Table 2

Model coefficients for final birth weight model and each internal-external cross validation cycle, with study specific intercepts

	Continuous outcome model, coefficient
	Pooled data	Excluding Allen et al, 2017 cohort*	Excluding Rumbold et al, 2006 cohort†	Excluding STORK Groruddalen, 2010 cohort‡
Gestational age at delivery (weeks)
Weeks⁻²	24 200 000	24 300 000	24 600 000	24 200 000
Weeks⁻² × ln weeks	−9274661	−9278365	−9383827	−9256070
Maternal weight (kg)	2.708811	2.706337	2.702486	2.712717
Maternal height (cm)
cm³	0.0000752	0.0000750	0.0000747	0.0000749
Maternal age (years)	3.138301	3.142642	3.160154	3.160331
Nulliparous	−92.03335	−91.72014	−91.86725	−91.48258
Smoker	−118.0368	−118.025	−119.9714	−118.4065
Ethnic group
White	Reference	Reference	Reference	Reference
Black	−174.2521	−174.4343	−174.5623	−174.2543
South Asian	−73.23465	−71.06526	−73.76615	−72.71608
Hispanic	−9.562515	−9.582163	−10.10826	−9.50801
Mixed	−64.73106	−62.95441	−65.91944	−64.19719
Other	−60.38814	−59.96023	−60.27113	−62.70106
History of hypertension	−36.27748	−36.01454	−36.19573	−36.47012
History of diabetes	149.9896	150.6165	150.6321	150.0034
Assisted conception	−78.7545	−81.1364	−79.92499	−93.85787
Any previous pre-eclampsia	−84.16068	−84.04261	−83.93942	−84.10901
Any previous stillbirth	−13.59535	−13.11023	−13.67015	−13.1444
Any previous baby small for gestational	−481.7414	−486.7372	−481.4254	−485.4757
Intercept (average for all studies)	9210.304	9212.973	9259.176	9200.492
Heuristic shrinkage factor	0.9997	0.9997	0.9998	0.9997