Intrauterine insemination, or IUI, is a common fertility treatment that may help you conceive. One of four types of artificial insemination, IUI is a fairy simple procedure, and IUI side effects are generally minor, although some can be serious. Understanding what IUI is, how it works, and the risks associated with it can help you make the best decision when it’s time to explore your options for fertility treatments.

Intrauterine Insemination and IUI Side Effects

What Is Artificial Insemination? 

Artificial insemination was originally used on livestock, but it’s now one of the most common solutions to infertility for many couples and involves inserting sperm directly into cervix, uterus, or fallopian tubes. Artificial insemination is most commonly used when:

  • A couple is unable to have intercourse due to erectile dysfunction or another condition.
  • A woman’s cervical mucus doesn’t allow sperm to pass through, or it contains an antibody to sperm, which kills the sperm before they can reach the egg.
  • A woman has mild to moderate endometriosis.
  • A woman or man has a sperm allergy.
  • A man produces too few sperm, or the sperm isn’t mobile enough to reach the egg.
  • A same-sex couple wishes to conceive with donor sperm.
  • No cause of infertility can be found, but the couple has tried unsuccessfully to conceive.

Four Types of Artificial Insemination 

IUI is the most common insemination procedure used today. During IUI, up to one milliliter of sperm from a woman’s partner or a donor are washed in a lab to isolate the sperm from the solution surrounding it. The washed sperm is injected directly into the uterus.

The other three types of artificial insemination are:

  • Intracervical insemination, or ICI, which is less expensive than IUI but not quite as effective. The ICI procedure involves placing the semen directly into the cervix.
  • Intratubal insemination, or ITI, during which washed sperm are injected directly into the fallopian tube or near the entrance. ITI is more invasive than IUI, and its success rate isn’t much higher, making it the least-used method of artificial insemination.
  • Intravaginal insemination, or IVI, which is also known as self-insemination because it can be done by couples trying to conceive. During IVI, semen is injected into the vaginal canal near the cervix. This method is far less effective than IUI, but it’s virtually free. 

A Closer Look at IUI 

An IUI is scheduled just after ovulation, when you’re the most fertile. If you have a 28-day menstrual cycle, this will be around day 14. If your menstrual cycle is irregular, you’ll probably use an ovulation prediction kit that detects hormones in the saliva or urine and accurately predicts when you’ll ovulate.

If donor sperm is used for the IUI, it will be obtained from the sperm bank and tested for transmittable diseases. If your partner’s sperm will be used, the sperm sample will be collected through masturbation. If your partner is unable to ejaculate due to a medical condition, the sperm will be surgically removed directly from the testicles or epididymis. The sperm is washed to separate them from the fluid that surrounds them. The fastest, healthiest sperm are then collected for the IUI.

During the procedure, a speculum is used to open the vaginal walls and expose the cervix. A catheter is inserted through the cervix and into the uterus, and the sperm are injected through the catheter.

After the procedure, you’ll rest for a short time and then go home and wait six to fourteen days before taking a home pregnancy test, which should be followed up by a blood test to confirm the results either way.

Intrauterine Tuboperitoneal Insemination 

Intrauterine tuboperitoneal insemination, or IUTPI, is a newer method of IUI that uses a larger quantity of prepared sperm. The larger volume fills up the uterus and forces it into the fallopian tube as it overflows. During an IUTPI, a special device known as a double-nut bivalve, or DNB, speculum is used to clamp the cervix closed to prevent the excess sperm from flowing back out.

IUTPI has a higher success rate than IUI, according to a study published in the journal Sterility and Fertility, but it’s more expensive.

IUI Side Effects 

The side effects of the IUI procedure itself are minimal. Some women report mild cramping during and after the IUI, but many report little to no pain during the procedure. In some cases, a vaginal infection may occur due to the introduction of bacteria. This may cause burning or itching, discharge, and a foul odor. In rare cases, bleeding or spotting may occur if the cervix is injured during the procedure.

Fertility Drugs and IUI 

In some cases, such as when the cause of infertility is unknown, fertility drugs may be used along with IUI to increase the chances of success by stimulating your ovaries to produce more eggs, a process known as “superovulation.” The most common fertility drugs used with IUI include:

  • Clomid, or clomipene citrate, which is an oral drug that works by blocking estrogen receptors in the brain, stimulating the release of follicle simulating hormone (FSH) and luteinizing hormone (LH) to promote egg development.
  • Gonadotropins like hMG, which is administered daily by injection for a week or two to promote the development of eggs in fluid-filled sacs known as ovarian follicles. Blood tests and ultrasounds monitor their development, and when the follicles are big enough, a shot of hCG triggers the follicles to release the eggs into the fallopian tubes.
  • Aromatase inhibitors, such as letrozole, which inhibit the enzyme aromatase to suppress estrogen levels and increase the output of FSH.

While IUI side effects are typically mild, the side effects of the fertility drugs can be more intense. 

Common side effects of Clomid include:

Serious side effects that require a call to your doctor include vision problems, yellowed skin or eyes, bloating, and stomach or pelvic pain.

Common side effects of gonadotropins include irritation at the injection site, headaches, and fatigue. Serious side effects include vomiting, breathing difficulties, and abdominal swelling.

