Search PubMed⌕ Search

Biomedical subjects

M B Landon

Publications and source records attributed to M B Landon.

53 records · Page 3Linked to original sources
PubMed1989

Doppler umbilical artery velocimetry in pregnancy complicated by insulin-dependent diabetes mellitus.

The mean peak systolic to end-diastolic (S/D) umbilical artery ratio was measured in 291 Doppler studies performed during pregnancy in 35 insulin-dependent diabetic women. A normal decline was observed in the umbilical artery S/D ratio, from 4.2 +/- 0.21 at 18 weeks to 2.18 +/- 0.22 at 38 weeks. There was no significant correlation between mean third-trimester S/D and either glycosylated hemoglobin (r = 0.25) or mean blood glucose levels (r = 0.15). Fetuses of women with vascular disease (class F/R or chronic hypertension) had a mean third-trimester S/D of 3.0 or higher in five of ten cases, compared with three of 25 in patients with uncomplicated diabetes (P less than .03). Mean second- and third-trimester S/D ratios differed significantly in patients with and without vascular disease: 4.34 +/- 0.7 and 3.2 +/- 0.65 versus 3.72 +/- 0.42 and 2.55 +/- 0.32, respectively (P less than .03). Two of three women without vascular disease who demonstrated an elevated mean S/D ratio developed preeclampsia and delivered appropriate for gestational age infants. In women with vascular disease, four of five with an abnormal mean third-trimester umbilical artery S/D ratio were delivered of growth-retarded infants, whereas all five with normal umbilical artery S/D ratios had appropriate for gestational age infants. In three of the abnormal cases, elevated S/D ratios were present in the second trimester before ultrasound documentation of fetal growth retardation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1988

Diabetes and pregnancy.

Despite improvement in perinatal outcome over the past several decades, controversy still exists regarding both the management and pathophysiology of pregnancy complicated by diabetes mellitus. In this article, potential factors contributing to morbidity observed in the offspring of diabetic women are considered. The clinical management of insulin-dependent and gestational diabetes is also discussed.

Delivery, Obstetric↗
PubMed1988

Cerebrospinal fluid shunts in pregnancy. Report of two cases and review of the literature.

With the introduction of silicone indwelling cerebrospinal fluid (CSF) shunts in the 1960s, the prognosis for children with hydrocephalus changed dramatically. These individuals are leading normal and productive lives today. Many women with CSF shunts are not entering the childbearing years. Previously, only 13 cases of pregnancy occurring in patients with CSF shunts have been reported. We present two cases here and review the complications and outcome of the other reported cases. Shunt malfunction appears to be common in pregnancy due to increased intraperitoneal pressure and the enlarging uterus. Rarely is surgical correction or premature delivery necessary. A successful pregnancy ending in the vaginal delivery of a term infant can be expected in the majority of these patients.

Adult↗
PubMed1988

Sonographic diagnosis of fetal growth disorders.

In summary, accurate identification of fetal growth disorders remains a difficult clinical challenge. Many diagnostic parameters have been devised to diagnose these conditions, however, no single test alone allows a confident antenatal diagnosis of IUGR or macrosomia to be established. Until new criteria or new methods such as Doppler analysis of umbilical artery flow permit a more accurate prediction of growth disturbances, multiple parameters should be monitored. Evaluation of the amniotic fluid volume, BPD, FL, AC, and EFW should be included in all studies. In high risk cases (unexplained oligohydramnios, previous history of growth retardation, poor nutritional status, abnormal sonographic parameters, maternal obesity, diabetes mellitus, etc.) additional measurements such as the HC/AC ratio and the FL/AC ratio should also be evaluated. Similarly, evaluation of suspected excessive fetal growth requires careful evaluation of AC measurements. Patients with suspected growth disorders should be reevaluated with serial scans at 2 to 3 weeks intervals. Careful monitoring of fetuses with suspected IUGR and macrosomia may decrease much of the morbidity and mortality associated with these conditions.

Amniotic Fluid↗
PubMed1988

Amniotic fluid cholesteryl palmitate in pregnancies complicated by diabetes mellitus.

