Postpartum Headache

Etiology

The most common cause of a headache in the postpartum period is an exacerbation of primary headache syndromes, such as migraine, cluster, and tension headaches.[1] Post-dural puncture headaches (PDPH) are also common in the setting of neuraxial blockade for labor, with more than half the patients who had an accidental dural puncture reporting subsequent headaches.[2] Primary headache syndromes and PDPH are prognostically benign and account for over half the presentations of severe headaches in the postpartum period.[1] The life-threatening causes of headaches in the puerperium are all secondary and may result from complications of anesthesia in the delivery, primary intracranial pathology, or obstetric complications.

The diagnosis of secondary causes of postpartum headaches is difficult and hindered because women with primary headache disorders are at increased risk for the development of hypertensive disorders of pregnancy and intracranial vascular catastrophes, all secondary causes of postpartum headaches.[3][4][5][6] Besides the physiologic changes associated with the postpartum period, women in the puerperium are at increased risk of domestic and intimate partner violence, leading to an increased risk in traumatic intracranial pathology.[7] Life-threatening causes of headaches in the postpartum period include intra-cranial mass, preeclampsia, meningitis, strokes, sinus venous thrombosis (SVT), and reversible cerebral vasoconstrictive syndromes, also known as Call-Fleming syndrome or postpartum cerebral angiopathy.

Epidemiology

Headaches affect approximately 40% of women in the postpartum period and are more common in women with a prior headache history, older age, increased parity, or a shorter second stage of labor.[1]

Pathophysiology

The sharp increase in both primary and secondary headache presentations in the puerperium results from the many social and physiologic changes in this period. The postpartum period is rife with factors that may exacerbate primary headache disorders. These women also experience sleep deprivation, increased stress levels, disordered sleep cycles, and irregular nutritional intake, all of which can trigger primary headaches.[8] The dramatic fluctuations in estrogen, serotonin, and oxytocin levels associated with childbirth and breastfeeding may also exacerbate underlying primary headache disorders.[8] The physiologic changes of the puerperium also contribute to an increased risk of secondary headache syndromes. Ischemic stroke incidence rises due to hypercoagulability in pregnancy, reaching its peak in the immediate postpartum period.[9][10] Rising estrogen and progesterone levels lead to vasodilation and increased vascular distensibility, which contributes to the higher rate of rupture of vascular malformations and intracranial hemorrhages in the puerperium.[11]

History and Physical

History and physical examination are vital in distinguishing benign from life-threatening headache presentations in the postpartum period. Important historical points to elicit include: 

• Time of delivery
• Vaginal vs. surgical delivery
• Complications of the pregnancy, such as pre-eclampsia or gestational hypertension
• Delivery complications, including bleeding and postpartum fevers
• Use of epidural anesthesia
• New medications
• Illicit drug use
• Personal or family history of hypercoagulability or bleeding syndromes
• Shortness of breath
• Chest pain
• “Thunderclap” onset

Physical examination findings that raise suspicion for a life-threatening secondary cause of a headache in the puerperium include: 

• Hypertension
• Decreased urination
• Lower extremity swelling
• Visual changes
• Abnormalities on neurological examination, including hyperreflexia

Evaluation

The diagnosis of primary headache disorders and PDPH is clinical; no additional laboratory or imaging studies are necessary. Laboratory workup for secondary headache syndromes in the puerperium includes a urinalysis, a spot urinary protein to creatinine ratio, complete blood count, comprehensive metabolic panel, and lactate dehydrogenase. Lumbar puncture with fluid analysis is necessary if meningitis is suspected. The imaging modality of choice differs based on the most likely suspected diagnosis. Non-contrasted head CT is rapid and non-invasive but is not sensitive for early ischemic strokes and sinus venous thrombosis.[12][13] It is most appropriate for the diagnosis of spontaneous and traumatic intracranial hemorrhage. For sinus venous thrombosis, CT venography is as sensitive as MR venography and is more readily available.[13] MRI is most sensitive for early ischemic strokes. 

Treatment / Management

Management of postpartum headaches varies by the cause of the headache. Management of primary headache exacerbations includes analgesia and counseling regarding the importance of consistent nutrition and sleep. The treatment of choice for PDPH is bed rest, analgesia, intravenous hydration, and caffeine supplementation. Patients who do not respond to this treatment within 48 hours may require a blood patch. The treatment of secondary causes of headache in the postpartum period often requires collaboration with consulting services both for acute management and risk factor modification. Headaches caused by preeclampsia resolve with treatment of the condition, including initiation of magnesium and anti-hypertensive medications and admission to an obstetrics service for monitoring. Ischemic stroke should undergo management with the aid of a neurologist for consideration of the initiation of thrombolytics or endovascular intervention. Spontaneous and traumatic intracranial hemorrhages may require neurosurgical intervention. Sinus venous thrombosis treatment is with systemic anticoagulation.[14](A1)

Differential Diagnosis

• Cerebral infarction 

• Cortical vein thrombosis

• Meningitis

• Migraine 

• Non-specific/ tension headache 

• Post dural puncture headache 

• Pre-eclampsia

• Sinusitis

• Space occupying lesion-brain tumour 

• Subarachnoid haemorrhage 

Prognosis

The prognosis of exacerbations of primary headache disorders and PDPH is excellent as neither of these diseases is life-threatening. However, both conditions can lead to a delayed return to function, economic hardship, and additional emotional turmoil during an already stressful life change. Physicians should consider these non-mortality-centered issues when counseling patients, giving discharge instructions and arranging for follow-up care. The prognosis for other causes of secondary headaches depends on the primary disease. Patients with postpartum courses complicated by preeclampsia have a mortality rate of 6.4 per 10,000 cases.[15] Multiple studies have shown African American women to be at greater risk than the general population for the development of postpartum preeclampsia, progression to eclampsia, and morbidity and mortality from hypertensive diseases of pregnancy and the puerperium.[16][15] Meningitis in the postpartum period has approximately a 20% mortality, resulting primarily from a delay in diagnosis rather than significant antibiotic resistance in this patient group.[17][18] Strokes in the postpartum period carry a 5% mortality rate, with hemorrhagic strokes having greater mortality than ischemic strokes and resulting in greater deficits leading to permanent functional decline[4]. Patients with hypertensive disease of pregnancies have a higher risk of complications, including the need for mechanical ventilation and prolonged hospital stay.[4][19] 

Complications

Prompt diagnosis and treatment initiation is imperative in secondary headache syndromes as delay can result in loss of life or permanent disability. The young age of this patient population makes the diagnosis of the life and limb-threatening disease particularly important, as it represents an opportunity for acute intervention that accounts for a significant increase in both years lived and disease-free time. It also adds significant social and medicolegal consequences for missed or delayed diagnosis.