***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 To compare the degree of insulin resistance in women with gestational diabetes mellitus ( GDM ) who do and do not develop preeclampsia . RESEARCH DESIGN AND METHODS We conducted a prospect i ve cohort study of initially normotensive women with GDM who underwent oral glucose tolerance tests ( OGTTs ) , intravenous glucose tolerance tests ( IVGTTs ) , and glucose clamp studies in the early third trimester ( n = 150 ) and 15 months postpartum ( n = 89 ) . After delivery , the women were categorized as nonpreeclamptic or preeclamptic ( systolic blood pressure [ SBP ] > or = 140 mmHg , diastolic blood pressure [ DBP ] > or = 90 mmHg , and at least > 1 + proteinuria or > 300 mg/24 h ) . Metabolic parameters between the groups were compared by chi2 or Fisher 's exact tests and ANOVA with P < 0.05 as significant . RESULTS A total of 29 women ( 19 % ) developed preeclampsia , which was mild in 21 and severe in 8 women . At entry , there were no differences in age , weight indexes , and glycemic measures between the nonpreeclamptic and preeclamptic groups . Those with preeclampsia were significantly taller ( 61.5 + /- 2.4 vs. 60.1 + /- 2.3 in , P = 0.003 ) , were more often nulliparous ( 38 vs. 16 % , P = 0.01 ) , and had higher entry SBP ( 112 + /- 10 vs. 103 + /- 6.9 mmHg , P < 0.0001 ) and DBP ( 64 + /- 9 vs. 59 + /- 5 mmHg , P = 0.002 ) . No significant differences between the groups were found in any measures of the OGTT glucose levels , insulin sensitivity index , glucose effectiveness , acute response to glucose , or disposition index , nor were there any differences found in the euglycemic clamp measures of basal or steady-state levels of glucose , insulin , free fatty acid , hepatic glucose output , peripheral glucose clearance , C-peptide , or glucagon . At 15 months postpartum , blood pressure levels remained significantly higher in the preeclamptic group ( n = 19 ) compared with the nonpreeclamptic group ( n = 70 ) . No differences in any glycemic or insulin resistance measures were found . CONCLUSIONS Women with GDM were uniformly insulin resistant . Those who developed preeclampsia , when compared with those who remained nonpreeclamptic , were not more insulin resistant in either the third trimester or 15 months postpartum . However , women who developed preeclampsia had blood pressure levels that were significantly higher , although still in the normal range , than those of women who remained nonpreeclamptic BACKGROUND Investigation of a possible effect of metformin on and rogen levels in pregnant women with polycystic ovary syndrome ( PCOS ) . METHODS A prospect i ve , r and omized , double-blind , placebo-controlled pilot study was conducted . Forty pregnant women with PCOS received diet and lifestyle counselling  and were r and omized to either metformin 850 mg twice daily or placebo . Primary outcome measures were changes in serum levels of dehydroepi and rosterone sulphate , and rostenedione , testosterone , sex hormone-binding globulin , and free testosterone index . Secondary outcome measures were pregnancy complications and outcome . Two-tailed t-tests and chi2-tests were used . RESULTS Maternal and rogen levels were unaffected by metformin treatment in pregnant women with PCOS . While none of the 18 women in the metformin group experienced a severe pregnancy or post-partum complication , seven of the 22 ( 32 % ) women experienced severe complications in the placebo group ( P = 0.01 ) . CONCLUSIONS Metformin treatment did not reduce maternal and rogen levels in pregnant women with PCOS . In the metformin-treated group we observed a reduction of severe , pregnancy and post-partum complications .  