I had my son via C-section a week before his due date for two reasons: he was breech, and because I had gestational diabetes that I had difficulty controlling. Based on his ultrasounds, my midwife was worried that he would be too large for a natural birth at 40 weeks. When he was born, though, my son was only 3.4 kg. I would like to try for a VBAC next time around, but if I have gestational diabetes again, is it worth waiting until 40 weeks?