A fresh embryo transfer is a procedure in in vitro fertilization (IVF). It involves placing embryos into the uterus shortly after they have been created and cultured in a laboratory, without undergoing a freezing process. This means the transfer occurs within the same treatment cycle as the egg retrieval and fertilization, typically a few days later.
The IVF Cycle Leading to Fresh Transfer
This cycle begins with ovarian stimulation, where a patient receives hormonal medications to encourage the ovaries to produce multiple mature eggs. This phase lasts about 10 to 14 days, with regular monitoring through ultrasound scans and blood tests to track follicle growth and hormone levels.
Once follicles reach an appropriate size, a “trigger shot” is administered, signaling eggs to mature fully. Shortly after, the egg retrieval procedure takes place, using an ultrasound-guided needle to collect eggs from the ovaries. Eggs are then transported to the embryology laboratory.
In the lab, eggs are fertilized with sperm, either through conventional insemination or intracytoplasmic sperm injection (ICSI). Embryos are cultured and monitored for several days (3 to 5 days) to observe their development. Embryologists assess their quality, often aiming for the blastocyst stage, which is usually reached by day 5 or 6.
The Fresh Embryo Transfer Procedure
The fresh embryo transfer procedure is a quick and minimally uncomfortable process. It typically occurs on day 3 or day 5 of embryo development. Patient preparation often includes having a full bladder to help visualize the uterus via ultrasound.
During the procedure, a speculum is placed to visualize the cervix. A thin, flexible catheter, pre-loaded with the selected embryo(s), is then carefully guided through the cervix and into the upper portion of the uterus. Ultrasound guidance ensures precise placement within the uterine cavity.
Once the catheter tip is in the ideal location, the embryo(s) are released into the uterine lining. The catheter is withdrawn and checked to confirm no embryos remain. The entire procedure takes about five minutes and typically does not require anesthesia or sedation.
Deciding on a Fresh Embryo Transfer
The decision for a fresh embryo transfer is collaborative, based on various factors. Considerations include the number and quality of embryos developed in the laboratory. A fresh transfer may be considered if there are sufficient healthy, well-developing embryos.
Another factor is the patient’s ovarian response to stimulation. High hormone levels or a risk of ovarian hyperstimulation syndrome (OHSS) might lead a doctor to recommend a frozen embryo transfer instead. A fresh transfer offers a quicker path to pregnancy, avoiding the waiting period of freezing and thawing.
Another element is the desire for a synchronous uterine environment, where the uterine lining prepares alongside the embryos. However, high hormone levels from stimulation might negatively affect uterine receptivity. If preimplantation genetic testing (PGT) is planned, a fresh transfer is not an option, as embryos must be frozen while awaiting results.
What to Expect After the Transfer
Following a fresh embryo transfer, patients are advised to rest briefly; bed rest is not required. Most regular activities can be resumed within one to two days, but strenuous exercise, heavy lifting, and hot baths are discouraged. Mild symptoms, such as light spotting and mild cramping, are common in the days following the procedure.
Other symptoms include mild bloating, fatigue, and mood swings, attributed to hormonal changes and medications. The presence or absence of these symptoms does not indicate success or failure, as they can be side effects of fertility medications.
The period after the transfer is often referred to as the “two-week wait,” a time of anticipation before a pregnancy test confirms the outcome. A blood test, measuring hCG levels, is performed 9 to 14 days after transfer to determine pregnancy. This blood test provides a more accurate result than home pregnancy tests in the early stages.