Metformin treatment of pregnant PCOS women may reduce complications during pregnancy and in the post-partum period AIM OF STUDY To evaluate the 50 g glucose challenge test as a screening tool for gestational diabetes in pregnant women with no risk factors , to determine the prevalence of gestational diabetes in this population and to determine the perinatal outcomes of pregnancy according to the glucose challenge test . METHODOLOGY A descriptive prospect i ve study . A total of 146 patients with no risk factors who booked a particular obstetrician and delivered between May 1996 and April 1997 were recruited . Pregnancy outcomes were assessed by the gestation and mode of delivery , neonatal outcomes included birth weights , apgar scores and other neonatal complications . RESULTS The detected incidence of gestational diabetes was 8.2 % . With the threshold plasma glucose level at 7.1 mmol/l , 53 women or 36 % needed to undergo the 75 g oral glucose tolerance test and 12 women were found to have gestational diabetes . The diagnostic yield was 22.6 % . With 7.8 mmol/l as the threshold value , 28 women or 20 % needed the oral glucose tolerance test and eight women with gestational diabetes were detected . The diagnostic yield was 28.6 % . Perinatal outcome for these diabetic women who were well-controlled during pregnancy was similar to the rest of the women with normal glucose challenge test . CONCLUSIONS The 50 g glucose challenge test is a useful screening test for diabetes in Singaporean women with no risk factors . A threshold value at 7.8 mmol/l with a smaller number of women requiring the 75 g oral glucose challenge test may be more acceptable OBJECTIVE Our purpose was to assess maternal-fetal outcomes in patients with increasing carbohydrate intolerance not meeting the current criteria for the diagnosis of gestational diabetes . STUDY DESIGN We conducted a prospect i ve analytic cohort study in which nondiabetic women aged > or = 24 years , receiving prenatal care in three Toronto teaching hospitals , were eligible for enrollment . A glucose challenge test and an oral glucose tolerance test were administered at 26 and 28 weeks ' gestation , respectively ; risk factors for unfavorable maternal-fetal outcomes were recorded . Caregivers and patients were blinded to glucose values except when test results met the current criteria for gestational diabetes . RESULTS Of 4274 patients screened , 3836 ( 90 % ) continued to the diagnostic oral glucose tolerance test . The study cohort was formed by the 3637 ( 95 % ) patients without gestational diabetes , carrying singleton fetuses . Increasing carbohydrate intolerance in women without overt gestational diabetes was associated with a significantly increased incidence of cesarean sections , preeclampsia , macrosomia , and need for phototherapy , as well as an increased length of maternal and neonatal hospital stay . Multivariate analysis showed that increasing carbohydrate intolerance is an independent predictor for various unfavorable outcomes . CONCLUSION Increasing maternal carbohydrate intolerance in pregnant women without gestational diabetes is associated with a grade d increase in adverse maternal-fetal outcomes OBJECTIVES To assess the prevalence and association of frequently used screening risk factors for gestational diabetes mellitus ( GDM ) and to compare the validity and cost of universal screening with risk factor screening . METHOD A cross-sectional survey of 768 pregnant women at > or = 24 weeks ' gestation who were attending the antenatal clinic at the Hospital Universiti Kebangsaan Malaysia ( HUKM ) was made . Risk factors were determined using a question naire . An abnormal oral glucose tolerance test was defined as a 2-h post-pr and ial blood sugar level of > or = 7.8 mmol/l . RESULTS A total of 191 pregnant mothers ( 24.9 % ) had GDM . The most commonly identified screening factors were positive family history of diabetes mellitus ( 31.4 % ) , history of spontaneous abortion ( 17.8 % ) , vaginal discharge and pruritus vulvae in current pregnancy ( 16.0 % ) , and maternal age greater than 35 years ( 14.7 % ) . Five hundred and thirteen mothers ( 66.8 % ) had at least one risk factor . All screening risk factors , except past history of diabetes mellitus in previous pregnancy and maternal age , were not significantly associated with abnormal glucose tolerance ( GT ) .  