Policy of Reducing Multiple Births following In Vitro Fertilisation / Intracytoplasmic Injection (IVF/ICSI) Treatment Introduction When you really want to have a child, the idea of becoming pregnant with more than one baby as a result of your fertility treatment may sound ideal, especially if you have been waiting a long time. However, there are some significant risks associated with multiple pregnancies. Indeed, a multiple pregnancy is considered the single greatest health risk to both mother and child following IVF. Up until recently, about 1 in 4 IVF/ICSI pregnancies lead to the birth of twins or higher order multiple births (e.g. triplets). This means that after IVF/ICSI treatment, you are around 20 times more likely to have a multiple pregnancy than you would be if you conceived naturally. The reason for this high rate of multiple pregnancy is because, in most cases, more than one embryo is transferred during treatment. Research has also shown that women receiving fertility treatment are more likely to have identical twins (that is 2 babies derived from a single embryo), although this only accounts for a small proportion of the total number of twin pregnancies. In order to reduce the rates of multiple pregnancy, the Human Fertilisation and Embryology Authority (HFEA) has established regulations and targets, with which all fertility centres providing IVF/ICSI treatments must comply. What are the risks of a Multiple Pregnancy? A table comparing the risks of multiple and singleton pregnancies is available separately from this leaflet. Risks to the Mother All the risks of pregnancy and birth are significantly increased for women who are SDFC161 | Issue 5 | Author – David Chui | Authorised by – Jane Skelton 1 Publish Date: May 2020 | Review Due: May 2022 pregnant with more than one baby. The more babies a woman is carrying, the higher are all these risks, which include: • Miscarriage, hypertension/pre-eclampsia (high blood pressure with subsequent risks of kidney and heart problems), anaemia (iron deficiency), haemorrhage (bleeding), early labour and caesarean section or delivery with forceps. • Although the risk of mortality to the mother is very small, it is doubled for women expecting twins compared to women who are pregnant with a single baby. • Up to 25% of multiple pregnancies are complicated by pregnancy-induced high blood pressure and the chance of developing diabetes during pregnancy is two to three times more than in singleton pregnancies. • The risks of high blood pressure in pregnancy increases almost three times for twin pregnancies and is nine times higher for women with triplets. Risks to the Babies The chances of illness, disabilities and death are highly increased for multiple pregnancies, because the babies are premature. Some of the other risks include: • 50% twins are born prematurely (before 37 weeks of pregnancy) and have a low birth weight (less than 2500 grams or 5.5 lbs). • Triplets have a 90% chance of being born before 37 weeks of pregnancy and of having a low birth weight. • The risk of death for premature babies around the week of birth is five times higher for twins and nine times higher for triplets compared to singletons. Some effects of prematurity can affect a child well into their childhood. • Identical twins have a significantly increased risk of congenital abnormalities (birth defects). • Twins are 4 times more likely to have cerebral palsy than singleton babies and triplets are 18 times more likely to have this condition. Apart from the health risks associated with multiple pregnancies, you should also bear in mind the possible effects on your emotional and financial resources, which are often overlooked. • It has been shown that parents who have twins after fertility treatment find it harder to cope than parents of naturally conceived twins. • Some mothers and families with twins experience severe parenting stress, particularly first-time parents. • Depression in mothers of twins is more common than in mothers of singletons. This is not just after the birth but in the early years as well. 2 • Parents of twins are more likely to go through marital stress and divorce after the birth of the children than parents of singleton babies. Elective Single Embryo Transfer Policy As part of our duty to take account of the welfare of the child born as a result of licensable treatment including IVF/ICSI, and to reduce risks to potential mothers, the Sussex Downs Fertility Centre (SDFC) has introduced a policy that aims to reduce our IVF/ICSI multiple birth rate. This is in accordance with regulations and targets established by the HFEA. The rate of multiple pregnancy has to be progressively reduced to below 10% (comparing to the pre-2009 figure of 24%) of all IVF/ICSI pregnancies. This policy involves putting back a single embryo back