Renal reserve during human pregnancy .
Sturgiss, Sn, R Wilkinson, and Jm Davison.
Departments of Obstetrics & Gynecology, and Medicine, The
Medical School, University of Newcastle-upon-Tyne, NE1 4LP
APStracts 2:0216F, 1995.
Pregnancy in healthy women is associated with increments in glomerular
filtration rate (GFR) and effective renal plasma flow (ERPF). We
hypothesised that the hyperfiltration of normal pregnancy attenuates
or exhausts renal reserve. In 21 healthy women studied serially in
early and late pregnancy and then on average 15 weeks postpartum, GFR
and ERPF were determined by inulin and para-aminohippurate
clearances, respectively, before and during either an amino-acid
infusion (Vamin 9, Kabi Pharmacia)(n=14) or a control infusion of
Hartmans solution (n=7), both infused at 4ml/min for 210 mins. In
early and late pregnancy, GFR increased significantly in response to
amino-acid infusion (from 137 +/ 29 to 162 +/- 35 ml/min
{p<0.001} and from 134 +/- 29 to 148 +/- 40 ml/min
{p<0.01}, respectively), with the increments (18% and 10%,
respectively) not significantly different from postpartum (non
-pregnant), when GFR increased by 12% from 94 +/- 22 ml/min to 105 +/-
23 ml/min (p<0.002). Amino-acid infusion significantly increased
ERPF from 874 +/- 188 to 980 +/- 215 ml/min in early pregnancy
(p<0.01), from 684 +/- 135 to 773 +/- 181 ml/min in late
pregnancy (p<0.01) and from 507 +/- 121 to 560 +/- 141 ml/min
postpartum (0.006), increments of 12%, 13% and 10%, respectively. GFR
did not change in response to control infusion. We conclude that
despite gestational increments in renal hemodynamics of > 40%,
pregnancy does not attenuate the renal response to amino-acid
infusion.
Received 10 July 1995; accepted in final form 29 November 1995.
APS Manuscript Number F219-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 12 December 95