IVF Due Date Calculator
IVF pregnancies have a precisely known conception date, making due date calculation more accurate than natural pregnancies. Enter your embryo transfer date and embryo age to calculate your estimated due date, current gestational age, and trimester.
Unlike natural conception where the exact date of fertilization is uncertain, IVF provides a known fertilization date. For a Day 5 blastocyst transfer, the embryo was fertilized 5 days before transfer, making the due date 261 days after transfer (266 days of gestation minus 5 days of embryo age). For a Day 3 cleavage-stage transfer, the due date is 263 days after transfer. Gestational age is calculated by adding 14 days to the fetal age (days since fertilization), which corresponds to the equivalent last menstrual period used in standard obstetric dating.
The average pregnancy lasts 266 days from conception (280 days from LMP, or 40 weeks). However, only about 5% of babies are born on their exact due date. The due date represents the center of a normal delivery window of 37–42 weeks gestation. IVF pregnancies may be monitored more closely, and your reproductive endocrinologist or OB-GYN may adjust dating based on early ultrasound measurements.
This calculator provides an estimate for informational purposes. Your healthcare provider will confirm dating with clinical assessment and ultrasound imaging.