THIS MEDICATION MAY CAUSE HARM TO YOUR BABY:
Pregnancy is not considered a reason to withhold omalizumab due to the risk of negative effects on both mother and baby associated with poorly controlled or uncontrolled asthma during pregnancy. There have been limited human studies that have looked at the safety of omalizumab during pregnancy, but the available evidence suggests a low risk of harm with use of this medication during pregnancy. It is important to evaluate the benefits to the mother and potential harm to the nursing baby before deciding to continue or discontinue breastfeeding while on this medication.
What is omalizumab?
Omalizumab is currently only available as a brand name medication (Xolair™) and is available as a solution for subcutaneous injection (a shot under the skin). Omalizumab is dosed based on body weight and antibody levels before treatment, is given every 2 to 4 weeks and may require injection over several sites in doses greater than 150 mg (see product insert for more detailed information on dosing this medication). Initial injections require medical supervision and 2 hour monitoring. Injections after the first one require medical supervision and at least 30 minutes of monitoring due to the risk of an anaphylactic reaction (a severe allergic reaction). This medication is only available by prescription from your doctor.
What is omalizumab used to treat?
Omalizumab is used to treat severe and chronic asthma that is unresponsive to inhaled corticosteroids in children over 6 years old, adolescents, and adults. Omalizumab is also used to treat chronic hives unresponsive to antihistamines in children over 12 years old, adolescents, and adults. It is estimated that 4% of pregnancies are impacted by asthma. During pregnancy, women with asthma may see either a worsening or improvement in their asthma symptoms. Asthma attacks are most common between weeks 17 and 24 during pregnancy. Asthma control during pregnancy is important to avoid negative effects in both the mother and baby. Pregnant women with asthma should undergo regular monitoring and avoid asthma triggers during their pregnancy.
How does omalizumab work?
Omalizumab is a human monoclonal IgG antibody that works by interfering with allergy-causing IgE antibodies that bind to receptors in the body to cause inflammation and asthma.
If I am taking omalizumab, can it harm my baby?
There are limited human studies or case reports that have looked at the safety of this medication in pregnancy. Animal studies show that taking omalizumab during pregnancy suggests a low risk of harm to your baby. Omalizumab is expected to pass through the placenta from mother to baby. Uncontrolled or poorly controlled asthma during pregnancy has been associated with harm to both mother and baby (for example, preeclampsia, preterm birth, low birth weight, and death). Pregnancy should not be a reason to withhold omalizumab. The American College of Obstetrics and Gynecologists recommends having good control of asthma before and during pregnancy.
Evidence from animal studies with omalizumab:
When given to pregnant monkeys at doses 10-12 times the maximum recommended human dose, omalizumab produced no adverse effects on the babies.
Evidence for the risks of omalizumab in human babies:
Women in early clinical trials (n=29) most often stopped omalizumab after pregnancy was determined. A total of 11 out of 12 women participating in ongoing clinical studies reported healthy pregnancies and deliveries. The rate of miscarriage is estimated to be 14% in women who took omazliumab during pregnancy which is similar to rates in the general U.S. population. Case reports from Japan, Denmark, and Poland reported healthy pregnancies in women who took omalizumab throughout pregnancy. The Xolair Pregnancy Registry, also known as the EXPECT Pregnancy Registry, followed pregnant women exposed to omalizumab during a minimum of the first trimester of pregnancy. As of 2012, registry results from 188 pregnancies showed birth defects occurred in 12.5% of births and only 4.4% were considered major birth defects. The risk of major birth defects in the general U.S. population ranges from 2% to 4%. Omalizumab is similar to other asthma medications studied in pregnant women because it has been associated with preterm delivery and low birth weight; however, it is unknown if these side effects are due to the medication or the severity of asthma during pregnancy. In 2019, data from 250 women exposed to omalizumab during pregnancy (primarily the first trimester) in the EXPECT Pregnancy Registry were compared to control data from 1153 pregnant women with asthma who were unexposed to omalizumab, finding similar rates of major birth defects, premature births, and live births.
Bottom line: Omalizumab should only be used during pregnancy if required. While human studies are limited, they suggest a low risk of harm to mother and baby. However, poorly controlled or uncontrolled asthma during pregnancy is expected to pose a greater risk to the baby than omalizumab exposure.
If I am taking omalizumab and become pregnant, what should I do?
If you are taking omalizumab and become pregnant, you should contact your doctor immediately. Your doctor will determine if your medication is medically necessary, or if it should be discontinued until after the birth of your baby. Omalizumab does not have to be stopped because of pregnancy, but overuse should be avoided.
If I am taking omalizumab, can I safely breastfeed my baby?
The effect of omalizumab exposure on breastfed infants is unknown. Omalizumab is expected to be found in breast milk. The manufacturer reports no cases of infection in 186 infants exposed to this medication while breastfeeding. It is recommended to evaluate the benefits to the mother and potential harm to the nursing baby before deciding to continue or discontinue breastfeeding.
Bottom line: Omalizumab is expected to pass into breast milk. It is recommended to evaluate the benefits to the mother and potential harm to the nursing baby before deciding to continue or discontinue breastfeeding while using omalizumab.
If I am taking omalizumab, will it be more difficult to get pregnant?
A study in monkeys found doses of omalizumab up to 10 times the recommended human doses had no negative effects on fertility in males or females.
If I am taking omalizumab, what should I know?
Omalizumab should only be used during pregnancy if required. While human studies are limited, they suggest a low risk of harm to either mother or baby. However, poorly controlled or uncontrolled asthma during pregnancy is expected to pose a greater risk to the baby than omalizumab exposure.
No adverse events have been reported in infants exposed to omalizumab through breastfeeding. The potential risks and benefits of omalizumab should be weighed before continuing to use this medication while breastfeeding.
If I am taking any medication, what should I know?
This report provides a summary of the available information about the use of omalizumab during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.
You may find Pregistry's expert report about asthma here, and reports about various other health conditions as well as the individual medications used to treat allergies and other conditions here. Additional information can also be found in the resources below.
For more information about omalizumab during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links:
UpToDate: Asthma and pregnancy (Beyond the Basics)
Gene dot com: Xolair prescribing information
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.