Speaking as a home care nurse...
Please do not "request" a C-section. it is really hard on everybody involved. the chance of infection rises exponentially. As for being diabetic... did you only have the 1 test? or has the mid-wife been dipping your urine weekly? (or every visit) and what has the results been?
your baby will come when s/he is good and ready. Dont rush mother nature.. she has a way of kicking yr butt for it. 
risks of a C- section
    *  Infection. The uterus or nearby pelvic organs such as the bladder or kidneys can become infected.
    * Increased blood loss. Blood loss on the average is about twice as much with cesarean birth as with vaginal birth. However, blood transfusions are rarely needed during a cesarean.
    * Decreased bowel function. The bowel sometimes slows down for several days after surgery, resulting in distention, bloating and discomfort.
    * Respiratory complications. General anesthesia can sometimes lead to pneumonia.
    * Longer hospital stay and recovery time. Three to five days in the hospital is the common length of stay, whereas it is less than one to three days for a vaginal birth.
    * Reactions to anesthesia. The mother's health could be endangered by unexpected responses (such as blood pressure that drops quickly) to anesthesia or other medications during the surgery.
    * Risk of additional surgeries. For example, hysterectomy, bladder repair, etc.
    * Risk of adhesions.
    * Risk to future fertility and babies.
    * Increased risk of placenta previa in future pregnancies.
    * Risk that all future births may be surgical.
    * Maternal death (very rare). (6 in 100,000 for a scheduled cesarean birth.) 
In cesarean birth, the possible risks to the baby include the following:
    * Premature birth. If the due date was not accurately calculated, the baby could be delivered too early.
    * Breathing problems. Babies born by cesarean are more likely to develop breathing problems such as transient tachypnea (abnormally fast breathing during the first few days after birth).
    * Low Apgar scores. Babies born by cesarean sometimes have low Apgar scores. The low score can be an effect of the anesthesia and cesarean birth, or the baby may have been in distress to begin with. Or perhaps the baby was not stimulated as he or she would have been by vaginal birth.
    * Fetal injury. Although rare, the surgeon can accidentally nick the baby while making the uterine incision.
    * Increased risk of asthma in babies born via cesarean section.