IVF Side Effects: Common Symptoms, Rare Risks, and How to Prepare
IVF is considered one of the most effective fertility treatments available — but it can come with physical, emotional, and hormonal side effects that vary from person to person. This guide breaks down common and rare IVF side effects at each stage of the process, from common symptoms to rare complications, so you can feel informed, supported, and better prepared.
Author
Tassia O’Callaghan
Reviewed by
Kayleigh Hartigan
20 min read
Updated 7th July 2025
Treatment Spotlight:
- Some people experience side effects from the fertility medication taken for IVF, although they’re often mild. [1]
- Ovarian Hyperstimulation Syndrome (OHSS) is the most serious IVF side effect, but severe cases are rare — affecting between 0.1% to 1% of IVF cycles carried out in the UK. [2,3]
- Serious complications like infection or injury during egg retrieval are uncommon, and your clinic will monitor for these closely. [4]
- Multiple pregnancies used to be more likely with IVF, which increases the risk of complications such as preterm birth, high blood pressure, and gestational diabetes, but this is less common due to changes in practice in recent years, due to the HFEA’s ‘One at a time’ campaign. [5]
- Recent studies have shown that there may be a link between high blood pressure and frozen embryo transfers, although research is ongoing. [5]
- Some studies suggest a slightly higher risk of birth defects or rare imprinting disorders with IVF, especially when ICSI is used, but the overall risk remains low. [6]
- Emotional side effects are common but often overlooked — counselling is recommended before, during, and after treatment. [7]
What are IVF side effects?
IVF side effects are the physical and emotional responses your body might have to the medications and procedures involved in treatment — and they’re a normal part of the process for many people. These can include bloating, hot flushes, breathing difficulty, mood swings, heavy periods, breast tenderness, insomnia, increased urination, spots, headaches, weight gain, dizziness, and vaginal dryness. [1,5]
Most IVF side effects are mild and temporary, and they don’t necessarily indicate whether the treatment is working or not. While serious complications are rare, your clinic will monitor you closely throughout your cycle to help prevent and manage any risks that arise.
Treatment Essentials: IVF
Curious about IVF and how it all fits together? From the early steps to embryo transfer, our in-depth guide breaks down the process, potential risks, and what to expect.
What are IVF side effects?
IVF side effects are the physical and emotional responses your body might have to the medications and procedures involved in treatment — and they’re a normal part of the process for many people. These can include bloating, hot flushes, breathing difficulty, mood swings, heavy periods, breast tenderness, insomnia, increased urination, spots, headaches, weight gain, dizziness, and vaginal dryness. [1,5]
Most IVF side effects are mild and temporary, and they don’t necessarily indicate whether the treatment is working or not. While serious complications are rare, your clinic will monitor you closely throughout your cycle to help prevent and manage any risks that arise.
Hormonal stimulation
IVF typically involves stimulating the ovaries to produce multiple eggs in one cycle. This is done using injectable hormones (usually gonadotropins). These can cause side effects like bloating, breast tenderness, mood swings, and fatigue as your hormone levels rise rapidly. [1,5]
It’s worth remembering that these are prescribed medications — and like all medications, they can cause side effects. The exact symptoms can vary depending on the brand and type of medication you’re taking, and the manufacturer will provide a full list. Hormones used in IVF are powerful and carefully dosed, but your response is unique — so always speak to your clinic if something doesn’t feel right.
Trigger shots, progesterone, and down-regulation medication
The trigger shot (often hCG or Lupron) matures the eggs ahead of retrieval and can contribute to abdominal discomfort or early signs of ovarian hyperstimulation syndrome (OHSS). Progesterone support — usually in the form of pessaries, injections, or gel — helps prepare the uterus, but may lead to vaginal irritation, headaches, chest pains, weakness, fatigue, and dizziness. If your protocol includes down-regulation (e.g. using a nasal spray or injection to suppress ovulation), it can mimic menopause, with symptoms like headaches, hot flushes, poor concentration, or low mood. [8,9,10]
Physical procedures like egg collection and embryo transfer
Egg retrieval is a minor surgical procedure, and while generally well tolerated, it can cause short-term cramping, spotting, and pelvic discomfort. Embryo transfer is typically painless, but you may still experience light spotting or mild cramps afterwards. [11,12,13]
The emotional side of IVF
The pressure, anticipation, and hormonal fluctuations can all take a toll emotionally. Anxiety, irritability, insomnia, and mood swings are common — especially during the two-week wait after embryo transfer. Even when physically manageable, IVF can be mentally exhausting, and it’s okay to seek support. [7,14]
When do IVF side effects start?
