The metabolic clearance rate (MCR) of arginine vasopressin (AVP) increases fourfold during human pregnancy. To explore whether circulating vasopressinase may play a role in this change, six women underwent a three-tier infusion clearance study, twice, in random order, to determine the MCRs of either AVP or 1-deamino-8-D-AVP (dDAVP, an analogue resistant to degradation by vasopressinase). [...]
Osmoregulation was studied in eight women during late pregnancy and again 8-10 wk postpartum. Base-line plasma osmolality (Posmol) was significantly lower during (280.9 +/- 2.1 mosmol/kg, SD) than after (289.4 +/- 2.1 mosmol/kg) pregnancy yet 24-h urinary volume and plasma arginine vasopressin (PAVP) measured in vasopressinase-inactivated blood was similar in both groups (pregnancy, 1.39 +/- [...]
Serial studies were designed to characterized changes in osmoregulation throughout gestation. Eight women underwent a 2-h infusion of hypertonic saline before conception, during gestational weeks 5-8, 10-12, and 28-33, and then 10-12 wk postpartum. Basal plasma osmolality (Posmol) was already significantly decreased by 5-8 wk (P less than 0.001) and remained 10 mosmol.kg-1 below nonpregnant [...]
An in-hospital prospective, observational cohort study was conducted to assess the effects of type of feeding (exclusively breastfed [EBF] vs partially breastfed [PBF]) on the hydration status of near-term newborns in the first week of life. A total of 205 babies of 35 to 37 weeks of completed gestation were enrolled (82 in the EBF [...]
No abstract available.
This study was conducted in 4 villages in India during the hottest and driest season of the year to determine whether exclusively breast-fed infants need additional water under extremely hot and dry climatic conditions. The ambient temperature was 35-40 degrees C and the relative humidity 10-35%, except during the early morning hours. 63 urine samples [...]
During normal pregnancy total body water increases by 6 to 8 liters, 4 to 6 liters of which are extracellular, of which at least 2 to 3 liters are interstitial. At some stage in pregnancy 8 out of 10 women have demonstrable clinical edema. There is also cumulative retention of about 950 mmol of sodium [...]
OBJECTIVE--To determine whether the fall in plasma osmolality in normal human pregnancy resulted in cellular overhydration. DESIGN--The changes in erythrocyte hydration, potassium and total osmoles in response to a decrease in osmolality in vitro and associated with the fall in plasma osmolality in normal pregnancy were determined. SUBJECTS--Fifty-one women were studied serially during pregnancy and [...]
Earlier results have shown that some infants born by elective Caesarean section start to sweat in a warm environment while others do not, and that sweating can be inhibited by feeding cold glucose. To determine whether these earlier observations, indicating a difference in postnatal temperature adaptation, could be reproduced in vaginally born infants, we measured [...]