Alterations of thermoregulation in women with hyperemesis gravidarum.

We investigated the thermoregulatory alterations to coldness in hyperemesis gravidarum. In pregnant women with hyperemesis (n=22), thermographic measurements for skin temperature and heat dissipation from the back were made during immersions of hands in 15 degrees C water for 50 s. A thermogenic ratio (TR) was calculated as (A-B)/B, where A and B represent the rate of heat dissipation (Cal/hr) from the interscapular and the whole back area, respectively. Simultaneously, changes in serum nonesterified fatty acids (NEFAs) were measured in response to the stimulus. A comparison was made between the women with and without hyperemesis (n=13). Skin temperature did not respond to slight cold stimulus. However, TR increased rapidly and kept increasing (P<0.01) and NEFAs increased (P<0.05) only in subjects with fasting hyperemesis. Increase in TR was closely associated with that of NEFAs (P<0.05) and weight loss. Characteristic thermoregulatory response is found in the interscapular skin region of hyperemesis gravidarum. This may be caused by elevated lipolytic activity associated with interscapular region in undernourished pregnant women.