Risk factor screening gave a sensitivity of 72.2 % and a specificity of 35.0 % . Universal screening would cost RM 12.06 while traditional risk factor screening would cost RM 11.15 per identified case and will have missed 53 of the 191 cases . CONCLUSIONS Risk factor screening scored poorly in predicting GDM . Cost analysis of universal compared with traditional risk factor screening showed a negligible difference . Thus universal screening appears to be the most reliable method of diagnosing GDM The relationship between pregnancy‐induced hypertension ( and pre‐eclampsia ) and gestational glucose intolerance was examined prospect ively in 81 women with gestational diabetes mellitus . A borderline group consisted of 203 women with a single abnormal value on an oral glucose tolerance test . Controls consisted of 327 healthy women with normal glucose tolerance test at 28–32 weeks of gestation . The women with gestational diabetes were older ( p > 0.01 ) and their prepregnancy weight and body mass index were higher ( p > 0.001 ) than those in the control group . Also the women in the borderline group had higher prepregnancy weight ( p > 0.01 ) and body mass index ( p > 0.001 ) than the women in the control group . However , the pregnancy weight gain was lower in the gestational diabetics than in the control women ( p > 0.001 ) . Birth weight , birth trauma , low Apgar scores and hypoglycemia did not differ between the groups . However , hyperbilirubinemia occurred more frequently ( 28.4 % vs. 3.7 % , p > 0.001 ) in the gestational diabetics than in the controls . The frequency of both chronic hypertension ( 2.5 % vs. 0.3 % , p > 0.05 ) and pregnancy induced hypertension and pre‐eclampsia ( 19.8 % vs. 6.1 % , p > 0.001 ) were higher in the gestational diabetes group , but not in the borderline group when compared with the controls Aim The efficacy and safety of insulin aspart ( IAsp ) , a rapid-acting human insulin analogue , were compared with regular human insulin ( HI ) as the bolus component of basal-bolus therapy for subjects with gestational diabetes mellitus ( GDM ) . Methods In a r and omized , parallel-group , open-labelled trial , 27 women with GDM ( age 30.7 ± 6.3 years , HbA1c < 7 % ) were r and omized to receive IAsp ( 5 min before meal ) or HI ( 30 min before meal ) . The trial period extended from diagnosis of GDM ( 18–28 weeks ) to 6 weeks postpartum . Results Both treatment groups maintained good overall glycaemic control during the study ( beginning and end of study HbA1c≤ 6 % ) . During the meal test , mean glucose at week 6 ( IAsp 4.2 ± 0.57 mmol/l , HI 4.8 ± 0.86 mmol/l ) was slightly lower than at week 0 ( IAsp 4.9 ± 0.59 mmol/l , HI 5.1 ± 0.36 mmol/l ) . However , change from baseline values for average glucose ( IAsp –1.09 ± 0.54 mmol/l , HI –0.54 ± 0.74 mmol/l ; P = 0.003 ) and C-peptide ( IAsp –0.50 ± 0.67 nmol/l , HI –0.30 ± 0.70 nmol/l ; P = 0.027 ) were significantly lower after IAsp treatment than HI treatment . No major hypoglycaemic events were reported during the study . Cross-reacting insulin antibody binding increased slightly from baseline in both treatments groups ( end of study : IAsp 2.1 ± 5.4 % , HI 6.4 ± 13.9 % ) , whereas antibodies specific to IAsp or HI remained relatively low ( < 1 % binding ) . Conclusion IAsp was more effective than HI in decreasing postpr and ial glucose concentrations . Duration of IAsp injection 5 min before a meal rather than 30 min prior to meals offers a more convenient therapy for subjects with GDM . Overall safety and effectiveness of IAsp were comparable to HI in pregnant women with GDM . Diabet . Med . 24 , 1129–1135 ( 2007 OBJECTIVE To evaluate whether there is increased maternal or neonatal morbidity in 
    Output:
    
Key questions : 1 ) Does screening for gestational diabetes lead to a reduction in perinatal morbidity and mortality for mother or infant ?
Summary of Evidence Key Question 1 Does screening for gestational diabetes lead to a reduction in perinatal morbidity and mortality for mother or infant ?
A ) After 24 weeks ' gestation ?
B ) During the first trimester and up to 24 weeks ' gestation ?
Key Question 2 What are the sensitivities , specificities , reliabilities , and yields of current screening tests for gestational diabetes ?
A ) After 24 weeks ' gestation ?