diff --git a/src/facilities/surgery/analyzePregnancy.js b/src/facilities/surgery/analyzePregnancy.js
index cd45a8f2bdcd07d677222710f3e578d9b6d740ea..5321dbd1997d6f11fe879253c06994413b5b3b76 100644
--- a/src/facilities/surgery/analyzePregnancy.js
+++ b/src/facilities/surgery/analyzePregnancy.js
@@ -75,7 +75,7 @@ globalThis.fetusAbnormalities = function(fetus) {
 	const abnormalitySpans = [];
 	for (const gene in fetus.genetics.geneticQuirks) {
 		const geneObj = quirkNames.get(gene);
-		const quirkName = (geneObj) ? geneObj.abbreviation || gene : gene;
+		const quirkName = (geneObj && geneObj.abbreviation) ? geneObj.abbreviation : gene;
 		const quirkColor = (geneObj && geneObj.goodTrait) ? "green" : "red";
 		if (fetus.genetics.geneticQuirks[gene] === 2) {
 			abnormalitySpans.push(App.UI.DOM.makeElement("span", quirkName, quirkColor));