What happens after an embryo transfer?
After the embryo transfer, you receive instructions before leaving the clinic. These instructions include what medication to take when your pregnancy test is going to be and any lifestyle restrictions such as bed rest, exercise, no alcohol or caffeine. Clinics vary in the extent of restrictions following transfer. As a rule of thumb: take it easy at least until you hear about the pregnancy test.
Once the embryo has been placed inside the uterus the cells keep dividing and the embryo grows bigger in size. At the blastocyst stage, around development day 6-7 the embryo will have hatched out of its shell and begins to attach to the uterine lining. The outer surface of the embryo cells are sticky and recognize molecules in the uterus, this allows the initial attachment to happen.
Over the next few days the embryo burrows down into the uterine lining and the tiny embryonic sac starts to form. Some people see a little bleeding at this stage referred to as implantation bleeding, so if you do see this don't be alarmed but make sure you tell your doctor as you might need extra progesterone.
The growing embryo cells secrete Human Chorionic Hormone (hCG), this is the hormone that is detected by a home pregnancy test or the blood test done at your doctor's office. Sometimes a positive HCG level can be detected 2-3 days before your official blood test is due. But certain fertility medication can cause a false positive and so make sure you wait long enough for that to clear out of your system before taking a pregnancy test.
You usually take a pregnancy test two weeks after your egg retrieval. On that day, you most likely will have a blood test to detect the exact level of hCG (alternatively a urine test may be done). A positive level indicates that the embryos have implanted. A follow-up test two days later checks if the pregnancy is progressing normally; the hCG level should approximately double every 48 hours.
Unfortunately, not all embryos develop normally; some pregnancies end in miscarriage. Your reproductive endocrinologist follows the hCG blood levels early in the pregnancy followed by one or two ultrasounds between 6 and 10 weeks of pregnancy.
Whatever the outcome of your fertility treatment, it’s very important to stay on all prescribed medication and follow your doctor’s instructions. A normal pregnancy will be followed until approximately 10 weeks gestation at the IVF clinic, at which time you will be referred to a regular obstetrician for prenatal care.
More Q&As from our experts
- Why did my in vitro fertilization (IVF) cycle fail?
- Can supplements improve egg quality for IVF?
- Are frozen embryo transfer (FET) success rates higher than fresh transfers?