This paper studied the optimal number of eggs needed to achieve 2 or more live births from a single in-vitro fertilisation (IVF) cycle. Researchers concluded that one fresh cycle with a high number of eggs retrieved is an optimal way to plan IVF treatment.

In-vitro fertilisation (IVF) is a procedure where the sperm fertilizes the egg in a laboratory dish outside the body, and is then implanted into the woman’s uterus. The ovaries are stimulated to produce eggs that can then be retrieved, fertilized and implanted. There is debate as to whether a high number of eggs retrieved (more than 15) could be associated with complications. It has recently been suggested that carrying out a single ovarian stimulation procedure with a single egg retrieval cycle may be safer than having multiple IVF procedures. Since multiple eggs can be retrieved and frozen, the result may still produce 2 or more live births.

The records of 2,226 patients who underwent a single stimulation IVF were analyzed. They were grouped based on the number of eggs retrieved: 1 to 3 eggs, 4 to 9 eggs, 10 to 14 eggs, 15-25 eggs, and more than 25 eggs. The number of live births per stimulated IVF cycle was recorded.

84.2% of patients had a fresh (not frozen) implantation of the fertilized eggs. Of these, 35.5% had at least one live birth. Of these live births, 20.4% were multiples (twins or triplets). An additional 761 fertilized eggs were thawed and implanted. Of these, 29.6% resulted in at least one additional live birth.

In total, 40% of all patients achieved at least 1 live birth. The pregnancy rate was 41.3% when more than 15 eggs were retrieved. This was significantly higher compared to when less than 15 eggs were retrieved (36.5%).

Overall, 22.4% patients achieved 2 or more live births from a single IVF cycle. When various factors were considered, as the number of eggs retrieved increased, the chance of 2 more live births increased. There was an 8% increased chance of live birth per additional egg retrieved.  

The authors concluded that a single stimulation IVF cycle could safely achieve 2 or more live births in almost a quarter of patients.