However, there is no clear evidence that has shown live vaccinations to increase the risk for miscarriage or fetal abnormalities.Some live vaccinations include: MMR, varicella, certain types of the influenza vaccine, and rotavirus. Treatments for cancer
Ionizing radiation levels given to a woman during cancer treatment cause miscarriage. Exposure can also impact fertility. The use of chemotherapeutic drugs used to treat childhood cancer increases the risk of future miscarriage. Pre-existing diseases
Several pre-existing diseases in pregnancy can potentially increase the risk of miscarriage, including diabetes, polycystic ovary syndrome (PCOS), hypothyroidism, certain infectious diseases, and autoimmune diseases. PCOS may increase the risk of miscarriage. Two studies suggested treatment with the drug metformin significantly lowers the rate of miscarriage in women with PCOS, but the quality of these studies has been questioned. Metformin treatment in pregnancy has not been shown to be safe. In 2007 the Royal College of Obstetricians and Gynaecologists also recommended against use of the drug to prevent miscarriage. Thrombophilias or defects in coagulation and bleeding were once thought to be a risk in miscarriage but have been subsequently questioned. Severe cases of hypothyroidism increase the risk of miscarriage. The effect of milder cases of hypothyroidism on miscarriage rates has not been established. A condition called luteal phase defect (LPD) is a failure of the uterine lining to be fully prepared for pregnancy.
This involves no radiation, no needles and no contrast agents that may cause allergic reactions. This test has good sensitivity and specificity.Typically duplex ultrasound scan is the only investigation required for decision making in carotid stenosis as it is widely available and rapidly performed. However, further imaging can be required if the stenosis is not near the bifurcation of the carotid artery.One of several different imaging modalities, such as a computed tomography angiogram (CTA) or magnetic resonance angiogram (MRA) may be useful. Each imaging modality has its advantages and disadvantages - Magnetic resonance angiography and CT angiography with contrast is contraindicated in patients with chronic kidney disease, catheter angiography has a 0.5% to 1.0% risk of stroke, MI, arterial injury or retroperitoneal bleeding. The investigation chosen will depend on the clinical question and the imaging expertise, experience and equipment available.For purpose of treatment, the degree of carotid stenosis is defined as:
percent stenosis = ( 1 − ( minimum diameter within stenosis) / ( poststenotic diameter ) ) × 100%. Screening
The U.S. Preventive Services Task Force (USPSTF) recommends against routine screening for carotid artery stenosis in those without symptoms as of 2021.While routine population screening is not advised, the American Heart Association and the Society for Vascular Surgery recommend screening in those diagnosed with related medical conditions or have risk factors for carotid artery disease.