Assisted reproductive techniques (ARTs) like In Vitro Fertilization (IVF) are offering a renewed sense of hope to thousands of couples facing infertility issues around the world. However, it is important for people planning parenthood through ARTs to understand the science of embryology involved in the procedure, in order to ensure a healthier and safer pregnancy.
For the uninitiated, embryology is the study of development of an embryo from the stage of ovum fertilization through to the fetal stage. The wall of dividing cells that results after fertilization is termed an “embryo” for eight weeks and from nine weeks after fertilization, the term used is “fetus.”
It is to be noted that embryologists play a key role in ART procedures. According to Goral Gandhi IVF consultant in Mumbai, the work of an embryologist starts right from the treatment planning stages. The embryologist decides many crucial factors during the treatment and prepares the laboratory with optimum conditions to grow the embryos.
On the egg retrieval day, as soon as the egg retrieval has been done and the semen has been analysed. Embryologists then inform the patient about how many eggs were retrieved, how the sperm sample looks, and what will be the fertilization procedure utilized for the cycle (conventional IVF or ICSI).
“Apart from analysing the samples, creating as well as assessing the embryos and preparing a fertilization report for the patients, embryologists are also responsible for preparing the patients for the emotional journey that commences with the start of the fertilization cycle. All the patients doubt are clarified and their questions are answered by the embryologists in this duration,” says Dr Goral Gandhi.
The embryos are left undisturbed for development during this time. In most cases, either day 3 or day 5 is found to be ideal for the transfer of healthy embryos to the mother’s uterus. The embryologist assesses the development of the embryo on day 3, and then decides upon whether or not the transfer should be planned on day 3 or day 5. Goral Gandhi says that the decision to do a day 3 or a day 5 (Blastocyst) transfer is decided individually for each patient, depending on certain algorithms. In case it is decided to go in for a day 5 blastocyst transfer, then the embryo is cultured further. On day 5, the embryos are assessed by the embryologist once again, who then determines whether or not the embryos are healthy, and how many embryos are to be transferred to the mother’s uterus. This is followed by embryo transfer, performed together by the embryologist and the physician.
Post a successful transfer, the remaining embryos are either frozen by the embryologist or left in culture to develop into viable, freeze quality blastocysts until the end of day 6 and at times day 7. These embryos are segregated by the embryologist upon assessment; only the healthy embryos are frozen and unhealthy embryos are discarded due to poor embryo development.