When you’re struggling to conceive, the road to parenthood can feel like a maze of options and difficult choices. Two of the most common fertility treatments that may cross your path are intrauterine insemination (IUI) and in vitro fertilisation (IVF). It’s important to understand these options, so let’s dive into the key differences between the two approaches.
What is IUI?
Intrauterine insemination, or IUI, sometimes referred to as artificial insemination, is a relatively simple procedure. It involves preparing a high-quality sperm sample (partner or donor sperm can also be used with IUI) and introducing it directly into the uterus around the time of ovulation. This gives the sperm a head start, decreasing its distance to the egg and bypassing any potential issues with cervical mucus.
IUI is carefully timed to coincide with ovulation, and sometimes, there may be some mild ovarian stimulation with fertility drugs to encourage the development of a few egg-containing follicles. And/or possibly a trigger shot to time ovulation; it is around this time the IUI is done. Sperm is prepared before the procedure by being “washed” in a laboratory to remove seminal fluid and concentrate the healthiest sperm.
During the procedure, a catheter is inserted through the cervix into the uterus, and the prepared sperm is injected. This process is usually quick and involves minimal discomfort. One of the advantages of IUI is that you don’t need an embryology lab since fertilisation occurs within the body.
What is IVF?
In vitro fertilisation, or IVF, is a more complex and multi-step process. It begins with ovarian stimulation with medications to produce multiple eggs during a single cycle. Once mature, these eggs are then retrieved and combined with sperm in carefully controlled laboratory culture dishes to facilitate fertilisation. Alternatively ICSI (intracytoplasmic sperm injection) might be used, where the eggs may be injected with a single sperm in order to overcome a sperm quality issue.
IVF is also an option for those using donor sperm or donor eggs or using a surrogate. The resulting embryos are carefully monitored for a few days before one or two of the healthiest ones are transferred into the uterus with the goal of achieving a successful pregnancy.
The chances of pregnancy through IVF rely heavily on factors such as the woman’s age, the underlying cause of infertility, and various patient-specific and laboratory-related factors. There are steps that can be taken to best prepare your body for IVF including choosing healthy habits, maintaining a healthy diet, trying fertility supplements such as Impryl, and concentrating on mental and physical wellbeing.
What are the main differences between IUI and IVF?
The main differences between IUI and IVF lie in the location where fertilisation takes place. With IUI, fertilisation happens internally after the sperm is directly injected into the uterus, allowing for potential embryo implantation, while IVF involves external fertilisation in a laboratory, where the sperm and egg are combined, and the resulting embryos are transferred into the uterus for implantation and pregnancy. There are many other differences to consider, and here, we discuss each in more detail.
The process
With IUI, the prepared sperm is inserted into the uterus. IVF, however, is more complex and involves retrieving eggs surgically, fertilising them in a lab, and transferring the embryos back into the uterus. The IVF process tends to be longer and more involved. Despite the widespread use of IVF, the IVF process is misunderstood by many. Here, we break it down in more detail, including the usual timeline and factors that can make the IVF cycle longer.
For IUI, the process is much shorter and simpler. If criteria are met for couples struggling with conceiving, mild fertility drugs are used to mature just a few follicles. With IVF, medication stimulates the ovaries to release many eggs for retrieval. This increases the risk of ovarian hyperstimulation syndrome (OHSS).
The cost
Because IUI avoids many of the complex laboratory and clinical procedures of IVF, it is generally much more affordable. Being a simpler procedure where sperm is directly inserted into the uterus, there are fewer medical appointments and less medication. Research suggests that while IVF has higher success rates per cycle compared to IUI, IUI is closer in effectiveness than previously thought and is significantly cheaper and safer. IVF can also lead to a higher chance of multiple births, increasing costs covered by health services. Given these factors, the conclusion from these studies suggests that it’s advisable to consider IUI before IVF from a cost perspective.
The higher cost of IVF stems from factors like lab fees, anaesthesia for egg retrieval, and the need for embryologist and laboratory services. This use of medical interventions and specialised equipment drives up the cost. This results in IVF being significantly more expensive than IUI due to its high demands on resources, technology and professional oversight.
