Management of envenomations during pregnancy

Abstract

Context: Envenomations during pregnancy pose all the problems of envenomation in the nonpregnant state with additional complexity related to maternal physiologic changes, medication use during pregnancy, and the well-being of the fetus.

Objective: We review the obstetric literature and management options available to prevent maternal morbidity and mortality while limiting adverse obstetric outcomes after envenomation in pregnancy.

Methods: In January 2012, we searched the U.S. National Library of Medicine Medline/PubMed, Toxline, Reprotox, Google Scholar and Micromedex databases, core surgery and internal medicine textbooks, and references of retrieved articles for the years 1966 through 2011. Search terms included "envenomation in pregnancy," "stings in pregnancy," "antivenom use in pregnancy," "anaphylaxis in pregnancy," and variants of these with known venomous animals. Reference lists generated further case reports and articles. We included English language articles and abstracts. Levels of Evidence (LOE) for the reports cited and Grades of Recommendations (GOR) based on LOE for our recommendations use the National Guidelines Clearinghouse metric of the US DHHS.

Results: Recommendations for the management of envenomation in pregnancy are guided primarily by studies on nonpregnant persons and case reports of pregnancy. Clinically significant envenomations in pregnancy are reported for snakes, spiders, scorpions, jellyfish, and hymenoptera (bees, wasps, hornets, and ants). Adverse obstetric outcomes including miscarriage, preterm birth, placental abruption, and stillbirth are associated with envenomation in pregnancy. The limited available literature suggests that adverse outcomes are primarily related to venom effects on the mother. Optimization of maternal health such as management of anaphylaxis and antivenom administration is likely the best approach to improve fetal outcomes despite potential risks to the fetus of medication administration during pregnancy. Obstetric evaluation and fetal monitoring are imperative in cases of severe envenomation.

Conclusion: The medical literature regarding envenomation in pregnancy includes primarily retrospective reviews and case series. The limited available evidence suggests that optimal management includes a venom-specific approach, including supportive care, antivenom administration in appropriate cases, treatment of anaphylaxis if present, and fetal assessment. The current available evidence suggests that antivenom use is safe in pregnancy and that what is good for the mother is good for the fetus. Further research is needed to clarify the optimal management schema for envenomation in pregnancy.