Browsing by Author "Nastic, D. (6602473098)"

Objective To evaluate the effect of Rh alloimmunization and intrauterine transfusion on fetal stress hormone levels. Method Umbilical venous samples were obtained immediately prior to transfusion in 51 anemic fetuses and in a control group of 30 non-anemic fetuses. In 16 of the anemic fetuses a repeat sample was obtained post-transfusion. Samples were assessed for hematocrit, pH and levels of β-endorphin, cortisol and adrenocorticotropin. Results The mean initial hematocrit was significantly lower, while the median concentrations of β-endorphin and cortisol were higher in anemic compared with non-anemic fetuses at initial sampling. In contrast, fetal adrenocorticotropin levels did not differ between the groups. Among anemic fetuses, both serum β-endorphin and cortisol levels displayed a strong negative correlation with fetal hematocrit (r =- 0.46, p = 0.006 and r = - 0.54, p < 0.001, respectively). Among anemic fetuses sampled before and after transfusion, levels of β-endorphin were significantly lower, while cortisol levels were significantly higher post-transfusion. Maternal cortisol levels also increased post-transfusion. Conclusion Fetal anemia is associated with increased β-endorphin and cortisol levels. While intrauterine transfusion is associated with a decline in β-endorphin concentrations, fetal cortisol levels increase following transfusion, potentially reflecting transplacental passage of post-transfusion increases in maternal cortisol.

Thyroid hormones, thyroxine-binding globulin (TBG) and thryrotropin (TSH) concentrations were measured in 46 paired fetal and maternal blood samples collected between 17 and 36 weeks of gestation. The samples were selected retrospectively from fetuses that had undergone cordocentesis for prenatal diagnosis, had been found to be unaffected and confirmed healthy at birth. In maternal serum, total thyroxine (TT4) and triiodothyronine (TTj) concentrations were high, but free thyroxine (FT4) and free triiodothyronine (FT-*) were within normal adult ranges: reverse T3 (RT3) increased and TSH levels decreased towards term. Fetal TT4, FT4, TT3. FT3, TBG and TSH levels significantly increased whereas RT3 sharply decreased with gestational age. The ratio of fetal TSH/FT4 significantly decreased, suggesting that the set point for negative feedback of pituitary TSH secretion is changing while the sensitivity of the thyroid gland to TSH increases throughout gestation. There was no significant correlation between the maternal and fetal TBG, TSH, TT4 and FT4, whereas maternal TT3 was positively correlated with fetal TT4. FT4, TT3 and FT3. Normal reference values for maternal and fetal iodothyronines, TBG and TSH throughout the second half of gestation provide insight into fetal thyroid development and may be useful for prenatal diagnosis. © 1991 S. Karger AG, Basel.

Thyroid hormones, thyroxine-binding globulin (TBG) and thryrotropin (TSH) concentrations were measured in 46 paired fetal and maternal blood samples collected between 17 and 36 weeks of gestation. The samples were selected retrospectively from fetuses that had undergone cordocentesis for prenatal diagnosis, had been found to be unaffected and confirmed healthy at birth. In maternal serum, total thyroxine (TT4) and triiodothyronine (TTj) concentrations were high, but free thyroxine (FT4) and free triiodothyronine (FT-*) were within normal adult ranges: reverse T3 (RT3) increased and TSH levels decreased towards term. Fetal TT4, FT4, TT3. FT3, TBG and TSH levels significantly increased whereas RT3 sharply decreased with gestational age. The ratio of fetal TSH/FT4 significantly decreased, suggesting that the set point for negative feedback of pituitary TSH secretion is changing while the sensitivity of the thyroid gland to TSH increases throughout gestation. There was no significant correlation between the maternal and fetal TBG, TSH, TT4 and FT4, whereas maternal TT3 was positively correlated with fetal TT4. FT4, TT3 and FT3. Normal reference values for maternal and fetal iodothyronines, TBG and TSH throughout the second half of gestation provide insight into fetal thyroid development and may be useful for prenatal diagnosis. © 1991 S. Karger AG, Basel.