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Biomedical subjects

M Miodovnik

Publications and source records attributed to M Miodovnik.

At least 91 records · Page 5Linked to original sources
PubMed1993

A longitudinal study describing confidence limits of normal fetal cardiac, thoracic, and pulmonary dimensions from 20 to 40 weeks' gestation.

The current prospective, longitudinal study was designed to define the confidence limits and characteristics of growth for fetal cardiac, thoracic, and pulmonary dimensions from 20 to 40 weeks' gestation. We tested the hypotheses that (1) CC/TC, (2) CC/AC, (3) TC/HC, and (4) TC/AC ratios remain constant throughout this period of gestation. The four-chamber view of the fetal heart in diastole, in the absence of fetal breathing, was used as a standard reference for sonographic measurement of cardiac, thoracic, and left and right pulmonary dimensions in a longitudinal study of 45 uncomplicated pregnancies. Cardiac growth is best fit by a quadratic function: -8.147 + 0.900 (GA) - 0.0078 (GA)2. Similarly, thoracic growth is best fit by a quadratic function: -14.072 + 1.757 (GA) - 0.018 (GA)2. The characteristics of growth of the left and right lungs are best described by linear growth equations: -1.71 + 0.426 (GA) and -1.62 + 0.539 (GA), respectively. Each of the CC/TC, CC/AC, TC/HC, and TC/AC ratios changed significantly over time.

Adult↗
PubMed1993

Sonographic estimation of fetal weight based on a model of fetal volume.

OBJECTIVES: To derive a formula for sonographic estimated fetal weight (EFW) based on a two-compartment model of fetal volume and to test it against two widely used formulas, especially at the extremes of fetal weight for which existing formulas are generally inaccurate. METHODS: We analyzed 865 consecutive sonograms that met the following inclusion criteria: singleton pregnancy, normal anatomy, delivery within 3 days of sonography, and measurements of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). The weight of the fetal head was modeled to be proportional to HC3, and the weight of the trunk proportional to AC2 x FL. The proportionality constants were found by multiple linear regression on 380 sonograms performed in 1990 (the "derivation set"). The new formula was tested for accuracy of prediction of actual birth weight against the formulas of Hadlock et al and Shepard et al using 485 sonograms from 1991-1992 (the "validation set"). RESULTS: In the derivation set, the formula EFW = (0.23718 x AC2 x FL) + (0.03312 x HC3) was fit; the correlation with actual birth weight had an r value of 0.996. In the validation set, the new formula produced smaller systematic errors and smaller absolute errors than either the Hadlock or Shepard formula both overall and in fetal weight strata from less than 1000 g to over 4000 g. CONCLUSION: The new formula makes geometric sense and provides accurate estimates of fetal weight across a broad range of weights.

Birth Weight↗
PubMed1993

Early-pregnancy proteinuria in diabetes related to preeclampsia.

OBJECTIVE: To test the hypothesis that the risk of preeclampsia in diabetic mothers is increased with incipient diabetic nephropathy as well as with overt nephropathy. METHODS: Pregnancy outcome was studied in 311 women with class B-RF diabetes from two institutions. Using 104 women without chronic hypertension followed at the University of California, San Francisco, we constructed a receiver-operating characteristic curve relating 24-hour urinary total protein before 20 weeks' gestation to the subsequent development of preeclampsia. From the curve, a predictive cutoff level of proteinuria was selected and tested in two validation groups not used to construct the curve: 158 women without chronic hypertension followed at the University of Cincinnati and 49 women with chronic hypertension from both institutions. RESULTS: The receiver-operating characteristic curve showed an increased risk of preeclampsia with early-pregnancy proteinuria of 190 mg/day or more. In the Cincinnati validation group, the rate of preeclampsia was 7% in women with early-pregnancy proteinuria of less than 190 mg/day, 31% with proteinuria of 190-499 mg/day, and 38% with proteinuria of 500 mg/day or more. In the chronic-hypertension validation group, the rates were 0, 50, and 58%, respectively. By multiple logistic regression, the increased risk of preeclampsia with proteinuria above 190 mg/day persisted after controlling for the effects of parity, chronic hypertension, retinopathy, and glycemic control. CONCLUSIONS: Diabetic gravidas with early-pregnancy proteinuria of 190-499 mg/day are at increased risk for preeclampsia. The risk is comparable to that in women with overt diabetic nephropathy and is independent of chronic hypertension. We speculate that diabetic women with proteinuria in this range have incipient or subclinical diabetic nephropathy.

