1. What is the Pregnancy Due Date Calculator?

The Pregnancy Due Date Calculator is a standard medical tool used by healthcare providers to estimate the expected delivery date based on the first day of the last menstrual period (LMP). This calculation follows Naegele's Rule, which is widely accepted in obstetric practice.

2. How Does the Calculator Work?

The calculator uses the standard obstetric 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 represent 40 weeks of gestation from the LMP.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for proper prenatal care, monitoring fetal development, scheduling important tests, and planning 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. The calculator will provide the estimated due date based on standard obstetric calculations.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this due date calculation?
A: This method is about 70% accurate for predicting delivery within ±7 days of the estimated date, and 90% accurate within ±14 days.

Q2: What if my menstrual cycle is longer or shorter than 28 days?
A: For cycles longer than 28 days, add the extra days to the due date. For shorter cycles, subtract the difference. Your healthcare provider can adjust accordingly.

Q3: Can ultrasound change the due date?
A: Yes, first-trimester ultrasound dating is more accurate than LMP dating and may be used to adjust the due date, especially if there's uncertainty about LMP dates.

Q4: What percentage of babies are born on their due date?
A: Only about 4-5% of babies are born exactly on their due date. Most births occur within two weeks before or after the estimated date.

Q5: When should I confirm my due date with a healthcare provider?
A: It's recommended to schedule your first prenatal appointment within the first 8 weeks of pregnancy to confirm dating and begin proper prenatal care.