Amniotic fluid cholesteryl palmitate, as measured by thin-layer chromatography, appears to be a very sensitive and specific predictor for the risk of respiratory distress syndrome (RDS) in newborns of normal pregnancies. To assess the effect of diabetes mellitus on fetal pulmonary maturation, we measured cholesteryl palmitate concentration, the lung profile, and total phosphatidylcholine in amniotic fluid obtained from 35 well-controlled diabetic and 39 control pregnancies at term. In women with diabetes, the mean (+/- SD) third-trimester glycosylated hemoglobin level was 6.96 +/- 2.3% (normal 6-8%). Mean cholesteryl palmitate concentration in the diabetic population was 79.12 +/- 13.17 micrograms/mL, versus 153.71 +/- 16.77 micrograms/mL in the control group (P less than .001). The mean cholesteryl palmitate concentration was also significantly different for gestational diabetics and class B-R gravidas (112.75 +/- 26.2 versus 54.45 +/- 7.34 micrograms/mL; P less than .005). Cholesteryl palmitate was decreased despite the presence of a mature lecithin/sphingomyelin ratio and, in most cases, phosphatidylglycerol. These data suggest that even in well-controlled diabetic pregnancies, alterations in maternal metabolism may affect either the biosynthesis or degradation of cholesteryl palmitate.

Amniotic Fluid↗
PubMed1988

Diabetes mellitus and Graves' disease in pregnancy complicated by maternal allergies to antithyroid medication.

The pregnancy of a women with diabetes mellitus was complicated by Graves' disease and maternal allergies to propylthiouracil and methimazole. Preparations for surgical removal of the thyroid gland were being made until pregnancy intervened. Several well-documented mechanisms of hyperthyroidism, including increased intestinal absorption of glucose, decreased insulin responsiveness, and increased glucose production may exacerbate glucose intolerance; the daily insulin requirement of this patient rose 80% from her pregestational dosage. When large doses of propranolol failed to control her thyrotoxic symptoms and led to severe, recurrent hypoglycemic episodes, subtotal thyroidectomy was performed. A 42% decrease in insulin requirements was observed postoperatively, with return to the euthyroid state. A propensity for symptomatic postoperative hypoglycemia should be anticipated in diabetic patients undergoing thyroidectomy.

Adult↗
PubMed1987

Neonatal morbidity in pregnancy complicated by diabetes mellitus: predictive value of maternal glycemic profiles.

The relationship between glycemic control and perinatal outcome was assessed in a relatively uniform population of 75 White Class B through D pregnant diabetic women. All patients used glucose reflectance meter self-monitoring and performed a minimum of four determinations daily. Mean capillary blood glucose was calculated from a minimum of 16 weeks of determinations. Regression analysis confirmed a correlation between these values and third-trimester hemoglobin A1 (p less than 0.001). The study population was divided into two groups on the basis of mean capillary blood glucose values: group I, mean capillary blood glucose less than 110 mg/dl (43 patients) (mean = 96.8 +/- 7.1); group II, mean capillary blood glucose greater than 110 mg/dl (32 patients) (mean = 126 +/- 9.0). Of the 32 patients in group II, eight had mean capillary blood glucose greater than or equal to 130 mg/dl. The degree of maternal glycemic control appeared to affect perinatal outcome. At least one form of infant morbidity was present in 33% of group I infants compared with 53% of group II. Significant differences were observed for the incidence of hypoglycemia (p less than 0.05), macrosomia (p less than 0.05), and respiratory distress syndrome (p less than 0.01). One of six group I infants delivered at 35 to 36 weeks developed respiratory distress syndrome, compared with four of seven group II patients. The appearance of phosphatidylglycerol in amniotic fluid appeared delayed in group II patients at term. These data suggest that maintaining mean capillary blood glucose values less than 110 mg/dl may serve to reduce several major forms of morbidity in the infant of the diabetic mother. This information is helpful in establishing objectives for glycemic control in pregnant women using self-monitoring techniques.

Adult↗
PubMed1987

Management of the diethylstilbestrol-exposed pregnant patient: a prospective study.

