Carol A. Major

Postprandial versus Preprandial Blood Glucose Monitoring in Women with Gestational Diabetes Mellitus Requiring Insulin Therapy

BACKGROUNDnThe fetuses of women with gestational diabetes mellitus are at risk for macrosomia and its attendant complications. The best method of achieving euglycemia in these women and reducing morbidity in their infants is not known. We compared the efficacy of postprandial and preprandial monitoring in achieving glycemic control in women with gestational diabetes.nnnMETHODSnWe studied 66 women with gestational diabetes mellitus who required insulin therapy at 30 weeks of gestation or earlier. The women were randomly assigned to have their diabetes managed according to the results of preprandial monitoring or postprandial monitoring (one hour after meals) of blood glucose concentrations. Both groups were also monitored with fasting blood glucose measurements. The goal of insulin therapy was a preprandial value of 60 to 105 mg per deciliter (3.3 to 5.9 mmol per liter) or a postprandial value of less than 140 mg per deciliter (7.8 mmol per liter). Obstetrical data and information on neonatal outcomes were collected.nnnRESULTSnThe prepregnancy weight, weight gain during pregnancy, gestational age at the diagnosis of diabetes and at delivery, degree of compliance with therapy, and degree of achievement of target blood glucose concentrations were similar in the two groups. The mean (+/- SD) change in the glycosylated hemoglobin value was greater in the group in which postprandial measurements were used (-3.0 +/- 2.2 percent vs. 0.6 +/- 1.6 percent, P < 0.001) and the infants birth weight was lower (3469 +/- 668 vs. 3848 +/- 434 g, P = 0.01). Similarly, the infants born to the women in the postprandial-monitoring group had a lower rate of neonatal hypoglycemia (3 percent vs. 21 percent, P = 0.05), were less often large for gestational age (12 percent vs. 42 percent, P = 0.01) and were less often delivered by cesarean section because of cephalopelvic disproportion (12 percent vs. 36 percent, P = 0.04) than those in the preprandial-monitoring group.nnnCONCLUSIONSnAdjustment of insulin therapy in women with gestational diabetes according to the results of postprandial, rather than preprandial, blood glucose values improves glycemic control and decreases the risk of neonatal hypoglycemia, macrosomia, and cesarean delivery.

The effects of carbohydrate restriction in patients with diet-controlled gestational diabetes.

Objective To determine the effect of carbohydrate restriction on perinatal outcome in patients with diet-controlled gestational diabetes mellitus (GDM). Methods Women with diet-controlled GDM were divided non-randomly into two groups based on their dietary carbohydrate content: those with low dietary carbohydrate content (below 43%) and those with high dietary carbohydrate content (exceeding 45%). Subjects kept dietary accounts and were followed with daily fasting and postprandial glucose assessments. Subjects also were tested daily for urinary ketones. Glycosylated hemoglobin, mean fasting and postprandial glucose values, incidence of macrosomia and large for gestational age (LGA) infants, cesarean deliveries for cephalopelvic disproportion and macrosomia, and need for insulin therapy were compared between the groups. Results The two groups were identical in terms of demographic characteristics. Significant reductions in the postprandial glucose values were seen among subjects in the low-carbohydrate group (P < .04). Fewer subjects in the low-carbohydrate group required the addition of insulin for glucose control (P < .047; relative risk [RR] 0.14; 95% confidence interval [CI] 0.02, 1.00). The incidence of LGA infants was significantly lower in the low-carbohydrate group (P < 0.35; RR 0.22; 95% CI 0.05. 0.91). Subjects in the low carbohydrate group also had a lower rate of cesarean deliveries for cephalopelvic disproportion and macrosomia (P < .037; RR 0.15; 95% CI 0.04, 0.94). Conclusion Carbohydrate restriction in patients with diet-controlled GDM results in improved glycemic control, less need for insulin therapy, a decrease in the incidence LGA infants, and a decrease in cesarean deliveries for cephalopelvic disproporftion and macrosomia.

Gestational diabetes: Does the presence of risk factors influence perinatal outcome?

