Pregnancy-related carpal tunnel syndrome: This condition is common in pregnancy due to fluid retention and swelling, which can compress the median nerve, leading to shooting pain and numbness in the arms and hands. Insomnia can be related to discomfort or pain.

Preeclampsia: Although typically associated with high blood pressure and proteinuria, preeclampsia can cause a variety of symptoms including headaches, vision changes, and potentially pain in the arms due to the systemic nature of the disease. Insomnia could be secondary to discomfort or anxiety related to the condition.
Musculoskeletal strain: Pregnancy can lead to changes in posture and gait, potentially straining muscles and leading to pain in the arms and shoulders. Insomnia could exacerbate or be exacerbated by musculoskeletal discomfort.
Restless Leg Syndrome (RLS): Common in pregnancy, RLS can cause discomfort and pain in the legs but sometimes can be associated with similar sensations in the arms, leading to insomnia.

Stroke or Transient Ischemic Attack (TIA): Although less common in young pregnant women, stroke and TIA are emergencies that can present with sudden onset of arm pain or weakness and must be considered, especially if accompanied by other neurological symptoms. Insomnia is less directly related but could be present.
Pulmonary Embolism: This is a life-threatening condition that can present with sudden onset of pain, which might be referred to the arms, and can be associated with insomnia due to anxiety or discomfort. Pregnancy increases the risk of pulmonary embolism.
Myocardial Infarction: Though rare in young women, myocardial infarction can occur during pregnancy and may present atypically, including arm pain. It's crucial to consider this diagnosis, especially if there are other risk factors or symptoms like chest pain or shortness of breath.

Multiple Sclerosis: An autoimmune disease that can present with a wide range of neurological symptoms, including pain and numbness in the arms. Pregnancy can sometimes exacerbate symptoms, and insomnia could be related to discomfort or anxiety.
Neuropathies: Various neuropathies can cause arm pain and are rare but possible in pregnancy. These could include conditions like brachial neuritis or other less common neuropathic pain syndromes.
Thoracic Outlet Syndrome: This condition involves compression of the nerves and/or blood vessels that pass into the thoracic outlet (the space between your collarbone and first rib), which can cause pain in the arms and hands. It is less common but could be considered in the differential diagnosis.