Who it is for
Blocked or absent tubes, endometriosis, repeated failure of insemination, advanced maternal age, prolonged unexplained infertility, or sperm too abnormal for insemination — in which case ICSI is used.
The cycle, day by day
- Days 1 to 10–12: stimulation. One subcutaneous injection a day at a regular hour, which you learn to give yourself. A second drug prevents premature ovulation. Three to five scans with blood tests, often at seven in the morning: this is the heaviest constraint of the whole process, more than the injections.
- The trigger. One injection at a precise time, thirty-five to thirty-six hours before collection. The hour is not indicative: too early and the eggs are immature; too late and ovulation has already happened.
- Egg collection. Twenty minutes, transvaginally under ultrasound guidance, with local anaesthetic or light sedation. Eight to twelve eggs on average. A few hours of observation, then home, with period-like pain for a day or two.
- The laboratory. Eggs and sperm are put together the same day. Fertilisation is checked the next morning: on average two eggs in three fertilise. Embryos are then cultured two to six days; the blastocyst stage allows a better choice.
- The transfer. Painless, no anaesthetic, a few minutes. One embryo in the great majority of cases: single transfer collapsed twin rates without lowering cumulative births. The others are vitrified.
- The wait. Twelve to fourteen days. No precaution improves the odds: not bed rest, not diet, not time off. Strict rest has even been associated with worse outcomes. An early urine test only manufactures anxiety — the trigger injection can make it falsely positive.
Reading the numbers
A clinic may quote a rate per transfer, per collection or per cycle started: these are not the same figure. The only one that matters to a couple is the cumulative live birth rate once every embryo from one collection has been used, fresh and frozen. It depends above all on age: high under 35, clearly lower after 38, low after 42 with one's own eggs.
A clinic that will not publish its results, or publishes only a rate "per transfer", is giving you an unusable number.
What the process costs beyond money
A cycle takes about six weeks and a dozen early-morning trips. Fatigue, strain on the couple and waiting weigh as much as the drugs. Clinics that offer counselling are not being decorative: dropping out after one or two failures is common, and rarely for medical reasons.