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Biomedical subjects

G Gennser

Publications and source records attributed to G Gennser.

At least 55 records · Page 3Linked to original sources
PubMed1978

Intrauterine growth of twins judged by BPD measurements.

Both earlier growth charts of twins composed of birth weight at different gestational ages and recent reports on twin biparietal diameter (BPD) growth, indicate that twins' growth is less than that of singletons during the later period of gestation. In the present study, growth curves are constructed separately for the first and the second twin from 489 paired ultrasonic BPD measurements of 119 twin pregnancies. The distribution of BPD values in twins was found to be slightly wider than our normal range curve for singletons. The mean BPD values of twins were close to those of singletons in the second trimester. From the 32nd week on, the twins' mean weekly BPD increment decreased, this lesser growth rate being more marked than that of singletons. The second twin's BPD growth curve ran consistently below that of the first. Our results agree with the earlier findings that the growth of twins is retarded during the later part of pregnancy. They point to different BPD growth patterns between the first and the second twin.

Birth Weight↗
PubMed1978

Electronic analysis of foetal breathing movements: a practical application of phase-lock-loop principles.

Measurement of foetal breathing movements is becoming more common as a means of monitoring processes occurring in the human foetus. Conventional time-period analysis of breathing movements is prone to error owing to their complexity, and it is laborious to decipher any frequency pattern. The described apparatus has been designed to give an on-line visual indication of the instantaneous frequency of foetal breathing movements when measured by a time-distance recorder connected to an echoscope. It is affected insignificantly by spurious signals, and can be build cheaply with easily-available components. Practical trials suggest that frequency analysis by this device can be of value for examining episodes of continuous breathing movements in the foetus.

Electronics, Medical↗
PubMed1978

Intrauterine breathing movements and fetal presentation.

Fetal breathing movements in 14 twin pregnancies were examined with ultrasonic technique. The twin fetuses I in cephalic presentation showed a significantly higher percentage of apnea and periodic breathing compared with twin fetuses II. No such difference was found in twin pairs with Twin ti in breech presentation. Also in the control group of 27 singleton pregnancies, the fetuses in cephalic presentation had a higher incidence of apnea and periodic breathing than those in breech presentation. The position of the fetus seems to be decisive for the character of the breathing movements before birth.

Female↗
PubMed1977

Fetal cortisol and the initiation of labour in the human.

The role of the fetal adrenal activity in the initiation of parturition in the human has been investigated. Women were studied in the last trimester of pregnancy during treatment with betamethasone for prevention of the idiopathic respiratory distress syndrome. Although betamethasone caused a considerable drop in the cortisol concentrations of fetal plasma and amniotic fluid, the time to spontaneous delivery in this group was similar to that in matched controls. Moreover, cortisol in fetal scalp blood at the onset of parturition in untreated women did not differ between those with spontaneous and those with induced labour. Evidence is given that increase of circulating cortisol in the fetus during the course of parturition predominantly reflects a rise in maternal cortisol under the influence of labour. The strain of labour seems to partly override the betamethasone-induced inhibition of maternal cortisol release. The possible ability of the fetal adrenals to respond to stimuli is illustrated by comparison of cortisol concentrations in cord plasma after various forms of complicated deliveries.

Adrenal Glands↗
PubMed1977

Effect of betamethasone administration on estrone, estradiol-17 beta, and progesterone in maternal plasma and amniotic fluid.

As part of a series of studies on the endocrine consequences of corticosteroid treatment during late pregnancy, the levels of unconjugated estrone (E1), estradiol-14 beta (E2), and progesterone were followed in maternal plasma and amniotic fluid before and after treatment. Ten gravidas in the 30th-35th gestational week received 12 mg betamethasone daily for 3 days for prevention of idiopathic respiratory distress syndrome (IRDS) and were compared to 5 controls. The steroid concentrations were determined by radioimmunoassay. The plasma levels of E1 and E2 were depressed to 38% and 29%, respectively, while that of progesterone was not affected. No significant change of the steroid concentrations in amniotic fluid was observed. The decreased E2: progesterone ratio in maternal blood after betamethasone treatment in the human is in contrast to the increased ratio observed in ruminants after corticosteroid administration and preceding the spontaneous onset of labor. The fall in the E2: progesterone ratio accords with the earlier observed inability of intramuscular corticosteroid treatment of elicit labor in women at this stage of gestation. The earlier demonstrated marked depression of cortisol in fetal plasma after betamethasone seems paradoxical in view of the seemingly high availability of progesterone, considered as a precursor for the cortisol biosynthesis in the human fetal adrenal cortex.

