Table 5. Pregnancy complications in patients treated with metformin and placebo, women with and without GDM.

		GDM			Non-GDM
		Metformin	Placebo	p-value	Metformin	Placebo	p-value
WHO 1999 criteria	N	97	103		248	258
	Hypertension	3 (3)	3 (3)	0.31	14 (6)	14 (6)	0.92
	Preeclampsia	6 (6)	3 (3)	0.26	14 (6)	20 (8)	0.34
	Late miscarriage/preterm birth	2 (2)	10 (10)	0.023	10 (4)	26 (10)	0.008
	SGA/LGA	9 (9)/9 (9)	16 (16)/10 (10)	0.33	29 (12)/24 (10)	23 (9)/21 (8)	0.47
	Birth weight, g	3527 ± 511	3366 ± 761	0.08	3580 ± 522	3571 ± 600	0.86
	Birth weight, z-score	-0.09 ± 1.05	-0.18 ± 1.11	0.09	-0.06 ± 1.07	0.04 ± 0.96	0.27
	Gest. age, days	277 ± 11	270 ± 30	0.036	278 ± 16	277 ±20	0.45
	Maternal weight gain, kg	6.6 ± 7.6	9.2 ± 5.2	0.009	9.8 ± 4.9	11.8 ± 4.7	<0.001
	Insulin treatment	9 (9)	14 (14)	0.339	1 (0.4)*	0 (0)	0.31
WHO 2013 criteria	N	139	150		198	215
	Hypertension	9 (6)	5 (3)	0.23	8 (4)	11 (5)	0.78
	Preeclampsia	9 (6)	10 (7)	0.95	11 (6)	13 (9)	0.83
	Late miscarriage/preterm birth	3 (2)	18 (12)	0.001	9 (5)	20 (10)	0.06
	SGA/LGA	9 (6)/14 (10)	20 (14)/15 (10)	0.12	26 (13)/17 (9)	21 (10)/16 (8)	0.51
	Birth weight	3631 ± 480	3406 ± 811	0.005	3521 ± 533	3556 ± 592	0.54
	Birth weight, z-score	0.10 ± 1.03	-0.08 ± 1.11	0.17	-0.17 ± 1.05	0.01 ± 0.95	0.06
	Gest. age, days	277 ± 19	270 ± 30	0.022	278 ± 11	277 ± 20	0.49
	Maternal weight gain, kg	8.0 ± 5.4	10.0 ± 5.6	0.004	9.9 ± 4.8	11.8 ± 4.4	<0.001
	Insulin treatment	10 (7)	14 (9)	0.51	0	0

Values given as mean ± SD or N (%) as appropriate. SGA small for gestational age, LGA large for gestational age.

*One patient receiving metformin was treated with insulin due to GDM diagnosed using the new WHO 2013 criteria, but she did not have GDM using the WHO 1999 criteria.