***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 This study was design ed to test the null hypothesis that first trimester ultrasound crown-rump length measurement for gestational age determination will result in no difference in the rate of induction of labor for postterm pregnancy , compared with second trimester biometry alone . STUDY DESIGN Two hundred eighteen women were r and omly assigned to receive either first trimester ultrasound screening or second trimester ultrasound screening to establish the expected date of confinement . Sample size was calculated by using a 2-tailed alpha=.05 and power (1-beta)=80 % . Data were analyzed with chi(2 ) and Fisher exact tests . RESULTS Of 104 women r and omly assigned to the first trimester screening group , 41.3 % had their gestational age adjusted on the basis of the crown-rump length measurement . Of 92 women r and omly assigned to the second trimester screening group , 10.9 % were corrected as a result of biometry ( P < .001 , relative risk=0.26 , 95 % CI=0.15 - 0.46 ) . Five women in the first trimester screening group and 12 women in the second trimester screening group had labor induced for postterm pregnancy ( P=0.04 , relative risk=0.37 , 95 % CI=0.14 - 0.96 ) . CONCLUSION The application of a program of first trimester ultrasound screening to a low-risk obstetric population results in a significant reduction in the rate of labor induction for postterm pregnancy Background In high-re source setting s , obstetric ultrasound is a st and ard component of prenatal care used to identify pregnancy complications and to establish an accurate gestational age in order to improve obstetric care . Whether or not ultrasound use will improve care and ultimately pregnancy outcomes in low-re source setting s is unknown . Methods / Design This multi-country cluster r and omized trial will assess the impact of antenatal ultrasound screening performed by health care staff on a composite outcome consisting of maternal mortality and maternal near-miss , stillbirth and neonatal mortality in low-re source community setting s. The trial will utilize an existing research infrastructure , the Global Network for Women ’s and Children ’s Health Research with sites in Pakistan , Kenya , Zambia , Democratic Republic of Congo and Guatemala . A maternal and newborn health registry in defined geographic areas which documents all pregnancies and their outcomes to 6 weeks post-delivery will provide population -based rates of maternal mortality and morbidity , stillbirth , neonatal mortality and morbidity , and health care utilization for study clusters . A total of 58 study clusters each with a health center and about 500 births per year will be r and omized ( 29 intervention and 29 control ) . The intervention includes training of health workers ( e.g. , nurses , midwives , clinical officers ) to perform ultrasound examinations during antenatal care , generally at 18–22 and at 32–36 weeks for each subject . Women who are identified as having a complication of pregnancy will be referred to a hospital for appropriate care . Finally , the intervention includes community sensitization activities to inform women and their families of the availability of ultrasound at the antenatal care clinic and training in emergency obstetric and neonatal care at referral facilities . Discussion In summary , our trial will evaluate whether introduction of ultrasound during antenatal care improves pregnancy outcomes in rural , low-re source setting s. The intervention includes training for ultrasound-naïve providers in basic obstetric ultrasonography and then enabling these trainees to use ultrasound to screen for pregnancy complications in primary antenatal care clinics and to refer appropriately . Trial registration Clinical trials.gov ( NCT # 01990625 OBJECTIVE --To examine any associations between routine ultrasonography in utero and subsequent brain development as indicated by non-right h and edness at primary school age and neurological development during childhood . DESIGN --Follow up of 8 and 9 year old children of women who took part in two r and omised , controlled trials of routine ultrasonography during pregnancy . SETTING --Clinics of 60 general practitioners in Norway during 1979 - 81 . Maternal and child health centres . SUBJECTS--2161 ( 89 % ) of 2428 eligible singletons were followed up , partly through a question naire to their parents and partly through information from health centres . MAIN OUTCOME MEASURES --The dominant h and of the child was assessed by 10 questions . Deficits in attention , motor control , and perception were evaluated by five questions . Impaired neurological development during the first year of life was assessed by an abbreviated version of the Denver developmental screening test . RESULTS --The odds of non-right h and edness were higher among children who had been screened in utero than among control children ( odds ratio 