IUI vs ICSI: Differences, Risks, Benefits And More

IUI vs ICSI: Differences, Risks, Benefits And More

Considering fertility treatments but unsure if IUI (Intrauterine Insemination) or ICSI (Intracytoplasmic Sperm Injection) might be the better option for you? You’ve come to the right article.

It can be extremely challenging to find a fertility treatment that best suits your needs, especially if you are not in the medical field or do not know anyone who has been through fertility treatments.

The sheer amount of information available online regarding them can be overwhelming and it doesn't help that many are sprinkled with medical jargon or presented in the form of complicated biology concepts.

To cut through the noise, this guide seeks to explain what IUI and ICSI are, and compare them in terms of risks, benefits and costs. 


What is IUI (Intrauterine Insemination)?

IUI is a type of artificial insemination fertility treatment that involves inserting sperm directly into the uterus [1]. It is a fast, painless, less invasive and more affordable treatment for those who do not have severe fertility problems [2].

IUI can be helpful in the following scenarios [1,3]:

  • Unexplained infertility
  • Infertility due to medical conditions (e.g. endometriosis or low sperm count)
  • Physical or emotional problems that restrict penetration during sex
  • Conditions that may restrict unprotected sex (e.g. sexually transmitted diseases)
  • Same-sex couples or single women looking to conceive using donor sperm


How does IUI work?

To ascertain if this is the right treatment for you, fertility specialists will first conduct a medical history review and order diagnostic tests to ensure fallopian tubes are unobstructed and the uterus is healthy [3]

For those experiencing fertility issues, your doctor may prescribe you prescribe you with medications to be taken orally (e.g. Clomid), and/or to be self-injected (e.g. hCG (human Chorionic Gonadotropin) and FSH (Follicle Stimulating Hormone)).

Timing is important here because this procedure can only take place when you are ovulating. Once it is ascertained that you are (via an ovulation test kit or transvaginal ultrasound), your partner or donor will provide a sperm sample to lab technicians who will perform a sperm wash to obtain high-quality sperm for insemination [3]

Once the sperm has been washed, it is put into a vial and attached to the end of a small catheter, ready for insemination. Here’s where you come in. The doctor would insert a speculum into your vagina, followed by inserting the small catheter into your vagina, through the cervix and into the uterus. The washed sperm is then pushed through the tube into the uterus [4]

Viola! The procedure is over.

The entire process should take no longer than 20 minutes [4] to complete and is relatively pain-free. That said, there have been some reports of mild discomfort during and 1 to 2 days after the insemination procedure. 

The procedure’s success is verified after 2 weeks with a pregnancy test [3].


What is ICSI (Intracytoplasmic Sperm Injection)?

Think of ICSI as a modified version of In Vitro Fertilisation (IVF). In conventional IVF, healthy eggs and washed sperm are put together in a culture dish in hopes that the egg is fertilised naturally. ICSI takes it one step further by injecting a single sperm directly into an egg [5]

ICSI can be helpful in the following scenarios [5]:

  • The infertility cause is unknown
  • Low sperm production or quality
  • When using cryopreserved eggs
  • Other fertility treatments, like IVF, have failed


How does ICSI work?

Just like IUI and all other fertility treatments, it starts with fertility specialists conducting a series of diagnostic tests to check on your hormone levels and ovaries. Once the test results confirm that you are suitable for this treatment, you will be given a series of medications that include FSH and luteinizing hormone (LH) to boost egg production. After a few weeks, a hCG (or similar) trigger shot is then given to kick-start ovulation [6]

Time is of the essence once the trigger shot is given as egg retrieval needs to happen within 34 to 36 hours [7] — before ovulation takes place. To retrieve the egg or eggs, a thin needle is inserted through the vagina into the ovary and follicles containing the eggs, using ultrasound as a guide [6].

While that is taking place, a sperm sample is being retrieved from your partner and sent to the lab for a sperm wash to ensure that only quality sperm is brought to the egg. If the sperm is a frozen sample or from a donor, the fertility specialist will verify the details with you before it is taken to the lab for washing [6]

Once the eggs have been retrieved and the sperm washed, it is then handed over to an embryologist who will inject a single sperm into each egg retrieved. The embryo (fertilised egg) or embryos are then left in the lab to mature for the next 1 to 5 days before being transferred to your uterus [5].

To perform the transfer, the doctor will insert a thin and flexible catheter, containing the embryo or embryos suspended in a small amount of fluid, into your uterus from the vagina. Using an ultrasound as a guide, the doctor then pushes the embryo or embryos into your uterus [6].

The procedure’s success is verified after 2 weeks with a pregnancy test [6].


What are the differences between IUI and ICSI?

Now that you understand the procedures and how they work, let's compare their treatment duration, risks, costs, success rate, and other factors. 

Treatment duration

An IUI cycle may begin at any point in your menstrual cycle and is dependent on the regularity of your menstrual cycle. It ends with a pregnancy test 2 weeks after the procedure [1].

The ICSI cycle may start at any time depending on your body’s reaction to the medication and ends with a pregnancy test 2 weeks after the procedure [6]


All medical procedures carry a certain amount of risk, fertility treatments are no different.

IUI is a relatively simple procedure and the risks involved are low. However, there's a minor chance of infection and vaginal bleeding, and the medication used to induce ovulation may increase the risk of having multiple pregnancies (twins, triplets, or more!) [4].

