Almost Everything You Need To Know About Migraine During Pregnancy
Cerebral TorqueShare
This post is for educational purposes only and may contain errors. Please talk to your neurologist and ob/gyn.
Epidemiology
- Migraine affects approximately 18% of females in the United States. Prevalence peaks during the childbearing years.
- 2% of women develop their first migraine during pregnancy, usually in the first trimester.
Pathophysiology
- Migraine is influenced by fluctuations in estrogen levels. High AND low level changes can trigger migraine attacks and increase their severity. However, during pregnancy, high estrogen levels are more sustained and stable, rather than fluctuating dramatically such as during the menstrual cycle. This sustained elevation of estrogen is believed to prevent migraine attacks in many pregnant women, especially those with menstrual migraine patterns triggered by estrogen drops before menstruation. Therefore, the steady high levels in pregnancy seem to have a protective effect against migraine attacks.
- Migraine attacks may increase during the first trimester due to the abrupt rise in estrogen.
- The rapid drop in estrogen after delivery is thought to explain the postpartum recurrence of migraine.
- There is also improvement of migraine during menopause when estrogen levels are low. This is also likely due to the stabilization of hormones compared to the fluctuations of the menstrual cycle.
Clinical Course
- 60-70% of pregnant patients with migraine experience improvement in migraine frequency and severity during pregnancy for the reasons we have already mentioned. This is more likely with menstrual migraine, migraine without aura, and those with improvement in the first trimester.
- Only 5% report worsening of migraines during pregnancy.
- 25-35% report no change in migraine frequency, severity, or duration.
- Migraine recurrence is most common in postpartum when estrogen levels decline dramatically. Recurrence rates are 34% in the first week and 55% within one month postpartum.
- Breastfeeding protects against postpartum migraine, likely due to more stable estrogen levels. Studies show a lower prevalence of postpartum migraine in breastfeeding women.
Effect on Pregnancy Outcomes
- Migraine increases the risk of hypertensive disorders of pregnancy, including preeclampsia, by approximately 50% compared to females without migraine.
- Miscarriage, preterm birth, admission to the NICU, respiratory distress, and low birth weight may be modestly increased in females with migraine.
- No clear increase in fetal growth restriction or congenital anomalies.
- Increased risk of stroke, particularly in women with migraine with aura. Risk also elevated in the postpartum period.
Evaluation
- Preeclampsia must be excluded in pregnant women ≥20 weeks gestation with headache.
- Any new headache or a change of pattern requires a full neurologic evaluation to rule out secondary causes. See red flags list: https://www.cerebraltorque.com/blogs/migrainescience/do-i-need-neuroimaging-for-my-headache
- Exclusion of secondary headache disorders are necessary.
- Previously diagnosed migraine patients require no further testing if symptoms are unchanged.
- Primary headaches like migraine are diagnosed by standard ICHD criteria.
- MRI is preferred for neuroimaging when needed in pregnant migraine patients. Gadolinium use should be avoided in most cases.
- Lumbar puncture is not contraindicated, but usually unnecessary in pregnant patients with migraine.
Treatment
The most important aspect to treatment is pain mitigation without harming mother or fetus. This means low dosages, using medications that are not teratogenic, limiting the number of medications used, and starting with the medications with the best safety profiles for fetus.
Furthermore, it is important to listen to the patient. What worked for them in the past? What didn’t? Do they understand the risks? Are they willing to accept the risks to alleviate the pain? Informed consent is necessary, and patients that advocate for themselves and desire treatment should receive it (this is why it is important to advocate for yourself!)
Non-Pharmacologic
- Biofeedback, cognitive behavioral therapy, trigger avoidance, physical therapy
Acute Pharmacologic Management
- First-line:
Acetaminophen (best safety profile for fetus). Use in combination with other medications if nonresponse:
- w/metoclopramide (dystonic reaction possible.)
- w/codeine (may cause dependence/withdrawal if taken near term. Shared decision making is necessary if taken in the first trimester.)
- w/butalbital and caffeine. (ACOG advises against the use of butalbital during pregnancy. May cause dependence if taken near term. Shared decision making is necessary if taken in the first trimester.)
- Second-line:
NSAIDs during second trimester before 20 weeks gestation. Anything outside this range and for extended time requires shared decision making. If nausea/vomiting, parenteral administration is available.
- Third-line:
Opioids. May cause addiction and neonatal withdrawal. May worsen constipation and nausea/vomiting. Nervous system malformation risk.
Triptans. (https://www.cerebraltorque.com/blogs/migrainescience/triptans). For moderate to severe symptoms. From a theoretical standpoint, it is possible that the blood vessels supplying the placenta could vasoconstrict and the uterus could demonstrate increased tonicity (uterotonic activity). Shared decision making needed.
Refractory, Severe Migraine Management
- First-line: IV fluids, antiemetic, and IV opioid (administer diphenhydramine to prevent akathsia).
- Second-line: Triptan w/ droperidol. (Possible extrapyramidal symptoms and materal QTc prolongation, torsades de pointes.)
- Third line: IV magnesium sulfate, corticosteroids (prednisone or methylprednisolone, not the commonly used dexamethasone are preferred), peripheral nerve block.
Nausea/Vomiting Pharmacologic Management
- First-line:
Meclizine or diphenhydramine or promethazine.
- Second-line:
Metoclopramide or prochlorperazine or chlorpromazine. (As stated above, dystonic reaction possible.)
(Ondansetron may be used for nausea/vomiting associated with severe migraine)
Remember, all medications during pregnancy require shared decision making and informed consent.
Preventive Pharmacologic Management
- First-line:
Beta blockers (e.g. propranolol). Not teratogens, but beta blockade may still impact fetus with daily use. Possible growth restriction worst with atenolol.
Calcium channel blockers (e.g. verapamil).
- Second-line:
Tricyclic antidepressants, SNRIs (eg. venlafaxine). May have neonatal effects if taken in 3rd trimester.
Gabapentin
Supplements
- Magnesium, Riboflavin. No studies for use in pregnancy but commonly used.
Avoid valproate, ergotamines, ACE inhibitors
(Refer to your physician for a full list. This is only a resource to use with your physician.)
Breastfeeding Considerations
- Most migraine medications compatible with breastfeeding
- Avoid ergot alkaloids (may cause gastrointestinal illness, weakness, etc.)
- Limit triptans (sumatriptan preferred. Refer to your physician as to the time frame needed between dose and breastfeeding)
- Avoid opioids (may cause CNS depression and even overdose)
- Avoid butalbital (this includes Fioricet).
