Specialist Markers

Phosphorylated tau 181 measured in EDTA plasma using the Roche Elecsys assay. It supports clinical assessment of cognitive concerns in adults aged 55 to 80. A positive result does not confirm Alzheimer's disease, and a negative result does not rule out other causes of cognitive decline. Results from different assays are not interchangeable.

Anti-Müllerian Hormone (AMH) is a protein produced by the small, developing follicles in the ovaries. Each follicle contains an immature egg, and the amount of AMH they collectively release into the bloodstream provides a useful window into your ovarian reserve: an indication of your remaining egg supply, not an egg count. This makes AMH a useful marker for women who are planning ahead or considering options such as egg freezing or IVF. Understanding your AMH level matters because, unlike many other hormones that fluctuate significantly throughout your menstrual cycle, AMH remains relatively stable from day to day, which makes it a convenient and reliable test that can be taken at any point in your cycle. Your ovarian reserve naturally declines with age. This is a normal part of reproductive biology, and AMH provides an objective measure of where you sit on that spectrum compared to other women of a similar age. It is important to understand, though, that AMH reflects the quantity of remaining eggs, not their quality, and egg quality is more closely linked to age. Think of AMH as a fuel gauge for your ovarian reserve: it tells you roughly how much is left in the tank, but it does not tell you about the quality of the fuel or how efficiently the engine is running. A higher AMH generally suggests a larger pool of remaining eggs, while a lower reading suggests a smaller pool. In the context of assisted reproduction, knowing your AMH helps fertility specialists tailor treatment protocols to give you the best possible chance of success. Several factors can influence your AMH level. Age is the most significant: levels typically peak in your early twenties and gradually decline from there. Hormonal contraception can temporarily suppress AMH readings, so your clinician may advise testing after a break from the pill. Conditions such as polycystic ovary syndrome (PCOS) can be associated with higher-than-expected AMH levels. Smoking has been linked to lower levels, and vitamin D status may also play a small role. If you would like to understand what your AMH result means for your personal fertility journey, your GP or a fertility specialist can provide tailored guidance and discuss any next steps that might be appropriate for you.

Blood Group testing determines your ABO blood type (A, B, AB, or O) and your Rhesus (Rh) factor (positive or negative), giving you a complete classification such as A positive, O negative, or B positive. These categories are based on the presence or absence of specific proteins, called antigens, on the surface of your red blood cells. Your blood group is determined entirely by your genetics and remains the same throughout your entire life, so this is a test you only ever need to have done once. Knowing your blood group is a valuable piece of personal health information for several practical reasons. Matching blood groups is essential if you need a blood transfusion, as receiving incompatible blood can cause a serious immune reaction. It is also important during pregnancy, particularly the Rhesus factor: if an Rh-negative mother is carrying an Rh-positive baby, a simple preventive treatment can be given to avoid complications. Beyond these clinical situations, your blood group is simply an interesting fact about yourself. Think of the antigens on your red blood cells as a kind of identity badge. Your immune system is trained to recognise your own badge as friendly, but if blood with a different badge enters your system, your immune system may mount a defence against it. The ABO system has four main types: O has no A or B antigens (O negative is the universal donor), AB has both (AB positive is the universal recipient), and A and B each carry their own antigen. The Rhesus factor adds another layer, the D antigen, which is either present (positive) or absent (negative). Together, these create the eight common blood groups. Nothing you eat, drink, or do in your daily life will change your blood group: it is hardwired into your DNA from birth. The distribution of blood groups varies across populations; in the UK, O positive is the most common (around 35 per cent of people), while AB negative is the rarest (roughly 1 per cent). Once you know your blood group, it is worth keeping a note of it with your personal health records. If you have any questions about what your blood group means for you, particularly if you are planning a pregnancy or have an upcoming medical procedure, your GP or midwife will be happy to talk it through with you.