The success rate
While studies show IVF statistically has higher success rates per cycle, the chances depend heavily on factors like maternal age and the underlying cause of infertility. With advancements in assisted reproductive technologies, IVF has become safer and more effective over time. The latest research indicates that women under 35 years of age experience a 31% success rate with IVF, which decreases to 11% for those aged 40-42. Success rates vary across clinics, but they have tripled over the past 30 years. Male infertility, particularly poor sperm quality, significantly impacts the success of IVF. Other factors like ovarian hyperstimulation syndrome (OHSS), obesity, and smoking can also affect outcomes, with lifestyle adjustments and supplements like Impryl recommended to enhance fertility chances.
That said, IUI remains a viable option and a good starting point for some couples, with evidence demonstrating its effectiveness as a fertility treatment. In cases where IVF fails due to implantation issues, IUI may be a useful alternative as it bypasses the intrauterine insemination step. Plus, IVF offers a versatile approach through methods like intracytoplasmic sperm injection (ICSI), which can address male fertility issues, making it suitable for various fertility problems.
Who might benefit from IUI?
Intrauterine insemination could be beneficial for couples dealing with unexplained infertility, mild male factor infertility, or requiring the use of donor sperm. IUI can also benefit couples facing conception difficulties stemming from factors other than infertility, such as demanding work or travel commitments or issues related to sexual function. For IUI to be a viable option, the woman must have functional ovaries capable of producing viable eggs, at least one functioning unobstructed fallopian tube, and the availability of 5-10 million motile sperm after processing the male partner’s semen sample. Although cheaper than IVF, the success rate is lower, so the choice should also be made considering the age of the female partner. As this is a key issue in the success of any fertility treatment, you might choose the treatment with the higher success rate if time is short. IUI remains a good option for women on the waiting list for IVF.
Who might benefit from IVF?
In vitro fertilisation is often recommended for women with ovulation disorders, fallopian tube blockages, endometriosis, concerns about transmitting specific genetic disorders, or severe male factor infertility where ICSI may be needed. It is also frequently used by older women, those with diminished ovarian reserve, or those who have failed IUI cycles. Preimplantation genetic diagnosis (PGD) is a procedure that may be helpful for patients with concerns about genetic conditions. IVF can be used not only in association with identifying genetic disorders (PGD), but also chromosomal abnormalities (PGS/PGT) in embryos, assisting in the selection of the most suitable embryo for transfer.
No matter which fertility treatment path you choose, the road to parenthood is often paved with hope, perseverance, and deeply personal choices. By understanding the key differences between IUI and IVF, you can make an informed decision that aligns with your unique situation and gives you the best possible chance of achieving your dream of starting or growing your family.
References
Ben Cohlen, Aartjan Bijkerk, Sheryl Van der Poel, Willem Ombelet, IUI: review and systematic assessment of the evidence that supports global recommendations, Human Reproduction Update, Volume 24, Issue 3, May-June 2018, Pages 300–319, https://doi.org/10.1093/humupd/dmx041
Keller E, Botha W, Chambers GM. Does in vitro fertilization (IVF) treatment provide good value for money? A cost-benefit analysis. Front Glob Womens Health. 2023 Mar 1;4:971553. doi: 10.3389/fgwh.2023.971553. PMID: 36937042; PMCID: PMC10014591.
Mendieta MA, Aranda AS, López JFM, Sánchez AMR, Mondragón EC, Monterrosas LÁD, Ambe AK. Comparative analysis of the pregnancy rate via in vitro fertilization vs. previous artificial insemination in patients with unexplained infertility. JBRA Assist Reprod. 2022 Jan 17;26(1):22-27. doi: 10.5935/1518-0557.20210038. PMID: 34415121; PMCID: PMC8769183.
Duran HE, Morshedi M, Kruger T, et al. Intrauterine insemination: a systematic review on determinants of success. 2002. In: Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK69036/