As ICSI is more invasive and requires greater artificial manipulation, it carries a higher amount of risk. Some of them include [8]:

  • Multiple pregnancies
  • Premature delivery and low birth weight
  • Miscarriage
  • Bleeding or infection 
  • Ectopic pregnancy (when the egg implants outside the uterus)
  • Congenital disabilities
  • Ovarian hyperstimulation syndrome (enlargement of the ovaries)


Each IUI cycle, including consultations, pre-treatment screenings, medication and procedure, costs between £600 [10] and £1,800 [11] in the United Kingdom and upwards of S$1,000 in Singapore [12].

On the other hand, one cycle* of ICSI can cost approximately £7,200 [12] in the United Kingdom and upwards of S$13,000 in Singapore [13]. It might be good to note that although ICSI has a higher success rate, it is important to consider that you may need more than just one cycle to conceive. 

*One cycle means the transfer of one embryo into the womb. Additional good-quality embryos may be stored to be transferred later. 

Success rate

IUI’s success rates highly depend on fertility problems and age (due to depreciating egg quality). Success rates range from 25% for women aged 30 or younger, and 5% for women aged 40 and above [14].

Similar to IUI, ICSI’s success rate also depends on the extent of fertility problems. It hovers around 30% for the first attempt and increases to 56% on the fourth attempt [15, 16]

Other things to keep in mind when choosing a fertility treatment

The entire procedure can take a few months before you conceive. As such, it is crucial that you find a reliable fertility specialist that you are comfortable speaking to and whose charges fit your budget.

To add, with all the consultations, medication and potential setbacks involved, fertility treatments can be tiresome and stressful — not just on the body but also the mind. Before embarking on this journey, you may want to consider building a strong support system [17]. By that we mean, friends, family, therapist and most importantly, your better half. 



Both IUI and ICSI have their own unique set of pros and cons. On the one hand, IUI is more affordable, faster, less invasive and carries a lower risk. However, its success rate depends heavily on age. 

On the other hand, ICSI has a greater success rate but it is also more expensive, invasive and risky (for both mother and child).

At the end of the day, it isn’t so much about which fertility treatment is better than the other because it all boils down to the fertility status of both you and your partner and the medical advice you get from a trusted doctor. 

Still on the fence about fertility treatments like IUI or ICSI? Then perhaps conception aids like the twoplus Sperm Guide might be something you would like to consider. Non-surgically invasive, designed with fertility experts, affordable and comes with free discreet delivery, learn more through the button below. 

[1] National Health Service (NHS), Intrauterine insemination (IUI), https://www.nhs.uk/conditions/artificial-insemination/ 
[2] Complete Fertility Centre, IUI or IVF for same sex couples?, https://www.completefertility.co.uk/blog-resources/blog-news/iui-or-ivf-for-same-sex-couples  
[3] Hopkins Medicine, Intrauterine Insemination (IUI) Treatment, https://www.hopkinsmedicine.org/gynecology_obstetrics/specialty_areas/fertility-center/infertility-services/intrauterine-insemination.html  
[4] Mayo Clinic, Intrauterine Insemination (IUI), https://www.mayoclinic.org/tests-procedures/intrauterine-insemination/about/pac-20384722 
[5] ReproductiveFacts.Org, What is Intracytoplasmic Sperm Injection (ICSI)?, https://www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/documents/fact-sheets-and-info-booklets/what-is-intracytoplasmic-sperm-injection-icsi 
[6] Glasgow Royal fertility Clinic, ​​ ICSI Intracytoplasmic Sperm Injection, https://glasgowroyalfertilityclinic.co.uk/treatments-and-updates/icsi/ 
[7] Health & Fertility Centre For Women, In-Vitro Fertilisation (IVF) Fertility Treatment Singapore, https://www.healthfertility.com.sg/infertility/ivf/ 
[8] Mayo Clinic, In Vitro Fertilisation (IVF), https://www.mayoclinic.org/tests-procedures/in-vitro-fertilization/about/pac-20384716  
[9] National Health Service (NHS), Risks IVF, https://www.nhs.uk/conditions/ivf/risks/ 
[10] Salisbury Fertility Centre, Prices, https://salisburyfertilitycentre.nhs.uk/salisbury-fertility-treatment-prices/ 
[11] The Hewitt Fertility Centre, What Will My Treatment Cost In Total?, https://www.thehewittfertilitycentre.org.uk/costs-and-funding/costs/ 
[12] Singapore Medical Group, What You Should Know About Intrauterine Insemination (IUI), https://smgwomenshealth.sg/doctors-guide/fertility/iui/
[13] Thomson Fertility Centre, Managing the full cost of IVF, https://thomsonfertility.com.sg/ivf-cost/ 
[14] Pacific Fertility Centre, IUI Success Rates and Outcomes, https://www.pfcla.com/blog/intrauterine-insemination-success-rates 
[15] Alireza Zarinara, Hojjat Zeraati, Koorosh Kamali, Kazem Mohammad, Maryam Rahmati and Mohammad Mahdi Akhondi, The Success Rate and Factors Affecting the Outcome of Assisted Reproductive Treatment in Subfertile Men, https://pubmed.ncbi.nlm.nih.gov/32461941 
[16] Julia Rehnitz, Sabine Rösner, Juliane Harsch, Jens Dietrich, Thomas Bruckner, Edison Capp, Thomas Strowitzki and Ariane Germeyer, Factors Influencing Success Rate of Intracytoplasmic Sperm Injection with Azoospermic Male Patients, https://pubmed.ncbi.nlm.nih.gov/32675833
[17] Awtani M, Mathur K, Shah S, Banker M. Infertility stress in couples undergoing intrauterine insemination and in vitro fertilisation treatments. Journal of Human Reproductive Sciences. 2017;10(3):221, https://pubmed.ncbi.nlm.nih.gov/29142452/