Effect of Metformin Intervention during Pregnancy on the Gestational Diabetes Mellitus in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Table 1

Metformin studies included in the meta-analysis.

Number	Authors	Author study type	Data collection	Malformation described
22	Vanky et al., 2012 [22]	CO (RCT with placebo)	P	No description.
25	Khattab et al., 2011 [25]	CO	P	No miscarriages or neonatal loss occurred in either group.; One baby girl born with major birth defect (tracheoesophageal fistula).
26	Vanky et al., 2010 [26]	CO (RCT with placebo)	P	Metformin group: one postpartum pulmonary embolism, one postpartum circulatory shock, one peripartum cardiomyopathy, and one sudden infant death.; Placebo group: three spontaneous abortions, ileus in one patient with former gastric bypass operation, and one perinatal infant death caused by serious asphyxia.
27	Nawaz and Rizvi, 2010 [27]	CC	P	No description.
28	Begum et al., 2009 [28]	CO	P	No description.
29	Nawaz et al., 2008 [29]	CC	P	No stillbirths, perinatal deaths, or major birth defects. One baby in group A had polydactyl.
30	Fougner et al., 2008 [30]	CO (RCT with placebo)	P	No description.
31	Glueck et al., 2008 [31]	CO (self as control)	P	No maternal lactic acidosis and no maternal or neonatal hypoglycemia. Of the 180 live births to; the 142 nondiabetic women with PCOS, there was one major birth defect (sacrococcygeal teratoma), as determined by pediatricians without knowledge of metformin dose or duration.
32	Vanky et al., 2004 [32]	CO (RCT with placebo)	P	No description.
33	Glueck et al., 2004 [33]	CO (self as control)	P	No maternal lactic acidosis or maternal hypoglycemia; no major birth defects; there have been no congenital defects or evidence of intrauterine growth. Seventy of the 84 fetuses have had a favourable outcome; no cases of neonatal hypoglycemia.
34	Glueck et al., 2002 [34]	CO	P and R	None developed lactic acidosis. Intermittent diarrhea or gastritis was common in the first 3 weeks of metformin therapy but resolved spontaneously and was not limiting factors. No major fetal malformations or fetal hypoglycemia occurred.
35	Salvesen et al., 2007 [35]	CO (RCT with placebo)	P	No description.
36	Hameed et al., 2011 [36]	CO	P	delivered spontaneously at 33 weeks gestation with; neonatal asphyxia due to respiratory distress syndrome and; died 2 days later.

Note: CO: cohort; CC: case-control; P: prospective; R: retrospective.