• The IVF Two Week Wait (2WW) Defined

      What is the two week wait?

      The IVF two week wait (2WW) is the length of time between embryo transfer and either when your period begins or when you get a positive pregnancy test. The first part of a cycle is busy with ultrasound exams, injections, suppositories and visits to the lab for various blood tests. But once the embryo transfer has occurred, there is nothing to do but start the dreaded two week wait.

      While the 2WW is essentially the same for women no matter how they are trying to conceive, it starts at slightly different times depending on whether you are hoping to conceive naturally or are doing an IVF cycle. The following chart takes a look at the 2WW for an average fertile cycle and then shows the difference in the two week waits between charted cycles, ovulation induction (OI), in vitro fertilization (IVF) and frozen embryo transfer (FET).

      Average cycle
      In an average cycle of a fertile woman, ovulation typically occurs two weeks after the start of her last period. This means if a fertile couple has had intercourse around the time of ovulation (generally a few days before and a few days after ovulation), the 2WW will begin on day 14 of the cycle.
      Charted cycle In a natural charted cycle (by monitoring either basal body temperature or LH surge on a fertility monitor), the 2WW begins the day after the body temperature begins to rise or when the fertility monitor reads positive.
      OI (ovulation induction) In an ovulation induction cycle (where medication is used to "trigger" ovulation), the 2WW begins 36 hours after the trigger injection.
      IVF (in vitro fertilization), 3-day embryo
      With a 3-day IVF embryo transfer, the 2WW starts on the day of transfer.
      IVF (in vitro fertilization), 5-day embryo Like the 3-day IVF embryo transfer, the 2WW starts on the day of transfer. Because the 5-day embryo is more mature by two days than that of a 3-day embryo, the 2WW is shorter - meaning you will likely get a positive pregnancy test two days earlier.
      IVF FET (frozen embryo transfer) The 2WW is calculated the same for frozen embryos as it is for fresh embryos. A frozen embryo may implant into the uterus slightly later than a fresh embryo would; however, this difference in implantation timing is not enough to change the length of the 2WW and the quantitative hCG pregnancy test.

      Now that you know all about the 2WW, it's time to focus on just what's happening during that time.

      Next ...
      Early Symptoms of Pregnancy During the Two Week Wait
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