IVF side effects don’t usually begin all at once — they tend to show up in stages, depending on where you are in your treatment cycle and how your body responds to the medication.
During ovarian stimulation (typically days 2–14 of your cycle)
This is when most physical side effects begin. As you start daily hormone injections to encourage your ovaries to mature multiple eggs, you might experience bloating, breast tenderness, fatigue, headaches, or mood swings. These are a result of rapidly rising estrogen levels and the ovaries working harder than usual. Some people also notice injection site soreness or mild allergic skin reactions. [1,5]
After the trigger shot and egg retrieval
The trigger shot, given to finalise egg maturation, can sometimes cause abdominal discomfort or mild nausea — especially if your hormone levels are already high. After egg retrieval, you may feel crampy or tired for a few days, with possible spotting or pelvic heaviness. [8,10,11,12,13]
During the luteal phase (the two-week wait)
This is when progesterone support begins, either through vaginal pessaries, gel, or injections. Progesterone side effects can peak during this time, including vaginal irritation, headaches, and fatigue. These symptoms can feel like early pregnancy signs — which can make this phase even more emotionally charged. [9]
After your cycle ends — whether it results in a pregnancy or not
Once you stop taking medication, most side effects will begin to fade (possibly to be replaced with early pregnancy symptoms). However, emotional and hormonal effects can linger for days or even weeks. It’s not uncommon to feel mentally and physically drained, especially if the outcome wasn’t what you’d hoped for. Post-cycle support matters — whether that’s rest, counselling, or simply space to recover. [7,14]
Rare and serious IVF complications
IVF is generally a safe and well-monitored procedure, but like any medical treatment, it does carry some risk. While most people only experience mild, short-term side effects, a small number may develop more serious complications. These are rare — but important to be aware of, so you can act quickly if something doesn’t feel right.
Infection
After egg retrieval, there’s a small risk of pelvic infection. This can happen if bacteria enter the reproductive tract during the procedure. Most infections are mild and treatable with antibiotics, but in rare cases, hospitalisation or surgery may be needed — especially if there’s a history of endometriosis or previous pelvic infections. [4]
Ovarian torsion
This is an uncommon but painful complication where an enlarged ovary twists on its own blood supply, often due to swelling from stimulation. It causes sudden, severe lower abdominal pain and may require emergency surgery to untwist (or in some cases, remove) the ovary. Thankfully, ovarian torsion is very rare, with most research carried out on a case-by-case basis, rather than on numbers of people who have experienced it. [15,16,17]
Blood clots
Although extremely rare, IVF-related hormone changes — especially in people at higher risk — can increase the likelihood of blood clots forming in the legs or lungs. Symptoms include swelling, pain, shortness of breath, or chest pain. Blood clots are a medical emergency and should be treated immediately. [18,19]
Allergic reactions to medication
Most IVF medications are well tolerated, but allergic reactions can occasionally occur, particularly with injectable drugs. These may cause redness, itching, or swelling at the injection site — or in rare cases, more serious reactions like difficulty breathing or full-body rash.
If you experience severe abdominal pain, significant swelling, difficulty breathing, chest pain, dizziness, or fainting — contact your clinic or seek emergency medical attention immediately. It’s always better to check than to wait. [20,21]
What is OHSS and how likely is it?
Ovarian Hyperstimulation Syndrome (OHSS) is a potentially serious complication that can arise during fertility treatment, particularly IVF, when the ovaries respond too strongly to stimulation medications. OHSS occurs when overstimulated ovaries enlarge and release chemicals that cause fluid to leak into the abdomen and, in severe cases, around the heart or lungs.
