1. What is Perinatology Gestation Calculation?

Perinatology gestation calculation determines the gestational age in weeks based on the last menstrual period (LMP) and current date. This is a fundamental calculation in obstetrics for tracking fetal development and planning prenatal care.

2. How Does the Calculator Work?

The calculator uses the standard gestation formula:

Where:

• \( Current Date \) — Today's date or specified assessment date
• \( LMP \) — First day of last menstrual period
• \( \left\lfloor \right\rfloor \) — Floor function (rounding down to nearest integer)

Explanation: The calculation determines the number of complete weeks that have passed since the last menstrual period began.

3. Importance of Gestation Calculation

Details: Accurate gestation calculation is essential for monitoring fetal growth, scheduling prenatal tests, determining expected delivery date, and identifying potential pregnancy complications.

4. Using the Calculator

Tips: Enter the current date and the first day of the last menstrual period. The calculator will automatically compute the gestation in completed weeks.

5. Frequently Asked Questions (FAQ)

Q1: Why use LMP instead of conception date?
A: LMP is more reliably known and provides a standardized reference point for gestational age calculation in clinical practice.

Q2: How accurate is LMP-based gestation calculation?
A: Generally accurate within ±2 weeks, though ultrasound dating may be more precise, especially if LMP is uncertain.

Q3: What if menstrual cycles are irregular?
A: For irregular cycles, ultrasound dating is recommended as LMP-based calculation may be less accurate.

Q4: When should gestation calculation be performed?
A: Ideally at the first prenatal visit and confirmed with early ultrasound when available.

Q5: Are there limitations to this calculation?
A: Less accurate with uncertain LMP dates, irregular cycles, or when ovulation occurs significantly later than day 14 of the cycle.