Application of botulinum toxin in pregnancy and its impact on female reproductive health

ABSTRACT

Introduction: Botulinum toxin (BoNT) is a protein secreted by the anaerobic Gram-negative bacterium Clostridium botulinum. Among the seven known subtypes, type A is the most commonly used in women to treat diseases. It primarily blocks presynaptic release of acetylcholine at the neuromuscular junction, resulting in temporary muscle paralysis; thus, it is suitable for treating dystonia and other systemic diseases. BoNT is used widely for treating diseases that persist throughout, and may worsen during, pregnancy, such as cervical dystonia and achalasia. Thus, it is important to investigate whether BoNT injection during pregnancy causes side effects in pregnant women, fetuses, or newborns.

Areas covered: This review highlights the efficiency and safety of BoNT injection in pregnancy. and assessed current literature with respect to the use of BoNT for disease treatment during pregnancy.

Expert opinion: BoNT injection does not increase the risk of complications in pregnant women and fetuses. However, the use of BoNT to treat disease during pregnancy requires fully informed consent from patients. In addition, further research is needed to determine how to reduce the side effects of BoNT injection during pregnancy (e.g., by improving drug composition, or adjusting the amount of BoNT or the injection interval).

KEYWORDS:

• Botulinum toxin
• safety
• dystonia
• achalasia
• hemimasticatory spasm
• chronic pelvic pain
• pregnancy
• fetus

Article highlights

• Overview of the recent studies on the safety of botulinum toxin (BoNT) injection during pregnancy.

• BoNT is a purified neurotoxin which is not expected to enter the systemic circulation with intramuscular injection.

• BoNT is often used for treating diseases in women, including primary focal dystonia, as well as conditions that persist and may worsen during pregnancy.

• It is important to consider the safety of BoNT treatment during pregnancy and its impact on the fetus.

• The existing reports showed that BoNT injection did not increase the risk of pregnant women, fetuses nor newborns.

• The safety of BoNT injection during pregnancy relates to the product type, the dose of injection and the interval of treatment.

This box summarizes key points contained in the article.

Author contributions

M Tang was involved in the conception and design, W Li was involved in the analysis and interpretation of the data; the drafting of the paper. M Tang is responsible for the final approval of the version to be published; all authors agree to be accountable for all aspects of the work.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This work was supported by the Zhejiang Provincial Health Department Key Discipline Platform Project (No. 2018ZD016).