While mild OHSS is relatively common (affecting up to 33% of IVF patients), moderate or severe OHSS is rare — affecting just over 1 in 100 (about 1%) of IVF cycles. HFEA’s 2023/24 data reports that severe and critical OHSS incidents occurred in fewer than 0.1% of UK fertility treatment cycles. [2,3]
People with PCOS, a high number of follicles, or elevated estradiol levels are more likely to develop OHSS. To reduce the risk, clinics monitor closely during stimulation and may adjust your medication dose or recommend a “freeze-all” cycle to delay embryo transfer until symptoms settle. [2,3]
Symptoms often begin after the trigger shot or egg retrieval, ranging from mild to severe:
- Mild: Abdominal discomfort, mild swelling, and nausea
- Moderate: More pronounced swelling, abdominal pain, vomiting
- Severe: Extreme thirst, dehydration, reduced urine output, difficulty breathing, and — rarely — blood clots or kidney/liver complications
Mild discomfort after egg collection is common and usually settles within a week or two, but moderate or severe symptoms need medical attention.
Are IVF side effects a sign of success?
Unfortunately, no — the presence (or absence) of IVF side effects has no proven link to whether your cycle will be successful.
It’s a common — and completely understandable — urge to look for signs that treatment is working. After everything you’ve invested emotionally, physically, and financially, it’s natural to want something to mean something. But the truth is, side effects are a reflection of how your body responds to medication, not whether an embryo will implant or lead to a pregnancy.
Some people feel bloated, emotional, and exhausted throughout IVF and still get a negative result. Others sail through the cycle with barely a cramp and go on to get a positive pregnancy test (BFP). Hormone sensitivity is highly individual and doesn’t correlate with success rates.
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Choosing a fertility clinic is a big decision — and we’ve made it clearer. Our guide walks you through what to look for, what to ask, and how to feel confident in your shortlist.
Can IVF side effects impact long-term health?
For most people, the side effects of IVF are short-term and reversible, resolving soon after treatment ends or hormone levels return to baseline. Bloating, mood swings, fatigue, and tenderness typically ease once medication is stopped, whether the cycle results in a pregnancy or not.
Understandably, many people worry about whether repeated hormone stimulation could have lasting consequences — especially when going through multiple cycles. This is an area of ongoing research, but the current consensus is reassuring.
There’s no conclusive evidence that IVF increases the long-term risk of cancer, including breast, ovarian, or uterine cancer. Early studies raised concerns about a possible link between fertility drugs and certain cancers, but more recent, large-scale studies — including those accounting for age and underlying infertility — have not found a clear or consistent association.
Some research is exploring the cumulative effects of multiple IVF cycles, particularly in people who undergo many rounds of stimulation over several years. So far, any potential long-term risks appear to be low, but it’s an area scientists continue to monitor carefully. [22]
Is IVF still safe?
Yes, IVF is considered safe for the vast majority of people, and most side effects don’t leave lasting damage. If you have a personal or family history of hormone-sensitive conditions (like certain cancers), your clinic may recommend additional screening or adapt your treatment plan accordingly. And if you’re planning multiple IVF cycles, it’s worth discussing your long-term health with your care team to make informed choices that support both your fertility and your future wellbeing.
How to manage IVF side effects
While IVF side effects can be physically and emotionally challenging, many are manageable with the right support and a few simple strategies. Understanding what’s happening in your body — and how to respond to it — can make a big difference in how you feel throughout the process.
Bloating
As your ovaries grow and hormone levels rise, it’s common to feel swollen or uncomfortable.
While you can ask your fertility clinic for more specific advice, it’s often recommended to drink plenty of water to help reduce fluid retention, try some gentle movement, like walking or stretching, to ease pressure and keep digestion moving, and eat smaller, more frequent meals.[23]
Mood swings and anxiety
Hormonal changes, high emotional stakes, and the stress of treatment can all contribute to feeling overwhelmed. The NHS recommends fertility counselling tao “talk about your problems and feelings in a confidential environment.” [7]
Injection discomfort
Daily hormone injections can cause sore spots, bruising, or irritation over time. Try rotating injection sites regularly (e.g. left vs. right side of the abdomen or thigh), and using ice before to numb the area and apply a warm compress after to relax the muscle. If any site becomes red, hot, or painful, let your clinic know.