Adult↗
PubMed1992

Human in situ dosimetry: differential insertion loss during passage through abdominal wall and myometrium.

We constructed a specialized in vivo exposimetry system and determined selected ultrasonic field quantities. We examined two groups of non-pregnant women (nulliparas = 14, multiparas = 9) under conditions of full and empty bladder. A calibrated 7-element linear array hydrophone was placed in the anterior fornix of the vagina in each subject. In the full bladder condition, the sound beam traversed the anterior abdominal wall and full bladder, whereas after voiding, the sound beam traversed the abdominal wall and anteverted uterine fundus. Each study was conducted using a 3.5 MHz mechanical sector transducer. Calibration data were recorded after completion of each in vivo experiment. Data from both groups were pooled for analysis. Assuming (1) the sound path through the full bladder is loss less, the insertion loss (ILFULL) should represent the insertion loss for the abdominal wall (ILABD WALL) 8.2 +/- 5.6 dB; whereas (2) for the empty bladder condition, (ILEMPTY) represents (ILABD WALL+ILUTERUS). Subtracting ILFULL from ILEMPTY yields ILUTERUS = 5.8 +/- 6.8 dB. Therefore, knowing the respective path lengths and normalizing for frequency, the mean tissue attenuation coefficients (A) are estimated to be AABD WALL = 1.39 dB/cm-MHz and AUTERUS = 0.14 dB/cm-MHz. These attenuation data suggest that the abdominal wall is the principal source of ultrasonic energy loss.

Abdominal Muscles↗
PubMed1992

Progression of diabetic retinopathy in pregnancy: association with hypertension in pregnancy.

OBJECTIVE: To test the hypothesis that women with insulin-dependent diabetes and chronic or pregnancy-induced hypertensive disorders are at increased risk for developing retinopathic complications during pregnancy. STUDY DESIGN: One hundred fifty-four women with insulin-dependent diabetes were prospectively followed in an intensive program of diabetes in pregnancy. Ophthalmologic evaluations were obtained through pregnancy and at 6 to 12 weeks post partum, and findings were graded by a standard scale. Association of retinopathic progression with risk factors was tested with chi 2 and multiple logistic regression analysis. RESULTS: Fifty-one women had progression of retinopathy during pregnancy; postpartum regression was observed in 13 women. Changes in glycemic control early in pregnancy, chronic hypertension, and pregnancy-induced hypertension were significantly associated with progression of retinopathy. CONCLUSION: Women with insulin-dependent diabetes who have hypertensive disorders in pregnancy are at increased risk for progression of retinopathy.

Diabetes Mellitus, Type 1↗
PubMed1992

Birth trauma in insulin-dependent diabetic pregnancies.

Infants of insulin-dependent diabetic mothers are considered to be at high risk for birth trauma, presumably due to macrosomia. With current management of diabetes in pregnancy, including strict glycemic control, the rate and the severity of macrosomia should be decreased. The frequent use of ultrasound to assess fetal growth and weight and the use of cesarean delivery in case of fetal macrosomia should further decrease the risk for birth trauma in these infants. We therefore undertook this study to test the null hypothesis that with current management, insulin-dependent diabetic mothers have a rate of birth trauma similar to that of infants of nondiabetic mothers (normal glucose challenge test at 28 weeks' gestation) matched for gestational age at birth, presence or absence of labor, delivery method (vaginal versus cesarean), and race. We studied 118 insulin-dependent diabetic mothers (White classes B-RT) and 354 control subjects (three matches for each insulin-dependent diabetic mother). The rate of birth trauma was 3.4% in insulin-dependent diabetic mothers, not significantly different from controls (2.5%). Logistic regression analysis in which birth trauma was the dependent variable and diabetes, race, presence or absence of labor, mode of delivery (vaginal versus cesarean), infant weight, and infant head circumference were independent variables revealed that only vaginal delivery was a significant risk factor for birth trauma in infants in both groups (p = 0.01). Most frequently observed birth traumas were brachial plexus injury, facial nerve injury, and cephalohematoma. Of the three infants with brachial plexus injury (insulin-dependent diabetic mothers, two; controls, one), two were delivered with use of midforceps.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Umbilical artery aneurysm: prenatal diagnosis and management.

