According to a new study, transferring two embryos during the process of IVF can lessen the possibility of conceiving by more than a quarter if one of the embryos is not in good health.
A study was done on almost 1,500 embryos that were implanted in females of all age groups. It revealed that placing back an embryo in good health with one in a poorer condition completely reduces the possibility of successful impregnation compared to just implanting one embryo.
Researchers behind the research think that the human body starts focusing on the embryo described to be in a poorer condition and refuses the possible impregnation, rather than concentrating on the healthy fetus that would result in successful pregnancy.
The research, being shown at the British Fertility Society annual conference in Edinburgh, included details of 1,472 fresh single and double embryo transfers at Blastocyst stage. The embryo transfers were done between June 2009 and December 2013 at the Nurture Fertility clinic located in Nottingham.
Foetuses were marked by a clinical embryologist while transferring it with the help of a standardised grading system. The end result proved that compared to implanting one embryo, transferring two embryos where one was in good health and one was poor quality culminated in a 27% decreased chance of becoming pregnant.
“The current feeling is that a good embryo will be recognised by the body and will be captured for implantation. But a poor quality embryo should be rejected by your body; your endometrium will reject it. What our research suggests is that if you put a poorer quality embryo back with a good one, it’s more likely to compromise the chance of the good one implanting,” Nick Raine-Fenning, medical director and research lead at Nurture Fertility, said.
Nick Raine-Fenning suggested that any female with a good embryo – particularly elderly women – should have only one embryo transferred in their body. “This research shows the importance of quality over quantity. Most patients understandably expect adding a second embryo will increase or even double their chances but this has never been the case,” he added.
This research indicates the risks associated with multiple births which include that twin baby are six times more likely to be born untimely than single babies. ”Long-term health problems of prematurity include breathing difficulties, cerebral palsy and other physical and learning problems.”