1. What is Doctor's Due Date Calculation?

The Doctor's Due Date calculation estimates the expected delivery date using Naegele's Rule, which adds 280 days (40 weeks) to the first day of the last menstrual period (LMP). This is the standard method used by healthcare providers worldwide.

2. How Does the Calculator Work?

The calculator uses the standard medical formula:

Where:

• \( EDD \) — Estimated Due Date
• \( LMP \) — First day of Last Menstrual Period
• \( 280 \text{ days} \) — Standard pregnancy duration (40 weeks)

Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represents 40 weeks of gestation.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for monitoring fetal development, scheduling prenatal tests, preparing for delivery, and identifying potential complications like post-term pregnancy.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate as this forms the basis for all subsequent pregnancy dating.

5. Frequently Asked Questions (FAQ)

Q1: Why is LMP used instead of conception date?
A: LMP is more reliably known than conception date for most women, making it the standard reference point in obstetric practice.

Q2: How accurate is this calculation?
A: Only about 5% of women deliver on their exact due date. Most deliveries occur within 2 weeks before or after the calculated date.

Q3: What if my cycle isn't 28 days?
A: For women with irregular or longer cycles, the due date may need adjustment. Ultrasound dating in early pregnancy can provide more accurate estimation.

Q4: When is ultrasound used to confirm due date?
A: Ultrasound is typically used if LMP is uncertain, cycles are irregular, or if there's significant discrepancy between LMP dating and ultrasound measurements.

Q5: Can the due date change during pregnancy?
A: The due date is usually established in the first trimester and remains unchanged unless early ultrasound reveals significant discrepancy with LMP dating.