Pregnancy-related blastocyst technique developed

Updated: Aug 09, 2011, 16:16 PM IST

Nagpur: A city-based embryologist and his wife, a specialist in IVF (in vitro fertilisation), claimed to have developed a technique called `blastocyst culture` to enhance the prospects of pregnancy and to reduce pregnancy related complications.

Dr Natachandra Chimote and his wife Dr Meena, who recently presented a research paper titled `Spontaneous In Vitro Hatching or Hatched Blastocyst Vs. Expanded Blastocyst Transfer: What is better?` at Stockholm (Sweden) at the recently held 29th annual conference of European Society for Human Reproduction and Embryology (ESHRE).

On his return, Dr Natachandra Chimote told PTI that in a routine test tube baby procedure, the average pregnancy rate is only 30 percent, in which, three to four cell embryos are transferred to the uterus (conventionally called as day three transfer).

"In the conventional method, there is always a much higher chance of multiple pregnancies like triplet or even quadruplet, in which, the mother as well the foetus is at a very high risk of pregnancy complications. In addition to this, the social, psychological and economic burden on the couple is tremendous," he said.

The technique of blastocyst culture has been developed in the past 10 years, in which, the embryo is grown up to five days to the stage of blastocyst and then transferred to the uterus on day five.

"In the blastocyst culture technique, the embryo can be grown up to six to seven days, when the blastocyst hatches spontaneously from the outer cover of the embryo called zona pellucida, which is an essential step for its implantation in the uterus," he added.

Thus, the embryo that has natural potential to implant and much reduced risk of genetic abnormalities can be selected in the laboratory itself, without human intervention.

The transfer of only one such spontaneously hatched embryo on day six/ seven has resulted in a very high pregnancy rate of above 63 per cent, with a singleton pregnancy that can reach full term without much of a risk to mother and foetus, Dr Chimote said.

This new technique of transferring spontaneously hatched blastocyst can benefit infertile couples undergoing IVF treatment with reduced cost and risk of pregnancy complications, especially in developing countries like India.

"The advantage of this technique is that only two blastocysts may be transferred, which result in at the most twins with an increased average pregnancy rate of 40-42 percent," Dr Chimote said.

So far, assisted hatching with chemical or LASER method was tried in the world without any improvement in pregnancy rate, he added.

This research by the Chimotes was appreciated by the world-renowned IVF specialists from Belgium, France, Egypt, England & world-renowned embryologists from Italy.

The doctor couple was assisted by Nishad Chimote, Bindu Mehta, Nazneen Sheikh, Dr Nirmalendu Nath and Dr Amiya Mukherjee during the research work.

PTI