Table 3.

Associations of the eight metabolite modules with each preterm delivery (PTD) subgroup, compared to women with term delivery

Modulea	Nmetabolite	Top hub metaboliteb	mPTD + preeclampsia		mPTD only		sPTD
			Beta ± SEc	P	Beta ± SEc	P	Beta ± SEc	P
Blue	54	C44:1 TAG	0.000 ± 0.003	0.98	− 0.011 ± 0.004	0.004*	− 0.003 ± 0.002	0.10
Yellow	38	C16:0 CE or C36:2 DAGd	0.016 ± 0.003	7.8 × 10–7*	− 0.001 ± 0.004	0.86	− 0.004 ± 0.002	0.06
Pink	26	C18:1 LPC	0.009 ± 0.003	0.007	0.005 ± 0.004	0.24	0.005 ± 0.002	0.03
Red	36	C32:2 PC	0.001 ± 0.003	0.76	− 0.008 ± 0.004	0.03	− 0.002 ± 0.002	0.30
Turquoise	63	C16:0 sphingomyelin	− 0.001 ± 0.003	0.74	0.001 ± 0.004	0.71	0.000 ± 0.002	0.85
Black	34	C14:1 carnitine	0.015 ± 0.003	1.6 × 10–5*	0.009 ± 0.004	0.02	0.002 ± 0.002	0.33
Brown	41	Valine	0.003 ± 0.003	0.38	0.001 ± 0.004	0.77	0.001 ± 0.002	0.66
Green	37	Pseudouridine	0.011 ± 0.003	7.0 × 10–4*	0.002 ± 0.004	0.54	− 0.006 ± 0.002	0.003*

mPTD medically indicated PTD, CE cholesteryl ester, DAG diacylglycerol, LPC lysophosphatidylcholine, PC phosphatidylcholine, TAG triacylglycerol

^aThe WGCNA analysis was conducted on 1330 samples using the “unsigned” network, where the highly correlated (either positive or negative) metabolites were grouped into the same module

^bThe top hub metabolite was defined as the one with the highest mean correlation with the other metabolites in the same module

^cAdjusted for maternal age at delivery, maternal ethnicity/race, maternal birthplace, pregestational BMI category, pregestational diabetes, chronic hypertension, marital status, highest education level, parity, smoking during pregnancy, illicit drug use, lifetime stress, and fetal sex

^dC16:0 CE is negatively correlated with the “yellow” module score while C36:2 DAG is positively correlated with the “yellow” module score

*Significant after Bonferroni corrections for multiple testing on 8 metabolite modules