Clinical management of the fetus with markedly diminished umbilical artery end-diastolic flow

This study was conducted to evaluate prospectively a management protocol for fetuses with a markedly abnormal umbilical artery velocity waveform. The study population consisted of fetuses whose systolic/diastolic ratio was greater than 2 SD above the mean for gestational age. The matched control population consisted of fetuses with similar gestational ages, indications for testing, and estimated fetal weights with normal systolic/diastolic ratios. Abnormal Doppler results were used only to determine the frequency of fetal testing. Biophysical profile testing was performed semiweekly on all patients. Patients with absent or reversed end-diastolic flow were admitted for daily testing. The following criteria were used as indications for delivery: (1) worsening maternal condition, (2) oligohydramnios, (3) intrauterine growth retardation with lung maturity, and (4) biophysical profile score less than or equal to 4. Fifty-one patients (7%) had abnormal Doppler blood flow velocity studies. When the study population was compared with the control population at the time of delivery, there were no differences in umbilical artery pH, Apgar score, or incidence of intrauterine growth retardation. However, study patients were delivered at a significantly lower gestational age and lower birth weight and experienced a higher likelihood of neonatal intensive care unit admission. When study patients with documented end-diastolic flow were compared with study patients with no end-diastolic flow, there were no differences in umbilical artery pH, Apgar score, or incidence of intrauterine growth retardation. However, fetuses with no end-diastolic flow had a significantly shorter test-to-delivery interval, lower gestational age, lower birth weight, and more neonatal intensive care unit admissions. There were no perinatal deaths among the study patients. The range of systolic/diastolic ratios for the five patients who failed to follow our protocol for intensive maternal-fetal surveillance was 4.3 to infinity; all experienced fetal death within 18 days. These results suggest that immediate delivery of the fetus with diminished end-diastolic flow may not be mandatory. The combined use of fetal biophysical testing and commonly used criteria for delivery results in acceptable fetal outcome and prolongation of gestational age.

Management of women with one abnormal oral glucose tolerance test value reduces adverse outcome in pregnancy

In this study we sought to test the hypothesis that treatment of women with one abnormal oral glucose tolerance test value will result in reduction of adverse outcome. One hundred twenty-six women with one abnormal oral glucose tolerance test value and 146 women in the control group (normal oral glucose tolerance test values) participated in a prospective study during the third trimester of pregnancy. The subjects with one abnormal test result were randomized into treated (group 1) and untreated groups (group II). Group 1 subjects were treated with a strict diabetic protocol to maintain tight glycemic control by means of diet and insulin therapy. Group 2 subjects tested their capillary blood glucose for a baseline period. The study revealed that the level of glycemic control was similar before initiation of therapy (mean capillary blood glucose 118 +/- 14 vs. 119 +/- 15 mg/dl, p = NS) for groups 1 and 2, respectively. There was a significant difference in mean capillary blood glucose (95 +/- 10 vs. 119 +/- 15 mg/dl, p less than 0.0001), preprandial, and postprandial determinations between the treated and untreated groups. The overall incidence of neonatal metabolic complications (4% vs. 14%, p less than 0.05) and large infants (6% vs. 24%, p less than 0.03) was significantly lower in the treated group. Comparison between the control (normal oral glucose tolerance test) and the untreated groups showed a significantly higher incidence of large infants and metabolic complications. No difference was found between the normal and treated groups. Thus we conclude that treatment of individuals with one abnormal oral glucose tolerance test value will result in significant reduction in adverse outcome in pregnancy.

Discordant twins--a prospective study of the diagnostic value of real-time ultrasonography combined with umbilical artery velocimetry

