Biomedical subjects

O Langer

Publications and source records attributed to O Langer.

At least 91 records · Page 5Linked to original sources

PubMed1991

Insignificant transfer of glyburide occurs across the human placenta.

No data exist concerning human placental transfer of oral hypoglycemic agents during pregnancy. This study characterizes the transport of glyburide in 10 term human placentas with the single-cotyledon placental model. Serial samples were taken from both the maternal and fetal reservoirs during each 3-hour perfusion, and the percent transport and metabolism of tritiated glyburide was calculated with liquid scintillation spectrometry and high-performance liquid chromatography. Antipyrine labeled with carbon 14 was added to the perfusate solution during these experiments as a control. Virtually no transfer of glyburide occurred, and no appreciable metabolism of the drug was detected. Neither variation in the albumin concentration nor increase in the maternal glyburide levels to 100 times therapeutic concentration materially altered the rate of transport. These data show that insignificant transport of glyburide occurs across the human placenta in vitro and suggest that fetal exposure to maternally administered glyburide likewise may be insignificant.

Diazepam↗

PubMed1991

Shoulder dystocia: should the fetus weighing greater than or equal to 4000 grams be delivered by cesarean section?

A total of 75,979 women who were delivered vaginally in the period 1970 to 1985 were stratified into diabetic and nondiabetic groups. Overall, the incidence of macrosomia (greater than or equal to 4000 gm) was 7.6% (5674/74390) in the nondiabetic group and 20.6% (328/1589) in the diabetic group. Patients were further subdivided by weight categories at 250 gm intervals. Eight percent of shoulder dystocia occurred in the diabetic group when fetal weight was greater than or equal to 4250 gm. In contrast, 20% of shoulder dystocia in the nondiabetic group could have been prevented by elective cesarean section when the fetal weight was greater than or equal to 4500 gm. Furthermore, logistic regression analysis demonstrated that birth weight, diabetes, and labor abnormalities were the principal contributors to shoulder dystocia. Elective cesarean section is strongly recommended for diabetics with fetal weights greater than or equal to 4250 gm, and trial of vaginal delivery for nondiabetic fetuses with weights greater than or equal to 4000 gm is recommended. In all cases the clinician must be watchful for labor abnormalities in macrosomic fetuses.

Birth Weight↗

PubMed1991

A longitudinal evaluation of the efficacy of umbilical Doppler velocimetry in the diagnosis of intrauterine growth retardation.

In a prospective study of 149 patients, the interrelationship among abnormal umbilical artery systolic/diastolic (S/D) ratios, maternal hypertension and IUGR was examined. Abnormal S/D ratio was defined as a value greater than or equal to 3 in the third trimester. Results suggest that the incidence of abnormal S/D ratios are significantly higher in hypertensive as compared to normotensive pregnancies, as well as in small for gestational age (SGA) compared to appropriate for gestational age (AGA) deliveries. Although umbilical artery velocimetry was more predictive of IUGR in hypertensive than normotensive pregnancies, overall 45% of SGA births were not identified by this technique. Further classification of potential etiologies and mechanisms of IUGR based on maternal factors should improve the positive predictive value of the abnormal S/D ratio in subgroups of pregnant women. In the interim the results strongly suggest that abnormal S/D ratio in a hypertensive pregnancy should alert the obstetrician to the probability of IUGR.

Blood Flow Velocity↗

PubMed1991

Prevention of macrosomia.

In summary, appropriate assignment of patients to treatment modality utilizing verified blood glucose determination and targeting mean blood glucose level throughout pregnancy to 5.3 mmol/l (similar to normal nondiabetic blood glucose levels) will result in neonatal size comparable to the general population. Today, we have the knowledge and the technology not only to strive for the target but also, more importantly, to achieve the goal of pregnancy outcome in the diabetic comparable to the non-diabetic population. To return to our original research question: Is it glucose or insufficient knowledge of the management approach that maintains macrosomia levels? It is evident that glucose is the prime cause of macrosomia, although other nutrients have a secondary role. Proper management of glucose abnormality will result in a significant decrease in the rate of macrosomia.

Blood Glucose↗

PubMed1991

Association between umbilical artery cord pH, five-minute Apgar scores and neonatal outcome.

