Table 1.

Characteristics of studies included in the systematic review and meta-analysis

Study	Year	Type of study	Setting	Year of patients’ enrollment	Percent biopsy proven on study entry (n/total)	Pregnancies with LN (n)	Pregnancies without LN (n)	Mean maternal age at delivery (years)* (LN/non-LN)	NOS scores	STROBE checklist (total=22)
Carmona et al21	2005	Cohort	Spain	1995–2001	100% (45/45)	54	54	29.2/29.7	8/9	17
Cavallasca et al49	2008	Cohort	Argentina	1986–2004	NA	20	52	28.1	7/9	13
Whitelaw et al50	2008	Cohort	South Africa	1992–2002	100% (10/10)	15	32	28.3	7/9	13
Wagner et al22	2009	Cohort	USA	1976–2007	73.1% (19/26)	43	47	26.4/28.3	7/9	16
Al Arfaj and Khalil51	2010	Cohort	Saudi Arabia	1980–2006	NA	153	230	25.6	9/9	19
Gladman et al20	2010	Cohort	Canada	1970–2003	NA	81	112	28.3/30.8	9/9	18
Bramham et al24	2011	Cohort	UK	2000–2008	100% (31/31)	43	64	31.6/32.5	9/9	21
Ko et al52	2011	Cohort	Korea	1998–2010	NA	37	144	30	8/9	20
Kwok et al26	2011	Cohort	Hong Kong	1985–2008	100% (30/30)	30	25	30.1/30.7	8/9	19
Saavedra et al13	2012	Cohort	Mexico	2005–2009	74.3% (26/35)	35	60	26.2/26.9	7/9	19
Fatemi et al53	2013	Cohort	Iran	1998–2012	38.5% (5/13)	14	58	28.7/25.8	9/9	19
Madazli et al54	2014	Cohort	Turkey	2002–2011	NA	9	56	28.8	7/9	14
Lv et al25	2015	Cohort	People’s Republic of China	2005–2013	54.2% (13/24)	24	28	28.5/29.4	9/9	20
Mbuli et al55	2015	Cohort	South Africa	2003–2013	100% (29/29)	29	32	27.2	7/9	19
Ku et al23	2016	Cohort	People’s Republic of China	2004–2014	NA	29	35	28.2	7/9	19
Teh et al19	2017	Cross-sectional	Malaysia	2006–2015	80.6% (29/36)	49	66	29.7	6/8	16

Notes: Total scores are 9 for the cohort studies, and 8 for the cross-sectional studies.

^*If there is only one value in the table, it refers to the mean age of both women with lupus nephritis and non-lupus nephritis.

Abbreviations: LN, lupus nephritis; NOS, Newcastle-Ottawa Scale; STROBE, Strengthening the Reporting of Observational Studies in Epidemiology; NA, not available.