1. What is the EDD Calculator?

The EDD (Estimated Due Date) Calculator estimates the expected delivery date based on the last menstrual period (LMP) using the standard Naegele's rule, adding 280 days (40 weeks) to the first day of the LMP.

2. How Does the Calculator Work?

The calculator uses the standard EDD formula:

Where:

• \( EDD \) — Estimated Due Date
• \( LMP \) — Last Menstrual Period (first day)
• \( 280 \text{ days} \) — Standard gestation period (40 weeks)

Explanation: This calculation is based on Naegele's rule, which assumes a 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represent the average human gestation period.

3. Importance of EDD Calculation

Details: Accurate EDD calculation is crucial for prenatal care planning, monitoring fetal development milestones, scheduling important prenatal tests, and preparing for delivery. It helps healthcare providers track pregnancy progress and identify potential complications.

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 calculations. The calculator will automatically compute your estimated due date.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the EDD calculation?
A: The EDD calculated from LMP is an estimate. Only about 5% of women deliver on their exact due date. Most deliveries occur within 2 weeks before or after the calculated date.

Q2: What if my menstrual cycle is irregular?
A: For women with irregular cycles, the LMP method may be less accurate. In such cases, an early ultrasound (first trimester) provides a more reliable due date estimation.

Q3: Can the due date change during pregnancy?
A: Yes, healthcare providers may adjust the due date based on early ultrasound measurements, especially if there's a significant difference from the LMP-based calculation.

Q4: What is Naegele's rule?
A: Naegele's rule is the standard method for calculating EDD: add 7 days to the first day of LMP, then subtract 3 months, and add 1 year (equivalent to adding 280 days).

Q5: Are there other methods to calculate EDD?
A: Yes, other methods include ultrasound measurements (most accurate in first trimester), conception date (if known), and IVF transfer date for assisted reproduction pregnancies.