Pregnancy Calculator
The Pregnancy Calculator can estimate a pregnancy schedule based on the provided due date, last period date, ultrasound date, conception date, or IVF transfer date.
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About Pregnancy Calculation
Due Date Calculation: Pregnancy is typically calculated as 280 days (40 weeks) from the first day of your last menstrual period (LMP). This is based on Naegele's rule, which assumes a 28-day menstrual cycle with ovulation occurring on day 14.
Ultrasound Dating: Early ultrasounds (before 20 weeks) are the most accurate for dating pregnancy. The ultrasound measures the baby's size and compares it to standard growth charts to estimate gestational age.
IVF Pregnancy: For IVF pregnancies, the calculation is based on the embryo age at transfer. A day 3 embryo transfer is equivalent to 17 days after LMP, while a day 5 transfer is equivalent to 19 days after LMP.
Pregnancy Trimesters
First Trimester (Weeks 1-13)
The first trimester is a time of rapid development. The fertilized egg implants in the uterus, and the placenta begins to form. Major organs and structures develop, and the risk of miscarriage is highest during this period.
Second Trimester (Weeks 14-27)
Often called the "honeymoon phase" of pregnancy, the second trimester brings relief from early pregnancy symptoms. The baby grows rapidly, and you may begin to feel movement. Most major organs are fully formed by the end of this trimester.
Third Trimester (Weeks 28-40)
The final stretch of pregnancy brings rapid growth and development. The baby gains weight, and organs mature in preparation for birth. You may experience increased discomfort as the baby grows larger.