Final answer:
In a case-control study on coffee consumption during pregnancy and low birth weight infants, smoking is a potential confounder. Smoking can have adverse effects on the health of both the mother and the baby. The 2x2 table is used to assess the association between coffee drinking and low birth weight.
Step-by-step explanation:
In a case-control study investigating the relationship between coffee consumption during pregnancy and low birth weight (LBW) infants, smoking is considered a potential confounder. Smoking can have adverse effects on the health of both the mother and the developing baby, including premature birth, LBW, stillbirth, and Sudden Infant Death Syndrome (SIDS). To assess the association between coffee drinking and LBW, a 2x2 table is used. It compares the proportion of coffee drinkers and non-coffee drinkers among LBW infants and non-LBW infants.