Acute Fatty Liver


The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What is acute fatty liver of pregnancy?

Fatty liver of pregnancy (AFLP) is a complication that can occur during the third trimester of pregnancy (usually between 28-40 weeks gestation, and especially weeks 35-36), or in a mother soon after delivering a baby.  In AFLP, high levels of fat accumulate in the mothers liver. Normally, fat comprises about 5 percent of the livers content, but in AFLP the liver consists of 13 -19 percent fat, and this may be due to problems in the rearrangement and breakdown of molecules called fatty acids coming from the developing baby.

How common is acute fatty liver during pregnancy?

Liver disease of some kind develops in about 3 percent of pregnancies. AFLP, in particular, occurs in 1 per 7,000 – 16,000 pregnancies. It is important, and also sometimes challenging, to distinguish AFLP from other liver conditions that can occur during pregnancy, the main ones being hyperemesis gravidarum (an extreme kind of nausea and vomiting that affects the womans biochemistry), intrahepatic cholestasis of pregnancy, pre-eclampsia, eclampsia, and HELLP syndrome.

How is acute fatty liver of pregnancy diagnosed?

Early diagnosis of AFLP is vital, but it can be challenging, since the symptoms of AFLP overlap with those of hyperemesis gravidarum (an extreme kind of nausea and vomiting that affects the womans biochemistry), intrahepatic cholestasis of pregnancy, pre-eclampsia, eclampsia, and HELLP syndrome, all of which also occur during pregnancy. AFLP also can look like hepatitis caused by a virus, which can occur both during pregnancy and outside of pregnancy. The factor that can help to distinguish AFLP is that it occurs mostly during late pregnancy, and sometimes even after delivery. If you are suspected of having AFLP, doctors will want to obtain an image of your liver, using ultrasound examination or computed tomography (CT). Both of these tests can reveal an accumulation of fat in the liver, but unfortunately, the tests are not specific or sensitive enough to confirm an AFLP diagnosis. However, usually, the combination of findings on the physical examination, imaging, and some laboratory tests are enough for physicians to rule out other conditions involving the liver, such as preeclampsia, and to be reasonably sure the AFLP is the problem. Such laboratory tests include antibody tests for hepatitis due to virus coming out negative, and certain biochemical tests showing results that are consistent with AFLP. Physicians almost never do a biopsy of the liver (taking a sample of the organ through a needle, or through surgery), because the procedure can provoke bleeding if the patient really does have AFLP. Furthermore, if doctors are deciding between a diagnosis of AFLP or preeclampsia, its not necessary to pin down the diagnosis as the treatment is the same for both conditions: deliver the baby as soon as possible (see below).

Does acute fatty liver cause problems during pregnancy?

Along with symptoms such as nausea, vomiting, abdominal pain, fatigue, headache, and lack of appetite, AFLP can lead to low blood sugar and severely altered states of consciousness or coma. Heartbeat irregularities can happen, as well as bleeding in the gastrointestinal tract and throughout the body. Patients can develop whats called diabetes insipidus, which means that their blood is getting too diluted and they are urinating excessively. They also can develop whats called metabolic acidosis, which means that the pH inside their bodies is too low, a condition that disrupts body chemistry. Multiple organs can be disrupted, including the kidneys, brain, liver, and pancreas. This can lead to kidney failure and/or liver failure, even to the point that the only way to save the patient is with a liver transplant.

Does acute fatty liver during pregnancy cause problems for the baby?

Because of the decreased pH in the mothers body in AFLP, the acid-base balance in the developing baby can be disrupted as well, putting the life of the baby at risk until it is delivered.

What to consider about taking medications when you are pregnant or breastfeeding:

  • The risks to yourself and your baby if you do not treat the acute fatty liver
  • The risks and benefits of each medication you use when you are pregnant
  • The risks and benefits of each medication you use when you are breastfeeding

What should I know about using medication to treat acute fatty liver during pregnancy?

The only way to cure AFLP is to deliver the baby. Usually, this is done by cesarean section, but delivery cannot be performed safely until the mothers condition is stabilized. The best way to achieve this is for the mother to be admitted into the intensive care unit (ICU) for monitoring of her condition, and for correction of any abnormalities, including blood pressure, bleeding problems, blood sugar levels, and levels of various blood chemicals. Medications that can be required are thus drugs that have a role in correcting and stabilizing blood pressure, blood sugar, and blood clotting systems. These are all very delicate body systems that can make the difference between life and death, and so AFLP is one example of a condition in which the well being of the baby depends on the success of life-saving measures used to treat the mother within a short period of time. Consequently, concerns about possible long-term effects of medications are not the issue.

Who should NOT stop taking medication for acute fatty liver during pregnancy?

Because of the reasons outlined in the previous section, whatever medication is needed to stabilize the mother is vital and must not be withheld.

What should I know about choosing a medication for my acute fatty liver during pregnancy?

You may find Pregistrys expert reports about the individual medications used to treat AFLP here. Additional information can also be found in the sources listed at the end of this report.

What should I know about taking a medication for my acute fatty liver when I am breastfeeding?

Because AFLP can develop at the end of pregnancy, or even after delivery, its possible for a new mother to be undergoing treatment for AFLP during the time when she has a newborn who must eat. Since this is a critical situation, however, where care is usually given in an ICU setting, sometimes even with the mother on a ventilator, its unlikely that she will be in a condition to breastfeed.

What alternative therapies besides medications can I use to treat acute fatty liver during pregnancy?

As suggested in previous sections, medications given in the care of AFLP are for support. They help stabilize the mother to enable delivery of the child, which then can lead to the AFLP resolving. When medications are needed for support, there is no alternative.

What can I do for myself and my baby when I have acute fatty liver during pregnancy?

Cooperate with your physicians. AFLP is a serious complication of pregnancy, but if recognized early and managed efficiently it is frequently survivable both for mother and child.

Resources for acute fatty liver in pre

For more information about AFLP during and after pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations:


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Last Updated: 02-10-2019
General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.

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