***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: OBJECTIVE We evaluated the association between mothers ' use of multivitamin supplements and their infants ' risk for omphalocele , a congenital anomaly of the abdominal wall . Omphalocele can occur in certain multiple congenital anomaly patterns with neural tube defects , for which a protective effect of multivitamins with folic acid has been demonstrated . METHODS We used data from a population -based case-control study of infants born from 1968 - 1980 to mothers residing in metropolitan Atlanta . Case-infants with nonsyndromic omphalocele ( n = 72 ) were actively ascertained from multiple sources . Control-infants ( n = 3029 ) , without birth defects , were selected from birth certificates by stratified r and om sampling . RESULTS Compared with no use in the periconceptional period , periconceptional use of multivitamin supplements ( regular use from 3 months before pregnancy through the first trimester of pregnancy ) was associated with an odds ratio for nonsyndromic omphalocele of 0.4 ( 95 % confidence interval [ CI ] : 0.2 - 1.0 ) . For the subset comprising omphalocele alone or with selected midline defects ( neural tube defects , hypospadias , and bladder/cloacal exstrophy ) , the odds ratio was 0.3 ( 95 % CI : 0.1 - 0.9 ) . These estimates were similar when the reference group also included women who began using multivitamins late in pregnancy ( during the second or third month of pregnancy ) . The small number of participants limited the precision of subgroup analyses and translated into wide confidence intervals that included unity . CONCLUSIONS Periconceptional multivitamin use was associated with a 60 % reduction in the risk for nonsyndromic omphalocele . These findings await replication from additional studies to confirm the findings , generate more precise estimates , and detail possible mechanisms of actions To study the relation of maternal periconceptional vitamin use  to the risk of  a congenital urinary tract anomaly ( CUTA )  , we conducted a case-control study using the Washington State Birth Defect Registry . We identified CUTA cases with no known chromosomal abnormality in seven counties in western Washington State occurring between January 1 , 1990 , and December 31 , 1991 . We r and omly selected a sample , as controls , of all infants delivered in five large hospitals in King County who did not have a birth defect and who were born in the same year as the cases . About 55 % of all infants in King County and a smaller proportion of infants in the other six counties are delivered in these five hospitals . We interviewed mothers of 118 cases and 369 controls to obtain information about their vitamin use during the pregnancy and during the year before the conception . After adjustment for maternal race , family income , county of maternal residence , and birth year , we found that women who used multivitamins during the first trimester had only 15 % the risk of bearing a child with a CUTA compared with women who did not take vitamins [ odds ratio ( OR ) = 0.15 ; 95 % confidence interval ( CI ) = 0.05–0.43 ] . The reduction was smaller for use restricted to the second or third trimesters ( OR = 0.31 ; 95 % CI = 0.09–1.02 ) . Among women who used vitamins during the first trimester , vitamin use before conception was not associated with any further reduction in the risk , nor did there appear to be an association with the amount or br and of vitamin used . Restricting the analysis to residents of King County did not change the results . Our results indicate that prenatal multivitamin use , particularly during the first trimester , may reduce the risk of a CUTA . Because all of the preparations taken by study participants contained many vitamins as well as folic acid , it was not possible to identify which one ( or several ) chemical(s ) may have been responsible for the reduced risk of a CUTA OBJECTIVE --To study the effect of periconceptional multivitamin supplementation on neural tube defects and other congenital abnormality entities . DESIGN --R and omised controlled trial of supplementation with multivitamins and trace elements . SETTING --Hungarian family planning programme . SUBJECTS--4156 pregnancies with known outcome and 3713 infants evaluated in the eighth month of life . INTERVENTIONS --A single tablet of a multivitamin including 0.8 mg of folic acid or trace elements supplement daily for at least one month before conception and at least two months after conception . MAIN OUTCOME MEASURES --Number of major