Urinary metabolic profiles in early pregnancy are associated with preterm birth and fetal growth restriction in the Rhea mother–child cohort study

Table 3 Dose–response relationships between levels of selected metabolites and frequency of birth outcomes

Outcome	Metabolite	Q1	Q2	Q3	Q4	Pvalue for trend
All PB types (n = 114)	Steroid conjugate: 0.63 (s)	21%	22%	25%	32%	0.01*
	Formate	32%	25%	23%	20%	0.02*
SPB (n = 88)	Steroid conjugate: 0.63 (s)	20%	22%	24%	34%	0.01*
	Lysine	14%	30%	26%	31%	0.03*
	Trimethylamine-N-oxide	26%	28%	28%	17%	0.10
	Glycine	26%	34%	20%	19%	0.07
	N-methyl-2-pyridone-5-carboxamide	19%	19%	30%	32%	0.03*
	Formate	32%	25%	24%	19%	0.02
IPB (n = 26)	N-acetyl glycoprotein fragments	8%	23%	19%	50%	0.01**
	Phenylacetylglutamine	42%	27%	12%	19%	0.03*
FGR (n = 36)	Tyrosine	33%	36%	17%	14%	0.03*
	Lactate	33%	33%	17%	17%	0.05*
	Alanine	39%	31%	11%	19%	0.03*
	Acetate	39%	31%	22%	8%	0.004**
	Citrate	33%	39%	14%	14%	0.02*
	Trimethylamine	50%	19%	17%	14%	0.002**
	Glycine	33%	39%	11%	17%	0.03*
	Formate	39%	28%	19%	14%	0.02*
SGA (n = 19)	Leucine	16%	16%	26%	42%	0.06
	Lactate	37%	37%	16%	11%	0.05*
	Alanine	42%	32%	16%	11%	0.03*
	Acetate	42%	21%	32%	5%	0.05*
	N-acetyl neuraminic acid	21%	11%	16%	53%	0.04*
	Trimethylamine	47%	16%	21%	16%	0.07
	Glycine	42%	37%	11%	11%	0.02*

Percentage of each birth outcome frequency across pregnant women stratified by metabolite levels (into quartiles: Q1, Q2, Q3, and Q4).
*P < 0.05 and **P < 0.01 for a significant trend in outcome (Cochrane-Armitage trend test, highlighted in bold).
FGR, fetal growth restriction; IPB, induced preterm birth; SGA, small for gestational age; SPB, spontaneous preterm birth.

ISSN: 1741-7015