This study was undertaken to evaluate the role of Doppler velocimetry combined with intertwin differences in ultrasonographically derived estimated fetal weight, biparietal diameter, abdominal circumference, and femur length as a comprehensive test for the prediction of discordancy. The following cutoff values were used to indicate abnormal test results: delta biparietal diameter greater than 6 mm, delta abdominal circumference greater than 20 mm, delta femur length greater than 5 mm, delta estimated fetal weight greater than 15%, and delta systolic/diastolic ratio greater than 15%. Discordancy was identified when the birth weight difference exceeded 15%. The study population consisted of 58 consecutively evaluated third-trimester twin gestations. Eighteen sets of twins were discordant. None of these tests was uniformally successful in identifying twin discordancy; in three instances, all test results were normal. The diagnostic accuracy provided by ultrasonography was not significantly different from that provided by Doppler velocimetry. Overall the best predictor appeared to be the presence of either delta systolic/diastolic ratio greater than 15% or delta estimated fetal weights greater than 15%, which correctly identified 14 of the 18 discordant twins and misclassified only five of the 40 concordant pairs. This combination also had the highest positive and negative predictive values (73% and 90%, respectively).

Macrosomia in the postdate pregnancy: is routine ultrasonographic screening indicated?

Macrosomia is a potential but often overlooked consequence of the postdate pregnancy. A total of 317 consecutive patients with well-dated pregnancies who were seen because of fetal surveillance at greater than 41 weeks' gestation had an estimation of the fetal weight based on femur length and abdominal circumference at the initial visit. The incidence of macrosomia at 41 weeks' gestation was 25.5%. There was a higher incidence of cesarean section because of arrest and protraction disorders in the postdate pregnancies in which the infant was macrosomic (22%) versus those in which the infant was not macrosomic (10%, p less than 0.01). In a control group of 100 consecutive women delivered between 38 and 40 weeks' gestation, the incidence of macrosomia was 4%, significantly lower than the rate in the postdate patients (p less than 0.01). Incidence of cesarean section because of arrest and protraction disorders was significantly lower in this group (6%, p less than 0.05). The sensitivity and specificity of an estimated fetal weight greater than 4000 gm to predict a birth weight greater than 4000 gm were 60.5% and 90.7%, respectively, with a positive predictive value of 70% and a negative predictive value of 87%. We conclude that routine ultrasonographic screening for macrosomia may be a valuable adjunct to current fetal surveillance protocols used in the postdate pregnancy.

Maternal hemoglobin F levels may have an adverse effect on neonatal birth weight in pregnancies with sickle cell disease

A total of 26 patients with sickle cell disease were followed up through 32 pregnancies. There was no correlation between days in hospital or number of painful crises and either birth weight or birth weight percentile. The number of dense irreversibly sickled and least deformable cells was negatively correlated with birth weight percentile (r = -0.63, p less than 0.01). Patients' initial hemoglobin levels were positively correlated with birth weight percentile (r = 0.52, p less than 0.004). Hemoglobin F, on the other hand, was significantly inversely correlated with birth weight percentile. Nine pregnancies with small-for-gestational-age infants had an average hemoglobin level of 9.1% +/- 4.5%. In contrast, patients who were delivered of appropriate-for-gestational-age infants (23 pregnancies) had an average hemoglobin F level of 3.6% +/- 2.9% (p less than 0.01). We conclude that total hemoglobin levels and dense cells are correlated with birth weight percentile; moreover, the higher the maternal hemoglobin F levels the higher the risk of small-for-gestational-age infants. We speculate that although high hemoglobin levels may be beneficial to the fetus, high maternal hemoglobin F levels could increase the desaturation of non-F cells and induce placental obstruction.

Glycemic control in gestational diabetes mellitus--how tight is tight enough: small for gestational age versus large for gestational age?

The relationship between optimal levels of glycemic control and perinatal outcome was assessed in a prospective study of 334 gestational diabetic women and 334 subjects matched for control of obesity, race, and parity. All women with gestational diabetes mellitus were instructed in the use of a memory-based reflectance meter. They were treated with the same metabolic goal according to a predetermined protocol. Three groups were identified on the basis of mean blood glucose level throughout pregnancy (low, less than or equal to 86 mg/dl; mid, 87 to 104 mg/dl; and high, greater than or equal to 105 mg/dl). The low group had a significantly higher incidence of small-for-gestational-age infants (20%). In contrast, the incidence of large-for-gestational-age infants was 21-fold higher in the mean blood glucose category than in the low mean blood glucose category (24% vs. 1.4%, p less than 0.0001). An overall incidence of 11% small-for-gestational-age and 12% large-for-gestational-age infants was calculated for the control group. A significantly higher incidence of small-for-gestational-age infants (20% vs. 11%, p less than 0.001) was found between the control and the low category. In the high mean blood glucose category an approximate twofold increase was found in the incidence of large-for-gestational-age infants when compared with the control group (p less than 0.03). No significant difference was found between the control and mean blood glucose categories (87 to 104 mg/dl). Our data suggest that a relationship exists between level of glycemic control and neonatal weight. This information is helpful in targeting the level of glycemic control while optimizing pregnancy outcome in gestational diabetes comparable to the general population.

