Alterations in the baroreflex occur late in pregnancy in conscious rabbits, , ,

Experiments were performed in conscious rabbits to investigate when during pregnancy cardiac baroreceptor reflex gain decreases. A decrease in gain was first observed after 3 weeks of gestation (–34.1 ± 4.9 to –15.7 ± 3.1 beats/min/mm Hg, p< 0.05) and became more pronounced after 4 weeks (–30.2 ± 4.7 to –8.6 ± 2.9 beats/min/mm Hg, p< 0.05). These results indicate that the attenuation of baroreflex function does not become fully manifest until late in pregnancy. (Am J Obstet Gynecol 1997;176:692-4.)