OBJECTIVEnOur purpose was to determine whether gestational diabetics with risk factors for gestational diabetes have worse glucose tolerance and poorer birth outcomes than those without risk factors.nnnSTUDY DESIGNnWe conducted a nonconcurrent cohort study of gestational diabetics identified by universal screening and delivered from Jan. 1, 1990, to Dec. 31, 1992. Multiple gestations and patients with chronic medical conditions were excluded. The following risk factors for gestational diabetes mellitus were abstracted: obesity (> 80 kg), family history of diabetes, previous gestational diabetes mellitus, and previous macrosomic, stillborn, or anomalous fetus. Patients with one or more risk factors were compared with those without risk factors. A group of low-risk nondiabetic patients served as controls. The incidences of A2 diabetes mellitus, cesarean section, neonatal macrosomia, and shoulder dystocia were the outcome variables of interest.nnnRESULTSnSelective screening would have failed to detect 43% of gestational diabetics. Twenty-eight percent of the missed gestational diabetics would have required insulin (class A2). When compared with controls, patients with gestational diabetes mellitus were at increased risk for macrosomia (26% vs 11%, p < 0.01), cesarean section (37% vs 15%, p < 0.01), and shoulder dystocia (9% vs 2%, p < 0.05). Patients with and without risk factors did not differ in mean maternal age, gestational age at delivery, birth weight, incidence of requiring insulin, macrosomia, or cesarean delivery. The similarities between those with and without risk factors remained after stratification by maternal age (> or = 30 years).nnnCONCLUSIONnGestational diabetics are at increased risk for adverse birth outcomes compared with low-risk controls. Class A2 diabetes mellitus and fetal macrosomia with its attendant risks are equally prevalent among patients with and without risk factors for gestational diabetes mellitus. Because > 40% of cases will be missed with selective screening, universal screening should be favored for detection of gestational diabetes mellitus.

Fetal gastroschisis and omphalocele: Is cesarean section the best mode of delivery?

There has always been controversy regarding the mode of delivery of fetuses with abdominal wall defects. Prior studies may have been biased in this evaluation as a result of the effects of delay in repair, transport of the fetus to level III facilities, and antenatal diagnosis compared with an unsuspected diagnosis. The purpose of this study was to evaluate mode of delivery at level III institutions with access to complete care to determine if cesarean section improved outcome. One hundred eight infants were treated in the study period for abdominal wall defects. Fifty-six infants met all criteria for admission to the study. No difference in neonatal morbidity or mortality was identified. No difference was found in infants who were born by elective cesarean section compared with infants delivered after labor ensued. In conclusion, we found no evidence that cesarean section or avoidance of labor improved outcome in fetuses with uncomplicated abdominal wall defects.

Preterm premature rupture of membranes and abruptio placentae: Is there an association between these pregnancy complications?

OBJECTIVEnOur purpose was to determine whether the incidence of abruptio placentae is increased in pregnancies with preterm premature rupture of membranes and to assess whether certain clinical risk factors in this group predispose them to have abruptio placentae.nnnSTUDY DESIGNnA retrospective cohort study over a 2.5-year period was performed. The study group consisted of 756 singleton pregnancies between 20 and 36 weeks gestation complicated by preterm premature rupture of membranes and managed expectantly. The control group consisted of 11,240 pregnancies not complicated by preterm premature rupture of membranes and delivered during the same time period. The incidence of abruptio placentae was compared between the two groups. The study group of patients with preterm premature rupture of membranes was further subdivided into cases with (n = 38) and without abruptio placentae (n = 718) and compared. Clinical factors such as admission amniotic fluid index, history of bleeding before or after rupture of membranes, incidence of intrapartum fetal distress, and low 5-minute Apgar scores (< 6), latency-to-delivery interval, gestational age and weight at delivery, and incidence of amnionitis and endometritis were compared.nnnRESULTSnThe incidence of abruptio placentae in the study group (38/756, 5%) was significantly higher than that in the control group (97/11, 240, 0.9%) (p < 0.001, odds ratio = confidence interval). Comparison of cases with preterm premature rupture of membranes with and without abruptio placentae demonstrated both groups to have a similar gestational age at delivery, birth weight, latency-to-delivery interval, amniotic fluid index, and infectious morbidity. The group with abruptio placentae had a significantly higher incidence of bleeding before rupture of membranes (six of 38, 15% vs eight of 718, 1%; p < 0.005) and of intrapartum fetal distress (18/38, 46% vs 49/718, 7%; p < 0.0009).nnnCONCLUSIONSnPregnancies complicated by preterm premature rupture of membranes that are managed expectantly are at significant risk for abruptio placentae. Preterm premature rupture of membranes in such cases is more often preceded by bleeding. These abruptions may predispose the patient to intrapartum fetal distress.

Sonographic prediction of shoulder dystocia in infants of diabetic mothers

Objective To determine if the difference between the abdominal diameter and biparietal diameter (AD-BPD difference), as measured by ultrasound examination, predicts shoulder dystocia in borderline macrosomic infants of diabetic mothers. Methods A retrospective study was performed of births occurring from January 1990 through June 1995. Eligibility requirements included diabetic pregnancy, ultrasound examination within 2 weeks of delivery, estimated fetal weight of 3800–4200 g, and vaginal delivery. The mean AD-BPD difference was compared in normal deliveries and those complicated by shoulder dystocia, using the Student t test and by multiple regression analysis. A receiver operating characteristic curve was generated to determine if an ADBPD cutoff value could be used clinically to predict shoulder dystocia. Results Thirty-one patients, six with dystocia, were eligible for the study. The mean AD-BPD differences for those with and without shoulder dystocia were 3.1 and 2.6 cm, respectively, a statistically significant difference (P = .05). Comparing the groups with and without shoulder dystocia, no significant differences could be found in mean age, parity, weight, birth weight, or gestational age. Shoulder dystocia occurred in six of 20 patients (30%) in whom the AD-BPD difference was at least 2.6 cm but in none of 11 patients in whom it was less than 2.6 cm, also a statistically significant difference (P = .05). Conclusion The AD-BPD difference was greater in borderline macrosomic fetuses of diabetic mothers who experienced shoulder dystocia than in those who had uncomplicated vaginal deliveries. Applying an AD-BPD cutoff value of 2.6 cm to this population prospectively would have provided excellent sensitivity, specificity, and predictive value in identifying those fetuses at high risk for birth injury.