Amniotic Fluid↗
PubMed1977

Placental transfer and metabolism of betamethasone in human pregnancy.

The concentration of betamethasone has been measured in maternal peripheral plasma, umbilical cord artery and vein, and amniotic fluid following maternal administration of betamethasone phosphate and betamethasone acetate on 3 consecutive days. Betamethasone was measured by radioimmunoassay following column chromatography. The findings show that betamethasone is transferred across the human placenta, circulates in the fetus and appears in amniotic fluid. During the 3 days after the start of treatment, levels of the betamethasone were similar in maternal and umbilical cord blood and in amniotic fluid. Thereafter, although levels in the mother were measurable for up to 7 days after the initial injection, the drug was detected in the cord plasma of only one baby. In vitro incubation studies of human placental tissue with 3H betamethasone identified 11-keto betamethasone as the major metabolite of betamethasone.

Amniotic Fluid↗
PubMed1976

Ultrasound and human-placental-lactogen screening early detection of twin pregnancies.

In the past five years gradual introduction of ultrasonic screening of pregnant women increased the ante-partum detection of multiple pregnancy from 60% in 1971 to 95% in the first half of 1975. At the same time the average gestational age for dection of multiple pregnancies diminished from thirty-three to twenty-five weeks. The corresponding figures for 1963 were 32% and thirty-six weeks. Plasma human-placental-lactogen concentrations were assessed for their value in selecting a smaller target group for subsequent ultrasonic screening. All but 2 of 39 twin pregnancies examined by single H.P.L. determinations had H.P.L. values more than 1 S.D. above the mean of the normal distribution. The use of plasma-H.P.L. screening might lower the proportion of patients requiring ultrasonography for antepartum diagnosis of multiple pregnancies to 16% of the total pregnant population.

Evaluation Studies as Topic↗
PubMed1976

Cortisol in amniotic fluid and cord blood in relation to prenatal betamethasone load and delivery.

The influence of maternal corticosteroid administration on the cortisol concentration in fetal blood and amniotic fluid (AF) was studied in women receiving betamethasone for prevention of IRDS. Thirty-four pregnant women in danger of spontaneous or induced preterm delivery were treated with 12 mg. of betamethasone daily for 3 days. AF was obtained by amniocentesis on the day before and the day following the betamethasone treatment and by amniotomy at delivery; cord arterial and venous blood was taken at delivery. Corresponding samples were obtained from 17 pregnant control subjects. All samples were analyzed in duplicate for cortisol by radioimmunoassay. The basal AF cortisol level rose with gestational age. The AF cortisol concentration fell from the basal value of 24.5 +/- 1.8 to 5.4 +/- 0.4 ng. per milliliter 3 days after the start of treatment, and it remained low at delivery if the treatment-delivery time was less than 1 week. An almost significant positive correlation (r = 0.543) was found between the cortisol concentration in cord arterial blood and AF. The cortisol concentration in cord blood in the controls was 108.2 +/- 14.3 ng. per milliliter in the arteries and 106.4 +/- 18.6 ng. per milliliter in the vein. Also, the cord blood cortisol level was depressed in betamethasone had been given within one week before delivery. The multifactorial influence on cord blood cortisol level prevents interpretation of the results as support for the concept that the human fetal adrenal is involved in labor initiation. The duration of gestation was not altered by the betamethasone treatment. The analysis of cortisol in the easily accessible amniotic fluid is suggested for estimating the function of the fetal adrenal cortex.

Amniotic Fluid↗