Risks – IVF

Risks associated with MAR treatments

Like any other medical technique, medically assisted reproduction (MAR) involves some risks. Our specialists are available to you to discuss these risks and answer all your questions.

Multiple pregnancies

These represent the greatest risk associated with MAR treatments. Complications affecting the mother during pregnancy are amplified in these situations (diabetes, hypertension, pre-eclampsia and premature birth, for example). In babies, they increase the risks associated with prematurity as well as the risks of malformation, for example.

We adopt several measures to prevent these risks:

  • In ovarian stimulation treatments with controlled sexual activity or insemination, the number of follicles (each containing one egg cell) is strictly monitored by ultrasound scans. The treatment cycle is interrupted if too many follicles develop, thus avoiding multiple pregnancy.
  • In the case of IVF and IVF-ICSI treatments, the risk of multiple pregnancy depends on the number of embryos transferred. Depending on the woman's age and the development of the embryos, our unit aims to transfer one or two embryos in order to maximise the chances of pregnancy while minimising the risk of multiple pregnancy. That being the case, the choice of transferring one or two embryos is the couple's responsibility. Although the RMA authorises the transfer of up to three embryos, we recommend, in accordance with good practices, the transfer of a maximum of two embryos except in exceptional situations.

Ovarian hyperstimulation syndrome (OHSS)

This complication may occur during hormonal stimulation of ovulation. It arises after the triggering of ovulation, which is induced by an injection of the hormone human gonadotropin (hCG). The symptoms are distended abdomen, abdominal pain, nausea, vomiting, laboured breathing and reduced urine volume. Thickening of the blood may increase the risk of thrombosis or pulmonary embolism. The exact causes of this syndrome are still not known, but are linked to a strong response (large number of follicles) during stimulation. Its management consists of treating the symptoms (hydration, anticoagulation), in principle as an outpatient, but hospitalisation may sometimes be necessary. In the event of pregnancy, the symptoms may persist up to the 10th week.

In the case of antagonist IVF protocols, if there is a strong ovarian response with a risk of a hyperstimulation syndrome, it is possible, in most cases, to trigger ovulation with a GnRH agonist (pituitary gonadotropin releasing hormone) instead of hCG. This strategy very greatly reduces the risk, but generally requires cancellation of transfer in this cycle. All the embryos are then cryopreserved for future transfer in a thawing cycle.

Egg cell puncture

During egg cell puncture, a thin needle is introduced under general or local anaesthesia through the vaginal wall and into the ovaries under imaging control (ultrasound scan). Neighbouring organs may be affected, such as perforation of the intestine, bladder or a blood vessel, for example. These complications are extremely rare and are treated according to the situation. Another risk is the transfer of germs (bacteria) into the ovaries or abdomen, leading to infection. This complication is also rare. If it occurs, it can be quickly detected and treated.

Extrauterine pregnancy

Extrauterine pregnancy (implantation of the embryo outside the uterus) occurs in 1 to 2% of pregnancies obtained after in vitro fertilisation. Blood tests and an ultrasound scan performed during pregnancy allow the embryo to be located so that action can be taken as quickly as possible.


The malformations rate during spontaneous pregnancies is about 3 to 6% of all births. In the case of IVF/ICSI, it is about 8%. This risk is thus slightly increased.

Any chromosomal abnormalities can be detected early on by preimplantation or prenatal diagnosis.

Long-term effects

It is currently impossible to know the long-term effects (e.g. reduced male fertility, cardiovascular risks and perhaps unknown risks), since the oldest children resulting from IVF and ICSI were born in 1978 and 1992, respectively. To avoid the risks of hereditary diseases in the case of male infertility, in some cases we perform complementary genetic analyses before proceeding to ICSI.


Fertility Medicine and Gynaecological Endocrinology
CHUV Maternity Unit
Av. Pierre-Decker 2
1011 Lausanne
Fax +41 21 314 32 74
 Last updated on 17/08/2018 at 10:46