Table 2.

Correlations between plasma hormone concentrations and plasma osmolality

Comparison/Group	N	r	r 2	P Value
RLN vs. Osm
0 CL
1 CL	63	0.020	0.000	0.878
>1 CL	54	−0.002	0.000	0.990
hCG vs. Osm
0 CL	68	−0.070	0.005	0.568
1 CL	63	−0.158	0.025	0.217
>1 CL	54	−0.27	0.073	0.048
E2 vs. Osm
0 CL	90	−0.254	0.064	0.016
1 CL	85	−0.367	0.135	0.001
>1 CL	73	−0.460	0.212	<0.001
P4 vs. Osm
0 CL	90	−0.397	0.157	<0.001
1 CL	85	−0.465	0.216	<0.001
>1 CL	73	−0.427	0.182	<0.001
PRA vs. Osm
0 CL	92	−0.281	0.079	0.007
1 CL	85	−0.335	0.112	0.002
>1 CL	69	−0.326	0.106	0.006
Aldo vs. Osm
0 CL	91	−0.313	0.098	0.003
1 CL	84	−0.377	0.142	<0.001
>1 CL	71	−0.381	0.145	0.001

Correlations included the measurements made before pregnancy and during the first trimester except for relaxin (RLN) and human chorionic gonadotropin (hCG), which included only the first trimester because they were undetectable before pregnancy. Aldo, aldosterone; E₂, estradiol; Osm, plasma osmolality; PRA, plasma renin activity; P4, progesterone. Boldface indicates significance. N, No. samples analyzed.