From the Guidelines
Asthma biologics should be continued during pregnancy if required for asthma control in the mother, as the risks of uncontrolled asthma typically outweigh theoretical risks of the medication. The safety of asthma biologics during pregnancy requires careful consideration of benefits versus risks. Generally, well-controlled asthma is safer for both mother and fetus than uncontrolled asthma, which can lead to complications like preeclampsia, preterm birth, and low birth weight [ 1 ]. If a pregnant woman's asthma cannot be adequately controlled with conventional treatments (inhaled corticosteroids, long-acting beta-agonists), biologics may be considered. Monoclonal antibodies, such as those used in asthma biologics, are not likely to cross the placenta in sufficient quantities to cause fetal harm [ 1 ].
Key Considerations
- The decision to use biologics during pregnancy should be individualized based on asthma severity and control.
- If a woman becomes pregnant while on a biologic, the general recommendation is to continue if her asthma is severe and the biologic has been effective.
- Consultation with both pulmonology and maternal-fetal medicine specialists is recommended for pregnant women with severe asthma requiring biologic therapy.
- Maintaining asthma control during pregnancy is important for the health and well-being of both the mother and her baby [ 1 ].
Evidence Summary
The most recent and highest quality study, published in 2020, suggests that monoclonal antibodies should be continued during pregnancy if required for asthma control in the mother [ 1 ]. This study, published in the European Respiratory Journal, provides the most up-to-date guidance on the management of reproduction and pregnancy in women with airways diseases. Previous studies, such as those published in 2005 [ 1 ] and 2007 [ 1 ], provide additional guidance on the management of asthma during pregnancy, but the 2020 study takes precedence due to its recency and high quality.
From the FDA Drug Label
8 USE IN SPECIFIC POPULATIONS
- 1 Pregnancy Risk Summary A registry study of XOLAIR exposure during pregnancy showed no increase in the rate of major birth defects or miscarriage There was an increased rate of low birth weight among registry infants compared to infants in the other cohorts, despite average gestational age at birth; however, women taking XOLAIR during pregnancy also had more severe asthma, which makes it difficult to determine whether the low birth weight is due to the drug or the disease severity In animal reproduction studies, no evidence of fetal harm was observed in Cynomolgus monkeys with subcutaneous doses of omalizumab up to approximately 5 times the maximum recommended human dose (MRHD)
The safety of omalizumab in pregnancy is not fully established, but a registry study showed no increase in major birth defects or miscarriage. However, there was an increased rate of low birth weight among infants exposed to omalizumab in utero, which may be due to the drug or the severity of the mother's asthma.
- Key points:
- No increase in major birth defects or miscarriage
- Increased rate of low birth weight
- Animal studies showed no fetal harm at doses up to 5 times the MRHD
- Clinical decision: Use omalizumab in pregnancy only if the potential benefits outweigh the risks, and closely monitor the level of asthma control. 2
8 USE IN SPECIFIC POPULATIONS
- 1 Pregnancy Risk Summary The data on pregnancy exposure are insufficient to inform on drug-associated risk. Monoclonal antibodies, such as mepolizumab, are transported across the placenta in a linear fashion as pregnancy progresses; therefore, potential effects on a fetus are likely to be greater during the second and third trimester of pregnancy In a prenatal and postnatal development study conducted in cynomolgus monkeys, there was no evidence of fetal harm with IV administration of mepolizumab throughout pregnancy at doses that produced exposures up to approximately 9 times the exposure at the maximum recommended human dose (MRHD)
The safety of mepolizumab in pregnancy is unknown due to insufficient data. However, animal studies showed no fetal harm at doses up to 9 times the MRHD.
- Key points:
- Insufficient data on pregnancy exposure
- No fetal harm in animal studies at doses up to 9 times the MRHD
- Clinical decision: Use mepolizumab in pregnancy only if the potential benefits outweigh the risks, and closely monitor the level of asthma control. 3
From the Research
Asthma Biologic Safety in Pregnancy
- The safety of asthma biologics during pregnancy is a concern due to the lack of clinical trials that include pregnant women 4.
- However, an international consensus suggests that asthma biologics can be used during conception and throughout pregnancy, with risk versus benefit discussions and shared clinical decision making 4.
- The use of asthma biologics during pregnancy may be necessary to control severe asthma, as uncontrolled asthma can lead to adverse perinatal outcomes 5, 4, 6, 7.
- Some studies have reported on the safety of asthma medications during pregnancy, including inhaled corticosteroids, which have not been associated with an increased risk of congenital malformations or other adverse outcomes 5.
- Oral corticosteroids, on the other hand, have been associated with reduced birth weight, an increased risk of preeclampsia, and an increased risk of oral clefts when used during the first trimester 5.
- The lack of adequate safety information for most medications taken during pregnancy highlights the need for further research and the use of surveillance systems like pregnancy registries or observational cohort studies to provide safety information 6, 7.
- Real-world efficacy studies of biological therapies for severe asthma, such as benralizumab, dupilumab, mepolizumab, and reslizumab, have shown improvements in clinical outcomes, including exacerbation rate and lung function 8.
- However, more data are needed to acquire accurate effect estimates in different subpopulations of patients, including pregnant women 8.