Naegele's Rule is used to estimate the due date by which adjustment?

• A. Subtract 3 months and add 7 days, then add 1 year
• B. Add 9 months and 7 days
• C. Subtract 6 months and add 28 days
• D. Add 12 months minus 1 week

Answer: (A)

Naegele's Rule is a method for estimating the due date based on the last menstrual period. It assumes a roughly 28-day cycle and that ovulation occurs around day 14. To apply it, take the first day of the last menstrual period, subtract three months, add seven days, and then add one year. This sequence gives the estimated due date, equivalent to LMP plus about 280 days. The option that follows this exact adjustment—subtract 3 months, add 7 days, then add 1 year—matches the rule. For example, LMP of February 10, 2024 would lead to an estimated due date of November 17, 2024. Other adjustments do not align with Naegele's Rule.