into the uterus (womb) during the course of IVF/ICSI treatment (“Single Embryo Transfer or SET). SET will be recommended to women who are more likely to become pregnant with twins or more babies if more than one embryo is transferred. As younger women are generally more fertile and have commonly more embryos of high quality, this recommendation will be mainly aimed at couples whose female partner is below the age of 40 (that is up to and including the age of 39). Although a woman’s age is the main influence in terms of the chance of multiple pregnancy, other factors will be taken into account to determine whether SET is suitable for a particular couple. These factors include the following: • Age under 40 • Whether the couple is having their first, second or third cycle of IVF/ICSI treatment (that is, there is no extended history of failed IVF treatment) • The presence and number of good quality embryos The procedure of SET is the same as that for conventional IVF/ICSI treatment – the only difference is that only one embryo is transferred: • As with stimulated IVF, the woman is given hormones to increase her egg production. • When the eggs are mature, they are collected from the ovaries and then mixed with sperm (or for ICSI, a single sperm is injected into each egg). • The fertilisation is monitored initially for 2 to 3 days, enabling the embryologist to carefully select the embryo that is most likely to implant itself in the womb. For women with a good number of high-quality embryos, the embryos may be allowed to grow and mature for 5 to 6 days to the “blastocyst” stage. (A separate leaflet is available to explain blastocyst culture and transfer) • One embryo or blastocyst, selected by the embryologist as having the best chance 3 of implantation and pregnancy, is transferred to the woman’s uterus. This may take place 2, 3 or 5 days after the egg collection, depending on the quality and development of the embryo. • Any remaining embryos that the embryologist judges to have a good chance of implantation are frozen and stored. It should be pointed out that not all spare embryos are suitable for freezing; indeed some couple will not have any to freeze. • If the woman does not become pregnant, the frozen embryos are thawed and transferred until the woman becomes pregnant or all the embryos have been used. Each couple having IVF/ICSI treatment at the Sussex Downs Fertility Centre will be given an explanation of our SET policy, and decision will be made whether it is applicable to the couple. In some couples, despite initially thought to be suitable for single embryo transfer, the progress of the treatment is such that it may be considered more appropriate to transfer more than one embryo. All couples will be fully informed of such variations. It should be understood that SET policy is regularly reviewed and changes may be adopted as experience and techniques are refined. Benefits of Single Embryo Transfer (SET) If you are a suitable patient and single embryo transfer (SET) or single blastocyst transfer (SBT) is correctly administered, it largely removes the risks of multiple pregnancy without significantly reducing the chance of a successful outcome. In Sweden, where SET is more widely used, recent research shows that, in appropriate patients, pregnancy rates are maintained when subsequent frozen embryo treatment is included. It is important that you have read and fully understood the information provided in this leaflet. Please do not hesitate to voice your concerns or queries regarding any aspect contained in this leaflet. FAQs on Single Embryo Transfer Won’t single embryo transfer halve my chance of becoming pregnant? While single embryo transfer may have some effect on your chances of becoming pregnant, it does not halve them, particularly if: • You have a good chance of becoming pregnant with IVF • A 5-6 day embryo (blastocyst) is transferred. 4 A paper published in 2008 concluded that selective single blastocyst transfer in women with a good chance of becoming pregnant can reduce the chances of having a multiple pregnancy after IVF while maintaining the overall likelihood of becoming pregnant. Other recent evidence suggests that transferring a single blastocyst on day 5 of in vitro culture is associated with a higher clinical pregnancy rate, compared with transfer of a single cleavage-stage (day 2 or 3) embryo. It should be appreciated that blastocyst transfer may not be suitable for all women, and it may be associated with fewer embryos to freeze. Isn’t single embryo transfer all about NHS trying to save money? No. The problem is that there are too many premature IVF twins being born with serious health problems in many cases. These very ill babies could have had a healthy start in life if they had been born as singletons. This is therefore an avoidable problem.