and mild congenital abnormalities . RESULTS --The rate of all major congenital abnormalities was significantly lower in the group given vitamins than in the group given trace elements and this difference can not be explained totally by the significant reduction of neural tube defects . The rate of major congenital abnormalities other than neural tube defects and genetic syndromes was 9.0/1000 in pregnancies with known outcome in the vitamin group and 16.6/1000 in the trace element group ; relative risk 1.85 ( 95 % confidence interval 1.02 to 3.38 ) ; difference , 7.6/1000 . The rate of all major congenital abnormalities other than neural tube defects and genetic syndromes diagnosed up to the eighth month of life was 14.7/1000 informative pregnancies in the vitamin group and 28.3/1000 in the trace element group ; relative risk 1.95 ( 1.23 to 3.09 ) ; difference , 13.6/1000 . The rate of some congenital abnormalities was lower in the vitamin group than in the trace element group but the differences for each group of abnormalities were not significant . CONCLUSIONS --Periconceptional multivitamin supplementation can reduce not only the rate of neural tube defects but also the rate of other major non-genetic syndromatic congenital abnormalities . Further studies are needed to differentiate the chance effect and vitamin dependent effect A r and omised double-blind prevention trial with a factorial design was conducted at 33 centres in seven countries to determine whether supplementation with folic acid ( one of the vitamins in the B group ) or a mixture of seven other vitamins ( A , D , B1,B2,B6,C and nicotinamide ) around the time of conception can prevent neural tube defects ( anencephaly , spina bifida , encephalocele ) . A total of 1817 women at high risk of having a pregnancy with a neural tube defect , because of a previous affected pregnancy , were allocated at r and om to one of four groups -- namely , folic acid , other vitamins , both , or neither .  1195 had a completed pregnancy in which the fetus or infant was known to have or not have a neural tube defect ; 27 of these had a known neural tube defect , 6 in the folic acid groups and 21 in the two other groups , a 72 % protective effect ( relative risk 0.28 , 95 % confidence interval 0.12 - 0.71 ) . The other vitamins showed no significant protective effect ( relative risk 0.80 , 95 % Cl 0.32 - 1.72 ) . There was no demonstrable harm from the folic acid supplementation , though the ability of the study to detect rare or slight adverse effects was limited . Folic acid supplementation starting before pregnancy can now be firmly recommended for all women who have had an affected pregnancy , and public health measures should be taken to ensure that the diet of all women who may bear children contains an adequate amount of folic acid Data from our trial of periconceptional vitamin supplementation for the prevention of neural tube defects have been analysed to assess the influence of various factors on recurrence rates of neural tube defect . Our data suggest that the risk of recurrence of neural tube defect is influenced by the number of previous neural tube defects , area of residence , immediately prior miscarriage , and interpregnancy interval . None of these factors , however , contributed any significant differential risk between supplemented and unsupplemented mothers . Hence we conclude that the highly significant difference in recurrence rates of neural tube defect between supplemented and unsupplemented mothers was due to vitamin supplementation OBJECTIVE In 1982 , Tolarova(4 ) found a reduction in the recurrence rate of isolated cleft lip ( CL ) with or without cleft palate ( CP ; CL + /- CP ) after periconceptional supplementation with a multivitamin including a very high dose ( 10 mg ) of folic acid . The Hungarian r and omized , double-blind , controlled trial of periconceptional supplementation with a multivitamin including a physiologic dose ( .8 mg ) of folic acid did not show any preventive effect on the first occurrence of isolated CL + /- CP and CP . However , the general evaluation of congenital abnormalities in the Hungarian Case-Control Surveillance of Congenital Abnormalities indicated , among others , a reduction of isolated CL + /- CP and CP after the use of high doses of folic acid in the critical period for the development of these congenital abnormalities in the 12-year data set between 1980 and 1991 . We hypothesized that the prevention of orofacial clefts by folic acid has a dose-dependent effect , and this hypothesis