Common side effects of letrozole include nausea and hot flashes, but negative effects are unusual due to the speed with which this drug is cleared from the body.

All three of these drugs increase your risk of a multiple pregnancy, although letrozole carries the lowest risk of multiples. 

IUI and Multiple Births 

Intrauterine Insemination and IUI Side Effects

If you’re not taking fertility drugs in conjunction with your IUI, your chances of having multiples are the same as if you conceived naturally. But most women who undergo IUI do take fertility drugs, and depending on the drug, this increases your chances of having twins, triplets, or other multiples. Around 10 percent of women taking clomid or letrozole and 30 percent of those taking gonadotropins will become pregnant with multiples.

While multiple pregnancies are a cause for celebration for couples struggling with infertility, multiple pregnancies increase the risk of complications, including:

Premature birth. Most single pregnancies last 39 weeks, while most twin pregnancies last 36 weeks and triplet pregnancies last 32 weeks. Nearly 60 percent of twins are born prematurely, while nearly 90 percent of triplets are delivered pre-term, according to the March of Dimes.

Low birth weight. Babies who are less than 5.5 pounds are considered to have low birth weight, which increases the risk of a range of problems, including vision and hearing loss and developmental problems.

Intrauterine growth restriction. The growth rate of multiples begins to slow around 30 weeks for twins, 27 weeks for triplets, and 25 weeks for quadruplets. This may either be due to the inability of the placenta to grow any larger or to the babies competing for nutrients.

Preeclampsia, a complication that can cause high blood pressure, damage to the kidneys, and seizures.

Gestational diabetes. A multiple pregnancy increases your risk of gestational diabetes, which can lead to high blood pressure and pre-term birth or stillbirth. Gestational diabetes also puts your babies at risk for breathing problems, jaundice, childhood obesity, and diabetes later on in life.

Placental abruption, a serious condition in which the placenta separates completely or partially from the uterus, potentially depriving the baby of oxygen and nutrients and causing severe bleeding that can dangerous to both you and your baby.

Birth defects. According to the University of Rochester Medical Center, multiple-birth babies are at twice the risk of birth defects like spina bifida and heart abnormalities. 

Cesarean birth. While twins are often delivered vaginally, triplets and larger numbers of multiples are more often delivered by cesarean section.

Twin-to-twin transfusion syndrome, or TTTS. This condition occurs in about 15 percent of twins who share a placenta, and treating it requires surgery or early delivery. In TTTS, the blood vessels that connect in the placenta sends blood from one of the babies to the other, and over time, the recipient baby may receive too much blood. 

Bed rest. In some cases of multiple pregnancies, bed rest is needed to stabilize the mother or the babies. Bed rest can help reduce or prevent stress on your heart, kidneys, and other organs, and it increases the flow of blood to the uterus and improves the delivery of nutrients to the babies. It can also help prevent early contractions by taking the pressure off the cervix.

Birth complications. Complications at birth may include cord entanglement, where the babies’ umbilical cords get tangled, and postpartum hemorrhage of the mother due to the over-distended uterus and the large placental area.

Each additional baby you carry increases your risk of complications. Your doctor will monitor your pregnancy closely and take steps to prevent or immediately treat these problems to help ensure a safe, healthy pregnancy and delivery. 

Factors Affecting IUI Success 

A study published in the Journal of Human Reproductive Sciences found that the pregnancy rates per IUI cycle range from eight to 22 percent. Researchers cite a number of factors affect the success of IUI cycles:

  • The IUI success rate in women over 40 is as low as 1.4 percent, according to the study.
  • Duration of infertility. The longer the duration of infertility, the less effective an IUI may be.
  • Type of infertility. The study found the success rate slightly higher in unexplained fertility cases than in endometriosis and male-factor infertility cases.
  • Endometrial thickness. With endometrial thickness of 6 millimeters and greater, the success rate was higher, but not significantly so.
  • Total motile fraction, or TMF, of sperm. When the TMF, or the number of “good” sperm in a sample, was in the range of 10 to 20 million, the success rate was highest, at a little over 18 percent. When the TMF was between five and 10 million, the pregnancy rate was a little over five percent. A motility rate of less than five million was associated with a 2.7 percent success rate.
  • Number of dominant follicles. A higher number of preovulatory follicles is associated with higher success rates. When fertility drugs are used to promote superovulation, the success rate is as high as 33 percent. 

What if IUI Doesn’t Work? 

Most doctors recommend three to six cycles of IUI. If you still haven’t become pregnant after six cycles, your doctor will likely recommend an alternative fertility treatment like in-vitro fertilization, or IVF. During IVF, eggs are extracted from the woman and fertilized manually with the male’s sperm in a laboratory dish. The resulting embryo is transferred into the uterus.

Infertility can be stressful. It takes a toll on your body, mind, and spirit, and getting plenty of support and keeping your stress levels down is important for your wellbeing and, according to many experts, for helping you conceive.

While you’re undergoing artificial insemination and other infertility procedures, spend time nurturing your relationship with your spouse or significant other. Engage in hobbies and other enjoyable activities to help you stay active and engaged with other areas of your life. Join a support group to help you maintain good mental health and keep you feeling positive and hopeful for the future. Remember that the majority of couples struggling with infertility will eventually conceive, and those who don’t have other options available, including surrogacy and adoption.