Over a 5-year period we have managed 63 diethylstilbestrol-exposed pregnant patients with a standardized protocol requiring weekly cervical examination and decreased physical activity of the patient. Twenty-six patients (42%) underwent a prophylactic cerclage for a history of second-trimester loss or a hypoplastic cervix on initial clinical examination (group I). Thirty-six patients (58%) were followed expectantly (group II). Sixteen patients (44%) in group II demonstrated cervical change and required an emergency cerclage. Twenty-one patients were managed expectantly with no cerclage. The gestational age at delivery for group I was 37.7 +/- 2.80 versus 34.5 +/- 6.9 weeks for patients without a cerclage (p = 0.04). There were no perinatal deaths if a cerclage was performed, whereas there were five deaths (24%) in the group without cerclage. The five deaths occurred at a mean gestational age of 24.40 +/- 4.0 weeks and a mean birth weight of 614.00 +/- 441.73 gm. Patients with a hypoplastic cervix or prior reproductive loss had a better outcome with early cerclage than patients with a normal cervix followed expectantly. We presently lack a reliable method to detect the diethylstilbestrol-exposed patient at greatest risk for perinatal loss. Based on our experience we believe that placement of a cerclage early in pregnancy should be a strong consideration.

Adult↗
PubMed1987

Primary sclerosing cholangitis and pregnancy.

Primary sclerosing cholangitis is a chronic, fibrosing, inflammatory disorder of unknown etiology affecting the biliary tree. We describe a case of a pregnancy complicated by this condition. Remarkably, maternal cholestasis improved with advancing gestation. Despite a marked elevation of bile acid levels in cord blood, the patient was delivered of a healthy term infant. The principles of management and potential effects of primary sclerosing cholangitis on pregnancy care are discussed.

Adult↗
PubMed1986

Capillary blood glucose screening for gestational diabetes: a preliminary investigation.

Home glucose monitoring with the use of reflectance meters is an important adjunct in the care of pregnant women with insulin-dependent diabetes. The accuracy of reflectance meters for the assay of capillary glucose specimens has been well documented. The present preliminary study was undertaken to determine the utility of outpatient screening for gestational diabetes mellitus with the use of a reflectance meter (Accu-Chek, Boehringer Mannheim Co.). One hundred twenty-five patients in our high-risk practice had a standard 50 gm glucose load at 26 to 28 weeks' gestation. Capillary glucose values were measured on site with the Accu-Chek. Venous plasma glucose levels were measured by the central laboratory chemistry analyzer. While the laboratory (x) and meter (y) glucose determinations between the two sets of values were highly correlated (R = 0.89, p less than 0.001), there was a significant difference in their average values (x = 111.74, y = 136.35, p less than 0.0001). With the use of a receiver operator characteristic curve, a meter value of 160 mg/dl was determined as the optimal threshold for performing a 3-hour glucose tolerance test. The sensitivity and specificity with the use of a meter value of 160 mg/dl were 93% and 96%, respectively, for detecting an abnormal screening test in venous plasma (greater than or equal to 135 mg/dl). A total of 32 glucose tolerance tests were performed, with four patients included who had venous values less than 135 mg/dl. All eight patients with gestational diabetes mellitus were correctly identified. These data suggest that a glucose reflectance meter can be used for accurate outpatient screening of gestational diabetes mellitus. The potential advantages of capillary blood glucose screening include both cost and efficiency. Patients with abnormal screening values can be promptly identified and scheduled for a follow-up 3-hour glucose tolerance test.

Blood Glucose↗
PubMed1986

Maternal acetaminophen overdose at 15 weeks of gestation.

Acetaminophen is a common drug used in pregnancy. A 32-year-old woman ingested 64 g of acetaminophen at 15 weeks of gestation. Treatment with N-acetylcysteine was given within 24 hours. The patient nonetheless developed severe hepatic necrosis and her hospital course was complicated by adult respiratory distress syndrome. With aggressive supportive treatment, the mother survived and delivered a viable infant at 32 weeks' gestation. The possible mechanisms of acetaminophen toxicity in the mother and the fetus are discussed.

Acetaminophen↗
PubMed1986

Total parenteral nutrition during pregnancy.