1.32 ; 95 % confidence interval 1.02 to 1.71 ) . No clear differences were found between the groups with regard to deficits in attention , motor control , and perception or neurological development during the first year of life . CONCLUSION --Our data suggest a possible association between  routine ultrasonography  in utero and subsequent non-right h and edness , whereas no association with impaired neurological development was found . As the question on non-right h and edness was one of six initial hypotheses , the observed results may be due to chance . None the less , the results suggest that the hypothesis may have some merit and should be tested in future studies OBJECTIVE To prospect ively assess the contribution of a high-frequency linear transducer and of moving target indicator ( MTI ) filtered color flow mapping in the visualization of cardiac fetal anatomy at the routine 11 to 13 + 6-week scan . METHODS This was a cross-sectional prospect i ve study , including 300 singleton fetuses at 11 to 13 + 6 weeks ' gestation . Patients were r and omized into four groups and a detailed fetal cardiac examination was conducted transabdominally using either a conventional curvilinear transducer , a conventional curvilinear transducer and MTI filtered color flow mapping , a high-frequency linear transducer or a high-frequency linear transducer and MTI filtered color flow mapping . Regression analysis was used to investigate the effect on the ability to visualize different cardiac structures of the following parameters : gestational age at ultrasound examination ; fetal crown-rump length ( CRL ) ; maternal body mass index ( BMI ) ; transducer-heart distance ; the technique used at ultrasound ; and the position of the placenta . RESULTS The four-chamber view was visualized in 89.0 % of fetuses and regression analysis showed this rate was correlated with CRL and the use of MTI filtered color flow mapping during ultrasonography , and inversely correlated with BMI and transducer-heart distance . Use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the four-chamber view in 97.3 % of fetuses , while this was only possible in 84.0 % of fetuses using a high-frequency linear transducer . The left and right outflow tracts were visualized in 62.3 and 57.7 % of fetuses , respectively . Regression analysis showed that the ability to visualize the left or the right outflow tract was correlated with the use of MTI filtered color flow mapping during scanning and was inversely correlated with transducer-heart distance . The use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the left and right outflow tracts in 96.0 and 97.3 % of fetuses , respectively , while this was only possible in 37.3 and 26.7 % of fetuses using a high-frequency linear transducer . CONCLUSIONS During the routine 11 to 13 + 6-week scan , the use of MTI filtered color flow mapping but not of a high-frequency linear transducer , improves visualization of cardiac anatomy The study was performed to investigate any associations between routine ultrasonography during pregnancy and subsequent reduced vision and /or hearing among children .  A follow-up was carried out of primary school children born to women who took part in two r and omized , controlled trials of routine ultrasonography during pregnancy . Of 2428 eligible singletons , 2161 ( 89 % ) were followed up with a parental question naire and with information from maternal and child health centers . Parents assessed vision and hearing in their children and reported their observations in question naires . At the age of 7 years , the children were also screened with bilateral visual acuity tests and pure tone audiometry  at public maternal and child health centers . No significant differences between ultrasound-screened children and their controls were found in the parental assessment of vision or hearing . The objective tests did not show any significant differences between children in the two groups with regard to visual acuity or hearing . The risk of reduced vision or hearing was no greater for children of mothers who had been offered routine ultrasonography during pregnancy than for those whose mothers had not received that offer Routine pregnancy ultrasound screening is frequently the norm in affluent societies . This open cluster r and omized trial was done to investigate the effect of routine second trimester ultrasound on obstetric management and pregnancy outcomes in a re source -constrained setting . The study was conducted in a peri-urban health district serving a working class population . The service does not offer routine ultrasound screening .  