Possible risks associated with IVF treatment
It is important to remember that any medical or surgical treatment has risks and adverse side effects. All pregnancies carry a risk to babies and their mothers, but thankfully the risk of serious adverse obstetric outcomes is rare in Australia.
Both short- and long-term studies have found generally reassuring findings for both mothers and offspring conceived with assisted reproductive technologies (ART). A lot of the obstetric risk is attributed to multiple pregnancy (see below). There are many confounding risk factors with ART such as advanced maternal age and the underlying cause of a patients sub- or infertility.
ART appears to be associated with a slightly higher incidence of low birth weight, premature delivery and pre-eclampsia. There is no clear evidence that infertility treatments increase the risk of malignancy (cancers) or birth defects.
Anyone taking medication should be aware of the possible side effects and report adverse responses to those managing their treatment.
Multiple pregnancy
One of the most significant adverse outcomes of IVF treatment in recent years has been the increase in the multiple pregnancy rate, contributed by improved response rate of treatment as well as improved implantation rates.
This factor can be somewhat confusing to an infertile couple who might welcome a multiple pregnancy as a bonus. In fact a multiple pregnancy carries significant risks to both the mother and the infants when compared to singleton pregnancies.
Medical complications through the pregnancy are increased and include a higher incidence of pre-eclampsia (a blood pressure issue) and antepartum haemorrhage (bleeding before the onset of labour). Neonatal complications are significant and include a higher incidence of growth retardation (of one or both infants) and premature birth.
Routine single embryo transfer has been implemented over the last decade to reduce the incidence of multiple pregnancy. Advancing technology has allowed extended embryo culture (up to the blastocyst stage) and greater success with embryo cryopreservation. This has enabled the use of single embryo transfers to achieve high pregnancy rates.
These factors should be considered carefully and discussed with the clinician and nurse coordinator throughout your IVF treatment cycle. Before each embryo transfer the clinician and embryologist will discuss with you the indications and benefits/ risks for a single or multiple embryo transfer.
Ovarian Hyperstimulation Syndrome (OHSS)
OHSS is a potentially dangerous medical condition that can occur in women who have had gonadotrophin for ovulation treatments or IVF therapies. We do not yet fully understand what causes it but we can take steps to minimise its risk/ impact. A small subset, approximately 1-2% of patients will develop what we classify as severe OHSS and require hospitalisation with close, intense medical supervision.
Women who are at more risk are young and thin or with polycystic ovarian syndrome. These patients often achieve excessive egg numbers, which seems to increase the risk of OHSS developing. OHSS is likely to occur in women who develop in excess of 20 eggs, but has been known to occur with fewer eggs. If we think a woman is at significant risk of developing this condition, we can cancel the cycle prior giving the HCG injection that triggers ovulation. This tends to prevent the development of severe OHSS.
The condition may be worsened by the establishment of a pregnancy. Therefore an option is to collect the eggs, fertilise them and freeze all of the embryos with a view to transferring an embryo in a future FET cycle (once the ovaries have returned to normal). There are other methods that may implemented to reduce the risk of OHSS or the severity of its symptoms.
Women with severe OHSS may have dramatic enlargement of their ovaries and fluid shifts from the blood stream into the abdominal cavity, causing distension and discomfort. Fluid may even enter the cavity around the lungs creating breathing difficulties. A further risk is that the decreasing volume of fluid in the blood vessels increases the viscosity (or thickness) of the blood leading to thrombosis or clotting. Some deaths have been recorded overseas from OHSS but thankfully no deaths have been recorded in our country. Needless to say severe OHSS is a potentially very dangerous medical condition.
The risk of OHSS in an otherwise healthy woman has to be balanced against any desire for pregnancy, and while the mechanisms are in place to minimise the risk, it cannot be absolutely avoided.
Follicle Stimulating Hormone (FSH)
These drugs are used to encourage development of a group of follicles in the ovaries. Because the ovaries are swollen with follicles, some tenderness and swelling of the abdomen may be experienced. The increase in the hormone oestrogen as a result of multiple follicle growth can cause breast tenderness.
Other common symptoms include slight nausea, dizziness and slight abdominal swelling or bloated sensation as with pre-menstrual syndrome.
Anaesthesia
Modern anaesthesia is particularly safe and is always performed by a specialist Anaesthetist who is trained to deal with any particular complications. It is not uncommon to have a sore throat following a procedure and post-operative nausea and vomiting occurs in some patients. There is often also a feeling of tiredness or drowsiness for some hours following the procedure.
Serious complications can occur with allergic reactions to the anaesthetic agents used and depression of the respiratory system. It is thought that 1 person in 20,000 who has an anaesthetic is likely to die as a direct result of anaesthesia. Specialist Anaesthetists are trained to minimise any risk to the patient and will see you prior to any anaesthetic procedure to inquire about your medical and past anaesthetic history.