Several years ago, most obstetricians would have thought that any disease severe enough to require parenteral nutrition would also lead to infertility or early pregnancy loss. Women with many complex disease states have now been successfully treated by TPN during pregnancy, resulting in favorable outcomes for both mother and fetus. Theoretically, these patients, if not supplied with an adequate amount of essential nutrients by TPN, might have experienced excessive perinatal morbidity and mortality. The difficulties involved with studying maternal-fetal exchange processes in humans leave considerable gaps in our current knowledge about nutritional requirements during normal pregnancy. Some have suggested that subtle degrees of malnutrition may jeopardize normal growth and development. In states of severe protein calorie malnutrition, there remains little doubt that intrauterine growth is diminished. In such cases in which there is poor maternal weight gain, it may be critical to initiate some method of nutritional support. Whereas TPN during pregnancy has been sporadically employed in the treatment of cases of suspected fetal growth retardation, limited experience with this therapy suggests that at present we primarily direct treatment toward patients with specific disease states that are accompanied by overt malnutrition. Parenteral nutrition support should begin only after a period of adequate nutritional assessment and monitoring. If such support is necessary, TPN should be administered by a team of qualified knowledgeable individuals who are very familiar with the techniques. The relatively high rate of premature delivery associated with patients requiring TPN during pregnancy requires the presence of an intensive care nursery in the institution.

Female↗
PubMed1985

Glucose monitoring and insulin administration in the pregnant diabetic patient.

Over the past decade, it has been apparent that the degree of glycemic control achieved in the pregnant patient with diabetes mellitus significantly affects perinatal outcome. While several studies have documented excellent perinatal outcome with good glucose control, the incidence of neonatal morbidity still remains substantially greater than that observed in the general population. Physiologic or "tight" control appears to further reduce the incidence of macrosomia, hypoglycemia, and other indices of neonatal morbidity. The application of home glucose-monitoring techniques to pregnancies complicated by diabetes can result in optimal glucose control. While one small comparative series did not document improvement in perinatal morbidity, fewer admissions for diabetic control and decreased patient expense were observed in the group using home monitoring. After pregnancy, most patients continued to use home monitoring. This probably reflects the degree of patient enthusiasm and interest generated by self-care. Programs using home blood glucose monitoring and individualized insulin regimens in the management of diabetes may have their greatest impact if implemented prior to conception. The degree of glucose control during early embryogenesis appears to determine the incidence of congenital malformations in the offspring of insulin-dependent diabetic women. Continued careful assessment of the degree of glycemic control may enable the patient and her physician to plan the optimal time for attempting a pregnancy.

Blood Glucose↗
PubMed1985

Antepartum fetal surveillance in gestational diabetes mellitus.

Pregnancy in patients with gestational diabetes mellitus (GDM) is associated with increased perinatal morbidity. Whether the perinatal mortality rate, particularly the fetal death rate, is greater in these patients remains controversial. The present study was undertaken to review the role of antepartum fetal monitoring in 69 patients with GDM controlled by diet only (class A) and 28 women requiring insulin therapy (class AB). Hypertension complicated 21.6% of these pregnancies. Antepartum fetal surveillance included outpatient nonstress testing, urinary estriol assays, maternal assessment of fetal activity, and clinical estimation of fetal weight. All insulin-requiring patients as well as fourteen class A patients with identifiable risk factors underwent testing. No perinatal deaths occurred. Only six patients required intervention for suspected fetal jeopardy and four of these women had hypertension. Macrosomia was correctly identified in only 6 of 16 infants weighing 4000 g or more. This study suggests that, in GDM, an outpatient program of fetal testing, using primarily the nonstress test and maternal assessment of fetal activity, can be employed in patients requiring insulin as well as class A patients with identifiable risk factors. This protocol resulted in a low rate of unnecessary intervention and good perinatal outcome. The risks for abnormal antepartum testing results appear increased in GDM with hypertension and prolonged pregnancy.

Cesarean Section↗
PubMedDate not supplied

Prenatal diagnosis of macrosomia in pregnancy complicated by diabetes mellitus.

OBJECTIVE: To provide a concise review of current practices regarding prenatal diagnosis of excess fetal growth in pregnancies complicated by diabetes mellitus. METHODS: A literature review of relevant publications. RESULTS: Sonographic estimation of fetal size at term is frequently undertaken in the management of diabetic pregnancy. Considerable error in fetal weight estimations, particularly in asymmetrically enlarged fetuses, may limit the accuracy and clinical utility of these measurements. CONCLUSIONS: The limitations and potential inaccuracy of current sonographic methods to detect the large-for-gestational age fetus of a diabetic mother are acknowledged. Customized formulae are of limited benefit so that further study of techniques aimed at assessing fetal fat content and distribution should be undertaken. These methods may improve detection of the large fetus and aid in clinical decision making.

Female↗