1. What is Perinatal Pregnancy Calculator?

The Perinatal Pregnancy Calculator estimates the due date and current gestational age based on the last menstrual period (LMP). It uses the standard calculation of adding 280 days (40 weeks) to the LMP date to determine the estimated due date (EDD).

2. How Does the Calculator Work?

The calculator uses the standard pregnancy calculation formula:

Where:

• \( EDD \) — Estimated Due Date
• \( LMP \) — Last Menstrual Period date
• \( 280 \text{ days} \) — Standard pregnancy duration (40 weeks)

Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represents 40 weeks of gestation from the first day of the last menstrual period.

3. Importance of EDD Calculation

Details: Accurate due date estimation is crucial for proper prenatal care, monitoring fetal development, scheduling important tests, and preparing for delivery. It helps healthcare providers track pregnancy progress and identify any potential complications.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the date field. The calculator will provide your estimated due date and current gestational age. For best accuracy, use the exact date of your LMP.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the 280-day calculation?
A: While 280 days is the standard, only about 5% of women deliver exactly on their due date. Most deliveries occur within 2 weeks before or after the estimated date.

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

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: Why is gestational age calculated from LMP rather than conception?
A: LMP is used because it's typically easier to recall than the exact conception date. This creates the apparent paradox where pregnancy is dated as 2 weeks longer than the actual time since conception.

Q5: What are the three trimesters of pregnancy?
A: First trimester: weeks 1-13, Second trimester: weeks 14-27, Third trimester: weeks 28-40+. Each trimester has distinct developmental milestones and care requirements.