An examination of mediation by DNA methylation on birthweight differences induced by assisted reproductive technologies

Table 3 Effects of DNA methylation on birthweight differences between fresh and frozen conceived newborns

	Total effect^{1, 2}	P value
Fresh embryo transfer (reference) vs frozen thawed embryo transfer	194 (89, 301)	3.22E−04

CpG name	Indirect effect^{1, 2} in grams	P value¹	Direct effect^{1, 2} in grams	P value	Mediation proportion	CHR³	MAPINFO³	UCSC RefGene Name³
cg12763919	35 (13,65)	7.96E−03	159 (55, 263)	2.74E−03	19.3%	9	125,137,580	PTGS1⁴
cg09258455	24 (6,47)	2.31E−02	170 (65, 276)	1.56E−03	13.2%	19	38,918,162	RASGRP4⁵

	Combined indirect effect^{1, 2}	P value^{1, 2}	Combined direct effect^{1, 2}	P value	Mediation proportion
The two CpGs combined	42 (16, 75)	4.71E−03	152 (47, 256)	4.30E−03	21.6%

¹Adjusted for maternal age, education, smoking status, pre-pregnancy BMI, parity, child’s sex, maternal intake of folic acid, and plate. Birthweight difference is in grams
²95% confidence intervals in parenthesis
³Derived from the Illumina MethylationEPIC v1.0 B5 manifest file. The archaic names of the genes were updated based on the data from https://www.genenames.org/
⁴Located within the 5’ untranslated region, 0–200 bases upstream of the transcription start site and the gene body depending on the transcript
⁵Located within 200–1500 bases upstream of the transcription start site of the gene

ISSN: 1868-7083