Assisted reproductive technology

Women with cancer face the possibility of infertility due to surgery, radiation, and chemotherapy. High risk women face certain infertility following surgery to remove their ovaries and tubes. Assisted Reproductive Technology (ART) is a multistep process which provides infertile women with the option to conceive biologic children in the future, even if they undergo menopause because of chemotherapy or surgery. The overall process can take anywhere from 2 to 3 weeks from start to finish. This is an option for women who are able to defer starting their cancer treatment for at least 2 weeks in order to allow time to create eggs and/or embryos which can be frozen and used later in life. Freezing eggs and embryos is the most effective way for women to preserve their fertility.

Here are the steps involved in ART:

• ovulation induction and egg retrieval 
• egg fertilization  
• egg and/or embryo freezing
• implantation and pregnancy

Ovulation induction steps

• Patients take hormone injections for 8-12 days to stimulate the follicles in the ovaries to grow.
• The ovarian response is monitored frequently (using bloodwork and ultrasound) so that medication dosage can be adjusted if needed.
• When a sufficient number of the woman's follicles are mature (reach 18mm in size), she undergoes a minor procedure under light sedation in which a fertility specialist extracts her eggs using ultrasound as a guide. It is an outpatient and minimally invasive procedure that takes less than 15 minutes.

 

Egg fertilization and embryo transfer

Once the eggs are harvested from the woman’s body they can be frozen in a process called egg freezing for later fertilization, or they can be immediately fertilized with sperm in order to form embryos. The embryos are grown in the laboratory for up to six days before being transferred to a woman’s womb. Alternatively, if a woman is not ready to become pregnant, the embryos can be frozen for later implantation. The embryo transfer procedure usually does not involve sedation and takes only a few minutes.

Egg freezing and embryo freezing

In a process known as cryopreservation, a woman’s unfertilized eggs can be harvested, frozen, and placed in long-term storage. Unlike embryo freezing, egg freezing does not require sperm for fertilization. As such, this is an ideal option for single women, or those who want to reserve the option to one day have children with a different partner. 

The egg-freezing process includes these steps:

• Patients take hormone injections for 8-12 days to stimulate the follicles in the ovaries to grow.
• The ovarian response is monitored frequently (using bloodwork and ultrasound) so that medication dosage can be adjusted if needed. 
• For the egg retrieval, the woman is sedated so that a fertility specialist can extract her eggs using ultrasound as a guide. It is an outpatient and minimally invasive procedure that takes less than 15 minutes. The eggs are frozen the same day. 

Embryo Freezing
The embryo-freezing process is similar to the egg-freezing process. After retrieval, eggs are fertilized with sperm to create embryos that are frozen for future implantation. When the woman wishes to become pregnant, the embryo can be thawed, and transferred into the uterus. This procedure usually does not involve sedation and takes only a few minutes.

Implantation and pregnancy

Women who have removed their ovaries but still have a healthy uterus may be implanted and can carry embryos to term. In order to do so, they need to receive hormones to help sustain the embryo in the early weeks of pregnancy.  

Women who have had a hysterectomy or for whom pregnancy is not considered safe will need a gestational surrogate - a woman agrees to carry the baby to term. 

Concerns for newly-diagnosed women

Some women with cancer have concerns that delaying or interrupting cancer treatment to freeze eggs or embryos could increase the risk of cancer recurrence or metastasis. Most women can start an egg or embryo freezing cycle at any point in the menstrual cycle, limiting treatment delays by a little more than two weeks from referral to chemotherapy.

Concerns for women at high risk for cancer

Women who are at high risk for cancer who are considering Assisted Reproductive Technology may be concernd that fertility medications could cause cancer. Currently, there is no evidence of any adverse effects of fertility drugs on cancer risk and outcomes.