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Pregnancy Week Calculation:
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The Pregnancy Calculator By Week estimates the current gestational age based on the last menstrual period (LMP) and current date. It provides an accurate assessment of pregnancy progress in weeks and days, which is essential for prenatal care and monitoring fetal development.
The calculator uses the standard pregnancy calculation formula:
Where:
Explanation: The calculation starts from the first day of the last menstrual period, as this is the standard method used in obstetrics for dating pregnancies.
Details: Accurate pregnancy dating is crucial for monitoring fetal growth, scheduling prenatal tests, determining due date, and identifying potential complications. It helps healthcare providers track developmental milestones and plan appropriate care.
Tips: Enter the first day of your last menstrual period and the current date (or any date you want to check). The calculator will determine how many weeks and days pregnant you are on that specific date.
Q1: Why is pregnancy calculated from LMP instead of conception?
A: LMP is used because it's typically easier to recall than the exact conception date. Pregnancy is traditionally calculated as 40 weeks from LMP, with conception occurring around 2 weeks later.
Q2: How accurate is this calculation method?
A: This method provides a good estimate, but ultrasound dating in early pregnancy (first trimester) is more accurate for establishing gestational age.
Q3: What if I have irregular periods?
A: For women with irregular cycles, LMP dating may be less accurate. An early ultrasound provides the most reliable dating in these cases.
Q4: When should I see a healthcare provider?
A: Schedule your first prenatal appointment around 8 weeks of pregnancy, or as soon as you confirm pregnancy for initial assessment and dating.
Q5: How is due date calculated?
A: Due date is typically calculated as LMP + 280 days (40 weeks). This is known as Naegele's rule: add 7 days to LMP, then subtract 3 months.