Table 2.

Gene expression differences in growth-restricted human placenta using microarrays.

Potential Contributing Factor	Fetal Size	Pathway	Gene Expression Change	Gene	Gene Function	References
	Small for gestational age (SGA)	Metabolism	Increased	LEP	Hormone involved in regulating body weight	[41]
		Gestation, stress response and metabolism		CRH	A marker that determines the length of gestation and the timing of parturition and delivery
		Growth factors		IGFBP-1	Binds to insulin like growth factors
Preeclampsia	Fetal growth restriction (FGR)	Angiogenesis	Increased	FLT1	Promotes angiogenesis	[42]
				ENG	Promotes normal structure and integrity of adult vasculature and regulates the migration of vascular endothelial cell
	FGR		Decreased	NRP-1	Multiple roles in angiogenesis, axon guidance, cell survival, migration, and invasion and implemented in multiple cancers	[43]
	IUGR	Cell growth	Decreased	PLAGL1q	Suppresses cell growth	[44]
		Unknown		GNAS	Imprinted allele
		Metabolism		GATM	Mitochondrial enzyme that belongs to the amidinotransferase family
		Growth		MEG3	Growth suppressor in tumour cells, Maternally imprinted
		Enzymatic activity		MEST	Loss of imprinting link to cancer growth
		Growth	Increased	PHLDA2	Plays a role in placental growth
		Gestation, stress response and metabolism		CRH	A marker that determines the length of gestation and the timing of parturition and delivery
		Metabolism		LEP	Hormone involved in regulating body weight
		Inflammatory response		HPGD	Metabolism of prostaglandins
				SLCO2A1	Transport of prostaglandins
	FGR	Immune regulation	Increased	PSG1	Roles in allograft tolerance of the fetus	[45]
		Unknown		PLAC4	Placental specific expression
		Neurological		TAC3	Excite neurons, evoke behavioural responses, are potent vasodilators and secretagogues, and contract (directly or indirectly) many smooth muscles
		Unknown		PLAC3	Unknown
		Gestation, stress response and metabolism		CRH	A marker that determines the length of gestation and the timing of parturition and delivery
		Growth		CSH1	Involved in stimulating lactation, fetal growth and metabolism
		Hormones		KISS1	Initiates secretion of gonadotropin-releasing hormone as well as other tumour-suppressing roles
		Metabolism		CPXM2	Metalloexopeptidase roles
	FGR	Cell–cell adhesion	Increased	CLDN1	integral membrane protein	[46]
		Protective role	Decreased	TXNDC5	induced by hypoxia and its role may be to protect hypoxic cells from apoptosis
		Cell–cell signaling and protein reuptake and metabolism		LRP2	Critical for the reuptake of numerous ligands, including lipoproteins, sterols, vitamin-binding proteins, and hormone
		Neurological	Increased	PHLDB2	involved in the assembly of the postsynaptic apparatus
	Large for gestational age (LGA)	Cell–cell adhesion	Increased	CLDN1	integral membrane protein
		Metabolism	Decreased	LEP	Hormone involved in regulating body weight
		Neurological		GCH1	Involved in making tetrahydrobiopterin a cofactor involved in the production of two neurotransmitters called dopamine and serotonin