Postdate fetal surveillance: is 41 weeks too early?

During an 18-month period, 293 patients had a nonstress test and ultrasonographic evaluation of amniotic fluid volume twice weekly beginning at 41 weeks' gestation. Patients were admitted for induction of labor for either an abnormal nonstress test result or oligohydramnios. A control population consisted of 59 low-risk patients who were delivered between 39 and 41 weeks' gestation and had antepartum testing within 4 days of delivery. Study patients who were delivered between 41 and 42 weeks' gestation had a significantly increased incidence of abnormal nonstress tests, oligohydramnios, cesarean sections for fetal distress, and admissions to the neonatal intensive care unit compared with control patients. The abnormal fetal testing and adverse perinatal outcome associated with pregnancies over 42 weeks were also found in pregnancies between 41 and 42 weeks' gestation. These data support the concept that postdate fetal testing should begin at 41 weeks of gestation.

Changes in the pattern of uterine contractility in relationship to coitus during pregnancies at low and high risk for preterm labor

This is a preliminary, prospective study of uterine contractility in response to sexual intercourse. The study population consisted of 30 pregnant subjects. Group I included 15 women treated for an episode of preterm labor with intravenous and oral tocolysis in this pregnancy, and group II was a matched control group of low-risk volunteers. The availability of home uterine tocodynamometric systems permitted monitoring of uterine contractility for three 60-minute time periods related to coitus. A significant increase in uterine contractility in the immediate postcoital period was observed for the high-risk women, but not for the controls. This increased uterine activity subsided spontaneously within 2-3 hours, returning to baseline. These initial preliminary observations of uterine response to coitus in a home environment are interesting; however, further research is suggested to establish their clinical implications.

The relationship between large-for-gestational-age infants and glycemic control in women with gestational diabetes

In this prospective study 246 women with gestational diabetes were followed up to determine the characteristics of metabolic control associated with large-for-gestational-age infants. Memory-based reflectance meters were used for self-monitoring blood glucose. Ambulatory glucose profiles were produced to characterize glycemic control levels throughout pregnancy. With these novel approaches to the collection and representation of glucose data, the severity of glucose intolerance (hyperglycemia) was found to be associated with both maternal and neonatal morbidity in terms of infant size and cesarean section rate. By use of hierarchical cluster analysis to identify three groups on the basis of control levels (low less than 87 mg/dl, mid 87 to 105 mg/dl, high greater than 105 mg/dl) we were able to show a positive outcome in the low group with reduced rates of large-for-gestational-age (2%) and macrosomatic (0%) infants. Furthermore, we showed that as mean blood glucose levels and instability in glycemic control increased from group to group, incidence of large-for-gestational-age and macrosomatic infants increased. Whereas obesity increased the relative risk of adverse neonatal outcome, type of treatment (insulin versus diet) did not appear to be significant. Appropriately monitored toward stability within a narrow range to achieve tight metabolic control, ambulatory glycemia in pregnancy is associated with a decreased risk of maternal and fetal complications.

Scientific rationale for management of diabetes in pregnancy. Recent approaches with innovative computer-based technology

A series of recent studies in women with gestational diabetes mellitus is reviewed. During the studies, which were designed to gain a better understanding of the etiology of perinatal morbidity, a novel means of collecting ambulatory blood glucose values was employed. Subjects used specially modified reflectance meters with onboard memories to record each value with corresponding time and date. The data were transmitted to a microcomputer and rapidly analyzed to permit effective follow-up in the study population. The system enabled the investigators to characterize metabolic control, evaluate different treatment modalities, and measure the association between glycemic control and fetal outcome. These studies indicate that patients with one elevated blood glucose value during formal glucose tolerance testings have higher blood glucose values under ambulatory conditions. Furthermore, these elevated ambulatory glucose values were significantly correlated with fetal macrosomia. Treatment regimens designed to lower verified ambulatory blood glucose measurements may help reduce fetal macrosomia in women with milder forms of gestational diabetes or in women with relative glucose intolerance without a substantial increase in severe hypoglycemia.

