High AFP in Pregnancy: What Does a Raised Result Mean?

A high AFP in pregnancy means the level of alpha-fetoprotein in your blood was above the range expected for how many weeks pregnant you are thought to be. It is a screening result, not a diagnosis. It can reflect a due date that is out, twins or more, or a false positive, and it can also flag a higher chance of certain conditions that a closer scan can look for.

MedlinePlus states plainly that abnormal AFP results do not always mean the baby has an increased risk of a serious problem. This guide explains what the result can and cannot tell you and helps you prepare for the conversation with your care team. It cannot interpret your own result.

A screening result does not cause symptoms, and waiting for follow-up should never delay care for warning signs. The NHS advises calling emergency services if you are pregnant and bleeding and the bleeding is heavy (soaking a pad soon after putting it on), or you have severe tummy pain, shoulder pain, or you feel faint, dizzy or lose consciousness.

For lighter bleeding or spotting, contact your maternity unit or early pregnancy service promptly. Later in pregnancy, if your baby is moving less than usual or the pattern changes, the NHS says to call your midwife or maternity unit immediately, even at night, and not to rely on a home heartbeat monitor.

Also seek urgent advice for a severe headache that does not ease, vision problems such as blurring or flashing lights, pain below the ribs, or sudden swelling of the face, hands or feet. These can be signs of pre-eclampsia.

AFP is a protein made mainly by the baby's liver. Some passes into the pregnant person's blood, where it can be measured. Cleveland Clinic describes the test as usually done between 16 and 22 weeks, and it may be part of a combined blood screen, such as the quad screen, which is done between about 15 and 20 weeks.

The test estimates the chance of certain conditions, including neural tube differences such as spina bifida and anencephaly. When AFP is part of a combined screen, the results are also used to estimate the chance of some chromosomal conditions. Screening sorts pregnancies into those that may benefit from more checks and those that probably do not; it does not confirm or rule out anything.

Whether AFP screening is offered, and in what form, differs between countries and services. In some places the mid-pregnancy anomaly scan is the main check for spina bifida rather than a blood test.

Yes. AFP levels change as pregnancy progresses, so the result is compared with the level expected for your stage of pregnancy. If your due date is wrong, MedlinePlus explains, your AFP can look abnormal even though it fits your true stage of pregnancy. Cleveland Clinic notes that a higher AFP could mean the pregnancy is further along than thought.

Each baby makes AFP, so levels are higher with two or more babies. If a multiple pregnancy was not already known, a scan will show this.

A false positive is also possible: the screen suggests a problem when none exists. This is why one number on its own is never treated as an answer.

Higher than expected AFP can be linked to an open neural tube difference, such as spina bifida or anencephaly, or to a difference in the baby's abdominal wall, such as gastroschisis or exomphalos. MedlinePlus also mentions differences of the oesophagus.

These are possibilities that further checks are designed to look for. A raised result raises a question; it does not answer it. Your care team will explain what your specific result means in your pregnancy.

If AFP results fall outside the expected range, Cleveland Clinic says a provider may recommend another blood test, an ultrasound or amniocentesis. In practice, a detailed ultrasound is often the first step, because it can confirm how far along the pregnancy is, count the babies and look closely at the baby's spine, head and abdominal wall.

The NHS mid-pregnancy scan, usually done between 18 and 21 weeks, checks for 11 conditions, including anencephaly, open spina bifida, gastroschisis and exomphalos. If something is found or suspected, you will be referred to a specialist who can explain further tests, such as amniocentesis, so you can decide whether to have them.

No scan can find every condition, and the NHS notes that some are seen more clearly than others. Ask your team what the scan was able to see and whether any views need repeating.

• Confirm the dates: was your due date set by an early ultrasound, and has it been rechecked?
• Count the babies: has a scan confirmed how many babies there are?
• Detailed anatomy scan: what did it show about the spine, head and abdominal wall?
• Further tests: is a diagnostic test being offered, and what would it add?

Bring the written screening result, the gestational age used to calculate it and any scan reports. These questions can help you leave with a clear plan.

• Was my due date confirmed by an early scan, and was it used when my AFP was calculated?
• Is my result reported as a level, a multiple of the median or a chance estimate, and how should I read it?
• Does the detailed scan explain the raised AFP, or is the reason still unclear?
• Are further tests being offered, what could they show, and what are their risks?
• If the scan looks normal, is any further monitoring planned for the rest of the pregnancy?
• Who should I contact with questions, and when will I hear about the next appointment?

On SameCase, patients and verified doctors share de-identified cases. Reading how others with a raised AFP result went through dating scans, detailed anomaly scans and follow-up conversations can help you think of questions to bring to your own appointment.

Other people's results cannot predict what will happen in your pregnancy, and we do not offer a diagnosis. Your care team, who know your full history and scan findings, are the right people to interpret your result.