Even neurologists — who diagnose and treat Parkinson's — may never have had to consider the combination of Parkinson's disease and pregnancy. They are aware that:
- The likelihood of developing Parkinson's disease increases with age — most patients are over 60, but the incidence is greatest among people over 85.
- Men are thought to have over twice the risk of developing Parkinson's.
- The female hormone estrogen appears to offer some kind of protection against Parkinson's, as it has anti-inflammatory and antioxidant qualities.
- Early onset Parkinson's disease — where symptoms show up before age 40 — applies to less than five percent of all patients. Only a few hundred women under 50 (those who may conceivably have the ability to get pregnant) are diagnosed with the disease in the US annually.
As more and more women delay having children and become mothers later in life — sometimes with the help of assisted reproductive techniques — we may be seeing more pregnant folks with Parkinson's disease around in future, however. Though this combination is rare enough that it hasn't been studied much, those who are pregnant and have Parkinson's disease depend on their neurologists to manage their health in the smartest possible way.
How does pregnancy affect the symptoms of Parkinson's disease?
Scientific research in this arena is limited by the small number of patients that can be studied. Available data suggest — perhaps frustratingly for pregnant Parkinson's patients — that pregnancy worsens the symptoms of Parkinson's disease about half the time (48 percent), while roughly the other half of all pregnant patients (52 percent) either notice a temporary improvement in their symptoms, or experience no changes. That means, simply said, that you've got no idea how Parkinson's will affect you during pregnancy before you experience it.
The whole "some women have reduced symptoms during pregnancy, some have worse symptoms, and some don't notice any difference" situation means that you can reasonably expect that you will experience symptoms of Parkinson's disease during pregnancy. These fall into the motor as well as non-motor realms, just as they do outside of pregnancy. Non-motor symptoms — like fatigue, depression, and gastrointestinal issues — seem to get better during the postpartum period, but the same isn't true for motor symptoms.
Research further, and unsurprisingly, reveals that the symptoms of Parkinson's disease are less intense during pregnancy if the patient continues taking their prescribed medications. Even in this case, one study found that nearly four in 10 women face increased symptoms during their pregnancies.
Why do the symptoms of Parkinson's disease get worse in pregnancy for some women? Science has no definitive answer, but there are some theories:
- Pregnancy — a time of great change — is often emotionally and physically stressful, and this stress could lead to more intense symptoms.
- The physical changes that go hand in hand with pregnancy cause your medications to work less well.
- Many pregnant women adopt different diets than they had before, perhaps interfering with the absorption of their medications.
As an interesting aside, you may have heard that greater lifetime exposure to estrogen decreases a woman's risk of developing Parkinson's in the first place. Despite the fact that estrogen plays an important role in pregnancy, women who have been pregnant for a longer total amount of time appear to have bigger odds of developing Parkinson's. This may be due to the fact that the estrogen a woman produces during pregnancy isn't quite the same as the form produced outside of pregnancy — estriol vs estradiol.
Does Parkinson's disease impact pregnancy outcomes?
This doesn't mean that Parkinson's disease won't impact your pregnancy in any way at all — subtler ways in which your chronic condition may affect you include:
- The diagnosis of Parkinson's disease is often hard to come to terms with, and knowing that you have a progressive degenerative disease can severely change how you see yourself. Your sex life may change, too, potentially making pregnancy less likely.
- Your Parkinson's disease symptoms may well mean that you will encounter difficulties in caring for your baby, and that you need help from others. This has a practical as well as emotional impact.
Are Parkinson's disease medications safe during pregnancy?
As you'll know, the pharmacological arsenal available to Parkinson's patients includes:
- Dopamine agonists
- COMT inhibitors
- Monoamine oxidase-B (MAO-B) inhibitors
- Anticholinergic medications
Again, the combination of Parkinson's and pregnancy is quite uncommon — and this, unfortunately, means that there isn't as much data on the safety of these medications during pregnancy as you'd ideally like.
Levodopa-carbidopa during pregnancy
Levodopa is the most commonly administered drug for Parkinson's, as well as the drug most often used during pregnancy. Whether alone or in combination with carbidopa (Sinemet), animal research suggests that using it during pregnancy may increase the risk of birth defects. So far, this doesn't seem to be the case in human pregnancies, however. Levodopa does pass into the placenta, meaning it reaches the baby, but carbidopa doesn't.
Dopamine agonists during pregnancy
Dopamine agonists are thought to be quite safe for using in pregnancy, and some of them, including pergolide, bromocriptine, and cabergoline have even been used as fertility treatments. These ergot-derived dopamine agonists have not been linked to pregnancy complications, birth defects, or any other harmful effects on the fetus. They do, however, interfere with breastfeeding by halting the production of breast milk.
Amantadine during pregnancy
Amantadine, an antiviral originally used for influenza, has been linked to heart defects in fetuses exposed to the drug during the first trimester of pregnancy. This drug is thus not considered safe as a Parkinson's disease treatment during pregnancy, and any woman with Parkinson's who is hoping to become pregnant should discuss her treatment options with her doctor beforehand.
What about other treatments?
- Selegiline (Eldepryl) does not appear to cause birth defects, while there is insufficient data to make any concrete statements on the safety of MAO-B inhibitors, anticholinergics, and COMT inhibitors during pregnancy.
- Deep brain stimulation (DBS), the revolutionary surgery for Parkinson's disease, seems to have a positive impact — by reducing your motor symptoms, it lessens your need for medications.