Lactose intolerance during pregnancy

Lactose intolerance occurs when lactase does not break down all the lactose in dairy. Unabsorbed lactose is fermented in the bowel, which can produce gas, cramps and loose stools. Pregnancy itself can alter bowel movement and make bloating or constipation more noticeable, so timing after dairy is useful but not diagnostic. Vomiting, severe pain, fever or diarrhoea can have other causes and may affect hydration. A midwife, obstetric clinician or primary-care doctor can help separate an intolerance pattern from pregnancy-related or infectious symptoms.

Record foods, portions and symptoms, then discuss a planned reduction or reintroduction rather than removing dairy indefinitely. Lactose-free dairy, yoghurt, hard cheese and fortified alternatives may provide useful calcium and protein, depending on your diet and tolerance. Check that plant-based drinks are fortified and suitable for your needs. Do not start supplements or make major dietary restrictions without discussing them with your maternity team. Nutrition Counselling can help meet pregnancy nutrition needs, while Food Intolerance Testing may be considered when the history remains unclear.

Contact your maternity team for ongoing diarrhoea, inability to keep fluids down, reduced urination, weight loss, blood in stool or pain that does not settle. Seek urgent care for severe abdominal pain, fainting, heavy bleeding, breathing difficulty or facial swelling. These symptoms require prompt assessment and should not be attributed to lactose intolerance without review.

Ask how to test whether dairy is triggering symptoms, which calcium-rich alternatives fit your pregnancy plan, and whether medicines or supplements are appropriate. Ask what dehydration signs should prompt same-day advice.