving vitamins and aspirin , 7 were complicated by preeclampsia . Birth weights were 2867 + /- 648 g compared with 1088 + /- 570 g in the previous pregnancies . CONCLUSIONS Vitamin B6 and folic acid correct the methionine loading test in patients with hyperhomocysteinemia . Perinatal outcome in patients with a history of preeclampsia or fetal growth restriction and hyperhomocysteinemia appears to be favorable BACKGROUND Increased total homocysteine ( tHcy ) may be associated with placental-mediated adverse pregnancy outcomes , but few prospect i ve studies have measured tHcy before pregnancy outcome . This study was undertaken to determine whether increased tHcy measured in early pregnancy is associated with  pregnancy loss , gestational hypertension ( GH ) , preeclampsia  , or small for gestational age ( SGA ) infants . METHODS We conducted a prospect i ve cohort study between 2002 and 2005 . We measured  tHcy and serum folate  in  blood sample s from pregnant women ( < 20 weeks ' gestation ) and collected detailed pregnancy information through a question naire and medical record review . RESULTS Of the 2119 women included in the study , 103 had a pregnancy loss , 115 had gestational hypertension , 65 had preeclampsia , and 129 had an SGA infant . Subjects with increased tHcy concentrations were at increased risk of pregnancy loss [ relative risk ( RR ) 2.1 , 95 % CI 1.2 - 3.6 ] or preeclampsia ( RR 2.7 , 95 % CI 1.4 - 5.0 ) than subjects with lower tHcy concentrations , but increased tHcy concentration was not associated with increased risk of developing GH or having an SGA infant . CONCLUSION The finding of high tHcy in early pregnancy as a risk factor for pregnancy loss and preeclampsia is consistent with a hypothesis that increased tHcy results in abnormalities of the placental vasculature Background Inadequate folate status has been associated with many negative reproductive outcomes , such as neural tube defects ( NTD ) , low birth weight and placental abruption . Aim of the study The objectives of this study were to evaluate the levels of dietary folate intake  during pregnancy in Japanese women and the subsequent birth weight of their babies . Methods A longitudinal prospect i ve study was conducted with 197 women with a singleton pregnancy in 2005 .  Dietary folate was investigated 3 times : in the first trimester at 12 weeks , in the second trimester at 20 weeks and in third trimester at 32 weeks using a diet history question naire ( DHQ ) . Non fasting blood sample s were collected from the women for measurement of homocysteine , hemoglobin , ferritin , unbound iron-binding capacity ( UIBC ) and total iron-binding capacity ( TIBC ) . Results Energy intake increased as pregnancy advanced , but not significantly . The daily intake of folate  increased from 248.5 ± 113.1 µg/d in the first trimester to 275.4 ± 100.2 µg/d in the third trimester ( P = 0.04 ) . This was well below the recommended level of 440 µg/d and only 10 % of mothers were above the levels . In the third trimester , plasma homocysteine concentration was significantly higher in the low folate group of less than 250 µg/d ( P = 0.02 ) , but not the first and second trimesters . Dietary folate intake and plasma homocysteine concentrations were not likely to be predictors of birth weight in our subjects . Conclusions Our study shows that Japanese women ’s energy and folate intakes do not meet their energy needs during pregnancy and are at an extremely low recommended dietary allowance level throughout pregnancy OBJECTIVE The aim of this prospect i ve study was to determine the impact of thrombophilia on the recurrence of preeclampsia . STUDY DESIGN In a multicenter , observational , cohort design , 172 white patients with a previous pregnancy complicated by preeclampsia were observed in the next pregnancy . They were evaluated for heritable thrombophilia ( factor V Leiden and factor II G20210A mutations , protein S , protein C , and antithrombin deficiency ) , hyperhomocystinemia , lupus anticoagulant , and anticardiolipin antibodies . Development of preeclampsia and maternal complications and both gestational age at delivery and birthweight were recorded . RESULTS Sixty women ( 34.9 % ) showed the presence of a thrombophilic defect . They had a higher risk for the recurrence of preeclampsia ( odds ratio [ OR ] , 2.5 ; 95 % confidence interval [ CI ] , 1 
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