Rate of recurrence of preterm premature rupture of membranes in consecutive pregnancies

The reported incidence of preterm premature rupture of membranes ranges between 1% and 2% of all pregnancies. The rate of recurrence is poorly defined. The goal of this study was to establish the frequency of recurrence in a high-risk referral practice. Over a 5-year period we identified 121 patients with preterm premature rupture of membranes who had a minimum of two consecutive pregnancies under our care, resulting in a total of 255 pregnancies for analysis. Recurrent preterm premature rupture of membranes occurred in 39 of 121 patients, for a rate of 32.2% (95% confidence interval, 23.9 +/- 40.5). We were unable to demonstrate an association between the estimated gestational age at the time of rupture in the index pregnancy, latency period, interval between pregnancies, and the probability of repeat preterm premature rupture of membranes in the next pregnancy. We conclude that patients with preterm premature rupture of membranes should be counseled regarding the significant risk of recurrence and need to have close follow-up in their subsequent pregnancies.

Accuracy of Self-Monitoring of Blood Glucose: Impact on Diabetes Management Decisions During Pregnancy

PURPOSE This study tested the hypothesis that the accuracy of self-monitoring of blood glucose (SMBG) values of patients with diabetes during pregnancy deviates substantially from reference values. METHODS The patients glucose values were measured on 6 different SMBG meters; reference values were from the HemoCue B Glucose Analyzer. Over a 5-year period, 1973 comparisons between SMBG values and reference values were recorded during clinic visits and used for this study. Data were analyzed for percent of values that varied more than ±10.5% and ±15.5% from the reference value. Out-of-range data at each variance level were analyzed to determine the impact on medical management if decisions were based solely on SMBG values. RESULTS One third of SMBG readings deviated significantly, which could adversely affect treatment for half of these patients if diabetes management was based on SMBG values. At the 10.5% deviation level, 34% of SMBG meter readings were out of range; 54% of these would have implied erroneous treatment. At the 15.5% deviation level, 18% were out of range; 63% of these would have implied erroneous management. CONCLUSIONS The accuracy of home meters should be verified at regular intervals, and SMBG values should not be the sole criterion for diabetes management during pregnancy.

Pulmonary injury associated with appendicitis in pregnancy: Who is at risk?

OBJECTIVEnOur purpose was to determine risk factors for pulmonary injury in women with antepartum appendicitis.nnnSTUDY DESIGNnThis case-control study included 49 patients with appendicitis during pregnancy. Patients who had pulmonary injury composed the study group (n = 9); the control subjects had no injury (n = 40). Records were abstracted for gestational age at surgery, type of anesthesia, presenting symptoms, findings on physical examination, vital signs, laboratory test results, use of tocolytics or antibiotics, and fluid management. Pulmonary injury was characterized by dyspnea, tachypnea, PaO2 < or = 70 mm Hg, and an abnormality on chest radiography.nnnRESULTSnPulmonary injury developed in nine study patients (18%) (adult respiratory distress syndrome, n = 2; pulmonary edema or infiltrates, n = 7) as a complication of appendicitis during pregnancy. All study group patients were at > 20 weeks gestation compared with 27 of 40 (67%) control subjects (p = 0.05). Univariate analysis showed that fluid overload > or = 4 L, maximum respiratory rate > 24 breaths/min, maximum heart rate > 110 beats/min, maximum temperature > or = 100.4 degrees F, general anesthesia, and tocolytic use were significant (p < 0.005). By multivariate analysis with the use of stepwise logistic regression a model of fluid overload > or = 4 L, respiratory rate > 24 breaths/min, maximum temperature > or = 100.4 degrees F, and tocolytic usage would predict 99% of injury cases.nnnCONCLUSIONSnIatrogenic factors such as injudicious fluid management and tocolytic use can greatly increase the risk for pulmonary injury with antepartum appendicitis.

Color flow Doppler-A useful instrument in the diagnosis of vasa previa

Vasa previa is associated with an increased perinatal mortality rate and rarely is diagnosed in the antepartum period. We present a case in which vasa previa was correctly diagnosed by use of color flow Doppler imaging. This modality is a valuable adjunct in the evaluation of patients suspected to have vasa previa.