4.4.3.0 Met­formin

Met­formin was as­so­ci­at­ed with a lower risk of neona­tal hy­po­glycemia and less ma­ter­nal weight gain than in­sulin in sys­tematic re­views (46,49,50); how­ev­er, met­formin may slight­ly in­crease the risk of pre­ma­tu­ri­ty. Like gly­buride, met­formin cross­es the pla­cen­ta, and um­bil­i­cal cord blood lev­els of met­formin are high­er than si­mul­ta­ne­ous ma­ter­nal lev­els (51,52). In the Met­formin in Ges­ta­tion­al Di­a­betes: The Off­spring Fol­low-‍Up (MiG TOFU) study’s anal­y­ses of 7- to 9-‍year-‍old off­spring, 9-‍year-‍old off­spring ex­posed to met­formin for the treat­ment of GDM were larg­er (based on a num­ber of mea­surements) than those ex­posed to in­sulin (53). In two RCTs of met­formin use in preg­nan­cy for poly­cys­tic ovary syn­drome, fol­low-‍up of 4-‍year-‍old off­spring demon­strat­ed high­er BMI and in­creased obe­si­ty in the off­spring ex­posed to met­formin (53,54). Fur­ther study of long-‍term out­comes in the off­spring is need­ed (53,54).

Ran­dom­ized, dou­ble-‍blind, con­trolled tri­als com­par­ing met­formin with other ther­apies for ovu­la­tion in­duc­tion in women with poly­cys­tic ovary syn­drome have not demon­strat­ed benefit in pre­vent­ing spon­ta­neous abor­tion or GDM (55), and there is no ev­i­dence-‍based need to con­tin­ue met­formin in such pa­tients once preg­nan­cy has been confirmed (56-58).