1. What is the Gestational Due Date Calculator?

The Gestational Due Date Calculator estimates a pregnant woman's expected delivery date based on the first day of her last menstrual period (LMP). This calculation follows Naegele's rule, which adds 280 days (40 weeks) to the LMP.

2. How Does the Calculator Work?

The calculator uses the standard formula:

Where:

• \( LMP \) — First day of last menstrual period
• \( 280\ days \) — Equivalent to 40 weeks gestation

Explanation: This calculation assumes a regular 28-day menstrual cycle with ovulation occurring on day 14. The actual delivery date may vary by ±2 weeks.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for proper prenatal care, monitoring fetal development, and determining if pregnancy is progressing normally.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the format YYYY-MM-DD. The calculator will add 280 days (40 weeks) to this date.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: About 4% of women deliver on their due date, while 60% deliver within 1 week and 90% within 2 weeks of the estimated date.

Q2: What if my cycles aren't regular?
A: For irregular cycles, early ultrasound dating is more accurate than LMP-based calculation.

Q3: Does this account for leap years?
A: Yes, the calculator automatically accounts for leap years in the date calculation.

Q4: When should I see my doctor about my due date?
A: Always confirm your due date with a healthcare provider, who may adjust it based on ultrasound measurements.

Q5: Can this be used for IVF pregnancies?
A: For IVF pregnancies, the embryo transfer date should be used instead of LMP for more accurate dating.