Terbutaline: effects on the fetal heart at term.

The aims of this study were to evaluate the cardiac effects of subcutaneous terbutaline on the mother and fetus. Terbutaline was given in 250 or 500 µg doses to term gravidas not in labor. The mean arterial pressure (MAP), pulse, and uterine activity were measured. The fetal heart rate (FHR), accelerations, and decelerations were recorded. There were significant increases in maternal heart rate, FHR, and FHR accelerations, and a decrease in uterine basal activity after 500 µg, but not significantly after 250 µg of terbutaline. MAP was not significantly increased with either dose, although a small mean increase was observed. Terbutaline has a direct effect on the fetal heart apart from the effect of uterine relaxation.

Heterogeneity in fetal immunocompetence during the second trimester of gestation. Implications for treatment of nonimmune genetic disorders by in utero transplantation.

OBJECTIVE: To address the role that alloreactivity may play and better define the window for histoincompatible stem cell transplantation in utero. SUBJECTS, MATERIAL AND METHODS: We studied 9 fetal blood specimens obtained by cardiocentesis during elective abortions in the second trimester by multicolor flow cytometry and in vitro stimulation. RESULTS: Lymphocytes ranged from adult levels (3/9) to >90% leukocytes. Six specimens had T cells within adult range. T cells in the other specimens were reduced, while B cells were conversely elevated. This variability did not correlate with gestational age, or leukocyte composition. Following 4 h of mitogenesis, fetal CD4+ and CD8+ T cells from 1 of 5 specimens showed a response similar to that of maternal T cells, while the other 4 specimens showed a diminished response (0.3 +/- 0.2-fold). This heterogeneity did not correlate with gestational age, or lymphocyte subset distribution. Following 18 h of in vitro mitogenesis, fetal T cells from 2 specimens showed a response similar to that of maternal T cells (0.8 +/- 0.2-fold). Despite that, one specimen gave a 3-fold greater response in a one-way mixed lymphocyte reaction vs. maternal cells compared to the other specimen. CONCLUSION: We determine that fetal immunocompetence differs greatly during the second trimester and assessment of host vs. donor reactivity prior to in utero transplantation is likely to potentiate more favorable outcomes.