Three techniques to create test-tube babies
Type one: In vitro fertilization and embryo transfer (IVF-ET)
IVF-ET mainly solves infertility caused by female factors. It can be understood as a technique in which sperms and eggs naturally combine to form fertilized eggs in vitro and are transplanted into a woman's uterus. The world's first "test tube" baby was born in 1978.
(1). Women with ovum transport disorders caused by various factors, such as bilateral tubal obstruction, agenesis of the fallopian tube and severe pelvic adhesions.
(2). Ovulation disorder: Patients with refractory ovulation disorders who have not achieved pregnancy after repeated routine treatments.
(3). Endometriosis: Women with endometriosis who are still not pregnant after routine medical or surgical treatment.
(4). Immune infertility and unexplained infertility: Repeated intrauterine insemination – or other conventional treatment – has not yet achieved pregnancy, etc.
(5). Men with mild oligozoospermia or asthenozoospermia.
Type two: Intracytoplasmic sperm injection (ICSI)
ICSI, a technique for in vitro fertilization in which an individual sperm cell is introduced into an egg cell, is mainly used to solve infertility caused by male factors. The first ICSI baby in the world was born in 1992.
(1). Severe oligoasthenozoospermia.
(2). Irreversible obstructive azoospermia, sperm obtained surgically.
(3). Failure of fertilization by conventional test-tube baby techniques or extremely low fertilization rates.
(4). Those with abnormal sperm function.
(5). This technique is also required in patients who need a preimplantation genetic diagnosis (PGD).
Type three: PGD
This technique can provide parents with genetic disorders the opportunity to have healthy children. From a genetic point of view, it helps humans choose the healthiest offspring to have.
At present, this technology is mainly used for high-risk populations with single gene genetic disorders, chromosomal disorders, sex-linked genetic disorders or possible birth defects. The first successful application of PGD took place in 1990.
(1). One or both of the prospective parents suffer from an abnormal chromosome number or structure.
(2). One prospective parent is a carrier of sex-linked genetic disorders, or a single gene disorder patient or carrier who can be genetically diagnosed, etc.
(3). Patients with a history of multiple adverse pregnancy and delivery cases of unknown reason; and patients with repeated implantation failure of IVF.
Embryo screening mainly addresses chromosomal abnormalities or well-defined monogenic diseases but does not address abnormalities caused by other factors. A routine obstetric examination is still required, and invasive prenatal diagnosis should be selected when necessary.
For embryo screening technology, the country has a strict access system and not every hospital engaged in assisted reproductive technology can do it. This is especially true of high-throughput gene sequencing-based PGD technology: Only 16 institutions, including Chongqing Health Center for Women and Children (CQHCWC), can carry out this procedure nationwide.