The initials IVF stand for in vitro fertilisation. An in vitro fertilisation procedure is a fertility technique used to help infertile couples become pregnant. During the procedure a woman is given fertility drugs to stimulate the production of multiple ovarian follicles. After the follicles ripen they are removed from her body, fertilised with her partner's sperm and then placed back in her uterus. Once the fertilised eggs have been placed there, she can become pregnant and bear a child or even more than one baby. A due date for a pregnancy after an IVF procedure can be easily calculated.
Make sure that you have all dates correct. The most important date you need to know is the date of the retrieval. Retrieval is the exact date that eggs were removed from your body or the body of someone who is donating eggs to you. A retrieval date is not the date that you took a trigger or the date when you started taking any medications. The only date that matters is when the eggs were removed. If you are calculating a due date from a frozen embryo transfer, you can subtract three days from the day the eggs were placed back in your uterus.
Subtract 15 days from the date of egg retrieval. Do this even if you have been taking medication for more or fewer days than this time frame. This 15-day period is considered the day of your LMP, or last menstrual period. Write this day down on a calendar to make it easier to keep track of it.
Once you have these dates you can calculate the official due date of the pregnancy. Most pregnancies last between 38 weeks and 42 weeks. Add 40 weeks to the date of your last menstrual period. This is your due date.
Work out the due date. For example if you had a transfer of the fertilised eggs on Jan. 1, your last menstrual period would be Dec. 16, or two weeks before the transfer. This would make the second trimester of your pregnancy start on March 12. The third trimester would start on June 23. Your estimated due date would be roughly Sept. 24. All due dates are approximate.
Subtract three weeks if you are carrying twins. A normal twin pregnancy lasts approximately 37 weeks. Subtract an additional three weeks if you are carrying triplets. If you are carrying more than triplets, consult with your doctor about your anticipated due date. A higher order multiple pregnancy due date varies from person to person.
Use an IVF due date calculator to confirm your calculation.