1. What is EDD Last Period Calculation?

The EDD (Estimated Due Date) Last Period calculation estimates the expected delivery date based on the first day of the woman's last menstrual period. This method adds 280 days (40 weeks) to the last period date, representing the typical duration of human pregnancy.

2. How Does the Calculator Work?

The calculator uses the standard obstetric formula:

Where:

• \( EDD \) — Estimated Due Date
• \( Last Period \) — First day of last menstrual period
• \( 280 days \) — Standard pregnancy duration (40 weeks)

Explanation: This calculation is based on Naegele's rule and assumes a regular 28-day menstrual cycle with ovulation occurring on day 14.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for prenatal care planning, monitoring fetal development, scheduling important 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 for the most reliable estimation. This method works best for women with regular menstrual cycles.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the last period method?
A: This method provides a good estimate but may vary by ±2 weeks. Ultrasound dating in early pregnancy is more accurate.

Q2: What if I have irregular periods?
A: For irregular cycles, this method may be less accurate. An early pregnancy ultrasound provides better dating.

Q3: Why 280 days instead of 9 months?
A: Pregnancy is calculated as 40 weeks (280 days) from the last period, which is approximately 9 calendar months plus one week.

Q4: When should I confirm with a healthcare provider?
A: Always confirm your due date with a healthcare provider, who may adjust it based on ultrasound measurements and clinical assessment.

Q5: Can the due date change during pregnancy?
A: Yes, healthcare providers may adjust the due date based on early ultrasound findings, especially if there's a significant difference from the last period calculation.