1. What is the EDD Calculator?

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

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 days — Standard length of pregnancy (40 weeks)

Explanation: This calculation assumes a regular 28-day menstrual cycle with ovulation occurring on day 14.

3. Importance of EDD Calculation

Details: Accurate EDD calculation is crucial for prenatal care scheduling, monitoring fetal growth, and determining post-term pregnancy management.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period (LMP) in the date field. The calculator will determine your due date and current gestational age.

5. Frequently Asked Questions (FAQ)

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

Q2: What if my cycles aren't 28 days?
A: For irregular or longer cycles, the EDD may need adjustment. Consult your healthcare provider for a corrected EDD.

Q3: When is an ultrasound more accurate than LMP?
A: Early ultrasound (especially first trimester) may be more accurate if LMP is uncertain or cycles are irregular.

Q4: What's the difference between gestational age and fetal age?
A: Gestational age counts from LMP (about 2 weeks before conception). Fetal age counts from actual conception.

Q5: Can the due date change during pregnancy?
A: Yes, based on ultrasound findings or if the original LMP date was uncertain. Later ultrasounds are less reliable for dating.