Fatigue
Many people report feeling unusually tired during IVF, especially in the stimulation and luteal phases. Aim to prioritise rest where you can by going to bed earlier or taking short naps, eat small, regular meals and snacks to keep your energy steady, and, if possible, consider asking for time off work or flexible hours during key stages of your cycle.
Keep a side effect diary
Tracking how you feel throughout your cycle — physically and emotionally — can help you identify patterns and advocate for changes in future rounds. If something feels too intense or disruptive, your clinic may be able to adjust your medication protocol or offer additional support.
What to ask your clinic about IVF side effects
Having clear, open conversations with your clinic can make a huge difference in how supported and informed you feel throughout IVF. Side effects are common — but how they show up can vary depending on your treatment protocol, personal health history, and how your body responds to hormones. These are some key questions to ask before (and during) your cycle:
What side effects should I expect based on my protocol?
There are different types of IVF protocols, and each comes with its own hormone combinations and timelines. Ask your clinic to walk you through the specific medications you’ll be taking, what they’re for, and what kinds of physical or emotional side effects you might experience. This helps set expectations — and means you’ll be more prepared if symptoms do crop up.
How will you monitor me for OHSS?
Ovarian Hyperstimulation Syndrome is rare, but can become serious if not caught early. Ask how your clinic plans to track your risk throughout the cycle — including how often they’ll check your hormone levels and follicle count. It’s also worth asking what their protocol is if OHSS does develop: will they recommend a freeze-all cycle? Will you be monitored post-retrieval?
What support do you offer for mental wellbeing?
IVF can be just as emotionally demanding as it is physical. Find out whether your clinic offers counselling, referrals to therapists who specialise in fertility, or any in-house support groups. Even just knowing where to turn if you’re struggling can make a difference to how you cope.
Can I speak to someone if something doesn’t feel right?
You should never feel like you’re being a burden or “overreacting.” Ask if there’s a dedicated nurse line, out-of-hours number, or named contact person you can speak to during your cycle — especially if you’re worried about symptoms like severe cramping, shortness of breath, or emotional overwhelm.
What happens if I need to adjust my medication?
If side effects become too difficult to manage, will they be able to lower your dose, change the medication, or pause the cycle if needed? Knowing what’s flexible and what’s not can help you feel more in control.
Are there any lifestyle changes that could help reduce side effects?
Ask if your clinic recommends any specific approaches around hydration, exercise, diet, or supplements during your cycle to help ease physical symptoms.
If I’ve had strong side effects in a previous cycle, how will that inform this one?
If this isn’t your first round, your clinic should use your past response to adjust your protocol. It’s worth asking how they’ll tailor your treatment to reduce any repeat issues.
How will I know the difference between side effects and early pregnancy symptoms?
The two-week wait is notoriously confusing. Ask what to look out for — and what not to overthink — so you’re not left symptom-spotting in the dark.
Will I need to take time off work?
Your clinic can help you plan for the practical side of treatment. Ask if there are points in the cycle (like egg retrieval or the two-week wait) when taking it easy — or taking time off — might be recommended.
What emergency symptoms should I look out for?
It can be reassuring to know which symptoms are normal, which might need a phone call, and which are a red flag. Ask for clear guidance so you’re never left second-guessing.
Summary
No IVF cycle is the same — and no side effect experience is “more valid” than another. Whether you breeze through or feel overwhelmed, it’s all real, and it’s all worthy of support.
IVF side effect FAQs
Do IVF side effects get worse with age?
Not necessarily. While age plays a big role in fertility treatment outcomes, it doesn’t directly determine how intense your IVF side effects will be. In fact, side effects are generally more closely linked to your individual hormone levels, ovarian response, and overall health than your age alone. [24]
Younger people — particularly those with a high ovarian reserve or conditions like PCOS — may actually be more prone to stronger physical side effects like bloating or ovarian hyperstimulation syndrome (OHSS), simply because their ovaries respond more actively to stimulation medication. On the other hand, older people may require higher doses of medication to achieve the same effect, but still have a gentler response with fewer noticeable side effects. [2,3]
If you’re concerned about how your body might react to IVF medication, your clinic can run tests (like AMH and follicle tracking) to tailor your treatment and reduce the risk of side effects, whatever your age.
How long do IVF side effects last?
