IUI vs. IVF
If you have been trying to conceive for some time and are considering fertility treatment, you may have been told about the options of intrauterine insemination, or IUI, and in-vitro fertilization, or IVF. You may be wondering what are the advantages of each approach and how to choose the path that is right for you. A treatment approach should be individualized, and your plan should be discussed with your doctor and based on your unique circumstances. That said, here we’ll review some of the main advantages of IUI and IVF, and why one might choose to start with one over the other.
What is IUI?
Intrauterine insemination involves washing and preparing a semen sample into a more concentrated sample of moving sperm. This prepared sample is inserted into the top of the uterus using a soft catheter. This brings the sperm closer to the egg and bypasses some of the barriers in the vagina and cervix. The sperm still needs to swim through the Fallopian tubes to find and fertilize the egg. IUI is timed around ovulation, so ovulation is typically monitored with ultrasound and occasionally blood work. Oral medication may be used to augment chances of success with IUI in a patient who is not ovulating regularly. In a patient who ovulates monthly, these medications may cause multiple eggs to be released, increasing the chance that at least one egg will be healthy and result in pregnancy.
What is IVF?
In vitro fertilization involves the use of injection medication for 1.5-2 weeks with monitoring visits every 1-3 days to stimulate the ovaries to mature multiple eggs in one cycle. The eggs are extracted through a vaginal egg retrieval procedure under anesthesia and then fertilized in the embryology lab with sperm to form embryos. The embryos can be biopsiedto test for chromosomal abnormalities or specific genetic conditions before being frozen. In the same or subsequent cycle, the uterus is prepared for embryo implantation using estrogen and progesterone.
What are advantages of IUI vs. IVF?
Visits and procedures: An IUI cycle involves fewer medications and fewer visits for monitoring and does not involve a procedure under anesthesia.
Success rates/time to pregnancy: IVF has a higher chance of success compared to IUI. IUI helps to give the sperm a boost and, if using oral medications, can give the eggs a boost, but it may only increase chance of success by a few percentage points. IVF is a more efficient and effective way of achieving a healthy pregnancy, especially if a chromosomally normal embryo is used.
Planning for your full family: We are often able to create more than one healthy embryo from one IVF cycle. All of these embryos can be frozen and used in the future. The chance of success is related to the health of the embryo and remains high even if a patient is older at the time of embryo transfer. This increases the chance of achieving a healthy pregnancy in the future when age may present a greater barrier.
Risks of multiple gestation: If oral medications are used to cause multiple eggs to ovulate with IUI, there is a risk of multiple pregnancy, which is considered a higher risk pregnancy for both the fetuses and the mother. With IVF, typically one healthy, high-quality embryo is transferred at a time, so the chance of multiple pregnancy is very low (in about 1-2% of cases the embryo can split, resulting in multiple pregnancy).
What are specific situations in which one might choose IUI vs. IVF?
Your individual diagnosis and personal circumstances are important to consider when choosing a treatment approach. Here are some diagnoses and factors that might lead one to choose IUI or IVF:
- Male factor infertility – If sperm counts are low, IUI can help give sperm a boost and increase chances of pregnancy. If sperm counts are extremely low, IUI is less likely to work and IVF is typically recommended. Sometimes a procedure may be required to extract sperm from the male and in those cases, IVF is typically recommended to achieve fertilization.
- Tubal factor infertility – If the Fallopian tubes are blocked or abnormal, IVF is needed to bypass the tubes.
- Polycystic ovary syndrome (PCOS) – Many patients with PCOS do not ovulate regularly. Oral medication can help induce ovulation and intercourse or IUI timed around ovulation can be effective in achieving pregnancy. IVF is also often highly effective in patients with PCOS because these patients often have a high ovarian reserve, which can lead to a high response to ovarian stimulation.
- Unexplained infertility – Clomid or letrozole with IUI is considered “first line” treatment for unexplained infertility. Typically, it is recommended to try 3 IUI cycles before considering IVF because after 3 unsuccessful IUI cycles, the chance that IUI works decreases. Some patients will choose to go directly to IVF due to higher success rates and the ability to save embryos for future use.
- Advanced reproductive age – Pregnancy becomes more difficult to achieve in the late 30’s and 40s due to decreases in the quality and quantity of eggs. IVF with PGT-A can help identify normal embryos that have a high chance of success, thereby assisting in achieving a healthy pregnancy. Additionally, extra embryos can be made that can stay frozen and give a high chance of becoming pregnant at older ages when it may be even more difficult to conceive without assistance.
- Diminished ovarian reserve – Patients with low ovarian reserve may choose to use IVF to maximize their chances of achieving a healthy pregnancy sooner, and to save embryos for future children. In cases of severely diminished ovarian reserve, patients may have no response or a low response to IVF. In cases where only 1-2 eggs are predicted to be retrieved, some patients may choose to proceed with IUI instead of IVF.
- Using sperm donation, egg donation, or surrogacy – Patients using a sperm donor will often start with IUI, especially if the patient does not have an underlying diagnosis of infertility. However, even in these cases, IVF can increase chances of achieving a healthy pregnancy sooner and saving extra embryos. Egg donors will undergo ovarian stimulation and egg retrieval, and the eggs will be fertilized with sperm and then transferred to a patient’s uterus or that of a gestational carrier. Patients using a gestational carrier with their own eggs will undergo ovarian stimulation and egg retrieval before the eggs are fertilized with partner or donor sperm, and an embryo will be transferred into the uterus of the gestational carrier.
These are just examples of the considerations behind choosing IUI or IVF. The choice to undergo IUI or IVF is highly personalized based on individual factors like one’s age, diagnoses, timeline, and desired family size. Don’t hesitate to schedule a consultation to discuss your unique circumstances and the right journey for you.