was tested in 2 recent Hungarian data sets . DESIGN In a prospect i ve cohort study , the occurrence of isolated CL + /- CP and CP was studied in the newborn infants born to mothers with or without periconceptional folic acid-containing ( .8 mg ) multivitamin supplementation . Supplemented women with confirmed pregnancy were recruited from the participants of the periconceptional service . Unsupplemented women were invited to take part in the study after the first visit between the 8th and 12th week of gestation in the antenatal care . Supplemented and unsupplemented women were matched based on age , socioeconomic status , and residence . In contrast , the occurrence of high-dose ( in general daily 6 mg ) folic acid supplementation was evaluated in the case-control pairs of CL + /- CP and CP , particularly during the critical period of these 2 types of orofacial clefts in the 17 years data set of the Case-Control Surveillance of Congenital Abnormalities , between 1980 and 1996 . Cases were selected from the population -based Hungarian Congenital Abnormality Registry , whereas population controls without congenital abnormality were ascertained from the national birth registry . Two population controls were matched to every case according to sex , week of birth , and district of parental residence . The drug uses , including pregnancy supplements as folic acid , were evaluated based on retrospective self-reported maternal question naire and prospect i ve medically documented data of antenatal care logbook . RESULTS In the prospect i ve cohort study , of 3019 informative offspring ( termination of pregnancies in the second and third trimesters because of fetal defect , stillborn fetuses , and liveborn infants ) in the supplemented group , 3 had CL + /- CP and 1 was affected with CP , whereas of 3432 informative offspring in the unsupplemented group , 2 had CL + /- CP and 1 had CP . The lack of preventive effect was in agreement with the result of the previous Hungarian r and omized double-blind controlled trial ; thus , these 2 data sets were combined . The preventive effect of a folic acid containing multivitamin used in the periconceptional period for the first occurrence of isolated CL + /- CP and CP was estimated by the Mantel-Haenszel test . Of 5488 supplemented women , 6 had CL + /- CP , and of 5821 unsupplemented women , 4 had CL + /- CP . Of 5489 supplemented women , 1 had CP , and of 5823 unsupplemented pregnant women , 3 had CP . The Hungarian Case-Control Surveillance of Congenital Abnormalities , 1980 - 1996 , included 38 151 population controls ( 1.8 % of the Hungarian births ) and 22 865 cases with congenital abnormalities . Within the latter group , 1368 had isolated CL + /- CP  , and 596 had CP . A significantly more frequent use of high-dose  folic acid ( in general daily 6 mg ) supplementation was found in controls than in cases of 1246 case-control pairs of CL + /- CP group and of 537 case-control pairs of CP group , respectively . ( ABSTRACT TRUNCATED A r and omised trial was initiated in Irel and in 1981 to determine if periconceptional supplementation with either folic acid alone or a multivitamin preparation alone could reduce the recurrence risk of neural tube defects ( NTDs ) in women with a previously affected pregnancy from 5.0 % to 1.0 % or less . The trial was concluded before the initial target number of study subjects was reached and without a clear treatment effect being observed . A total of 354 women were r and omised to receive one of three treatments : folic acid , multivitamins without folic acid , and folic acid plus multivitamins . At the end of the trial 257 women had had a first trial pregnancy outcome ( 261 infants/fetuses ) where the presence or absence of NTDs was ascertainable . There was one NTD recurrence in the 89 infants/fetuses of women in the multivitamin group and no recurrence in the 172 infants/fetuses of women in the folic acid groups , a non-significant difference . Otherwise eligible women who were pregnant when first contacted constituted a non-r and omised control group ; there were three recurrences among the 103 infants in this group . The difference in the recurrence rate between the folic acid groups and the non-r and omised controls 
    Output:
    
No effects were shown in preventing Down syndrome , pyloric stenosis , undescended testis , or hypospadias .
CONCLUSION Maternal consumption of folic acid-containing prenatal multivitamins is associated with decreased risk for several congenital anomalies , not only neural tube defects .