The embryo transfer process is one of the most important aspects in the IVF process. After the delicate and often tedious work by the embryologist to maintain the embryos we must now put the embryos back into the uterus in hopes of establishing a pregnancy. Embryo quality, the patient's age, and risks of multiple pregnancies need to all be carefully weighed when deciding how many embryos to transfer. The goal of the embryo transfer is to bring about a single pregnancy while reducing the risk of multiple pregnancies. The decision of how many embryos to transfer should be made only after consultation with the doctor on the day of the transfer. If applicable, both partners should be present. This can be a tough decision in some cases and straight forward in others. If there are good quality embryos remaining after your embryo transfer, the extras can be frozen for later use. This freezing process is called cryopreservation. [More information]
After the completion on the retrieval process you will be notified of the number of fertilizations that occurred. Be sure to leave a phone number where you can be reached. Phone calls are made before 1PM the day after retrieval.
Day of Transfer
You and the physician will discuss the transfer day when you are called with fertilization results. Embryo transfers are most commonly done on day 3 following the retrieval. Historically, embryos were transferred on day 2 following the embryo transfer. This did not allow much time to observe the growth and characteristics of the embryo. In an effort to watch the embryos to see which ones were "survivors", the blastocyst culture was developed. Blastocyst culture is used to separate the good embryos from those that will not survive. Embryos surviving to the blastocyst stage are commonly referred to as blasts. Pregnancy rates with blast transfers were thought to be higher, but caution is advised here. Watching embryos to the blastocyst stage does not make the embryos better, it just allows for selection of the ones that appear to be doing better. The pregnancy rate per embryo transfer may also be higher but this is because some women may not have embryos to transfer - because none of them survived to the blastocyst culture. This situation has sometimes been termed an early pregnancy test. Debate still exists as to whether or not the embryo culture conditions in the lab can match those of the woman's uterus. Recently, evidence has been accumulating that most good quality embryos can be identified on day 3. Day 3 transfers are becoming more common practice. In certain circumstances, blastocyst culture is still conducted. The most common reason is to select the appropriate embryos for the initial transfer when there is a large number of high quality embryos. Dr. Zeringue and the embryologists will decide which day is most appropriate for transfer based on the appearance and growth characteristics of your embryos. Or goal is getting you pregnant!
Number to Transfer
On the day of embryo transfer you will discuss the number of embryos to be transferred. The number of embryos surviving, their grade, your age, and information from previous cycles can influence the recommendations concerning the number of embryos to transfer. We want to maximize the chances of getting a single pregnancy while avoiding triplets. A general rule of thumb has been established by the American Society for Reproductive Medicine (ASRM) which recommends no more than 2 embryos be transferred into a woman under the age of 35. Older women should have no more than 3 embryos transferred. These guidelines do allow for more embryos to be transferred under certain circumstances. California IVF uses these guidelines in establishing the number of embryos to transfer. Patients may elect to have fewer embryos transferred.
Women are asked to arrive with a partially full bladder on the day of the embryo transfer. This is to help visualize your uterus using an abdominal ultrasound. Ultrasound guided embryo transfer has become one of the most important factors leading to successful embryo transfer. Physician skill with transfers and the conditions of embryo handling during the procedure are also very important. We work hard to minimize the time the embryos can be exposed to temperature and gas changes just prior to the transfer. These factors combined with an excellent embryology lab and staff help give us excellent pregnancy rates. The actual embryo transfer procedure is as follows:
- You will be taken to the procedure room where you will discuss the numbers of embryos to be transferred with the doctor.
- Once the embryo "report card" has been discussed and the number of embryos to be transferred has been decided, a signed requisition form is given to the lab staff for preparation of the embryos.
- You will then be assisted into the correct position.
- A normal speculum will be use to view the opening of the cervix.
- A special media/wash is used to clean the vaginal canal and cervix.
- Swabs are used to clear away the cervical mucous
- The abdominal ultrasound is used align the uterus and outer transfer catheter guide
- The embryologist will place the embryos into a thin plastic catheter that is then handed to the physician.
- The physician will place the catheter through the introducer and into the uterus under ultrasound.
- The embryo(s) will be transferred into the uterus
- The embryologist will inspect the catheter to make sure all the embryos are out of the catheter.
The procedure is usually fairly quick and does not cause any discomfort for most women. We will point out things to watch on the ultrasound. Most people are able to see the embryo transfer as it happens. This can be quite an emotional moment!
Post procedure Instructions
Following the completion of the procedure you will be able to get dressed and conduct your normal activities for the remainder of the day. Activity will not impact on the outcome of the pregnancy so there is no "medical" reason to restrict your activity. Patients should still limit their activities based on their own concerns and sense of "what is right". While there is no evidence suggesting activities will alter the pregnancy outcomes, we want to avoid any sense of guilt in the event of a negative pregnancy test. Rarely, there may be some leakage of fluid when standing for the first time. This is the cleaning media, not the embryos. Patients should do whatever they think is necessary so they will have no regrets if pregnancy does not result.
The post procedure instructions will have the date of the first pregnancy test. The wait can be very stressful. You should not use a home pregnancy test in the event it is falsely negative. Even in the event of vaginal spotting or bleeding, many women go on to have successful pregnancies. If the initial pregnancy test is positive, an confirmatory test is done 48 hours later to look for a rise in the hormone level that indicates a pregnancy has established. While there are still many more hurdles and milestones, most women will go on to have a baby at this point.