Oxytocin Verus Mesoprostol

Many women who have had or who are going to have children have researched the various methods of Induction and augmentation of labor. In fact, if you have had a 'prenatal class', you likely have heard the terms meso or pitocin in relation to labor. But what are these drugs really and what are the differences between them?

Let's begin this comparison of drugs with misoprostol or 'meso'. This is a synthetic drug that helps the cervix soften and dilate. This cervical softening and dilation would occur naturally in the birthing process over a few hours or even days. However, in a situation where it is essential that labor occur sooner than 'nature' would decide, due to pregnancy induced hypertension (PIH) or some other maternal or fetal issue, meso may be used to speed up this dilation. Meso is a synthetic prostaglandin, or protein that is like a hormone and helps soften the cervix and promote dilation. Once the cervix starts to soften, the dilation and progression of labor occurs. Once the cervix has started to soften and dilate, then oxytocin can often be administered to assist with uterine contractions.

Oxytocin (pitocin) is a drug that mimics the body's own naturally occurring pituitary hormone, oxytocin. This drug is administered intravenously to make uterine contractions more powerful. It is used in induction of labor to help the cervix start contracting more effectively, to help push the baby out sooner. This drug has to be monitored carefully so the contractions are not too fast (called tetanic contractions). While oxytocin is a hormone that naturally occurs in the body, the synthetic form of the drug makes the uterine contractions much stronger and more painful than the natural hormone does.

Mesoprostol as a drug was first approved for stomach problems and is now used quite frequently in labor. Personally, I was induced with mesoprostol because of my fluctuating blood pressures and alarmingly high kidney and liver function studies. Unfortunately, I was not informed of all the possible side effects of this drug -- one of which is uterine hyper stimulation. I found out later, that this can be called a 'meso labor'. This means that your uterus is almost constantly contracting, causing exhaustion for both the mother and the baby. In my case, my baby was so tired at the end of the labor, that his heart beat was going down after the contractions (late decelerations) instead of with the contraction. This is not normal and does not usually occur with a non-augmented (natural ) labor. With this hyper stimulation of the uterus, the fetus is not getting as much oxygen either, which is why he had decreasing heart beats, especially near the end of the labor.

Mesoprostol has been associated with uterine rupture in women who have previously had cesarean sections. Another adverse effect of meso is that it can cause disseminated intra vascular coagulopathy (DIC) which basically means your blood starts to coagulate all through the body, but it also increases the risk of hemorrhage. This is very serious and requires very fast and large amounts of blood transfusion for survival.

Pitocin (oxytocin), on the other hand, is used for labor as well, but has a half life of 3 minutes which means it can be 'shut off' pretty much any time and for sure it can be slowed down considerably because it is given intravenously and monitored very carefully. Meso is given in doses that cannot be removed. Once they are in (a tablet placed against the uterus or taken orally), they're in. My labor started 2 hours after I was given a quarter tab of meso and never stopped once. Normally meso (or so I was told) does not work with the first dose. It is given in multiple doses, spaced out a bit, to soften the cervix and prepare the uterus for contractions. Every case is different, and in my case, the meso caused my cervix to soften and my uterus to contract within 2 hours, nonstop.

Pitocin, like meso, can decrease blood flow to the baby by increasing the strength of uterine contractions-- more than the body would naturally contract the uterus. With Pitocin, unfortunately, the mom is on IV continuously and this means that, unlike with meso, you cannot get out of bed as easily and the medical personnel usually discourage a lot of movement once pitocin begins to flow. This in turn makes the natural desire to 'help' your own labor along by doing your exercise ball movements and various standing labor positions basically impossible.

Some other side effects of pitocin are that the placenta can separate from the uterus (placenta previa) because the contractions are so unnaturally strong. With both pitocin and meso, this is a risk, but especially with pitocin, because this is being dosed intravenously and therefore is fast-acting and can be dosed too high, too fast.

Basically, meso and pitocin are labor augmentations and have risks associated with them. Meso and pitocin labors are not going to be your 'normal' labor that they teach you in your pregnancy classes. I was so disappointed that I did not have that 'normal' progression of labor that I expected because I allowed induction of labor. Really, you have to decide what you are going to allow for your body, your labor and your baby. Be informed and know the possible side effects and alternatives of pitocin and meso (and other augmentations) so that you can choose and then know what to expect, in general, with each induction method. It is your body and you decide what is best for you and your baby. Make an informed decision about induction and know the differences between pitocin, meso and the other labor induction methods. And once he's out that little one makes you forget all about the process of labor -- almost.