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At least 163 records · Page 9Linked to original sources
PubMed1979

Premature onset of labor, neonatal patent ductus arteriosus, and prostaglandin synthetase antagonists--a rat model of a human problem.

Premature labor and patent ductus arteriosus are two potentially fatal hazards of the human newborn infant. Prostaglandin synthetase antagonists have thus been used to suppress early labor and to close the ductus of the neonate. Indomethacin has been most effective but not free of significant complications. Neuronal necrosis may result from numerous systemic aberrations. A controlled rat model study was therefore devised to investigate fetal neuronal necrosis in relation to maternal indomethacin dose. Dams were given various treatments of 2 mg/kg of 4 mg/kg indomethacin within the last 3 days of gestation. Liquid chromatography was used to assess serum maternal and fetal drug levels. From light microscopy of more than 200 brains it was apparent that fetal neuronal necrosis correlates with maternal dose.

Animals↗
PubMed1989

Radiologic evidence of a nuchal arm in the breech-presenting fetus at the onset of labor: an indication for abdominal delivery.

The occurrence of a nuchal arm during vaginal breech delivery is a potentially traumatic event associated with high perinatal morbidity and mortality. This problem usually cannot be anticipated and must be overcome immediately on diagnosis during the second stage of labor. The results of a retrospective analysis of radiologic studies of 115 cases of term singleton breech deliveries are presented here. A nuchal arm in the first stage of labor was diagnosed in five cases, an incidence of 4.35%. Of four vaginal breech deliveries, one case resulted in severe handicapping neonatal trauma. We suggest that radiologic diagnosis of a nuchal arm in the first stage of labor should indicate abdominal delivery.

Arm↗
PubMed1988

[Serum lipid and lipoprotein concentrations in pregnancy and at onset of labor in normal and complicated pregnancies caused by hypertensive gestosis and fetal growth retardation].

Cholesterol triglyceride and lipoprotein concentrations were determined in the sera of 220 pregnant women at different periods of their pregnancy. In 197 healthy pregnant women we found besides an increase in cholesterol level and in particular an increase in the beta-lipoprotein fractions, a marked increase in pre-beta-lipoprotein levels and more than twice as high triglyceride concentration in the course of the first to the third trimenon. Nothing abnormal was found on comparing the lipid and lipoprotein parameters of 13 pregnant women having hypertensive toxaemia, with those of healthy gravidae, with the exception of a marked increase in the pre-beta-lipoprotein levels in those patients who suffered from toxaemia. No connection was seen between infantile deficient development below the tenth percentile and the serum lipid and lipoprotein concentrations (n = 10) in the mother. Examinations carried out in 233 pregnant women and their children at the time of birth did not yield any connections between maternal and infantile protein patterns. All infants had definitely lower parameter concentrations than their mothers.

Adolescent↗
PubMed1992

Oxytocin and bovine parturition: a steep rise in endometrial oxytocin receptors precedes onset of labor.

Oxytocin receptors were measured in myometrium and intercaruncular endometrium of cows during pregnancy and parturition. Concentrations of estradiol-17 beta, estrone, and progesterone in peripheral blood were also measured. Receptor concentrations in the endometrium rose almost 200-fold from Day 20 to term (p < 0.0001, ANOVA), from 40 +/- 11 to 7300 +/- 1430 fmol/mg protein. Myometrial receptor concentrations increased 10-fold from 180 +/- 36 fmol/mg on Day 20 to 1850 +/- 360 fmol/mg protein at term (p < 0.0001, ANOVA). During labor, endometrial receptors (6600 +/- 1300 fmol/mg) remained at prelabor values, whereas myometrial receptor concentrations had decreased to 1190 +/- 316 fmol/mg (not significant) and declined further postpartum. Plasma concentrations of progesterone declined from 4-5 ng/ml to about 2 ng/ml between Days 250 and 282 and dropped to < 0.2 ng/ml shortly before delivery. Plasma concentrations of estrone and estradiol-17 beta were below 10-20 pg/ml until Day 230. Estrone concentrations were significantly (p < 0.05) increased by Day 250 and estradiol-17 beta by Day 270, and then both rose rapidly. During labor, plasma estrone was 1135 +/- 245 pg/ml and plasma estradiol-17 beta was 226 +/- 131 pg/ml. The molar ratio of estrone and estradiol-17 beta to progesterone rose from less than 0.01 to 4.4 during labor, and was correlated with oxytocin receptor concentrations in endometrium (r = 0.5160, p < 0.001), but not those in myometrium (r = 0.0122). The regulation of oxytocin receptors by ovarian hormones in the two tissues may therefore differ.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1980

Plasma steroid concentrations in maternal and umbilical circulation after spontaneous onset of labor.

Blood samples were obtained from the maternal peripheral vein (n = 17) during the second stage of spontaneous labor and from the umbilical artery (UA) and vein (UVn) immediately after delivery. Four delta 4-and five delta 5-steroids as well as estradiol were measured by RIA. Additionally, cortisol was determined in maternal plasma. The maternal concentrations were compared with our control values obtained from samples (n = 30) collected at term but not in labor. All delta 5-steroids and F were significantly higher during labor than before labor. In the umbilical circulation, progesterone and 17-hydroxyprogesterone were significantly higher in the UVn than in UA (P < 0.05). Whereas androstenedione was significantly higher in the UA [1.01 +/- 0.12 ng/ml (mean +/- SEM)] than in the UVn (0.72 +/- 0.07 ng/ml), testosterone was almost identical in the two (UA, 0.33 +/- 0.03 ng/ml; UVn, 0.35 +/- 0.08 ng/ml). Four of the five delta 5-steroids (dehydroepiandrosterone, dehydroepiandrosterone sulfate, pregnenolone sulfate, and 17-hydroxypregnenolone) had significantly higher concentrations in the UA than in the UVn (P < 0.05). However, pregnenolone levels were not significantly different (UVn, 21.8 +/- 2.0 ng/ml; UA, 18.0 +/- 2.0 ng/ml). No significant correlations were observed between maternal and umbilical steroid concentrations.

17-alpha-Hydroxypregnenolone↗
PubMed2000

Prediction of uterine dehiscence by measuring lower uterine segment thickness prior to the onset of labor: evaluation by transvaginal ultrasonography.

OBJECTIVE: Lower uterine segment thickness was measured by transvaginal ultrasound examination and its correlations with the occurrence of uterine dehiscence and rupture was examined. METHODS: The thickness of the muscular layer of the lower uterine segment was measured in 186 term gravidas with previous uterine scars and its correlation with uterine dehiscence/rupture was investigated. RESULTS: Uterine dehiscence was found in 9 cases or 4.7%. There were no cases of the uterine rupture. The thickness of the lower uterine segment among the gravidas with dehiscence was significantly less in than those without dehiscence (p< 0.01). The cut-off value for the thickness of the lower uterine segment was 1.6 mm as calculated by the receiver operating characteristic curve. The sensitivity was 77.8%; specificity 88.6%; positive predictive value 25.9%; negative predictive value 98.7%. CONCLUSION: Measurement of the lower uterine segment is useful in predicting the absence of dehiscence among gravidas with previous cesarean section. If the thickness of the lower uterine segment is more than 1.6 mm, the possibility of dehiscence during the subsequent trials of labor is very small.

Adult↗