Table 1.

Baby Genotypes and Influence on Birth Weight: Individual Studies and Meta-Analysis

Study	RS2/RS2	RS1/RS1	RS2/RS1	Pa	Mb	RS1 Effect Group	Effect Estimate (g)	95% CI (g)	p value
Moore	193	4	66	22	24	28	122	−43–286	0.15
UCL-FGS	292	5	88	20	11	16	68	−196–332	0.61
ALSPAC	6,649	128	2,008	465	51	179	88	6–170	0.03∗
Combinedc	7,134	137	2,162	507	86	223	93	22–163	0.01∗

The RS1 effect group consists of babies with maternally inherited RS1. RS1/RS2 heterozygous babies with heterozygous parents are uninformative for the parental origin of RS1 and were therefore removed from the analysis. All effect estimates (g) have been adjusted for the following covariates: gender, parity, maternal weight, gestational age, maternal smoking, diabetes, and hypertension. The observed genotype frequency had no evidence of deviation from the Hardy-Weinberg equilibrium. Asterisks represent p < 0.05. Three further alleles with different numbers of repeats were identified at the PHLDA2 RS locus in an extremely small number of individuals (n = 25) from the ALSPAC cohort and were thus excluded from the statistical analysis.

^aThe number of heterozygous babies with paternally inherited RS1.

^bThe number of heterozygous babies with maternally inherited RS1.

^cThe meta-analysis of all three cohorts.