Table 3.

Multivariate models explaining birth weight at 1^st, 2^nd and 3^rd trimester by use of various explanatory variables

Included variables in model	R 2	β	Standardized β	t	P-value	sr
1st trimestera
FFM	0.24	44.47	0.35	5.16	<0.001	0.35
2nd trimesterb
FFM	0.19	30.72	0.22	5.83	<0.001	0.19
Pre-pregnancy BMI		16.16	0.11	2.91	0.004	0.09
Gestational age		11.35	0.07	2.24	0.025	0.07
3rd trimesterc
FFM	0.12	68.3	0.38	3.31	0.002	0.38

Abbreviations: R ², standardised coefficients of determination; β, unstandardised multiple regression coefficients; sr, semipartial correlations

^aNo effect of maternal age, maternal pre-pregnancy BMI, BMI at the tested time, gestational age and FM

^bNo effect of maternal age, BMI at the tested time and FM

^cNo effect of maternal age, maternal pre-pregnancy BMI, BMI at the tested time, gestational age and FM