BACKGROUND: An umbilical artery aneurysm is an extremely rare lesion. The purpose of this report is to describe the prenatal sonographic characteristics of such a lesion and potential obstetric complications. CASE: A 26-year-old woman, gravida 2, para 1, at 30 weeks' gestation was referred for an ultrasound examination because of "an abnormality of the umbilical cord." An ellipsoid cystic lesion was noted in a single umbilical artery. Doppler and color flow Doppler examinations demonstrated nonpulsatile and turbulent blood flow within the lesion, consistent with a diagnosis of umbilical artery aneurysm. The aneurysm increased in size over time with a progressive decrease in amniotic fluid volume. Despite reassuring bi-weekly antenatal testing and planned delivery by 36 weeks' gestation, the fetus died in utero, probably because of acute umbilical venous compression by the aneurysm. Autopsy confirmed the presence of a large calcified aneurysm of a single umbilical artery. Dissection of the aneurysm demonstrated anatomical patency of the entire artery. The umbilical vein was histologically normal, as were sections of the artery. CONCLUSION: Although extremely rare, an umbilical artery aneurysm is a potentially lethal anomaly. We recommend delivery as soon as fetal lung maturity is assured when this diagnosis is made prenatally.

Adult↗
PubMed1991

In situ exposimetry: the ovarian ultrasound examination.

We have constructed a specialized in vivo exposimetry system and developed and tested customized software using specially fabricated hydrophones. We placed the hydrophones in the lateral vaginal fornix as close to the ovary as possible (usually 1-2 cm from the ovary) and determined selected first-order and second-order ultrasonic field quantities during a routine ultrasound examination of the ovary. Our sonographic measurements yielded mean ultrasound beam path distances of 7.6 cm. (n = 18) in the presence of a distended bladder and 7.0 cm. (n = 25) in the presence of an empty bladder with an average group insertion loss of 6.2 dB and 7.3 dB, respectively. Using a Fixed Attenuation Model, the tissue attenuation coefficient value was 2.98 dB/MHz; whereas for the Overlying Tissue Model the value was 0.72 dB/cm-MHz. These data are both specific and unique in that they have been systematically obtained in situ.

Body Constitution↗
PubMed1991

Umbilical cord ulceration and intestinal atresia: a new association?

In three fetuses, congenital intestinal atresia was associated with linear ulcerations of the umbilical cord. In two cases, hemorrhage was seen from the cord ulcer. Both fetuses required emergency cesarean section for fetal distress and were born anemic. The third fetus was mildly hydropic, attributed to hemorrhage, and was stillborn. The mechanism of the association could not be determined. These cases suggest a risk of prenatal umbilical cord hemorrhage in infants with intestinal atresia.

Adult↗
PubMed1991

Prenatal diagnosis of fetal left ventricular aneurysm: a case report and review.

Fetal echocardiography in a 30-year-old black woman, gravida 4, para 3, demonstrated left ventricular aneurysm. This was confirmed by color flow pulsed Doppler techniques. After delivery, neonatal echocardiography and magnetic resonance imaging further confirmed the diagnosis. The infant was followed closely and underwent surgical correction at 8.5 months of age. Before surgery, cardiac catheterization demonstrated normal hemodynamic function. A review of the literature revealed a paucity of information. Issues of prenatal diagnosis, antenatal surveillance, method of delivery, and neonatal follow-up are not well defined in either the obstetric or pediatric cardiology literature. A rationale for our approach to this complex problem is presented.

Adult↗
PubMed1991

Human versus animal insulin in the management of insulin-dependent diabetes: lack of effect on fetal growth.

