TABLE 3.

Study characteristics of the included studies

Study	No. of patients	Inclusion criteria for pregnancy loss	Inclusion criteria for aPL antibodies	Treatment	Comparator	Ref
			Aspirin vs. placebo
Pattison 2000	40	≥3 pregnancy losses	aCL antibodies or positive LAC on 2 occasions	Aspirin 75 mg/day	Placebo	27
			Heparin +Aspirin vs. Aspirin
Kutteh 1996a	50	≥3 spontaneous consecutive losses	Presence of aPL antibodies on 2 occasions a	UFH 5000 U bidaily + Aspirin 81 mg/day	Aspirin 81 mg/day	28
Rai 1997	90	≥3 consecutive losses	aCL antibodies or positive LAC on 2 occasions, at least 8 weeks apart	UFH 5000 U bidaily + Aspirin 75 mg/day	Aspirin 75 mg/day	29
Farquharson 2002	98	≥3 consecutive losses or 2 losses >10 weeks	aCL antibodies or positive LAC on 2 occasions, at least 6 weeks apart	Dalteparin 5000 U/day + Aspirin 75 mg/day	Aspirin 75 mg/day	30
Laskin 2009	42	≥2 unexplained consecutive losses <32 weeks	aCL antibodies or positive LAC on 2 occasions, at least 8 weeks apart	Dalteparin 5000 U/day + Aspirin 81 mg/day	Aspirin 81 mg/day	31
Bao 2017	1015	≥2 consecutive losses	Presence of any aPL antibodies on 2 occasions, at least 12 weeks apart	Nadroparin 4100 IU/day + Aspirin 75 mg/day	Aspirin 75 mg/day	32
			Heparin vs.ASPIRIN
Alalaf 2012	141	≥2 consecutive losses <20 weeks	aCL antibodies or positive LAC on 2 occasions, at least 8 weeks apart	Bemiparin 2500 IU/day	Aspirin 100 mg/day	33
			LMWH +Aspirin vs.UFH + Aspirin
Stephenson 2004	26	≥3 unexplained losses <10 weeks or ≥1 loss ≥10 weeks	aCL antibodies or positive LAC on 2 occasions, at least 6 weeks apart	Dalteparin 2500–5000–7500 IU/day b + Aspirin 81 mg/day	UFH 5000–7500–10000 U bid c + Aspirin 81 mg /day	34
Fouda 2011	60	≥3 consecutive losses <10 weeks	aCL antibodies or positive LAC on 2 occasions, at least 12 weeks apart	Enoxaparin 40 mg/day + Aspirin 75 mg/day	UFH 5000 U bidaily + Aspirin 75 mg/day	35
		Higher dose Heparin + ASPIRIN vs.lower dose Heparin + Aspirin
Kutteh 1996b	50	≥3 documented losses	Presence of aPL antibodies on 2 occasions a	UFH 5000 U bidaily (higher PTT) c + Aspirin 81 mg/day	UFH 5000 U bidaily (lower PTT) b + Aspirin 81 mg/day	36
Fouda 2010	60	≥3 consecutive losses <10 weeks	aCL antibodies or positive LAC on 2 occasions, at least 12 weeks apart	Enoxaparin 40 mg/day + Aspirin 75 mg/day	Enoxaparin 20 mg/day + Aspirin 75 mg/day	37

Abbreviations: aCL=anticardiolipin antibodies; aPL, antipohospholipid antibodies; LAC, lupus anticoagulant; LMWH, low molecular weight heparin; PTT, partial thromboplastin time; U, (international) units; UFH, unfractionated heparin.

^aaPL and timeframe between tests not specified; LAC positivity was an exclusion criterion.

^bLMWH 2500 IU/day in 1st trimester, 5000 IU/day in 2nd trimester, 7500 IU/day in 3rd trimester; UFH 5000 IU bidaily in 1st trimester, 7500 IU in 2nd trimester, 10.000 IU in 3rd trimester.

^cUFH dose adjusted to maintain the PTT at 1.2 to 1.5 times the baseline (high‐dose); UFH dose adjusted to maintain PTT at the upper limit of normal (low‐dose).