Table 3. Leiomyoma size and number and association with spontaneous abortion by study.

Study	Categories	n	Outcome Measure
Benson et al.			Prevalence of SAB†
Leiomyoma size	No leiomyomas	715	7.6%
	<2 cm	39	20.5%
	2-4 cm	58	8.6%
	>4 cm	46	15.2%
Leiomyoma number	No leiomyomas	715	7.6%
	Single leiomyoma	88	8.0%
	2	25	24.0%
	3	8	12.5%
	4+	22	27.3%
Hartmann et al.			Adjusted HR (95% CI)
Leiomyoma size*	No leiomyomas	4,741	1.00 [referent]
	Lowest quartile	143	1.12 (0.74–1.68)
	2nd quartile	140	1.02 (0.65–1.59)
	3rd quartile	141	0.52 (029–0.91)
	Top quartile	140	0.62 (0.34–1.14)
Leiomyoma number	No leiomyomas	4,741	1.00 [referent]
	1	398	0.84 (0.62–1.15)
	2+	166	0.79 (0.51–1.23)

SAB, spontaneous abortion; HR, hazard ratio; CI, confidence interval

^*Leiomyoma largest dimension: Lowest quartile [0.51–1.36 cm), 2nd quartile [1.36–2.35 cm), 3rd quartile [2.35–3.62 cm), Top quartile [3.62–13.20 cm]