From the Guidelines

Migraines often remit during pregnancy, but if treatment is continued, the potential for harm to the fetus demands special consideration.

Migraine remission: Many women experience a decrease in migraine frequency and severity during pregnancy, particularly in the second and third trimesters 1.
Treatment considerations: Despite relatively poor efficacy, paracetamol should be used as the first-line medication for acute treatment of migraine in pregnancy; NSAIDs can be used only during the second trimester 1.
Preventive treatment: Preventive migraine medications are best avoided during pregnancy owing to the potential for fetal harm, but if preventive therapy is considered clinically indicated, propranolol or amitriptyline can be used under specialist supervision 1.
Contraindicated medications: Topiramate, candesartan, and sodium valproate are contraindicated during pregnancy due to their potential to cause harm to the fetus 1.

Acute treatment: Paracetamol is the preferred acute medication for migraines during pregnancy, and metoclopramide can be used for nausea associated with migraine 1.
Preventive treatment: If preventive therapy is necessary, propranolol or amitriptyline can be used under specialist supervision, but topiramate, candesartan, and sodium valproate should be avoided 1.

From the Research

The frequency and severity of migraines tend to decrease during pregnancy, with most women experiencing an improvement in their migraine symptoms 2, 3.
However, some women may experience worsening of their migraine symptoms during pregnancy, and in rare cases, migraines may appear for the first time during pregnancy 4, 5.
The improvement in migraine symptoms during pregnancy is thought to be related to the uniformly high and stable estrogen levels during pregnancy, which may help to reduce the frequency and severity of migraine attacks 3, 6.

Non-pharmacological treatment methods, such as relaxation, sleep, massage, ice packs, and biofeedback, are recommended as the first line of treatment for migraines during pregnancy 6.
For acute migraine attacks, 1000 mg of paracetamol (acetaminophen) is considered the first choice drug treatment, while aspirin and ibuprofen may be used episodically but should be avoided during the last trimester of pregnancy 6.
Triptans, dihydroergotamine, and ergotamine tartrate are contraindicated in pregnant women, while prochlorperazine and metoclopramide may be used to treat nausea during pregnancy 6.

The persistence of migraines during gestation may affect neonatal outcomes, and several studies have indicated a link between migraines and an increased risk of developing gestational hypertension/preeclampsia and other vascular complications 3.
Breastfeeding may exert a protective action on migraine recurrence after delivery 3.