Once IVF is completed, the next steps include transferring embryos, pregnancy tests, and ultrasounds.
Number of embryos transferred
Why choose a single embryo transfer? Science says so. There is research that now shows that single embryo transfers lower the risk of having a baby with cerebral palsy. Learn why we encourage our patients to choose a single-embryo transfer.
The number of embryos to transfer depends on the age of the patient, the quality of the embryos and the stage of embryo development. The recommendation is to increase the number of embryos along with the age of the female partner, particularly after age 40. The patient’s willingness to risk multiple pregnancies influences the number of embryos to transfer as well.
Embryos are transferred at the blastocyst stage, which occurs at day 5 or 6. Single embryo transfer is frequently recommended to patients with high quality day-5 embryos. Each embryo has 25 to 30% chance of implanting depending on whether the genes have been evaluated. Implanting one embryo at a time decreases the risk of twins. We avoid replacing three embryos because of the risk of triplets, although some older patients may have three embryos replaced.
If an embryo is available for cryopreservation, it adds to the cumulative possibility of success of a patient. Below is a table regarding embryo quality and the recommended number of embryos to transfer according to the American Society of Reproductive Medicine.
| Embryo Quality | Favorable | Unfavorable |
|---|---|---|
| Age 35 | 1 | 2 |
| Age 35-37 | 2 | 2 |
| Age 38-40 | 2 | 3 |
| Age 40 | 3 | 3 |
Pregnancy test after IVF
Approximately 10 days after the embryos are transferred, a blood pregnancy test can be done. If it is positive, then it should be repeated to check if the pregnancy hormone is increasing rapidly as occurs in a healthy pregnancy. Later, once the pregnancy hormone level reaches around 2,000 or more, an ultrasound can be used to make sure the pregnancy is implanted in the uterus and is not a tubal pregnancy. About a week later, observation of a heartbeat hopefully can be noted on ultrasound.
During all of this time, the patient is on progesterone and other hormonal support, which is tailored to her particular situation.
Ultrasound after IVF
If you have gone through the IVF process and your blood hormone test has shown rapidly rising levels of hCG, then you should be able to get an ultrasound done a little after your beta-hCG level is 2,000. At that point, we can see the gestational sac picture.
Often, but not always, we can see the yolk sac. The yolk sac actually does the same in humans as it does for a chicken. It provides nutrients for the embryo. The embryo however is so small, you cannot see it on ultrasound at this stage.
The next time an ultrasound is useful, assuming all is going well, with no bleeding or problems, is about 10 days later. At that point, we can typically see the cardiac activity and an embryonic pole, which can be measured. If those measurements are right and the heartbeat is detected, then all is well. At that point, most of the time, reproductive endocrinologists who have been managing the hormone supplementation, will give instructions for tapering these medications down over the next month, and then transitioning to obstetrical care with the good news of a probable success. If there is a heartbeat present, there is 95% chance that a baby will be born.
