In vitro Fertilisation (IVF), colloquially known as ‘test tube babies’ remains one of the most efficacious methods of fertility treatment; its success, however, depends on many factors – approximately 200 variables. Presently, all interventional fertility treatments such as Intra Uterine Insemination (IUI), IVF, Intra Cytoplasmic Sperm Injection (ICSI) and all the allied procedures such as egg, sperm and embryo freezing and Pre-implantation Genetic Testing (PGT) among others are encompassed as Assistive Reproductive Techniques (ART), regulated in our country by the ART Act, 2021.
What happens in IVF?
Louise Brown, the world’s first IVF baby born in England on July 25, 1978, was conceived through a naturally developing follicle in her mother’s ovary. However, this ‘natural cycle’ is considered inefficient and difficult to replicate; hence a ‘stimulated cycle’ is the accepted standard of care through which more eggs are available for fertilisation, giving a greater chance of pregnancy. Many combinations of fertility hormones have been tried to improve outcomes, but the stimulated cycle remains the cornerstone of today’s IVF.
IVF consists of the following stages – stimulation of the ovaries to enable production of multiple eggs, triggering last-stage maturation of the eggs, retrieval of the eggs from the stimulated ovaries, fertilisation of the egg using sperm, culture of the resultant embryos, and finally, transfer of the embryo into the uterus. The eggs, sperms and embryos can also be frozen for future use.
Why safety is crucial
Safety is a very important aspect of fertility treatment. This includes the safety of: the patient – against any side effects and complications such as ovarian hyperstimulation syndrome, a potentially serious reaction; safety of the embryos – against mix-ups; safety of the unborn baby – as the aim is to have a healthy child and safety of health personnel involved – from transmissible diseases and hazardous substances.
Ovarian hyperstimulation syndrome (OHSS) is one of the major complications of IVF, one that can even be life threatening. Prevention of OHSS is of utmost importance. OHSS results due to the stimulation of ovaries with the intention of producing many eggs to be used during the process of IVF/ICSI and the choice of medicine that is given to trigger the final maturation of the eggs contributes to a large extent. OHSS increases the permeability of blood vessels, resulting in the outward movement of body fluid from the blood vessels into spaces such as inside the abdominal cavity, or in spaces surrounding the lungs and heart. This leads to clotting in blood vessels, starting a cascade that can have very serious consequences such as renal, liver and respiratory failure, and on rare occasions, can be fatal.
Risk factors of OHSS are patients who are under 35 years of age, polycystic ovary syndrome (PCOS/PMOS) with a high level of anti-Mullerian hormone (AMH), thin patients, high concentration of estradiol over 3,000 pg/ml, the number of ovarian follicles exceeding 20, choice of medicine used to trigger final maturation of eggs and the state of pregnancy.
OHSS can be mild, moderate or severe. Mild OHSS usually resolves by itself most of the time, while moderate or severe OHSS requires admission and close monitoring and management.
The true incidence of OHSS is not known; however it is estimated that 2-8% of IVF cycles may have moderate OHSS and approximately 0.1% may suffer from severe OHSS.
Towards better care
The aim of every IVF clinic now is be an OHSS free clinic. The concept of OHSS free clinic relies on three major changes leading to a “segmentation” approach to IVF:
Optimise stimulation: Choosing short GnRH antagonist protocol for ovarian stimulation
Safer triggering: Using a GnRH agonist rather than hCG to trigger final oocyte maturation
Freeze-all strategy: freezing all embryos, with the plan to transfer them into uterus in another planned menstrual cycle (Frozen Embryo Transfer aka FET).
These changes come with a large body of scientific evidence, including a recent large analysis of many randomised trials examining the efficacy and safety of 56 different protocols used in assisted reproduction (IVF and ICSI) that included 338 studies involving 59086 women who had undergone IVF, which also concluded that incidence of OHSS is lesser in short antagonist protocol.
To put things into practical perspective, I have seen the numbers drop from nearly 30% of patients experiencing OHSS on long GnRH agonist protocol, to the last moderate OHSS patient I treated being in 2012 after the introduction of these changes.
The goal, when it comes to fertility treatment, and specifically IVF, is to protect everyone involved so that the heartwarming experience of becoming a parent remains untainted.
(Dr. Priya Kannan is past president, Academy of Clinical Embryologists, India, and director and embryologist, Garbba Rakshambigai Fertility Centre, Chennai. kaypriya2000@gmail.com)
Published – July 25, 2026 06:00 am IST