1. What is Pregnancy Due Date Calculator?

The Pregnancy Due Date Calculator estimates the expected delivery date (EDD) based on the last menstrual period (LMP). It uses the standard calculation of adding 280 days (40 weeks) to the first day of the last missed period.

2. How Does the Calculator Work?

The calculator uses the standard obstetric formula:

Where:

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

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

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for monitoring fetal development, scheduling prenatal care, 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. Ensure the date is accurate as this forms the basis for all subsequent pregnancy dating and monitoring.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this due date calculation?
A: This method is accurate for women with regular 28-day cycles. Only about 5% of babies are born exactly on their due date, with most arriving within two weeks before or after.

Q2: What if my menstrual cycle is irregular?
A: For irregular cycles, an early ultrasound (first trimester) provides more accurate dating than LMP-based calculation.

Q3: Why 280 days instead of 9 months?
A: Pregnancy is calculated as 40 weeks from LMP, which equals 280 days. Actual fetal age is about 38 weeks (266 days) from conception.

Q4: 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 discrepancy with LMP dating.

Q5: What are the three trimesters of pregnancy?
A: First trimester: weeks 1-13, Second trimester: weeks 14-27, Third trimester: weeks 28-40+.