Table 3. Main characteristics of the studies included in the meta-analysis for IL‐1β +3954C>T .

Study (year)	Genotyping method	Disease	Country	Ethnicity	Case					Control					Cases	Controls	PHWE	PHWE*	Score
IL‐1β, +3954C>T						CC	CT	TT	C	T	CC	CT	TT	C	T
Reid et al. (2001)	PCR-RFLP	PE	UK	Caucasian	17	40	11	6	0	28	6	26	14	0	66	14	0.18	0.37	6
Ma et al. (2011)	PCR-RFLP	RSA	China	Asian	162	156	124	38	0	286	38	130	26	0	286	26	0.26	0.38	7
Mohajertehran et al. (2012)	PCR-RFLP	PE	Iran	Asian	54	50	28	20	6	76	32	28	20	2	76	24	0.49	0.59	6
Galvao et al. (2016)	RT PCR	PE	Brazil	Hispanic	168	449	5	58	105	68	268	181	87	181	449	449	0	0	7
Langmia et al. (2016)	MassArray	PTB	Malaysia	Asian	94	398	83	11	0	177	11	346	52	0	744	52	0.16	0.38	7
Tavakkol Afshari et al. (2016)	PCR-RFLP	PE	Iran	Arab	153	150	80	57	16	217	89	84	60	6	228	72	0.24	0.38	7
Wang et al. (2019)	PCR-RFLP	RSA	China	Asian	598	603	482	111	5	1075	121	474	121	8	1069	137	0.93	0.93	8

RSA: Recurrent spontaneous abortion; PE: Preeclampsia; PTB: Preterm birth; UK: United Kingdom; RT PCR: Real-time PCR. P_HWE: The P-value of chi- test for Hardy-Weinberg Equilibrium (HWE) in controls; P_HWE*: P_HWE corrected for multiple testing by FDR method.