A prospective study was conducted of 270 intrapartum patients admitted in labor to investigate the independent and combined relationships between umbilical arterial cord pH and Apgar scores and neonatal outcome. The results revealed that when assessed independently, a low 5-min Apgar score (less than 7) was associated with both NICU admission and neonatal sepsis. When categorized by both cord pH and 5-min Apgar, the majority of patients (75.9%) had both parameters normal, 20.7% had an abnormal pH (less than 7.20) and normal Apgar (greater than or equal to 7) and few patients had either both normal or an abnormal Apgar given a normal pH. Given a normal 5-min Apgar score, additional information about the cord pH did not enhance the predictability for either NICU admission or neonatal sepsis. Neonates with both an abnormal pH and 5-min Apgar had the highest incidence of NICU admission. For all neonates, the presence of meconium greatly increased the likelihood of being admitted to the NICU.

Acidosis↗

PubMed1991

Rationale for insulin management in gestational diabetes mellitus.

A prospective study was undertaken to test the hypothesis that insulin treatment in patients with gestational diabetes mellitus (GDM) with fasting plasma glucose (FPG) greater than 5.3 mM significantly reduces adverse perinatal outcome. Assigned to insulin or diet treatment based on FPG were 471 GDM women. Four factors believed to be associated with infants large for gestational age (LGA) were evaluated: FPG, overall glycemic control, maternal weight, and treatment regimen. We found that when glycemic control was optimized, the key factors related to large infants were FPG and treatment modality. In the low-FPG group (less than 5.3 mM), diet therapy achieved an incidence of 5.3% LGA. When insulin therapy was used to optimize control, an incidence of 3.5% LGA was found. Patients in the mid-FPG group (5.3-5.8 mM) had a higher increased rate of LGA (28.6%) for diet-treated versus insulin-treated women (10.3%). In addition, a fourfold increased risk for LGA was found in the diet-treated obese subjects in the mid-FPG group compared with insulin-treated obese women. Finally, treatment with insulin resulted in similar incidence of LGA within all FPG groups. We concluded that FPG greater than 5.3 mM can be the basis for initiation of insulin treatment in GDM subjects with optimization of glycemic control as the goal. This approach may contribute significantly to reduced neonatal risk and may foster a standardized method for rapid and effective assignment to treatment.

Adult↗

PubMed1991

Third-trimester prediction of small-for-gestational-age infants in pregnant women with sickle cell disease. Development of the ultradop index.

Twenty-seven women with homozygous sickle cell disease were followed from the third trimester until delivery. All the subjects underwent both Doppler and sonographic assessment at two points in pregnancy, periods I (28-30 weeks) and II (34-36 weeks). Estimated fetal weight (EFW) was calculated. Using a continuous wave Doppler instrument, mean systolic:end diastolic (S:D) ratios were calculated to characterize the umbilical waveforms. S:D ratios greater than or equal to 3 were designated abnormal. An index, the ultra-dop, was developed that combined ultrasound EFW less than or equal to 25th percentile and S:D greater than or equal to 3. Nine of 27 infants (33%) were small for their gestational age, with a mean gestational age of 38 +/- 2 weeks. The sensitivity, specificity and predictive values were calculated for smallness for gestational age utilizing ultrasound, Doppler velocimetry and the ultradop index for periods I and II. For period I, the highest sensitivity was obtained with the ultradop index--88.9% as compared to 77.8% with Doppler scanning and 11.1% with ultrasound. The ultradop also provided the highest positive predictive value, 88.9%; it was followed by Doppler at 77.8% and ultrasound at 50.0%. In period II the ultradop index and Doppler had the same sensitivity, 88.9%, which was much higher than for ultrasound (55.6%). As for period I, the ultradop had the highest positive predictive value, 88.9%. Our data suggest that the ultradop index provides a key assessment of women with sickle cell disease at 28-30 weeks' gestation with reference to the likelihood of their giving birth to small-for-gestational-age infants.

Adult↗

PubMed1990

Does fasting interval affect the glucose challenge test?

The relationship between fasting interval and glucose screening was assessed in a prospective study of 153 non-diabetic pregnant patients undergoing a standard 50g glucose challenge test. An interval of less than 3 hours after the last meal was found to be associated with a significantly greater insulin response as opposed to a fasting interval of more than 3 hours (121.3 pmol/l vs. 83.5 pmol/l, p less than .001) and a greater insulin/glucose index (0.92 vs. 0.66, p less than .001), with no difference in plasma glucose. Overall, obese patients had a higher glucose response than non-obese, but only higher insulin levels (107 pmol/l vs. 69 pmol/l, p less than .001) and insulin/glucose index (0.79 vs. 0.59, p less than .02) when the fasting interval was greater than 3 hours. Our data suggest that the fasting interval can influence insulin response during a glucose challenge test and the aberration in insulin secretion may effect screening results, especially in the high-risk gravida with glucose abnormality.

