. Author manuscript; available in PMC: 2012 Oct 1.

Published in final edited form as: Acta Obstet Gynecol Scand. 2011 Jun 27;90(10):1057–1069. doi: 10.1111/j.1600-0412.2011.01178.x

Table 1.

Randomized controlled studies on progestin treatment for prevention of preterm birth accomplished since 2003. Note the different progestins, vehicles, route of administration, inclusion criteria, number of patients and outcomes reported, which make the comparison of these studies difficult.

Study	Inclusion Criteria	Number of Patients Included	Progestin	Vehicle	Duration of Treatment	Route	Dose	Outcome	OR/RR (95% CI)

Meis et al., 2003 (58)	history of previous PTB	463	17-OH P	castor oil	16/20 – 36 wks	IM	250 mg weekly	PTB < 37 weeks	OR 0.66 (0.54–0.81)^*
Meis et al., 2003 (58)	history of previous PTB	463	17-OH P	castor oil	16/20 – 36 wks	IM	250 mg weekly	PTB < 32 weeks	OR 0.58 (0.37–0.91)^*

Fonseca et al., 2003 (47)	‘high risk’ (previous PTB, cerclage or uterine anomaly)	142	P4	NS	24 – 34 wks	vaginal	100 mg daily	PTB < 37 weeks	OR 0.40 (0.17–0.94)^*

Rouse et al., 2007 (76)	twin gestations	661	17-OH P	castor oil	16/20 – 35 wks	IM	250 mg weekly	PTB or fetal death < 35 weeks	RR 1.1 (0.9–1.3)

Fonseca et al., 2007 (48)	short cervix (≤15 mm)	250	P4	peanut oil, soy lecithin	24 – 34 wks	vaginal	200 mg daily	PTB < 34 weeks	OR 0.56 (0.36–0.86)^*

O’Brien et al., 2007 (49)	history of previous PTB	659	P4	Replens^®	18/23 – 37 wks	vaginal	90 mg daily	PTB <37 weeks	OR 1.08 (0.76–1.52)
O’Brien et al., 2007 (49)	history of previous PTB	659	P4	Replens^®	18/23 – 37 wks	vaginal	90 mg daily	PTB ≤ 32 weeks	OR 0.9 (0.52–1.56)

Facchinetti et al., 2007 (31)	preterm labor after tocolysis	60	17-OH P	castor oil	25/34 – 36 wks	IM	341 mg twice weekly	PTB < 37 weeks	OR 0.15 (0.04–0.58)^*

Borna et al. 2008 (66)	preterm labor after tocolysis	70	P4	NS	24 – 37 wks	vaginal	400 mg daily	Infant birthweight < 2500 g	RR 0.52 (0.28–0.98)^*

Rai et al., 2009 (62)	history of previous PTB	150	P4	NS	18/24 – 36 wks	oral	100 mg twice daily	PTB < 32 weeks	RR 0.20 (0.05–0.73)^*

Norman et al., 2009 (67)	twin gestations	500	P4	Replens^®	24 – 34 wks	vaginal	90 mg daily	PTB < 34 weeks	OR 1.36 (0.98–2.09)

17-OH P – 17 alpha hydroxyprogesterone caproate; P4 micronized (natural) progesterone; IM – intramuscular; OR – odds ratio; RR – relative risk; CI – confidence interval; NR – not reported; PTB – preterm birth; NS – not specified;

represents statistical significance