**Question:** A pregnant woman who has a lactase deficiency and cannot tolerate milk in her diet is concerned that she will not be able to produce milk of sufficient caloric value to nourish her baby. The best advice to her is which one of the following?

A. Consume lactose-containing milk to increase lactose production in breast milk, which could lead to increased caloric content
B. Avoid lactose-containing foods to reduce lactose production in breast milk
C. Explain lactase deficiency and lactose intolerance, but do not advise on lactose consumption
D. Encourage lactose-containing foods for the baby to meet their nutritional needs

**Correct Answer:** C. Explain lactase deficiency and lactose intolerance, but do not advise on lactose consumption

**Core Concept:**
Lactose intolerance is a common gastrointestinal disorder in pregnant women, particularly those with lactase deficiency. Lactase is an enzyme responsible for breaking down lactose, a sugar found in milk, into glucose and galactose, which are then absorbed into the bloodstream. In lactase deficiency, insufficient lactase production leads to lactose accumulation in the intestine, causing symptoms such as abdominal pain, bloating, and diarrhea after consuming lactose-containing foods.

**Why the Correct Answer is Right:**
The correct answer is to explain lactase deficiency and lactose intolerance to the pregnant woman. Avoiding lactose-containing foods minimizes lactose intake, which prevents lactose accumulation in the intestine and reduces the likelihood of gastrointestinal symptoms. However, advising lactose consumption might exacerbate her lactose intolerance symptoms.

**Why Other Options are Incorrect:**
A) Consuming lactose-containing milk may increase lactase production in breast milk, leading to higher lactose content in the breast milk. This misconception is incorrect as lactase production is determined during pregnancy and does not change significantly based on lactose intake.

B) Avoiding lactose-containing foods for the baby is not advisable, as the baby's nutritional requirements can be met through breast milk alternatives or through lactose-free formulas. However, explaining lactose intolerance to the pregnant woman is crucial to prevent potential gastrointestinal issues for both her and the baby.

D) Encouraging lactose-containing foods for the baby is incorrect as it does not address the woman's lactose intolerance and may lead to lactose accumulation in the woman's intestine, worsening her symptoms.

**Clinical Pearl:**
1. It is essential to educate lactose-intolerant pregnant women about lactose intolerance and its implications on the mother's health and the baby's nutrition.
2. Provide alternatives, such as breast milk substitutes or lactose-free formulas, to ensure the baby receives adequate nutrition without lactose.

✓ Correct Answer: C. The production of lactose by the mammary gland does not require the ingestion of milk or milk products.