Table 2.

The impact of IGFs on placental growth and function in vitro and in vivo

Treatment	Species	Treatment (txt)	Analysis day	Placental outcome	References
IGF-I	Mouse	In vivo: maternal txt D1–19	D19	↔ weight	(Gluckman et al. 1992)
		In vitro: primary ectoplacental cone trophoblast	1st trimester	↑ proliferation ↑ migration	(Kanai-Azuma et al. 1993)
	Rat	In vivo: maternal txt D10–21	D21	↔ weight	(Gargosky et al. 1991; Woodall et al. 1999)
	Guinea pig	In vivo: maternal txt D20–37	D40	↑ weight by 10%	(Sohlstrom et al. 2001)
		In vivo: maternal txt D20–38	D35 and D62	↔ weight or structure ↑ transfer of glucose and AIB	(Sferruzzi-Perri et al. 2006, 2007a,b)
	Sheep	In vivo: maternal txt for 4 h on ∼D132	D132	↑ lactate production	(Liu et al. 1994)
	Human	In vitro: villous explants	1st trimester	↑ trophoblast proliferation ↑ extravillous trophoblast migration ↓ trophoblast apoptosis	(Maruo et al. 1995; Lacey et al. 2002; Forbes et al. 2008)
		In vitro: villous explants	1st trimester	↑ secretion of hCG and hPL	(Maruo et al. 1995),
		In vitro: primary trophoblast	1st trimester	↑ proliferation ↑ migration ↑ invasion	(Hamilton et al. 1998; Hills et al. 2004; Kabir-Salmani et al. 2004)
		In vitro: primary villous trophoblast	1st trimester and term	↑ glucose and amino acid uptake	(Kniss et al. 1994; Karl, 1995; Roos et al. 2009)
		In vitro: villous explants	Term	↓ release of vasoconstrictors	(Siler-Khodr et al. 1995)
		In vitro: primary villous and syncytialised trophoblast	Term	↓ TNFα- and IFNγ-induced apoptosis	(Smith et al. 2002)
IGF-II	Mouse	In vitro: primary ectoplacental cone trophoblast	1st trimester	↑ differentiation into giant cells	(Kanai-Azuma et al. 1993)
	Rat	In vivo: maternal txt D16–22	D22	↑ 29% volume of junctional zone	(Van Mieghem et al. 2009)
	Sheep	In vitro: primary mononuclear trophoblast	1st trimester	↑ migration	(Kim et al. 2008)
	Guinea pig	In vivo: maternal txt D20–37	D40	↑ weight by 9%	(Sohlstrom et al. 2001)
		In vivo: maternal txt D20–38	D35 and D62	↔ weight ↓ area and proportion of the interlobium ↑ labyrinthine area, proportion and volume ↑ surface area for exchange ↔ thickness of the trophoblast barrier for exchange ↑ transfer of glucose	(Sferruzzi-Perri et al. 2006, 2007a,b)
IGF-II	Human	In vitro: villous explants	1st trimester	↑ trophoblast proliferation ↑ syncytial regeneration ↑ extravillous trophoblast cell migration ↓ trophoblast apoptosis	(Lacey et al. 2002; Forbes et al. 2008)
		In vitro: primary trophoblast	1st trimester	↑ proliferation ↑ migration ↑ invasion	(Irving & Lala, 1995; Hamilton et al. 1998; McKinnon et al. 2001; Hills et al. 2004; Qiu et al. 2005)
		In vitro: primary villous trophoblast	1st trimester and term	↑ glucose and amino acid uptake	(Kniss et al. 1994; Karl, 1995)

AIB, amino isobutyric acid; D, day of pregnancy; hCG, human chorionic gonadotropin; hPL, human placental lactogen; txt, treatment.