Part 3: VBAC Considerations
You may be wondering why I'm harping on blood sugar control so much in an article that is nominally about VBAC. The reason is that if your blood glucose is in excellent control, you dramatically improve your chances of being able to have a VBAC. For one thing, good control will reassure your provider that your diabetes is well-controlled and that you are less likely to have a gigantic baby that will not fit through your pelvis. Of course they will also estimate the baby's size via ultrasound and belly measurements, but if you can point to months of records demonstrating your tight control, that will help your case. Also, tight control will of course make it less likely that you will actually have a gigantic baby that won't fit through your pelvis.
Keep in mind that babies of diabetic mothers tend to put on weight in the upper torso and abdomen - you hear all the time about women who delivered 10-pound babies vaginally, but if the mother was not diabetic, the baby's weight was probably distributed more evenly, thus making it more likely that the baby would fit through the pelvis. Even a 10-pound baby born to a diabetic mother has a chance of being able to arrive vaginally, but many doctors aren't willing to take the risk of shoulder dystocia in such a circumstance. It's possible to estimate the baby's size via ultrasound, but not where the baby is putting on the fat, so it's impossible to know if you have a 10-pound baby with normal fat distribution, or a 10-pound baby with too much fat in the upper torso; this, too, is a case where having records showing your excellent blood glucose control may help your doctor decide that VBAC is an acceptable risk, because it's less likely that you'll have a shoulder dystocia-prone baby if your blood sugar has been in excellent control.
Your choice of care provider is vital to your chances of being able to VBAC. Many OB/GYNs are opposed to VBAC at all, much less in a high-risk patient such as a diabetic. It may be worth your while to "shop around" and find an OB/GYN who is familiar with care of diabetic patients and is still open to VBAC. This may be difficult, especially depending on the area you live in. Also depending on your area, you may be limited to OB/GYN care. When I was doing my research in the Seattle area, I could not find a single midwife who was willing to take me on as a diabetic VBAC patient. The best I could do was a midwifery practice who would see me in conjunction with an OB/GYN, and even in that case the OB/GYN would have been my primary provider, with the midwives just providing backup support.
Regardless of VBAC considerations, you are definitely going to want to find a provider who is familiar with the care of diabetic women. During my first pregnancy, I was diagnosed with gestational diabetes, not knowing that I probably had a pre-existing but undiagnosed case of true Type 2 diabetes. My provider was a regular OB/GYN with a small practice, and wasn't familiar with how to care for diabetics, so my diabetes care was farmed out to a separate diabetes clinic. The clinic staff were badly overworked and saw way too many patients, with the end result that my diabetes control during that pregnancy was not as good as it should have been.
With my second pregnancy, I found a perinatologist who specializes in diabetes. The difference in care was tremendous. This OB/GYN knew exactly how to handle my diabetes care, was on top of current research, and delivers dozens of babies of diabetic mothers every month. It was my good fortune that he was also relatively pro-VBAC - which brings me to my next point: If your choice is between a provider who is pro-VBAC and a provider who knows a lot about diabetes management, you need to very carefully consider what you want for your pregnancy. Poor control of diabetes during pregnancy can have lasting and profound effects on your baby; it may be worth it to you to go with a provider that is not willing to let you try a VBAC, if he or she is extremely talented in caring for diabetics. But this is a personal choice that you will need to make for yourself.
Even a provider who is willing to attempt VBAC is not likely to be gung-ho for VBAC with absolutely no reservations, of course. Your doctor is going to want to see that the baby is growing normally and isn't too large, that your blood glucose control is good, and that the placenta is not showing signs of aging.
When you're doing your research on care providers, one question you should consider asking is what their labor and delivery protocol is for diabetics. Some practices still want to deliver all diabetic women at 38-39 weeks. This is a holdover from the days before home blood glucose meters and tight control, when most diabetic women had iffy control and therefore had large babies and placentas that started to age prematurely. This premature aging of the placenta due to high blood sugar can cause fetal death in the final weeks of pregnancy. Again, very scary, but also very unlikely if you've been maintaining tight control of your blood sugar. But, many providers still want to deliver the baby early because of this factor. (This is also the reason you will likely have to undergo multiple non-stress tests and ultrasounds in your third trimester.) If possible, you will want to find a provider who is willing to allow you to progress to 40 weeks, assuming that all looks well with the fetus. It is unlikely, but possible, that you will find a provider who will actually let you progress past 40 weeks; but in general, I would simply suggest trying to find a doctor who isn't set in stone that the baby is going to have to arrive at 38 weeks no matter what. My first baby arrived with signs of prematurity thanks to my first OB's insistence on this policy.
If you can't find an OB who is this liberal, you might try negotiating with your OB. Ask if they would be willing to let you progress an extra few days past their cut-off mark, assuming the baby looks healthy and your blood sugar is in good control. Volunteer to come in for extra NSTs (non-stress tests) if that would help reassure them. Of course, by this point in the pregnancy you may just want to get it over with, but my feeling has always been that the baby should get as much time to develop in utero as possible.
The last remaining factor that will determine whether you can try for VBAC or not is the size of the baby. This is a tough one to deal with, because late-pregnancy ultrasounds are notoriously inaccurate, sometimes a pound or more off in either direction. Nevertheless, if your baby is looking big via ultrasound or belly measurement, your doctor is going to be much less willing to let you attempt VBAC. Again, this is due to the fear of shoulder dystocia. If your baby is looking big, don't beat yourself up about it too much; even women who have excellent blood sugar control throughout pregnancy sometimes have larger-than-average babies. Non-diabetic women do too! Some of us are just destined to have larger babies. The problem is that with diabetes, doctors are scared that the torso will be too big to deliver through the pelvis.
What can you do about this? Well, not much, unfortunately. If your baby is looking too big and your doctor doesn't want you to deliver it vaginally, your one real option is to ask to be induced early, before the baby grows even bigger. As a VBAC, this is extremely risky. Many doctors will not even do induction on VBAC patients, and those that will induce will generally only use very light doses of induction drugs, and then only when the cervix has already shown signs of ripening (effacing and dilating). If your cervix is tightly closed and your baby looks too big, you may be looking at a repeat c-section, unfortunately. There are home induction methods you could try, but I will simply repeat what I said earlier, which is that I've always felt that babies should get as much time in utero as they need. If the decision is between inducing early to get a vaginal birth, or waiting an extra week or so to do a c-section, I personally would always choose the c-section, as I think it's the healthiest option for the baby.
Next page: The Birth