Intrauterine growth retardation--a prospective study of the diagnostic value of real-time sonography combined with umbilical artery flow velocimetry

This study was undertaken to evaluate the role of umbilical artery flow velocimetry combined with sonographic estimation of fetal weight, head circumference to abdominal circumference ratio, femur length to abdominal circumference ratio, and qualitative determination of amniotic fluid volume as a comprehensive test for the detection of intrauterine growth retardation (IUGR). The following cutoff values were used to indicate abnormal test results: 1) umbilical artery peak systolic to end-diastolic ratio (S/D) above 3, 2) estimated fetal weight below the tenth percentile for gestational age, 3) head circumference to abdominal circumference ratio more than 2 SD above the mean for gestational age, 4) femur length to abdominal circumference ratio above 23.5%, and 5) qualitative amniotic fluid volume less than 2 cm. The study population consisted of 127 patients referred with a clinical suspicion of IUGR. Forty-five infants (35%) were small for gestational age. None of these five tests were uniformly successful in identifying growth-retarded infants. Overall, the best predictor appeared to be estimated fetal weight below the tenth percentile for gestational age, which correctly identified 39 of the 45 IUGR infants (sensitivity 87%, specificity 87%). The sensitivity of this test was nearly twice that of any other test. All indices performed similarly in predicting the non-IUGR infant (range of specificities 87-98%).

Pregestational diabetes: insulin requirements throughout pregnancy

The management of pregestational diabetes requires tight metabolic control to reduce maternal and perinatal morbidity and mortality. It has been suggested that type I diabetes is a disorder characterized by insulin deficiency and type II diabetes is characterized by insulin resistance; however, it may be hypothesized that a difference in insulin requirements should emerge throughout pregnancy to reflect the dissimilarities in these two metabolic disturbances. The current investigation of 103 women with pregestational diabetes used a novel approach (reflectance meters with onboard memories) to uncover the actual insulin dosages required to reach and maintain optimum metabolic control throughout pregnancy. It was found that both type I and type II diabetes appear to have a triphasic insulin pattern, with the patient having type II diabetes requiring significantly higher doses of insulin during each trimester. This seems to suggest that the hormonal changes in pregnancy may have a similar effect on both type I and type II diabetes but to a different degree. Thus this should be considered in the treatment of pregestational diabetes and in the development of an algorithm for diabetes management.

The application of uterine and umbilical artery velocimetry to the antenatal supervision of pregnancies complicated by maternal sickle hemoglobinopathies

To assess the efficacy of Doppler flow velocimetry in predicting fetal compromise and neonatal outcome in pregnant women with sickle cell hemoglobinopathies, a prospective study was conducted of 96 patients, 48 with sickle cell hemoglobinopathy (8 with SS and 40 with AS hemoglobin) and 48 low-risk AA hemoglobin controls. All subjects were followed biweekly from the third trimester of pregnancy through delivery with uterine and umbilical artery velocimetry, nonstress, tests, and hematocrit and blood pressure measurements. An abnormal systolic/diastolic ratio was defined as a value greater than or equal to 3. The incidence of abnormal systolic/diastolic ratios for uterine or umbilical arteries was significantly higher in pregnant women with SS hemoglobin (88%) when compared with patients with AS (7%) and AA (4%) hemoglobin. In addition, the abnormal systolic/diastolic ratios for both umbilical and uterine arteries are correlated with abnormal nonstress test results. The nonstress test results became abnormal on average 3 weeks after the systolic/diastolic ratios did. The presence of abnormal systolic/diastolic ratios for umbilical and uterine arteries is predictive of fetal distress and infants small for gestational age. The high incidence of concordant uterine and umbilical artery abnormal systolic/diastolic ratios in pregnant women with SS hemoglobinopathy, which were identified earlier than were abnormal nonstress results, suggests an important parameter in the monitoring of these high-risk pregnancies.

