Table I.

List of studies that examined the levels of Ang-1, Ang-2 and Tie-2 in placental specimens from pregnancies complicated by PE and IUGR.

Authors/(Refs.)	Year	Sample size	Gestational frame in weeks	Pregnancy complication	Ang-1	Ang-2	Tie-2
Dunk et al (27)	2000	6	28–36	Severe IUGR		NS
Zhang et al (36)	2001	9	31–40	PE		↓
Geva et al (35)	2002	5	25–41	Severe PE		NS
Sung et al (46)	2011	19		PE	NS	NS	NS
Han et al (47)	2012	16	28–41	Severe PE	NS	↑
Kappou et al (48)	2014	28 PE + 30 PE/IUGR	34–39	PE PE + IUGR	↓	↑	↑

PE, preeclampsia; IUGR, intrauterine growth restriction; NS, not significant; The upward arrows indicate the upregulated expression and the downward arrows indicate the downregulated expression of Ang-1, Ang-2 and Tie-2 in the indicated studies.