Background <p>OnabotulinumtoxinA (BoNT-A) is used widely for medical and aesthetic purposes in women of childbearing age. With the increasing number of approved indications, it is essential to assess BoNT-A safety and efficacy in pregnant women.</p> Methods <p>We conducted a systematic review of the studies reporting maternal and neonatal outcomes following BoNT-A treatment during pregnancy. PubMed, Scopus, and Web of Science were searched to retrieve relevant studies. Data were synthesized into summary tables outlining maternal characteristics, treatment regimens, and neonatal outcomes.</p> Results <p>A total of eighteen studies with 486 pregnancies were included. Maternal indications for treatment included cosmetic purposes, neurological disorders, and pain management. Most patients received BoNT-A in the first trimester. Pregnancy outcomes were available for 488 fetuses. 379 (77.7%) were healthy, 98 (20.1%) fetuses were lost (elective, therapeutic, and spontaneous abortions), and 11 (2.3%) had cases of birth defects.</p> Conclusions <p>This is the first systematic review to synthesize the published clinical outcomes of BoNT-A use during pregnancy. The current evidence remains insufficient to establish safety due to significant heterogeneity and insufficient data. Although no direct association between fetal harm or losses and BoNT-A treatment could be inferred, the evidence remains limited. Larger, well-designed studies are needed to establish the safety profile and identify potentially rare or delayed outcomes.</p> Level of Evidence IV <p>This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors <a href="http://www.springer.com/00266">www.springer.com/00266</a>.</p>