Introduction: Pregnancy is a physiological condition associated with profound adaptive changes in the maternal hemodynamics and cardiovascular system. Autonomic nervous system plays a central role in this adaptation to the various needs of pregnancy. One of the well known complication, that occurs commonly during pregnancy is pregnancy induced hypertension (PIH)/ preeclampsia (PE). Impairment of autonomic functions has been suggested as one of the cause of pregnancy induced hypertension. As sympathetic vascular reactivity has been reported as one of the indicators of autonomic status to predict the development of hypertension. Therefore, this study was undertaken to assess sympathetic vascular reactivity in the first and second trimesters of pregnancy. Materials and Methods: The study was conducted in the Department of Physiology, Uttar Pradesh University of Medical Sciences (UPUMS), Saifai, Etawah, in association with Department of Obstetrics and Gynaecology. The pregnant females in first and second trimesters reporting to the Out Patient Department (OPD) of Obstetrics and Gynaecology were included in the study. They were subjected to the Cold Pressor Test for the assessment of sympathetic vascular reactivity in sitting position by the method as described by Hines and Brown. Results: A total of 14 subjects were recruited in the study (7 subjects were in the first trimester and another 7 were in the second trimester). The 51.7 percent of the subjects during first trimester turned out to be the hyper- reactors while in second trimester this was true for the 71.4 percent of the subjects. Conclusion: As the subjects even in the first trimester showed increased blood pressure reactivity, thus it is hypothesised that assessment of sympathetic vascular reactivity reflected as blood pressure reactivity from early pregnancy may be a useful indicator for development of pregnancy induced hypertension and preeclampsia in later pregnancy.

Keywords: Pregnancy; Autonomic Functions; Sympathetic Vascular Reactivity; Pregnancy Induced Hypertension; Preeclampsia.