Rapid Intrauterine Fetal Death Caused by Listeria monocytogenes in Mid-Pregnancy: A Case Report and Literature Review.

BACKGROUND: Listeria monocytogenes (LM) is a foodborne Gram-positive bacillus capable of growth at refrigeration temperatures. Pregnancy-associated infection may cause placental invasion and fetal loss despite mild or nonspecific maternal symptoms. Intrinsic lack of cephalosporin activity can delay effective treatment when listeriosis is not suspected. CASE PRESENTATION: A 34-year-old primigravida at 22+6 weeks presented after 8 hours of fever and 6 hours of lower abdominal pain. Marked leukocytosis, neutrophilia, elevated C-reactive protein, fetal tachycardia, uterine contractions, and abnormal amniotic echogenicity suggested intra-amniotic infection. Ceftriaxone was started for fever of undetermined origin; intrauterine fetal death occurred 8 hours after admission. Cultures of throat swab, ear swab, and perianal secretion specimens obtained from the delivered fetus all yielded L. monocytogenes, and placental histopathology showed stage III, grade II acute chorioamnionitis. After fetal delivery, treatment was changed to intravenous ampicillin, with resolution of fever and inflammatory abnormalities. Refrigerated Arctic shrimp consumed 2 weeks earlier was considered a suspected, unconfirmed exposure. CONCLUSION: In febrile pregnant patients, the combination of fetal tachycardia, uterine activity, a marked inflammatory response, and no alternative infection source should prompt early consideration of listeriosis and LM-active empirical therapy after cultures are obtained. Dietary exposure history, appropriate specimen collection, and awareness of cephalosporin noncoverage are central to management and prevention.