Is Symbicort Safe in Pregnancy?
Yes, Symbicort (budesonide/formoterol) can be used safely during pregnancy, with budesonide being the preferred inhaled corticosteroid due to extensive reassuring human data showing no increased risk of congenital malformations. The benefits of maintaining asthma control during pregnancy outweigh theoretical risks, as uncontrolled asthma poses greater dangers to both mother and fetus.
Key Safety Evidence
Budesonide Component (Well-Established Safety)
Budesonide is considered low-risk in pregnancy and is the preferred inhaled corticosteroid for pregnant women with asthma. 1
Large epidemiological studies demonstrate safety: A Swedish registry study of 2,534 infants exposed to inhaled budesonide in early pregnancy showed congenital malformation rates of 3.6-3.8%, identical to the general population rate of 3.5% 2
No increased risk of orofacial clefts: Despite older literature suggesting corticosteroid-associated cleft risk, a nationwide cohort study of nearly 52,000 pregnancies with first-trimester corticosteroid exposure showed no increased risk 1
FDA Pregnancy Category B rating: Budesonide has more accumulated human safety data than other inhaled corticosteroids, which are rated Category C 1
Compatible with lactation: Budesonide is considered safe during breastfeeding 1
Formoterol Component (Limited but Reassuring Data)
No adequate human studies exist for formoterol specifically in pregnancy, though animal studies at therapeutic doses showed no teratogenic effects when given by inhalation 2
Animal toxicity only at extreme doses: Teratogenic effects occurred only at 1,600-65,000 times the maximum recommended human dose when given orally (not by inhalation) 2
Inhalation route is key: No teratogenic or embryocidal effects were seen in rats receiving inhalation doses up to 375 times the maximum recommended human dose 2
Clinical Rationale for Use
Disease Control Outweighs Medication Risk
Uncontrolled asthma during pregnancy poses significant risks including preeclampsia, preterm birth, low birth weight, and perinatal mortality. 1, 2
It is safer to treat asthma than to have symptoms: Maintaining lung function ensures adequate oxygen supply to the fetus 1
Monthly monitoring recommended: Asthma improves in one-third of pregnant women and worsens in one-third, necessitating regular assessment and medication adjustment 1
Important Caveats and Considerations
Use Lowest Effective Dose
Minimize dose when possible: As with all medications in pregnancy, use the lowest effective dose to maintain asthma control 1
Glucocorticoid doses >5 mg/day carry dose-related risks: Higher doses of systemic corticosteroids are associated with gestational diabetes, pregnancy-associated osteoporosis, and preterm birth 1
Labor and Delivery Considerations
- Beta-agonist effects on uterine contractility: Use during labor should be restricted to patients where benefits clearly outweigh risks due to potential interference with uterine contractions 2
Conflicting Animal Data Should Not Deter Use
One experimental study showed teratogenic effects: A 2021 chick embryo study found orofacial clefts and gastroschisis with budesonide and formoterol 3
However, rodents are more prone to corticosteroid teratogenicity than humans, and extensive human epidemiological data is reassuring 2
The human evidence vastly outweighs animal concerns: Over 6,600 human pregnancies with budesonide exposure show no increased malformation risk 4
Practical Recommendations
Continue Symbicort if already controlling asthma pre-pregnancy 1
If starting therapy during pregnancy, budesonide-containing products are preferred over other inhaled corticosteroids due to superior human safety data 1
Do not discontinue at 32 weeks gestation: The common practice of stopping immunomodulators late in pregnancy is not supported by current data 5
Monitor asthma control closely: Adjust therapy as needed to maintain optimal control throughout pregnancy 1