An association between hyperinsulinemia and hypertension during the third trimester of pregnancy

We studied 43 women in their third trimester of pregnancy whose fetuses were at significant risk of intrauterine growth retardation. To define metabolic subtypes for intrauterine growth retardation, a 100 gm glucose load was administered after an overnight fast. Twenty-seven women were normotensive and 16 had hypertension. The glucose tolerance of the hypertensive group was essentially the same as that of the normotensive group. However, 8 of the 16 women with hypertension had marked hyperinsulinemia in response to an oral glucose load. Of the five women with hypertension who gave birth to offspring of low birth weight, three had hyperinsulinemia.

Primary, secondary, and tertiary prevention. Program for diabetes in pregnancy

Over the past 2 yr the effectiveness of a program in primary, secondary, and tertiary prevention of diabetes in pregnancy was studied. The purpose of the program was to determine the degree to which preventive medicine in terms of early screening and diagnosis, rapid initiation of treatment, and close follow-up surveillance could reduce the morbidity and mortality associated with pregestational and gestational diabetes. The study compared the program in prevention with previous programs, and its results were measured against national criteria established by the Centers for Disease Control. A significant increase in early identification of gestational diabetes and a decrease in fetal and maternal complications were detected.

Intrapartum vibratory acoustic stimulation of the human fetus during episodes of decreased heart rate variability

The effects of intrapartum vibratory acoustic stimulation during periods of decreased fetal heart rate variability were studied in 25 healthy term fetuses. Fetal monitoring and real-time ultrasound scanning were used simultaneously to detect fetal response. Vibratory acoustic stimulation was provided by an artificial larynx generating a signal at 85 dB and 85 Hz. This stimulus was applied for 5 seconds on the maternal abdomen over the fetal head after a 20-minute period of decreased fetal heart rate variability. All fetuses reacted with an immediate fetal heart rate acceleration of at least 10 bpm (range: 10 to 35 bpm, mean +/- SD = 18.4 +/- 7.0), and 19 fetuses also had sudden fetal body movement. A deceleration of the fetal heart rate after the initial acceleration was observed in nine fetuses (range: 15 to 70 bpm, mean +/- SD = 45.5 +/- 16.5). The implications of these findings are discussed in relation to the possible use of fetal vibratory acoustic stimulation for intrapartum surveillance.

Fetal umbilical artery flow velocimetry in postdate pregnancies

This study prospectively examined the use of umbilical artery flow velocimetry for monitoring fetal health in postdate pregnancies. Forty-six patients with well-established dates were evaluated with semiweekly biophysical profiles and umbilical artery flow velocimetry (characterized by the ratio of the peak systolic to end-diastolic velocity). Their labor records were reviewed, and neonates were examined for signs of postmaturity. Twenty neonates had an abnormal test result or outcome (identified as an abnormal nonstress test, oligohydramnios, meconium, intrapartum fetal distress, or a 5-minute Apgar score less than 7). Nine neonates had a physical examination consistent with the postmaturity syndrome. Twenty-one neonates were entirely normal. Comparisons of the mean systolic/diastolic ratios for neonates with and without the complications associated with postdatism showed no significant differences. In addition, all systolic/diastolic ratios were within the normal range. Therefore, umbilical artery flow velocimetry is unlikely to be useful for the routine antenatal assessment of the postdate fetus.

Verified self-monitored blood glucose data versus glycosylated hemoglobin and glycosylated serum protein as a means of predicting short- and long-term metabolic control in gestational diabetes

Glycosylated hemoglobin and glycosylated serum protein have been suggested as tools for evaluation of long- and short-term glycemic control, respectively. Twenty-six patients with gestational diabetes were prospectively studied to determine the relationship of glycosylated hemoglobin and glycosylated serum protein to metabolic control. To verify the accuracy of blood glucose data, a memory-based reflectance meter was used for subjects with gestational diabetes who tested 6.5 +/- 1 times per day. Our analysis revealed that despite a statistically positive correlation between glycosylated hemoglobin, glycosylated serum protein, and verified data, their use as a clinical tool is limited because of their poor predictability.

