|When the Beatles sang "All You Need is Love", |
I bet they were singing about oxytocin.
Pitocin, fondly (or not so fondly) referred to as pit, is the synthetic form of oxytocin. Pitocin is a uterine stimulant and causes uterine contractions by changing calcium concentrations in the uterine muscles. It is derived from extractions of the pituitary glands of non-human mammals and is generally given through IV or an IM injection. During the course of normal labor oxytocin is released through bio feed back loops that exist between the cervix, the uterus, the brain, the pituitary gland and the baby plus all the other hormones in the mix. This process is complex and not completely understood; we have yet to even identify what exactly makes labor start. So far it seems to be one of those chicken or the egg type dilemmas. Did the oxytocin create the labor or did the labor create the oxytocin? We do know that in spontaneous labor oxytocin will ebb and flow as the body responds to labor and will slowly build so that contractions become closer and a baby is ejected. Of some interest is that oxytocin cannot cross the blood brain barrier. Therefore synthetic oxytocin is not recognized by the brain which leads to an interesting thought that a women induced with pitocin may be laboring, however her brain may not really know it. This lack of complete biological communication may then create some challenges in those hormonal and bio feed back loops that typically make labor effective.
The dosage of pit given varies widely based on provider's individual protocol. The suggested dose is to initiate the pitocin at 0.5-1 mU/min and increase it at 30-60 minute intervals by increments of 1-2 mU/min until the desired contraction pattern has been established. As labor progresses to 5-6 cm dilation, it is suggested the dose should be reduced by similar increments. Studies of the concentrations of oxytocin have shown that infusion rates up to 6 mU/min give the same oxytocin levels that are found in spontaneous labor and therefore higher rates should be given with great care.
If you have attended a pitocin induced birth or had one yourself, you're probably scratching your head...that is not how pit is typically administered in the real world. 6mU/min is closer to most starting doses rather than the final dose and almost never will you see careproviders turning the pit down after it has been turned up. Not being someone with the authority to make dosing decisions myself, I don't want to overstep my knowledge, but if a mom is in a induction situation and the pitocin is going up and up and up, the issue may be that mom has an impatient care provider and not that her uterus is working poorly. If you are considering an induction with pitocin, you will want to have a little chat with your careprovider about how he typically manages the use of pitocin and how he will do so in your unique situation.
There are a few other side effects listed for pitocin: allergic reaction; difficulty urinating; chest pain or irregular heart beat; difficulty breathing; confusion; sudden weight gain or excessive swelling; severe headache; and excessive vaginal bleeding. Luckily, these side effects are fairly uncommon. However the side effects that I want to highlight won't be found on the package insert. These include the need for an IV and IV fluids - which limit movement, the need for mom to have continuous fetal monitoring- which will limit movement, and depending on how the careprovider doses the pit, contractions that are so frequent that mom will experience more discomfort with less time to rest between contractions than would be typical in a natural labor. This usually leads to an epidural and the side effects of that epidural (need for a bladder catheter, pulse oximeter, lowered blood pressure, possible itching and shakiness and of course even less ability to move.)
Another side effect can be that it doesn't always work. If a women is induced and she fails to completely dilate it is called a failed induction. The remedy for that is usually a c-section particularly if the induction included the breaking of baby's amniotic sac. Also common is that babies don't tolerate the increased frequency of high dosage pitocin and show signs of fetal distress. The remedy for this is usually a c-section as well. I don't consider it too big of a statement to say that a common side effect of pitocin use is major abdominal surgery, particularly for first time mothers..
However, after doing some trash talking about pitocin in this post I must insist that your read Pit Stop Part 2 which I am almost done writing. I may have to turn in my natural birth advocate card after hitting publish, but I am going to talk about pitocin in a good light. Oh yes, I am....stay tuned.