Patient Selection and Safety With TNF Inhibitors - Episode 24
Christopher Robinson, MD, MSCR, FACOG: One of the first things a woman will begin to do when planning a pregnancy is look at herself and say, “What are the things that I may need to change?” Or “What are the things that I need to gain control over in the process of planning a pregnancy?” Often, especially if a person has never been pregnant before, 1 of their questions may be, “Can I become pregnant? Am I going to have problems? There may be fear or apprehension about the possibility of carrying a baby. And oftentimes women may even believe that they can’t have a baby. I think that’s 1 of the really sad aspects that we see. The majority of women can have a healthy pregnancy and a healthy baby. They just need to have specific planning take place to ensure that does take place.
Ideally, we want to get involved before the pregnancy even takes place, and plan the preconception care of the patient. But we realize that, in many cases, pregnancy may not be planned. It may be something that happens, and the woman finds out she is pregnant. Often we become involved very early in pregnancy. Between 8 and 12 weeks, we begin discussing the development of the baby, how we’re going to approach nutrition, and how we’re going to approach any deficiencies that mother may have. For instance, we know that certain autoimmune diseases carry risks for certain vitamin deficiencies or nutrient deficiencies that need to be addressed. We begin talking about weight gain and what goals for weight gain there may be as pregnancy goes forward. We also do a complete evaluation of the medications a person is on when going into pregnancy.
One of the misconceptions is that all medications are unsafe for pregnancy. And so 1 of the concerns we have is that women may stop all their medication, thereby putting them back into their disease activity with their autoimmune disease, potentially worsening the outcome for the pregnancy. So we like to get involved very early in pregnancy to begin dispelling some of those myths, really discussing what the optimal course of care is for this group of women.
When looking at autoimmune disease, if you go way back in autoimmune disease management, our mainstay was steroids. And certainly, 1 of the goals that we look at when going into pregnancy is, how can we minimize the exposure of steroids or reduce steroids to the maximum ability across that pregnancy? We know that steroids, for instance, contribute to things like gestational diabetes. They may also contribute to certain birth defects at high doses. Certainly, steroids can be used at moderate to low doses safely in pregnancy, and we can help guide that process.
We also look at things like what medications the person is on and which ones may require dose adjustments. Not all of them do, but in some cases, as body mass index increases, the dosing also changes for some medications to achieve that same therapeutic benefit that the patient had been achieving when she was not pregnant. During pregnancy, we see a massive increase in the amount of volume that’s circulating in your blood. This is to assist in the development of the pregnancy and the safety of the mother. Approximately 40% more fluid is circulating throughout the body. So obviously, these things adjust medications. And then also, the way that we get rid of medications is important.
With renally excreted medications, we know that women often report that they go to the bathroom a lot more commonly. They actually do filter 40% more through the kidneys. As a result, you may also see changes in medications through the amount that is eliminated. So you have to think about both what we’re putting in and what we’re taking out over the course of pregnancy. The pregnancy itself is modifying how the mom’s body works in order to support that baby.
Autoimmune diseases lead to inflammation. Inflammation is a process that’s occurring in our body. It’s mediated through our immune system, and it has a lot of impact. A lot of the impact of autoimmune disease stretches across that spectrum of how inflammation is affecting different body parts, whether that is our vascular system, or whether that is our kidneys, or other specific things. Medications can help in blunting that process. Importantly, high states of inflammation are also associated with problems with implantation at the time of conceiving a pregnancy. It may also lead to increased risk for miscarriage, small-birth-weight babies, preterm birth in some cases, as well as miscarriage in some cases. And so getting control of inflammation is really important in optimizing pregnancy.
If you think about the process, the baby is going to develop for 9 months. The implantation, or the establishment of the connection between the mother and baby through the placenta is perhaps the most important aspect of gaining a healthy course of pregnancy over time. That implantation takes place in the earliest weeks of pregnancy. This is 1 reason why that preconception-care piece is so important. If we can gain control of disease, and ideally that would be defined as keeping a person in disease remission for 3 months at minimum, or up to 6 months prior to going into that pregnancy, that would be ideal in controlling all the features of inflammation that could potentially impact a pregnancy outcome.