Taking a chance: IVF and biochemical pregnancy
During an IVF cycle, after the embryo has been transferred to the uterus, sometimes it fails to implant or does not develop normally. In the case of a biochemical pregnancy, although the initial pregnancy test may be positive, an ultrasound test is unable to show a fetal heartbeat. The embryologist is also unable to find any other signs of clinical pregnancy.
Feeling the loss: why biochemical pregnancy happens
Many people do not realize that chemical pregnancies are just as frequent after natural conception as they are following IVF. The reason they are noticed more after an IVF cycle is because blood pregnancy tests are taken much early following embryo transplantation. The main causes of biochemical pregnancy and early miscarriage include:
A large number of early pregnancy loses are due to an irregular number of chromosomes in the embryo. This is known as embryo aneuploidy. However, this is not the only reason an embryo fails to implant. Other chromosomal or metabolic issues can also lead to early pregnancy loss.
Implantation dysfunction is responsible for around 25% of early pregnancy loss. It occurs when the uterine environment is not receptive to implantation by the embryo. When this happens, the embryo is rejected. Implantation dysfunction can be caused by a thin endometrial lining, endometrial scar tissue, fibroids, or polyps.
Preparing to conceive again
Women who have gone through a biochemical pregnancy may want to know when it is safe to try an conceive again. Typically, they will resume their periods within four to six weeks. Medical experts recommend waiting for at least one normal menstrual cycle before attempting another IVF cycle. This time will allow hCG levels to return to zero.
Most women can return to their normal activities after a miscarriage, though they should avoid having intercourse for a few weeks and should not insert anything into their vagina including tampons. Although it may only take a short time to feel normal physically, many women need longer to heal from the emotional stress of a biochemical pregnancy.