In Vitro Fertilisation
உடலுக்கு வெளியே கருத்தரித்தல்
Infertility is not a failure of biology; it is a hurdle to be bypassed. IVF is not magic, it is precise laboratory manipulation of gametes. Do not confuse this with In Vivo fertilisation. If you miss the distinction, you lose the mark.
The idea
In Vitro Fertilisation (IVF) involves fertilising an ovum outside the female body in conditions simulating the internal environment. The zygote or early embryo is then transferred into the female reproductive tract. This is the foundation of ART (Assisted Reproductive Technology). It bypasses mechanical or physiological blocks in the fallopian tubes.
Why it matters
It allows fertilization to occur in a controlled laboratory environment when natural fertilization in the fallopian tube is blocked or impaired.
NEET lens
NEET focuses on the distinction between ZIFT and IUT. Remember: ZIFT involves zygote/early embryo (up to 8 blastomeres) into the fallopian tube, while IUT involves embryos with more than 8 blastomeres into the uterus. Expect questions on the specific site of transfer. Memorise the 8-cell threshold strictly.
Clinical significance
IVF is indicated for tubal blockages, endometriosis, or unexplained infertility. Failure occurs if the endometrium is not receptive for implantation or if gamete quality is poor. It remains the gold standard for couples unable to conceive naturally.
Introduction
IVF (In Vitro Fertilization) is an ART procedure in which eggs are retrieved from the ovaries after hormonal stimulation, fertilized with sperm in the laboratory, cultured to embryo stage, and transferred to the uterus for implantation.
Core concept
Steps: (1) Ovarian stimulation: FSH injections (8-14 days) → multiple follicle development. (2) Monitoring: ultrasound + estrogen levels. (3) Trigger: hCG injection → oocyte maturation (36 hours before retrieval). (4) Egg retrieval: transvaginal ultrasound-guided needle aspiration of follicles → oocytes collected. (5) Sperm preparation: fresh/frozen/donor sperm → capacitation. (6) Fertilization: insemination (oocytes + ~100,000 sperm) OR ICSI (1 sperm/oocyte). (7) Culture: fertilized eggs → embryos in incubator (Day 3 = 6-8 cells; Day 5 = blastocyst). (8) Embryo transfer: 1-2 embryos loaded into catheter → placed in uterus via cervix. (9) Luteal support: progesterone supplementation. (10) Pregnancy test: 14 days later. Success rates: ~40% per cycle in women under 35. Falls significantly with age.
Go deeper
Why multiple embryos created: stimulation protocols produce 8-15 eggs. Not all fertilize, not all develop normally. Extra embryos can be frozen (cryopreservation) for future use (frozen embryo transfer, FET) — avoids repeat stimulation cycles. Vitrification (ultra-rapid freezing) → survival rates >95% for embryos. Cryopreserved embryos can be stored for years.
From Class 10
IVF (In Vitro Fertilization) is the procedure where an egg and sperm are combined outside the body in a laboratory ('in vitro' = in glass) to create an embryo, which is then transferred to the uterus.