It is generally accepted that the human placenta is impermeable to free insulin and that insulin present in the fetus is entirely of fetal origin. A recent study suggested that antibody-bound animal insulin crosses the placental barrier and may exert direct effects on fetal growth. We hypothesized that mothers with insulin-dependent diabetes treated with animal insulin would have infants with higher birth weights and ponderal indices compared with mothers treated with human insulin. We studied 209 mothers with insulin-dependent diabetes who were enrolled in our program and who delivered after 28 weeks' gestation: 170 were treated with animal insulin and 39 with human insulin. There were no differences between the groups in the mean birth weight (adjusted by gestational age at delivery) or ponderal index of the infants. The rate of macrosomia (birth weight greater than the 90th percentile for gestational age or ponderal index above 2.85) was similar in both groups. The sample size was adequate to yield a power of 80% to detect a difference between groups of 179 g or more in birth weight and 0.1 g/cm3 in ponderal index. We suggest that the type of insulin (animal versus human) used by the pregnant insulin-dependent diabetic mother has no bearing on fetal weight gain.

Adult↗
PubMed1991

Patient experience in a diabetic program project improves subsequent pregnancy outcome.

There has been a notable improvement in the outcome of the pregnancies of insulin-dependent diabetics. This improvement has resulted from intensive health care programs and increased awareness among patients and health providers of the need for specialized prenatal care. We hypothesized that participation in a specialized program providing early glycemic control would benefit the patient's subsequent pregnancy, despite progression of the diabetic disease process. We prospectively studied 55 insulin-dependent diabetic patients enrolled before 9 weeks' gestation through two consecutive pregnancies: sequence 1 and sequence 2. A control group of 55 insulin-dependent diabetic patients, entering the program for the first time, were matched with the sequence 2 pregnancies of the study group by maternal age and year of pregnancy. Specific outcomes related to glycemic control in early gestation were significantly improved from sequence 1 to sequence 2 pregnancies: earlier week of entry (P = .0001), lower glycohemoglobin at 9 weeks (P = .005) and at 14 weeks (P = .02), and improved fetal outcome (decreased rate of spontaneous abortions or major malformations; P less than .01). Week of entry and glycohemoglobin at 9 and 14 weeks were also significantly improved compared with the control group. Seventy-three percent of the patients entered the program earlier in their sequence 2 pregnancies (P = .001) and had lower glycohemoglobin concentrations at 9 weeks (P = .005) compared with their sequence 1 pregnancies. Sixty-five percent of the patients in sequence 2 had advanced diabetic disease (White class D-RF), compared with 46% in sequence 1 (P less than .05) and 44% of the controls (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗
PubMed1991

Hypertension during pregnancy in insulin-dependent diabetic women.

Insulin-dependent diabetic patients are at increased risk for hypertensive disorders of pregnancy. This study was designed to study prospectively the rate of pregnancy-induced hypertension (PIH) in 175 insulin-dependent diabetic pregnancies (88 White classes B-C, 87 classes D-RT). Pregnancy-induced hypertension was defined as two or more occurrences after 20 weeks' gestation of a mean arterial pressure (MAP) of 105 mmHg or greater or an increase of 20 mmHg or greater from the baseline MAP. The rate of PIH in the diabetic population was 15.4% and was significantly associated with nulliparity, poor glycemic control in the first and second trimesters, and advanced White class. Neonatal outcome was not significantly altered in the presence of PIH. We speculate that improved glycemic control throughout pregnancy might reduce the rate of this complication in diabetic patients.

Adult↗
PubMed1991

Pre-conception management of insulin-dependent diabetes: improvement of pregnancy outcome.

