Q&A: The Basics of IVF
Are you considering doing IVF? Wondering how IVF works? Dr. Meera Shah explains the basics of in vitro fertilization (IVF).
How does IVF work?
The premise of IVF, or in vitro fertilization, is to increase the efficiency of the reproductive system. Human reproduction is by nature, a very inefficient process—largely due to the fact that in a woman’s natural cycle, only one egg is released every month. A normal part of ovarian aging is declining egg quality, so if the selected egg is not healthy, it will not result in a pregnancy. Several other eggs of varying quality are also available for recruitment each month; however, if they are not selected for ovulation, they will undergo atresia (degeneration). These eggs are capable of being ‘rescued,’ which can ultimately increase the likelihood that a healthy egg can be used to achieve a pregnancy.
The IVF process begins with a woman taking injectable hormones for approximately two weeks to stimulate the ovaries to produce multiple eggs. The eggs are then removed through a surgical procedure and prepared for fertilization in an embryology lab.
Fertilization takes place using either of two methods:
- Conventional insemination: Eggs and washed sperm are placed in close proximity and fertilization is left to happen naturally.
- ICSI, or intracytoplasmic sperm injection: Individual sperm are injected into each egg. The process of fertilization takes 16-18 hours. Once completed, the single cell divides to become a multicellular embryo. The embryo is then cultured for three to six days and either transferred immediately into the uterus or frozen and transferred at a later time.
Who is a good candidate for IVF?
IVF is used to treat several different types of infertility. See below for the most common reasons to turn to IVF:
- Age related fertility: The most common indication is for age related infertility. As a woman enters her late 30s/early 40s, both egg quality and quantity decline, and IVF may be needed to achieve a healthy pregnancy. IVF is also indicated if a woman’s fallopian tubes are damaged, blocked, or surgically removed.
- Ovulatory problems: It can also be used if a woman has an ovulatory problem and does not release eggs due to an underlying endocrine disorder (such as polycystic ovarian syndrome).
- Male factor: One of the earliest applications of IVF was for male factor, which is present in up to 30% of couples. When sperm counts or quality are low, natural fertilization is not possible and IVF and ICSI are necessary.
- Known genetic conditions or chromosomal abnormalities: IVF is also used for couples who may not have infertility, but have a known genetic condition which can affect their future offspring—for example, cystic fibrosis or BRCA (breast cancer gene). It might also be considered for fertile couples with a history of recurrent pregnancy loss due to chromosomal abnormalities.
- Same sex couples: Same sex female couples may choose to undergo reciprocal IVF so that one parent’s eggs are used to make the embryo and the other parent carries the pregnancy. Same sex male couples may choose to build a family using embryos created from a donor egg and their sperm. These embryos are then transferred into a gestational carrier.
How much will IVF cost?
The average cost of an IVF cycle in the United States is $10,000-15,000. The medications can potentially add $3,000-5,000 to the cost of the IVF cycle. The cost is largely dependent on insurance coverage and location.
How successful is IVF?
IVF success is largely age dependent. Below is the most recently published data (2017) from the Society for Assisted Reproductive Technology (SART).
Can an ectopic pregnancy happen after IVF?
Absolutely. An ectopic pregnancy is a pregnancy which implants outside of the uterus—most often in the fallopian tube and less often in the ovary, cervix or abdominal cavity. An ectopic pregnancy can be life threatening if not diagnosed and managed early. It can be managed by medication or surgery and is considered an emergency and needs close follow-up by an REI or OB/GYN.
Risk factors for ectopic pregnancy include:
- History of sexually transmitted infections
- History of smoking
- Previous abdominal surgery
When an embryo is transferred, it is performed under ultrasound guidance to be precise in placing the embryo in a specific location in the uterine cavity. However, the uterine environment is a dynamic one, and while in most cases the embryo implants in a location very close to where it was placed, it can sometimes migrate to other locations, including the fallopian tube.
Women with a history of an ectopic pregnancy have the highest rate of recurrence. One study found that the risk in a natural conception was as high as 15%, and for these same women undergoing IVF, the risk was 9%. IVF pregnancies are monitored very closely, so most ectopic pregnancies can be diagnosed very early and managed without surgery.
Is IVF painful?
IVF is generally not painful, but women may experience the process of IVF very differently. Most women experience only mild discomfort, while others may experience more significant bloating and abdominal pain during their cycle.
Most discomfort is experienced towards the end of the IVF cycle and in the days after the egg retrieval. This is mostly attributed to the enlarged ovaries and the fluid which accumulates within each follicle and outside the ovary. Many factors contribute to this level of discomfort, including the stimulation protocol used, response to hormones, and the development of OHSS, or ovarian hyperstimulation syndrome.
The egg retrieval procedure, which generally takes ten to 15 minutes, is performed under sedation to keep the patient comfortable. Most women can return to their routine schedules within one to two days of their procedure, and all symptoms of bloating and discomfort usually abate within one to two weeks.
How long does IVF take?
IVF consists of a preparatory phase and stimulation phase:
- Preparatory phase: In this phase, birth control pills or other medications may be used to prime the body for the ovarian stimulation phase. This may take two to four weeks depending on the protocol.
- Ovarian stimulation phase: This phase takes two weeks and usually consists of daily injectable medications and culminates in the egg retrieval. After the procedure, embryos are cultured for three to six days and either transferred into the uterus or frozen for future use.
Wondering whether IVF is right for you? The first step is talking with your OBGYN and/or fertility specialist.
Photo by Mona Eendra.