The significance of one abnormal glucose tolerance test value on adverse outcome in pregnancy

A matched control study of 126 women equally divided into three groups (normal oral glucose tolerance test, one abnormal test value, and gestational diabetes mellitus) was undertaken to examine the relationships among oral glucose tolerance test results, glycemic control in pregnancy, and adverse perinatal outcome. Characterization of metabolic control for the one abnormal oral glucose tolerance test value and the gestational diabetes mellitus groups (before treatment) showed no significant difference. After the start of treatment, however, a significant (p less than 0.01) difference between the groups in level of control was found. While no significant difference in the average birth weight between the three groups was discovered, the incidence of large infants (macrosomia and large for gestational age) was found to be significantly higher in the one abnormal oral glucose tolerance test group when compared with the normal (34% versus 9%; p less than 0.01) and gestational diabetes mellitus group (34% versus 12%; p less than 0.01). No significant difference for the incidence of an infant large for gestational age was found between the normal group and the patients with gestational diabetes mellitus after treatment. Neonatal metabolic disorders were found to be significantly higher for the one abnormal oral glucose tolerance test group (15%) when compared with the control and the gestational diabetes mellitus groups (3%). We conclude that, if left untreated, one abnormal value on an oral glucose tolerance test is strongly associated with adverse perinatal outcome.

Gestational diabetes: insulin requirements in pregnancy

A prospective study of 57 women with gestational diabetes mellitus was undertaken to determine actual insulin requirements throughout pregnancy. Women were placed on a multiple injection, mixed insulin regimen and monitored their blood glucose level 6.5 +/- 1 times per day using a memory-based reflectance meter to obtain verified data. A significant (p less than 0.01) increase in total insulin dose was found during the initial treatment period (7 +/- 2 days) until the target glucose range was achieved. Insulin requirements continued to significantly (p less than 0.01) rise until 30 +/- 1 gestational weeks, despite a stabilization of glucose level. Thereafter, there was no significant change (3%) in insulin requirement. A correlation of r = 0.58 (p less than 0.001) for the relationship between insulin dose at the 24 and 32 weeks' gestation, and an r = 0.99 (p less than 0.0001) for the relationship between insulin dose at 32 and 39 weeks' gestation was found. We concluded that an emphasis on ambulatory blood glucose control and insulin adjustments should occur in the early treatment phase of gestational diabetes.

Ambulatory glucose profile: representation of verified self-monitored blood glucose data

Sixty-nine individuals with diabetes (23 with type I, 15 with pregestational, and 31 with gestational) used specially modified reflectance meters containing memory chips enabling the instruments to store 440 individual blood glucose values with corresponding time and date. These data were organized into 14-day periods and then collapsed into a graphic depiction, the Ambulatory Glucose Profile (AGP), which was represented as the pattern of the 25th, 50th, and 75th percentiles of blood glucose values. These three curves illustrate the median level of control and provide an index of variability in control at each hour of a "typical day." We observed distinctive AGPs related to the variability in metabolic control and the type of diabetes. Comparisons between diagnostic groups showed consistent differences between groups, independent of level of glycemic control. Review of serial AGPs obtained for sequential 2-wk periods for 23 non-pregnant individuals with type I diabetes and 10 women with gestational diabetes revealed changes in AGP corresponding to alterations in regimen. The AGP provides a new approach to the evaluation of glycemic control, with applications to patient and physician education, clinical investigation, and individual patient care.

Diminished respiratory sinus arrhythmia in asphyxiated term infants

Spectral analysis techniques were used to quantitate the association between respiration and heart rate variability in eight healthy and eight asphyxiated infants born at term gestation. Respiratory sinus arrhythmia was demonstrated in all healthy infants. This arrhythmia was significantly diminished in asphyxiated newborn infants. We conclude that newborn infants with low Apgar scores have a reduced respiratory sinus arrhythmia and that this reduction could account for the loss of short-term heart rate variability commonly associated with asphyxia.