Gastrointestinal Infections in Pregnancy

The reduction in cell-mediated immune function in pregnancy leads to increased susceptibility to certain infections. Of the gastrointestinal pathogens, Listeria monocytogenes is an intracellular pathogen that may induce serious disease in the mother and/or fetus.

• Common causes of gastroenteritis in adults include Campylobacter, rotavirus, E coli, Salmonella, Shigella, Clostridium perfringens enterotoxin, adenovirus, astrovirus, Cryptosporidium, Giardia and Entamoeba.¹
• Toxoplasma gondii and Listeria monocytogenes have both been implicated as a cause of stillbirth.² If not promptly and adequately treated, listeriosis in pregnancy may present serious hazards to the fetus and newborn through direct infection of the placenta and chorioamnionitis.³
• Listeria in pregnancy affects 6-15/100,000 pregnancies. Epidemics occur.
• Pregnant women may be more susceptible to traveler's diarrhoea or its complications for a variety of reasons, e.g. lower acidity of the stomach during pregnancy may make it easier for bacteria to survive in the stomach.

• Listeria:
  • Fever, myalgia, headache, sore throat, cough, vomiting, diarrhoea, vaginitis.
  • Abortion (can be recurrent), premature labour, and stillbirth may occur.
• Campylobacter:
  • Commonly found in animals and the environment. Therefore, food-borne infection can result from eating undercooked meats (undercooked poultry meat has caused outbreaks), raw milk, and drinking non-chlorinated water.
  • Flu-like symptoms, followed by diarrhoea, abdominal pain, nausea and vomiting. Miscarriage and premature labour can occur.
  • To reduce risk, it is important to wash hands after animal contact, avoid raw milk and untreated water, fully cook meats and to follow the food safety guidelines.
• Salmonella:
  • Causes headache, abdominal pain, diarrhoea and vomiting.
  • Salmonella infection during pregnancy can cause stillbirth.⁴
• Giardia:
  • Can be caught by drinking, swallowing or swimming in untreated water (from lakes, rivers, springs, wells, ponds). Food can be contaminated, especially raw food like fruit and vegetables.
  • Symptoms are diarrhoea, abdominal cramps and nausea. The illness can last 4-6 weeks (occasionally longer).
• Cryptosporidium:
  • Can be caught in the same ways as Giardia.
  • Causes severe watery diarrhoea, and can be passed from an infected mother to her baby during the birth process.
  • Both Giardia and Cryptosporidium cause unpleasant illness, which may be severe.

• Blood tests: renal function and electrolytes
• Stool culture, and check for ova, cysts and parasites
• Listeria: diagnosis is from culture of blood, CSF, meconium, and placenta. Serology, vaginal and rectal swabs do not help (listeria may be commensal there).

• Most gastrointestinal infections in pregnancy only require rehydration and fetal monitoring.
• Hospital admission is required for any significant degree of dehydration or any indication of fetal distress.
• Specific antibiotics are rarely required but may be indicated depending on the results of stool culture and advice from microbiology.

• Severe dehydration in the pregnant woman can diminish blood flow through the placenta. Pre-existing nausea and vomiting in pregnancy may further limit fluid intake and increase the risk of dehydration.
• Gastrointestinal disease in women during pregnancy may be a risk factor for low-birthweight infants. Gastroenteritis during part of the pregnancy has been associated with a shortened pregnancy, but it had no other adverse effects on neonatal outcome. The reduction in the duration of pregnancy was probably of little clinical relevance.⁵
• Listeria:
  • 20% of affected fetuses are stillborn.
  • Fetal distress in labour is common.
  • An early postnatal feature is respiratory distress from pneumonia. There may be fits, hepatosplenomegaly, pustular or petechial rashes, conjunctivitis, fever, leucopenia. Meningitis presents more commonly after perinatal infection.
  • Infant mortality is 30%.
  • The baby should be isolated as may spread infection to others. Treatment is both supportive and intravenous antibiotics (amoxicillin and gentamicin).

• Pregnant women should be advised and practice a high standard of food hygiene (e.g. not allowing frozen food from shop to defrost before putting into freezer, prompt consumption and not leaving food in fridge for any length of time, and longer cooking and rewarming times), and personal cleanliness (e.g. regular hand washing, especially after using the toilet and also before preparing or eating food).
• Listeria monocytogenes can be transmitted to pregnant women by infected food. The bug has been found in a variety of foods at all stages of preparation, from raw to well-cooked left-overs and will still grow on food that is stored in a fridge. Certain foods should be avoided if possible. They include:
  • Pate
  • Processed and cold meats
  • Soft cheeses, e.g. brie, camembert, feta and ricotta
  • Pre-prepared salads, e.g. coleslaw
  • Cold, smoked or raw seafood, e.g. smoked salmon, oysters, sashimi