Ectopic pregnancy after IVF . How to make the diagnosis early to deal with this ticking time-bomb

 

When patients get pregnant after an IVF cycle, they are usually on top of the world . After all, the doctor transferred the embryo back in the uterus , and now they will have a baby after 9 months.

However, when they find out that the pregnancy is not in the uterus but in the fallopian tube ( what is called an ectopic pregnancy ), they have lots of question .

As Google will tell you, an ectopic pregnancy is potentially a life threatening problem , and they are upset and confused and distressed.

Doctor, how did it end up  in the fallopian tube when you transferred it into the uterus ? Did you transfer the embryos with too much force ? Or was it because the tip of the catheter was positioned very close to the cornual end of the fallopian tube ?

The reality is that when we do an embryo transfer , even under ultrasound guidance , once we put the embryo back inside the uterine cavity , we cannot stop it from travelling in any direction it wants to. Rarely, instead of implanting in the endometrial cavity ( where they are supposed to because this is where we deposited them), reverse peristaltic contractions of the uterine muscles force the embryo into the fallopian tube . They implant here, and this is when the patient ends up with an ectopic . While the risk of an ectopic pregnancy is not increased just by doing IVF, the risk is increased in those IVF patients who have tubal factor infertility ( where their tubes are damaged) because they have a increased risk of having ectopic even if they got pregnant on their own.

Sadly, we can’t prevent this,  which is why we monitor an early IVF pregnancy so carefully.

Some patients wonder if we can push the ectopic pregnancy into the uterus . Sadly, this is not possible, because once it has implanted in the tube, this means the fetus has established its blood supply from the tubal blood flow, and if we try to dislodge it, the fetus will definitely die .

 The early diagnosis of an ectopic today is made by exclusion, and we need both HCG levels as well as ultrasound scans to do so. The diagnosis is made when we can’t see the pregnancy sac in the uterus , even when the HCG level is more than 1000 mIU/ml.

Patients find this confusing.  Doctor, why can’t we wait until the sac is seen in the tube ? They are hopeful that the diagnosis is wrong, and that the sac will magically appear in the cavity if we are patient. The reason we can’t wait is because the fallopian tube wall is much thinner than the wall of the uterus, and if we wait until the sac becomes big enough to see in the tube, there is a real risk that the tube may rupture, resulting internal bleeding and shock.

The reason it’s much easier to see the pregnancy sac when it's in the uterus as compared to the fallopian tube is because an early  pregnancy ( gestation) sac consists of mostly fluid , which means the acoustic contrast between the fluid in the pregnancy sac and the solid muscle of the uterine muscle is very high. However, when the pregnancy sac is inside the fallopian tube , it will have to become much larger to be seen, because the fallopian tube is surrounded by other fluid filled structures , such as the intestine. However, we do not have the luxury of waiting, because if we make the diagnosis early,  we don't need to do surgery to remove the ectopic pregnancy , and can kill it by using an injection of methotrexate , which is an anticancer drug . Just because it is also used for treating an ectopic pregnancy doesn’t mean that a tubal pregnancy is a form of cancer . It’s just that the cells in an early pregnancy multiply rapidly, which is why a single injection of methotrexate is enough to kill them, without harming any other organs in the body.

 

If you are unlucky and do end up with an ectopic after IVF, you might want to request your doctor to surgically clamp your fallopian tubes by doing a laparoscopic clipping near the corneal ends, before doing the next embryo transfer , because the risk of having a repeat ectopic in your next IVF cycle will then become zero.

 

The biggest danger of a delayed diagnosis is that if the ectopic pregnancy grows , the pregnancy sac can cause the fallopian tube to rupture, which could risk the mother’s life because of internal bleeding, which is a completely preventable medical catastrophe.