A 28–year–old woman, a known patient of endometriosis (a painful womb condition that interferes in pregnancy), conceived and successfully completed the first trimester with the help of oocytes or human egg freezing technique that allows women to preserve her fertility for future use. This is claimed to be the first pregnancy in Pune using frozen eggs.

The uniqueness of the pregnancy was that the woman’s oocytes (eggs) that helped conception were retrieved and frozen on one day, fertilised the next day and the embryos that developed in the procedure were transferred in the womb after five months. Normally, the life of human eggs is 24 hours and the fertilisation potential is best within eight hours.

“This is for the first time in Pune that a woman conceived using a frozen oocyte, an assisted reproductive technology that has a success rate of just 2%,” gynecologist and infertility expert Amit Patankar told TOI on Friday. The unique procedure was carried out at Patankar Nursing Home’s IVF lab on September 7.

The woman, a patient of endometriosis, was treated for egg stimulation and was referred to Patankar’s IVF lab on April 6. Endometriosis is a condition in which cells that are normally found inside the uterus (endometrial cells) are found growing outside of the uterus.

“We retrieved the egg on the same day she visited the hospital. But the test tube baby or IVF procedure could not be performed as the woman’s husband was not present to give sperms,” said embryologist Ashok Patel of Genesis Fertility IVF and ICSI Centre at Patankar’s IVF lab.

As the sperms were not available, the embryologist froze the eggs. “We got the sperms the next day and then we thawed the oocytes, total nine in number and performed the IVF procedure using ICSI (Intracytoplasmic Sperm Injection technique). Two embryos developed from the frozen oocytes were transferred in the woman’s womb and the remaining embryos were again frozen for future use,” Patel said.

On the 12th day of IVF procedure, the doctors carried out the pregnancy test which showed negative results. The patient was counselled for transfer of remaining frozen embryos preserved in liquid nitrogen at minus 196 degree Celsius. The woman, after counselling, agreed to go for frozenthawed embryo transfer (FET).

“We could not do the procedure the same day she agreed as the receptivity of endometrium – linings of the uterus was not adequate for implantation of the embryos. We decided to carry out the procedure after the next menstrual cycle and as per the patient’s convenience,” Patel said.

The woman came to the hospital in July. She was given hormonal injections for the development of endometrium. When the endometrial development was optimum, FET was planned on September 7.

“On September 7, the remaining embryos which were frozen in the month of April were thawed — taken out of from liquid nitrogen and warmed to 37 degree temperature. We transferred three such frozen–thawed embryos in the woman’s womb on the day. On the 12th day, pregnancy test was carried out and woman tested positive for pregnancy,” Patel said.

The obstetric sonography test later confirmed single intra–uterine pregnancy. “Till date it has been possible to freeze only sperms in the semen banks. Hence, pregnancies with the help of frozen semen are quite normal and performed routinely. But freezing oocytes and achieving pregnancy is not only difficult but a very tedious and skillful job.”

“Until now, men have been able to use their previously frozen sperm for IVF treatment but women have not been able to do the same with their eggs. A new method of freezing human eggs will help to even out the inequality,” said infertility expert Sanjeev Khurd, former president of Pune Obsterics and Gynaecological Society (POGS).

Egg freezing also known as oocyte cryopreservation, has been around for several decades; however, it was not very successful until recently. Previously, the only method that could be used to freeze eggs was a slow–freezing method, which could cause ice crystals to form within the egg. A newer, specialized freezing technique called vitrification freezes the egg so quickly that ice crystals don’t have time to form.

Endometriosis is a condition in which cells that are normally found inside the uterus (endometrial cells) are found growing outside of the uterus. That is, the lining of the inside of the uterus is found outside of it. The lining of the uterus consists of a type of tissue called endometrium — composed of endometrial cells — that thickens each month to prepare for an egg. It is here where an egg cell implants and grows if it is fertilised. Endometrial cells are the cells that shed every month during menstruation, and so endometriosis is most likely to affect women during their childbearing years.