Universal vs. risk factor-based screening for gestational diabetes mellitus: detection rates, gestation at diagnosis and outcome. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. Insulin-requiring diabetes in pregnancy: a randomized trial of active induction of labor and expectant management.
Gestational diabetes mellitus (GDM) is associated with adverse maternal and fetal outcome. Screening for GDM is therefore recommended but the best screening method remains controversial. This prospective, randomized study compared a risk factor-based screening programme with a universally based one.
                Subjects were randomized at booking to one of two groups: the risk factor group had a 3-h 100-g oral glucose tolerance test (OGTT) at 32 weeks if any risk factor for GDM was present; the universal group had a 50-g glucose challenge test performed and if their plasma glucose at 1 h was > or = 7.8 mmol/l, a formal 3-h 100-g OGTT was then performed.
                Universal screening detected a prevalence of GDM of 2.7%, significantly more than the 1.45% detected in the risk factor screened group (P<0.03). Universal screening facilitated earlier diagnosis than risk factor screening - mean gestation 30 +/- 2.6 weeks vs. 33 +/- 3.7 weeks (P<0.05). A higher rate of spontaneous vaginal delivery at term, and lower rates of macrosomia, Caesarean section, prematurity, pre-eclampsia and admission to neonatal intensive care unit were observed in the universally screened, early diagnosis group.
                Universal screening for GDM is superior to risk factor based screening-detecting more cases, facilitating early diagnosis and is associated with improved pregnancy outcome. We conducted a randomized clinical trial to determine whether treatment of women with gestational diabetes mellitus reduced the risk of perinatal complications.
                We randomly assigned women between 24 and 34 weeks' gestation who had gestational diabetes to receive dietary advice, blood glucose monitoring, and insulin therapy as needed (the intervention group) or routine care. Primary outcomes included serious perinatal complications (defined as death, shoulder dystocia, bone fracture, and nerve palsy), admission to the neonatal nursery, jaundice requiring phototherapy, induction of labor, cesarean birth, and maternal anxiety, depression, and health status.
                The rate of serious perinatal complications was significantly lower among the infants of the 490 women in the intervention group than among the infants of the 510 women in the routine-care group (1 percent vs. 4 percent; relative risk adjusted for maternal age, race or ethnic group, and parity, 0.33; 95 percent confidence interval, 0.14 to 0.75; P=0.01). However, more infants of women in the intervention group were admitted to the neonatal nursery (71 percent vs. 61 percent; adjusted relative risk, 1.13; 95 percent confidence interval, 1.03 to 1.23; P=0.01). Women in the intervention group had a higher rate of induction of labor than the women in the routine-care group (39 percent vs. 29 percent; adjusted relative risk, 1.36; 95 percent confidence interval, 1.15 to 1.62; P<0.001), although the rates of cesarean delivery were similar (31 percent and 32 percent, respectively; adjusted relative risk, 0.97; 95 percent confidence interval, 0.81 to 1.16; P=0.73). At three months post partum, data on the women's mood and quality of life, available for 573 women, revealed lower rates of depression and higher scores, consistent with improved health status, in the intervention group.
                Treatment of gestational diabetes reduces serious perinatal morbidity and may also improve the woman's health-related quality of life. Our purpose was to assess whether a program of expectant management of uncomplicated pregnancies in mothers with insulin-requiring gestational or pregestational class B reduces the incidence of cesarean birth.
                Two hundred women with uncomplicated, insulin-requiring diabetes at 38 weeks' gestation who were compliant with care and whose infants were judged appropriate for gestational age were randomly assigned to (1) active induction of labor within 5 days or (2) expectant management. The expectant management group was monitored with weekly physical examination and twice-weekly nonstress tests and amniotic fluid volume estimation until delivery.
                Expectant management increased the gestational age at delivery by 1 week. Approximately half (49%) of the mothers in the expectant management group required induction of labor for obstetric indications. The cesarean delivery rate was not significantly different in the expectant management group (31%) from the active induction group (25%). The mean birth weight (3672 +/- 407 gm) and percentage large for gestational age, as defined by birth weight > or = 90th percentile, of infants in the expectantly managed group (23%) was greater than those in the active induction group (3466 +/- 372 gm, p < 0.0001, 10% large for gestational age). This difference persisted after controlling for gestational age and maternal age and body weight (p < 0.01).
                In women with uncomplicated insulin-requiring gestational or class B pregestational diabetes, expectant management of pregnancy after 38 weeks' gestation did not reduce the incidence of cesarean delivery. Moreover, there was an increased prevalence of large-for-gestational-age infants (23% vs 10%) and shoulder dystocia (3% vs 0%). Because of these risks, delivery should be contemplated at 38 weeks and, if not pursued, careful monitoring of fetal growth must be performed.
There was insufficient evidence to determine if screening for gestational diabetes, or what types of screening, can improve maternal and infant health outcomes.