Optimal fetal growth for the Caucasian singleton and assessment of appropriateness of fetal growth: an analysis of a total population perinatal database

Table 4 Parameter estimates modelling the square root of birth weight (grams)

Independent Variable	Parameter Estimate	Standard Error	t value Pr >\|t\|	95% confidence limits
Intercept	-14.08	0.73	-19.36 <.0001	-15.51	-12.66
GA ³ *	-1413.6	25.0	-56.43 <.0001	-1463	-1365
GA ³ In (GA ³) *	-2782.5	39.4	-70.55 <.0001	-2860	-2705
Male infant	1.185	0.027	44.22 <.0001	1.13	1.24
Maternal height cm#	0.1077	0.0024	45.63 <.0001	0.103	0.112
2nd birth	1.0277	0.031	33.40 <.0001	0.967	1.088
3rd birth	1.318	0.0399	33.04 <.0001	1.24	1.40
4th and subsequent birth	1.571	0.054	29.33 <.0001	1.46	1.68
GA# × Maternal height	0.00667	0.00123	5.42 <.0001	0.0043	0.0091
Adjusted R ² for this model is 0.405

* indicates non-centred but scaled GA, divided by 100
# indicates a centred variable – GA centred around mean of 40 weeks, maternal height centres around a mean of 162 cm

ISSN: 1471-2431