Participants included women with low risk pregnancies at 18 - 23 weeks by clinical estimation . R and omization was to ultrasound screening ( USS ) or no ultrasound ( controls ) . A cluster was defined as all eligible women presenting for prenatal care on a single day . Scans were done by an experienced licensed ultrasonographer . Both groups received further routine care from their institutions . Statistical comparisons employed Chi-squared and Fishers exact tests for categorical variables and Students t-test and Mann-Whitney test for continuous variables and calculation of relative riskswith 95 % confidence intervals . ( excerpt OBJECTIVE To assess whether the addition of four-dimensional ( 4D ) ultrasound to a conventional two-dimensional ( 2D ) scan in the second/third trimester of pregnancy facilitates maternal recognition of specific fetal structures and movements and causes an emotional impact , as subjectively perceived by the woman . METHODS Fifty-two women were r and omly assigned to 2D ultrasound only ( Group 1 ) , while 48 women underwent 2D plus 4D ultrasound ( Group 2 ) . All the women completed two question naires . One question naire listed the fetal structures and movements that the women had recognized during the 2D scan or , for those women who also underwent a 4D scan , during the combination of the two ; the other question naire required the women to score on an analog scale whether they had seen all the fetal parts and movements that they wished to see , whether they were satisfied with the scan , and if the scan had changed for the better their perception of the fetus . A subgroup of 46 women completed the Maternal Antenatal Attachment Scale ( MAAS ) design ed to measure antenatal emotional attachment . RESULTS Similar percentages of women in the two groups visualized fetal structures and movements , but facial expressions and h and -to-mouth movements were twice as likely to be seen with 4D ultrasound , although this difference did not reach statistical significance . The percentage of women who reported that they had seen all the fetal parts and movements that they wished to see , and of those who were satisfied overall with the scan , were similar in the two groups . There was no difference in the percentage of women who felt that the scan had changed for the better their perception of the fetus . Although the MAAS scores were similar in the two groups , there were more women with positive quality , intensity and global attachment among those who had undergone a 4D scan . Women who had seen all the fetal parts and movements they wished to see ( whether with 2D or 2D plus 4D ) answered more frequently that the scan had changed for the better their perception of the fetus . CONCLUSION This r and omized study indicates that the addition of 4D ultrasound does not change significantly the perception that women have of their baby nor their antenatal emotional attachment compared with conventional 2D ultrasound During a 19-month period , 95 % of all pregnant women in the greater Helsinki area , Finl and , entered a study to compare one-stage ultrasonography screening with selective screening according to antenatal hospital use , obstetric procedures , and fetal outcomes . Of 9310 women who entered the trial , 4691 were r and omly allocated to ultrasound screening between the 16th and 20th gestational weeks and 4619 to follow-up only . Screened and control groups otherwise had the same antenatal care , which included ultrasonography according to usual practice . Screened women made fewer visits to the antenatal outpatient clinic than did women in the control group ( 2.3 vs 2.6 ) . There were no differences in the number of labour inductions or mean birthweights in the two groups . Perinatal mortality was significantly lower in the screened than in the control group ( 4.6/1000 vs 9.0/1000 ) ; this 49.2 % reduction was mainly due to improved early detection of major malformations which led to induced abortion . All twin pregnancies were detected before the 21st gestational week in the screening group compared with 76.3 % in the control group ; perinatal mortality in the small series of twins was 27.8/1000 vs 65.8/1000 , respectively OBJECTIVES This r and omized clinical trial of 15,530 women was design ed to test the hypothesis that screening ultrasonography in low-risk pregnancies would improve perinatal outcome . A secondary hypothesis addressed in this article was that screening ultrasonography would have a favorable impact on maternal management or outcome . STUDY DESIGN Pregnant women without a specific indication for ultrasonographic examination in early pregnancy were r and omly assigned to have either two screening sonograms or conventional obstetric care . Pregnancy interventions and maternal out 
    Output:
    
Routine scans do not seem to be associated with reductions in adverse outcomes for babies or in health service use by mothers and babies .
Long-term follow-up of children exposed to scan in utero does not indicate that scans have a detrimental effect on children 's physical or cognitive development .
Early ultrasound improves the early detection of multiple pregnancies and improved gestational dating may result in fewer inductions for post maturity .