Provider: Silverchair Database: AmericanMedicalAssociation Content: text/plain; charset="UTF-8" TY - JOUR AU - Pourkarim, Fariba AU - Entezari-Maleki, Taher T1 - Metformin Plus Insulin for Preexisting Diabetes or Gestational Diabetes in Pregnancy PY - 2024 Y1 - 2024/05/07 DO - 10.1001/jama.2024.1380 JO - JAMA JA - JAMA VL - 331 IS - 17 SP - 1502 EP - 1502 SN - 0098-7484 AB - To the Editor The MOMPOD study revealed that for pregnant individuals with preexisting type 2 or early gestational diabetes, metformin, 1000 mg twice daily, starting before 23 weeks’ gestation and taken until delivery, did not reduce a composite adverse neonatal outcome but resulted in reduced numbers of large-for-gestational-age infants. However, we believe that safety issues regarding the long-term effects of metformin on male infant fertility should also be considered.Metformin is classified as US Food and Drug Administration pregnancy category B. However, prenatal exposure of human fetal testicular cells to metformin may significantly decrease testosterone secretion. Metformin concentration in umbilical cord blood has been shown to be equal to the concentration in maternal venous blood. The level of sex hormone–binding globulin was increased in newborns following metformin exposure in the first trimester of pregnancy, which could result in lower free androgen indexes. The production of fetal androgen is critical for masculinization of the fetal reproductive system and maintaining gonocyte integrity. Therefore, metformin exposure during fetal and neonatal periods could result in a reduction in testicular size, Sertoli cell numbers, and sperm count, and may result in hypospadias and subinfertility. Based on available data, use of metformin during pregnancy is still controversial, and further data are required to identify the long-term effects of metformin on fetal testicular cells and determine infertility rates among male infants who were exposed to metformin during pregnancy. Therefore, in the MOMPOD study, long-term monitoring of fertility in male infants is highly recommended for the possible effects of fetal exposure to metformin. Y2 - 5/20/2024 UR - https://doi.org/10.1001/jama.2024.1380 ER -