In vitro fertilization (IVF) is a complex process in which the gametes i.e. eggs from sperms are fertilized outside the body in a culture medium by a trained embryologist. The procedure can be done using the couple’s own eggs and sperms. Or it may involve eggs, sperm or embryos from an anonymous donor. The resulting embryo is transferred into the uterus of the female partner for implantation. This complete process takes about 3 weeks.

IVF is generally offered to a couple who is having trouble conceiving even after trying less invasive modalities such as intrauterine uterine insemination where the sperms are placed directly into the uterus around the time of ovulation.

However, in the following conditions, IVF is offered as the primary treatment mode:

1. Woman’s age more than 40 years. 

1. Fallopian tube blockage: blockage makes it difficult for sperm to travel towards egg to fertilize it and for the embryo to reach the uterus. If previously tubal ligation is done and the woman again wants to conceive, IVF is an alternative to tubal ligation reversal surgery. 

1. Ovulation disorder: If the number of eggs are very less or if ovulation is absent.

1. Endometriosis: When the uterine tissue grows elsewhere outside the uterus, it affects the function of ovary and tubes, making it difficult for fertilization and transport of embryo to uterus for implantation.

1. Problems in sperm production and motility: If sperm counts or motility is less or there is an abnormality in sperm shape and size, then it is difficult for sperm to fertilise the egg. In the IVF process, best sperms are selected and used to fertilise eggs. 

1. Unexplained infertility: where no cause is found during the evaluation of both partners for infertility.

The procedure will be explained to the patient as it has multiple steps:

Ovarian stimulation: 

• Hormonal medicines (injection FSH/HMG) are given to stimulate the ovaries to produce multiple eggs rather than the single egg that normally develops each month. Multiple eggs are needed because some eggs won’t fertilize or develop normally after fertilization.
• Monitoring: Vaginal ultrasound of ovaries is used to monitor the development of follicles where eggs mature. Additionally, blood tests are done to measure the response to ovarian stimulation medications — estrogen levels typically increase as follicles develop, and progesterone levels remain low until after ovulation
• Medications to prevent premature ovulation: prevent the body from releasing the developing eggs too soon.

Medications for oocyte maturation: When the follicles are ready for egg retrieval, generally after eight to 14 days, human chorionic gonadotropin (HCG) or other medications are given to help the eggs mature.

Egg collection

Egg retrieval usually planned 34 to 36 hours after the final injection and before ovulation. This procedure is done under sedation to make it pain-free.

• Transvaginal ultrasound aspiration is the usual retrieval method. Under ultrasound guidance, a thin needle is inserted into an ultrasound guide to go through the vagina and into the follicles to retrieve the eggs.
• The eggs are removed from the follicles through a needle connected to a suction device. Multiple eggs can be removed in about 20 minutes. The chances of conceiving increase with the number of eggs that are retrieved.
• After egg retrieval, the patient may experience cramping and feelings of fullness or pressure.
• Mature eggs are placed in a nutritive liquid (culture medium) and incubated. Eggs that appear healthy and mature will be mixed with sperm to attempt to create embryos.

Sperm retrieval

If a partner’s sperm is used, he’ll provide a semen sample through masturbation the morning of egg retrieval. Other methods, such as testicular aspiration — the use of a needle or surgical procedure to extract sperm directly from the testicle — are sometimes required or donor sperm also can be used.

Fertilization

Fertilization can be attempted using two common methods:

• Conventional insemination: In this, healthy sperms and mature eggs are mixed in a culture medium, where the sperm fertilizes the egg using its natural motility.

Intracytoplasmic sperm injection (ICSI): In ICSI, a single healthy sperm is injected directly into each mature egg. ICSI is often used when semen quality or number is a problem or if fertilization attempts during prior IVF cycles failed. 

Embryo transfer

• • Medications to prepare the lining of uterus:  On the day of egg retrieval, progesterone supplements are given to make the lining of your uterus more receptive to implantation. Embryo transfer usually takes place two to five days after egg retrieval.
  • A number of embryos to be transferred: The number of embryos transferred is typically based on age and number of eggs retrieved. Since the rate of implantation is lower for older women, more embryos are usually transferred. Extra embryos can be frozen and stored for future use for several years
  • The procedure is usually painless, although the patient might experience mild cramping. A long, thin, flexible tube called a catheter is inserted in the vagina, through the cervix into the uterus. A syringe containing one or more embryos suspended in a small amount of fluid is attached to the end of the catheter. The contents of the syringe are then pushed inside the uterus.

After the embryo transfer, the patient can resume normal daily activities. However, since ovaries may still be enlarged, the vigorous activity could cause discomfort and should be avoided.

It is best to contact the doctor if the following side effects are experienced: 

• High fever
• Abdominal pain
• Heavy bleeding
• Urinary issues 

About 12 days to two weeks after embryo transfer, blood test (beta-hCG) is used to detect whether the patient is pregnant.

• If b-HCG positive i.e pregnant, the doctor will start or refer the woman for prenatal care.

If b-HCG negative i.e. not pregnant, the woman is advised to stop taking progesterone and is likely get period within a week. If she has any remaining embryos frozen, then she will be offered frozen embryo transfer in next cycles.

Ovarian Hyperstimulation Syndrome

When women undergo ovulation stimulation, they take injectable hormone medications to increase the production of eggs. The problem arises when there are too many hormones in the system which could lead to Ovarian Hyperstimulation Syndrome (OHSS). It is a condition where the ovaries become swollen and cause an immense amount of pain. The patient could experience abdominal pain, vomiting, and shortness of breath. 

Multiple pregnancies: when more than one embryo is transferred, there is a risk of multiple pregnancies, which carry a risk of early labour and delivery of low birth weight babies.

Ectopic pregnancy: when the fertilized egg implants outside the uterus, usually in a fallopian tube. The fertilized egg can’t survive outside the uterus, and there’s no way to continue the pregnancy.

Birth defects: The age of the mother is the primary risk factor in the development of birth defects.