The big freeze: the new controversy over freezing embryos or eggs

It’s been a busy month at the maternity ward at Mater Dei Hospital. Four sets of triplets have been born over this period, piling pressure on the hospital to cope with needs of both mothers and babies.

As the average number of triplets born through IVF has been 2.5 per year over the last 10 years, the figure for January has caused some alarm.

The timing could not have been more inauspicious. Some weeks ago, Parliament’s Bioethics Committee –tasked with drawing a roadmap for the regulation of assisted fertility treatment - approved a policy which would allow for the freezing of embryos.

This policy has been severely criticised since then; but committee chairman Dr Jean Pierre Farrugia, a Nationalist MP, insists that regulation of IVF treatment is necessary, and blames hospital overcrowding for the untimely deaths.

“All levels of staff present at the hospital on Saturday have attributed the deaths of the infants to an infection that came about as a result of overcrowding. There are currently 28 babies in a ward that only has 18 cots; 12 of which require intensive care, when there is only space for six; nursing staff have to cope with three babies instead of the one that they are supposed to care for.”

Nursery facilities at Mater Dei are much smaller than they were at St Luke’s with a middle nursery, where premature babies are grown from one to two kilos, is completely absent, adding to the overcrowding issue.

Farrugia blames the overcrowding on the way IVF treatment is carried out locally: in that treatment is done in groups as the number of women treated is very small and these will then all fall due within the same timeframe resulting in an accumulation of births.

The committee in fact recommended freezing of embryos specifically to reduce the incidence of multiple births. They recommend fertilising four eggs, though transferring only two: freezing the remainder to be used if pregnancy does not occur. In the event that pregnancy does occur and the couple do not wish to make use of the remaining embryos, these will be put up for adoption.

Freezing of oocytes, before they are fertilised, was recommended by Dr Mark Asciak and supported by the Minister of Health, however Farrugia is sceptical.

“I would have no qualms with accepting ova vitrification if the success rate was the same as that of freezing of embryos. When this was discussed at committee level, clinical trials had only been done in mice and while Greece is claiming to have had some success, the fact that pioneering countries in artificial reproductive technologies (ART) like UK, USA and Germany have not reported any success with the technology merits caution.

Director of Gynaecology and Obstetrics at Mater Dei Hospital, Professor Mark Brincat echoes Farrugia’s opinion that freezing of oocytes can only be considered if the success rate is similar to that of freezing embryos, however freezing of embryos would still be necessary to ensure a successful procedure.

According to a study by Dr Luca Gianorli comparing the success rate of thawed oocytes and fresh sibling oocytes becoming useable zygotes, Gianorli found that the chance of producing top-quality embryos with frozen oocytes was reduced by 14%.

Prof. Brincat is quick to point out that the deaths of the infants were not a result of the procedure but of infection the mother contracted while in labour and passed on to the severely premature babies. He does admit that women undergoing IVF treatment are at higher risk of complication, though not as a result of the treatment but of “difficult reproductive histories.”

“Women are putting off having children until later on in life where problems with the reproductive system become amplified. A minor problem a woman experiences with reproduction at 17 may not cause infertility but that same woman may not be able to conceive at 30 as a result of the magnified problem.”

“We do not deny the fact that premature babies are often born to mothers who have undergone IVF, however it is the result of difficult reproductive histories stop these pregnancies being carried to term.

“The babies born last week were extremely premature and even came earlier than we expected. Not all triplets come prematurely and our experience has been varied with many going over 36 weeks of gestation.”

Prof. Brincat says that though IVF treatment is not available at the hospital it is a “reality of life that is here to stay.” People are seeking treatment from private clinics in Malta or abroad and having babies at Mater Dei Hospital.

“We provide fertility treatment including preparation for IVF, though we cannot complete the procedure at the hospital and patients have to go to a private clinic to complete the procedure.

“More multiple births have been attributed to women who undergo fertility treatment, which is available at Mater Dei hospital, than those undergoing IVF treatment.

Prof. Brincat claims that avoiding multiple births by fertilising just one egg is not a feasible procedure as these do not always result in an embryo. The success rate of using just one egg is reduced to just 5%. The patient has to undergo approximately €2,000 worth of medication prior to aspiration of eggs, therefore a number of eggs should be collected.

Prof. Brincat says that in his experience up to certainly not all oocytes produce embryos and even then not all of them implant Even in nature 80% of pregnancies are terminated, usually before the woman even knows she is pregnant, and a further 20% of pregnancies that result in clinical miscarriage.

Two to three embryos are transferred to increase the chances of pregnancy but this also increases the risk of multiple births.

Success rates of IVF are currently around 40% and in the future Profs Brincat envisages a much better success rate.

“A hundred years ago doctors at King’s College were happy with a Caesarean success rate of 40%, today the procedure has been perfected and the success rate is much higher. No one expects losses from Caesarean section today. In the future IVF technology will have improved enough for the procedure to be commonplace, safer and pregnancy rates and outcomes to be vastly improved.  

The science behind the procedure

Infertility has become a condition that is treatable through a number of technologies, including in vitro fertilisation (IVF).   

IVF involves the fertilisation of female ova with sperm cells, outside the body in a fluid medium. The fertilised egg (zygote) is then transferred to the uterus where pregnancy continues naturally.

The first successful “test tube baby”, Louise Brown, was born as early as 1978, in Manchester, UK. Robert G. Edwards, the doctor who pioneered the technology received the Nobel Prize in Physiology or Medicine in 2010. The first baby born through IVF in Malta was not born until 1991.

IVF has been used to treat both male and female infertility. Problems with fallopian tubes or sperm quality can be overcome by IVF resulting in pregnancies that would have been otherwise impossible. Where sperm quality is significantly low, intracytoplasmic sperm injection (ICSI) may be used where the sperm cell is injected directly into the ova.

Theoretically, IVF can be performed by aspirating ova from the fallopian tubes, mixing it with semen from the male and re-inserted into the uterus. However without additional techniques the chance of conception would be very small. Such techniques include ovarian hyper stimulation to retrieve multiple eggs, ultrasound guided oocyte retrieval directly from the ovaries, egg and sperm preparation as well as culture and selection of resultant embryos.

The IVF procedure involves the implantation of two to three embryos into the uterus to increase the success rate. However multiple embryos also greatly increase the risk of multiple births if more than one of the embryos is carried to term. One study found that IVF babies are 20 times more likely to be multiple birth babies than non-IVF babies.