IVF and Ectopic Pregnancies

Pregnancy is an amazing process that is tightly controlled by your body to give you and your child the healthiest experience possible. A complication of pregnancy that may strike you as strange is the ability of a fertilised egg to implant somewhere else rather than in the uterus (aka the womb) where it’s meant to. These pregnancies, called ectopic pregnancies, rarely go through to full term, but have the potential to do so.

How can an ectopic pregnancy happen and why?

Different factors contribute to a potential ectopic pregnancy, that being said between a third and a half of these pregnancies happen with no discernable cause. Infertility is a risk factor, as are previous ectopic pregnancies, smoking, and the use of an intrauterine device (IUD – a form of contraception) amongst many others.

It is thought that risk factors like the use of an IUD or pelvic inflammation etc. can cause damage to the fine hair like structures called cilia which line the Fallopian tubes. These are responsible for carrying a fertilised egg from the ovaries to the uterus, so it is not surprising that if the egg isn’t successfully carried to where it’s meant to go, it can implant in the Fallopian tube, which accounts for about 95% of ectopic pregnancies that are referred to as tubal pregnancies.

Age is now thought to be a potentially major contributory factor, as are smoking and exposure to chemicals like DES. However in many cases it is hard to distinguish a clear cut cause for an ectopic pregnancy, particularly when ectopic pregnancies aren’t tubal and the egg implants in the cervix, abdomen, or even in some dramatic instances locations as bizarre as the arm.

Do I have an ectopic pregnancy?

The tell-tale signs of ectopic pregnancy are a positive pregnancy test, pain in the abdomen, and vaginal bleeding. These symptoms can be confirmed as an ectopic pregnancy through an ultrasound scan which shows a baby heart beating within the fallopian tubes, the site of most ectopic pregnancies. Similarly an ultrasound scan of the uterus after a positive pregnancy test that shows no foetus supports the diagnosis of an ectopic pregnancy.

A hormone called B-human chorionic gonadotropin is present in abnormal quantities during ectopic pregnancies, so sometimes a blood test can be used to make the diagnosis. There are other signs and symptoms which a specialist can look out for, but the ones mentioned here are the main indications of an ectopic pregnancy.

Treating ectopic pregnancies

Ectopic pregnancies are rarely able to get to full term, and always pose a serious health hazard to both mother and foetus. The typical route of treatment is to surgically or medically abort the foetus, and while this can be emotionally devastating, is the only treatment that can protect the mother’s health. The main danger is a rupture which can cause potentially fatal bleeding. During the early stages of an ectopic pregnancy medical treatment through a drug called methotrexate is possible. This medication aborts the foetus, but only if it is smaller than 3.5 centimetres.

Ectopic pregnancies tend to involve vaginal bleeding, and if there has been significant bleeding then surgeries are often needed. Surgeons make use of a technique called laparoscopy to remove either the foetus or the fallopian tube it is in. This technique tends to be extremely efficient and successful.

Ectopic pregnancies and IVF

IVF (in vitro fertilisation) is a popular form of fertility treatment that carries with it an increased risk of ectopic pregnancy. IVF involves fertilising an egg in a laboratory setting before directly injecting it into the womb or uterus, so you might be wondering how it is possible for the pregnancy to be ectopic, particularly as the fallopian tubes, the site of most ectopic pregnancies, aren’t involved.

It is believed that the method of injecting the fertilised egg is what gives the greatest chance of an ectopic pregnancy during IVF. If the injection is too forceful it can drive the embryo into the fallopian tube where it implants. Similarly if the embryo is placed too far into the womb it might migrate elsewhere. The actual risk of an ectopic pregnancy through IVF is thought to be anywhere between 2 and 5%, while the risk of such a pregnancy in the general populace tends to be about 1%.

« IVF and Hyperstimulation Syndrome IVF and Multiple Births »