Poor glycemic control in early pregnancy in insulin-dependent diabetes is associated with an increased risk for spontaneous abortions and congenital malformations. Strict glycemic control from the initial stages of embryogenesis is one of the major goals of management in these pregnancies. We hypothesized that insulin-dependent diabetic patients attending a pre-conception program would have improved glycemic control compared with insulin-dependent diabetic patients who enrolled after conception and would have better pregnancy outcome, with fewer spontaneous abortions and fewer major malformations. Ninety-nine pregnant insulin-dependent diabetic patients were recruited before reaching 9 weeks' gestation and were followed prospectively throughout pregnancy. Twenty-eight had attended a pre-conception clinic to optimize glycemic control (study group) and 71 had enrolled after conception (control group). Early glycemic control was significantly better in the study group: Glycohemoglobin values at the first prenatal visit and at 9 and 14 weeks' gestation were significantly lower than in the control group. The rate of spontaneous abortion was significantly lower in the study group (7%) than in the controls (24%). There was one major malformation in the control group and none in the study group. We conclude that patients with insulin-dependent diabetes attending a pre-conception program have a decreased rate of early pregnancy loss compared with those receiving prenatal care early in pregnancy.

Abortion, Spontaneous↗
PubMed1990

High infectious morbidity in pregnant women with insulin-dependent diabetes: an understated complication.

Patients with insulin-dependent diabetes are prone to infection, possibly related to poor metabolic control. Relative immune deficiency exists in pregnancy. We hypothesized that pregnant patients with insulin-dependent diabetes are at an increased risk for infection and that infection is related to poor glycemic control. We matched 65 pregnant women with insulin-dependent diabetes to 65 nondiabetic pregnant controls. At least one episode of infection before delivery occurred in 83% of the women with insulin-dependent diabetes (26% in control group). The rate of postpartum infection was five times higher in the group with insulin-dependent diabetes and they were susceptible to more kinds of infections. Although there was no overall difference among the indices of glycemic control, hemoglobin A1 obtained before the infection was higher than during infection. We conclude that a high rate of infection exists in pregnant women with diabetes; infection and poor glycemic control may be associated, but it is unclear whether improvement in metabolic control will reduce this high infection rate.

Adult↗
PubMed1990

Early neonatal predictors of neonatal hypocalcemia in infants of diabetic mothers: an epidemiologic study.

Prematurity, neonatal asphyxia, hypomagnesemia, and advanced maternal diabetes are traditional risk factors for hypocalcemia in infants of diabetic mothers (IDMs). The aim of this study was to determine the relative contribution of these factors separately and combined in a cohort of diabetic pregnancies managed prospectively in the recent 9 years and to find accurate predictors of neonatal hypocalcemia in infants of diabetic mothers. We hypothesized that these factors plus low cord blood calcium (Ca) concentration allow prediction of IDMs who develop neonatal hypocalcemia. We studied 186 IDMs (White class B-RT); gestational age (GA, weeks) was by last menstrual period, confirmed +/- 2 weeks by Ballard score. The goals of glycemic control were: preprandial blood glucose less than 100 mg/dl and 90-minute postprandial blood glucose less than 140 mg/dl. Apgar scores, and cord, 24-, 48- and 72-hour serum calcium (Ca) (mg/dl) and magnesium (Mg; mg/dl) were determined. In univariate analysis, lowest serum Ca correlated with cord blood Ca (r = 0.48, p less than 0.001), GA (r = 0.37, p less than 0.001), and 1-minute Apgar score (r = 0.18, p = 0.09), but did not correlate with cord Mg or with advanced White class. In multiple regression, cord Ca and GA were dominant effects and other variables became insignificant. Lowest Ca (mg/dl) was predicted as follows: lowest Ca = 34.05 - 3.22 (Ca cord) - 0.84 (GA) + 0.10 (GA) (Ca cord). This equation predicts neonatal hypocalcemia (lowest Ca less than 8 mg/dl) with a sensitivity of 72% and a specificity of 75%. Thus, GA and cord Ca allow determination of IDMs at risk for neonatal hypocalcemia.

Asphyxia Neonatorum↗
PubMed1990

Histopathology of spontaneous abortion in diabetic pregnancies.

This study reviewed the histopathology of endometrial curettings following spontaneous abortion in diabetics and controls. The two groups did not differ significantly for an array of histologic features. The relationships between histopathology and diabetic White class, diabetic nephropathy or retinopathy, first trimester hemoglobin A1 percentage, and first trimester serum magnesium level were studied. The only significant correlation found was between diabetic retinopathy and decidual congestion with the presence of venous fibrin.

Abortion, Spontaneous↗