Adult↗

PubMed1990

Relationships between glucose levels and insulin secretion during a glucose challenge test.

The relationship between glucose and insulin levels was examined in a prospective study of 153 pregnant patients without diabetes who underwent a standard 50 gm glucose challenge test. One hundred eighteen women had normal screening results (glucose level less than 140 mg/dl) and 35 had abnormal screening values but a normal oral glucose tolerance test. Abnormal responders had greater insulin levels (149 vs 82 pmol/L, p less than 0.0001), and a higher insulin/glucose index (0.96 vs. 0.72, p less than 0.007). Patients with glucose levels less than 100 mg/dl had significantly lower insulin/glucose indices. Overall, obese patients had significantly greater glucose and insulin measurements than did nonobese women, but there was no difference within normal and abnormal groups. Glucose levels accounted for 52% of the insulin output and 29% of the insulin/glucose index variance. Neither age, parity, nor obesity contributed significantly to insulin levels in the multiple regression model. Therefore the accepted threshold for glucose screening reflects abnormal insulin output and this aberration may be indicative of the primary defect in gestational diabetes.

Adult↗

PubMed1990

Sonographic estimates of fetal weight in the intrauterine growth retardation population.

The efficacy of different methods of fetal weight estimation using sonographic measurements of the abdominal circumference (AC), biparietal diameter (BPD), and femur length (FL), either alone or in combination, was evaluated in the fetus with intrauterine growth retardation (IUGR). Eighty-one patients, referred with a clinical suspicion of IUGR, were studied. All patients had sonographic measurements within 7 days of delivery. Four regression equations were used to estimate fetal weight: AC (Hadlock), BPD-AC (Shepard), AC-FL (Hadlock), BPD-AC-FL (Hadlock). For the total study group, as well as for the infants who were found to be IUGR at birth, 75% of the estimates of fetal weight using the BPD-AC-FL method were within 10% of the actual birthweight. Nearly comparable results were obtained using the AC-FL method. In the fetus with IUGR, estimates of fetal weight that incorporated the FL correlated best with the actual birthweight.

Anthropometry↗

PubMed1990

Education does not improve patient perception of preterm uterine contractility.

In this prospective study, we sought to compare pregnant women's self-perception of their preterm uterine contractility versus electronically obtained data and to evaluate the impact of intensive patient education on increasing awareness of the presence of uterine contractions. Thirty-eight women each monitored their uterine activity at home for two 60-minute periods daily during a 21-day sequence. An event marker was used to document perceived contractions and after a 3-day baseline interval, an intensive nursing-service educational intervention was initiated for all subjects. Thirty-five percent of women underreported uterine contractions, whereas only 5% overreported their uterine activity during the study. Derived patient scores of underreporting and overreporting of contractions did not vary among seven consecutive 3-day study intervals. Analysis of the data revealed that patients perceived fewer than 10% of all contractions documented electronically. No improvement in the reliability of patient perception of preterm uterine contractility was obtained after the educational intervention.

Adult↗

PubMed1990

Uterine contractility patterns after an episode of preterm labor.

Uterine contractility patterns were studied in an attempt to identify those women on tocolytic therapy at risk for preterm delivery. One hundred sixteen women treated successfully after an episode of preterm labor were followed with an ambulatory tocodynamometer system. Contractions were monitored twice daily for 1 hour until delivery or until 36 completed weeks of gestation. In this group, 52 women (45%) delivered preterm and 64 (55%) delivered at term. The analysis revealed that 1) from 24-29 weeks' gestation, there was no significant difference in the uterine activity between the two groups; and 2) beginning at 30 weeks' gestation and continuing until the end of the 36th week of gestation, uterine activity was significantly greater in women destined to deliver preterm. These observations suggest that the patterns of daily uterine contractility observed in patients after an episode of preterm labor can identify those at greater risk for a preterm delivery.

Adult↗

PubMed1989

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.

Evaluation Studies as Topic↗

PubMed1989

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.

Adult↗

PubMed1989

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.

Blood Glucose↗

PubMed1989

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.

Anemia, Sickle Cell↗

PubMed1989

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.

Cesarean Section↗

PubMed1989

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).

Birth Weight↗