IVF: Why semen is cleaned of abnormal sperms

Dr George Ogweno, an IVF specialist in Nairobi says after consultation, tests and screening including blood tests, hormonal tests and fertility evaluation follows. A male partner, on the other hand, undergoes sperm tests.

"Once treatment starts, serial hormonal checks and ultrasounds are done periodically," explained Dr Ogweno.

Here is what happens thereafter:

• IVF starts on Day 1 or 2 of a woman's menses. A blood test to check hormone levels is done. A scan checks if the ovaries are healthy. If Okayed, the daily injections of a hormone called FSH - to stimulate the ovary to start maturing the eggs, starts. The injections happen daily at specific times for between 10 and 14 days.
• As the injections continue, regular scans monitor how follicles are responding to injections to gauge whether dosage needs increasing or not.
• After 10-14 days of daily injections, a last scan to gauge maturity of follicles (between 18 and 20 ml in diameter) is done. A trigger injection - which finally matures the egg - is given and after 36 hours, eggs are aspirated through the vagina using a special needle in the theatre. The harvest is given to an embryologist while the male partner provides semen sample.
• The semen sample is cleaned of abnormal sperms and the best sperms picked, its tail cut and the head injected into one egg. The fertilized egg is put in a warm place (at 37.2).
• The embryo starts growing from one cell to eight and so on. After three days, the embryologists checks for successfully developed embryos-of which a maximum of three are then transferred into the woman's womb (or a surrogate) using ultrasound. At least one embryo is expected to implant.
• The patient is then put on progesterone - the hormone that sustains the pregnancy - either through injections, swallowable tablets or medication through the vagina. In natural setting, the follicle that gives the egg collapses into a corpus luteum - which naturally produces progesterone.

But in IVF, the follicles are punctured during egg harvesting, hence the need for progesterone injections. Progesterone is given until the pregnancy reaches 13 weeks; after which it is left to naturally progress.