Risks of multiple pregnancies and benefits of fetal reductionThe increase in the incidence of multiple pregnancies in Hong Kong is a result of the rise in popularity and availability of Assisted Reproductive Technology (ART). The most common and effective type of ART, in vitro fertilisation (IVF), involves the process of transferring lab-fertilised embryos into a woman’s uterus to increase the chances of them developing into a baby, but this often results in a multiple pregnancy.
Multiple pregnancy has been proven to be associated with increased risks and adverse outcomes such as premature birth, low birth weight, stillbirth or death. Due to such risks, the Council on Human Reproductive Technology revised its Code of Practice (P.20) in 2013 and capped the maximum number of embryos allowed to be transferred per cycle during ART treatments to three.
A recent study, published by the Department of Obstetrics and Gynaecology from The Chinese University of Hong Kong (CUHK) earlier this month, examined the perinatal outcomes in women with a triplet pregnancy who underwent fetal reduction, the process of reducing the number of foetuses in a pregnancy, in comparison to those with expectant management. The study was the first to examine fetal reduction in triplet pregnancies in Hong Kong. Researchers looked at outcome measures including fetal loss, gestational age at delivery, birth weight, neonatal survival rate, neonatal death, neonatal complications, and the need for and length of stay in the neonatal intensive care unit.
The study reported that over 80% of the included triplet pregnancies were conceived by ART. A total of 52 triplet pregnancies were identified between January 2008 and September 2014 – and one pregnancy that was lost to follow-up and one that was terminated were excluded. Fetal reduction was performed in 26 of the pregnancies, representing more than half of the total – with 22 of those pregnancies reduced to twins and four to a singleton.
The study also found that a significantly higher number of pregnancies with expectant management resulted in a preterm birth. However, all pregnancies that underwent fetal reduction to a singleton resulted in a term birth.
Researchers also observed a significantly higher mean birth weight, lower neonatal death rate, and reduced need for admission to and length of stay in the neonatal intensive care unit in the fetal reduction group. The study concluded that the reduction of triplet pregnancies of at least one foetus is associated with a significant reduction in both maternal and fetal adverse outcomes and risks. As a result of the success and popularity of fertility treatments, multiple pregnancy is and will remain a major obstetric concern in Hong Kong.
Demand for fertility services and advancements in fertility technologyHong Kong couples are getting married and having children later in life, with growing numbers of women actively delaying motherhood to focus on their careers and personal goals. The number of women who gave birth over the age of 40 rose by almost 90% from 2005 to 2014. In addition, infertility is also on the rise, with recent data showing that one in six couples suffer from infertility – a jump from one in ten couples two decades earlier.
Doctors have warned women of the increase in difficulty of conceiving as they get older, and the increased risks of giving birth at the age of 35 and above – in which fertility declines rapidly for both men and women.
These factors have all facilitated the surge in demand for fertility services over the years. According to the Council on Human Reproductive Technology, the number of couples who sought fertility treatment in Hong Kong doubled from 2009 to 2016 – observing a rise from around 5000 procedures to more than 11,000 procedures per year. Of all the infertility cases in Hong Kong, the percentages of cases relating to either the man or the woman were equal at 30% each, with the remaining 40% attributing to a combination of both individuals as well as to cases with factors that couldn’t be explained or identified.
The Council of Human Reproductive Technology also reported an increase in the number of women paying for IVF to get pregnant, as well as an increase in overall age. One cycle of IVF costs about HKD15,000 in a public hospital. Nonetheless, the service is only available to women up to the age of 40, and is limited to a maximum of three cycles with a waiting list of around three years. In contrast, one cycle costs around HKD100,000 in a private hospital.
Fertility doctors have also observed a growing trend of women undertaking an additional DNA test, preimplantation genetic screening (PGS), of their embryos during IVF to screen for chromosomal abnormalities; thereby ensuring only healthy embryos are chosen. Although this has raised concerns in both religious and moral contexts, local doctors have argued that PGS could help boost the success rate of a woman’s pregnancy.
Since women produce fewer healthy eggs as time goes on, with a gradual decrease in ovary reserves and quality of eggs, undergoing PGS could help reduce the likelihood of a miscarriage in women aged 35 or above, and increase their chances of giving birth to a healthy baby.
With the social burden of infertility slowly shifting from just the woman to now the couple as a whole, many recent fertility advancements have targeted both women and men alike.
One technological advancement involves creating three-parent embryos, where genetic material from three parents is used to prevent the passing on of mitochondrial diseases. DNA is taken from a woman with a mitochondrial disease and put into the egg of a woman with healthy mitochondria – and the egg is fertilised with a man’s sperm. Another procedure involves re-energising ageing egg cells – catered for women without mitochondrial diseases that may simply have mitochondria that has degraded and sustained damage over time.
Last year, lab-built sperm was successfully created from mouse embryonic stem cells. It was able to fertilise eggs and generate offspring in mice – paving the way for possible new treatments for male infertility. A new method to test the viability and strength of an embryo before it is implanted via IVF has also been developed – based on the theory that the squishier the embryo, the better it will undergo cell division and thrive.
Technological advancements in uterus and penile transplants are also underway. If breakthroughs with fertility technology continue to be made, we may soon reach a threshold where age won’t matter – and women may be able to conceive at any age and stage of life. MIMS
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