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

Table 5 Parameter estimates modelling birth crown heel length to the power of 0.75 (cm)

Independent Variable	Parameter Estimate	Standard Error	t value Pr >\|t\|	95% confidence limits
Intercept	5.684	0.176	32.30 <.0001	5.34	6.03
Scaled gestational age squared*	209.9	3.66	57.31 <.0001	203	217
Scaled gestational age cubed*	-318.5	6.44	-49.43 <.0001	-331	-305
Male infant	0.2350	0.0047	50.08 <.0001	0.226	0.244
Maternal height c#	0.01665	0.00042	40.28 <.0001	0.0158	0.0174
2nd birth	0.07484	0.0054	13.89 <.0001	0.064	0.085
3rd birth	0.1161	0.0070	16.62 <.0001	0.102	0.130
4th and subsequent birth	0.1508	0.0094	16.09 <.0001	0.132	0.169
GA# × Maternal height	0.000763	0.000215	3.54 0.0004	0.00034	0.00120
Adjusted R ² for this model is 0.322

* 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