IVF side effects can last anywhere from a few days to several weeks, depending on your treatment plan, how your body responds to the medication, and whether or not the cycle results in a pregnancy.
For most people, side effects begin during the stimulation phase, when hormone injections are used to encourage egg development. These effects — such as bloating, mood swings, fatigue, and breast tenderness — usually peak around the time of egg retrieval, and start to ease once hormone levels begin to settle.
If you go on to have a fresh embryo transfer, you’ll likely continue taking progesterone support (via pessaries, injections, or gel), which can cause side effects to persist into the two-week wait — the window between embryo transfer and pregnancy test. Symptoms during this phase often include constipation, nausea, fatigue, and emotional sensitivity.
If the cycle ends with a negative result, side effects usually subside within a few days of stopping medication. If you become pregnant, some hormone-related symptoms may continue into the first trimester, as your body continues to adjust.
Can I take time off work because of IVF side effects?
Yes — and many people do. IVF can affect you physically and emotionally, and it’s entirely valid to need time off to rest, recover, or simply cope with the demands of treatment.
Common side effects like bloating, fatigue, mood swings, and cramping can make it difficult to concentrate or stay comfortable at work — especially during the stimulation phase, egg retrieval, or the two-week wait. Beyond the physical symptoms, the emotional weight of IVF is often underestimated. Taking time off can create space to manage stress, process feelings, or attend appointments without added pressure.
You don’t need to push through if you’re struggling. If you feel that side effects are impacting your ability to work, consider speaking to your GP or fertility clinic about a fit note (also known as a sick note) that you can give to your employer. Fit notes can cover both physical and mental health impacts, and don’t require you to disclose every detail of your treatment.
Some people also explore using annual leave, flexible working hours, or compassionate leave depending on their workplace policy. It’s worth checking if your employer has a fertility leave policy or if adjustments can be made during your cycle.
Do all IVF medications cause side effects?
Not necessarily. While many IVF medications come with the potential for side effects, not everyone experiences them — and those who do can have very different experiences in terms of type, timing, and intensity.
How you respond to IVF medication depends on several factors, including:
- The specific drugs you’re prescribed (e.g. stimulation meds, trigger shots, progesterone, or downregulation drugs)
- The dosage and duration of treatment
- Your hormone levels, ovarian reserve, and medical history
- Whether this is your first cycle or a subsequent one
For example, some people feel bloated and emotional during stimulation injections, while others have very few noticeable symptoms. Similarly, progesterone support can cause breast tenderness, constipation, or fatigue — but some barely feel a thing. The same applies to side effects like headaches, injection site reactions, or mood changes: they’re common, but not guaranteed.
What’s the difference between IVF side effects and early pregnancy symptoms?
Many symptoms overlap — like breast tenderness, fatigue, or nausea — but most during IVF are caused by hormones like progesterone, not necessarily pregnancy. The only reliable way to know is through a pregnancy test. [1,25]
Do side effects get worse with each IVF cycle?
Not always. IVF side effects don’t automatically intensify with each round — many people find they feel more prepared and resilient in later cycles, knowing what to expect and how to manage the process both physically and emotionally.
That said, experiences can vary. Some people notice increased fatigue, emotional burnout, or a greater sensitivity to medication the more cycles they go through. This may be due to cumulative hormonal changes, ongoing stress, or simply the toll of repeated treatment over time.
Your clinic can use what they’ve learned from previous cycles to adjust your medication protocol and reduce the chance of side effects recurring or worsening. If side effects are becoming harder to cope with, don’t hesitate to speak up.
Should I worry if I don’t have any side effects during or after IVF?
Not at all. It’s completely normal to wonder if something’s wrong when you don’t feel much during IVF — especially when so many people talk about bloating, mood swings, or other intense symptoms. But a lack of side effects doesn’t mean the treatment isn’t working.
Everyone’s body responds differently to IVF medication. Some people are more sensitive to hormonal changes and feel everything, while others go through a cycle with hardly any noticeable symptoms. Neither experience is more “correct” — and neither can predict your outcome.
There’s no proven link between how many side effects you have and whether the treatment will be successful. Many people have minimal side effects and still go on to get a positive pregnancy test. Others experience every symptom in the book and still don’t get the result they hoped for. Every body is different.
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