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  • Writer's pictureDr Katie Psarou

IVF Weight Gain: What’s normal and how to control it?

Updated: Jul 3

Are you on your IVF journey and worried about unexpected weight gain and the impact on your body? 

Have you already experienced weight gain after IVF and now want to lose it? 

As a Fertility Dietitian with over 20 years of experience, I'm here to guide you through the nuances of weight changes during IVF. 

In this blog, we'll explore the reasons behind IVF-related weight gain, how to manage it, and empower you to have a better experience in this process and increase the chance of IVF success.

Let’s get right into it

IVF injections and timer referring to ivf weight gain

Table of Contents

Does IVF cause weight gain?

IVF can cause weight gain but not all women will experience weight gain. In fact, some women will lose weight in this process. If you are going through IVF or ovulation induction, you will know that tracking body weight is not part of the treatment plan. Unless of course you intentionally record your weight to explore the impact on your body. For this reason, there is limited research that gives sufficient information about what’s going on in a woman’s body during an IVF cycle.

How much weight gain to expect during an IVF cycle?

Studies showed that between the start of ovarian stimulation to trigger day shot with human Chorionic Gonadotropin (hCG) the average weight gain is 0.38kg (0.8lbs). Yet, this can vary between a weight loss of 0.3kg (0.6lbs) to weight gain of 1.1kg (2.4lbs). Some women can temporarily gain around 6-7kg (13-15lbs) in weight from the start to egg retrieval. 

The weight gain in most cases is not permanent and the body weight returns to its pre-treatment stage, when the treatment finishes. It's maybe the reason why you may feel like you’re losing weight after an embryo transfer. Although some women may retain that weight gain after their IVF cycle. (More on that later.) 

If you’re experiencing weight gain and you’re undergoing more than one ovarian stimulation cycle, then it's likely you will gain more weight with each cycle. If you’re not experiencing any weight gain, then it's unlikely that you will gain weight with subsequent cycles. 

Women who undergo more than 1 IVF cycle (within 4 months) can gain on average 3.6kg (7.9lbs) in weight during treatment and between cycles, while others can lose on average 2.9kg (6.4lbs). 

Rear view of woman with arms raised at beach during sunset. Ready to take control of fertility and body weight

Does IVF increase belly fat?

It is not clear if the weight gain after a whole IVF cycle is pure fat. Research is currently limited as to how body composition changes after IVF, that is whether your body fat levels change. Some women report a noticeable change in their body fat % following IVF, even if their body weight hasn’t changed. But it’s unlikely that the weight gain between ovarian stimulation and egg retrieval is body fat, because most often you will return to your pre-treatment weight. 

Is it bad to gain weight during IVF?

Limited research suggests that weight gain during ovarian stimulation may be beneficial. This means weight gain can indicate an increase in the number of eggs during egg retrieval and an increase in the fertilisation rate of these eggs. And so, the more eggs you get after an egg retrieval, the more weight you will gain.

The amount of weight you gain may depend on how many eggs you get after egg retrieval. 

woman measuring waist with tape refering to causes of ivf weight gain

What causes weight gain during IVF?

It can be hard to see your body change so much when you’re going through IVF. There are many potential reasons for gaining weight, even if you don't eat more than usual. The reasons include: 

1. Physiological and Hormonal Factors


Current evidence suggests that all medicines (Clomiphene, Letrozole, Gonadotropins) may cause some weight gain due to the hormonal interactions with hormones like oestradiol and progesterone. This means that fertility drugs can change metabolic or hormonal pathways which cause weight gain. 

In a typical menstrual cycle we know that progesterone increases appetite and food cravings following ovulation and, so the IVF drugs following ovarian stimulation may induce progesterone and oestrogen at higher levels than during a menstrual cycle. So, it’s very common to feel that you are more hungry than usual when you’re taking hormonal drugs. 

For some women they feel more nauseous or lose their appetite while taking fertility drugs. So your body naturally will make you want to choose foods that provide high energy, like foods high in fat and carbohydrates. 

If you’re starting an IVF cycle with a higher total dose of IVF drugs than your previous cycle, this does not guarantee weight gain but may guarantee a weight change. A study showed that women who start with higher doses of IVF drugs, have experienced either weight gain or weight loss during their cycles. 

Fluid retention / Ovarian Hyperstimulation Syndrome (OHSS)

Some of the IVF medicines also cause water retention. For many women this weight gain which is due to fluid retention can be mild and your body removes it after your last drug treatment. This type of weight gain is as a result of Ovarian Hyperstimulation Syndrome (OHSS), which can be more extreme (see question below). 

Feeling bloated 

Hormonal medications can slow down food transit in your gut. This can make you feel more bloated, gassy and constipated during IVF stimulation. This experience can show a slight weight gain on the scale, but it goes away eventually.

Hormonal Medical Conditions

Women with conditions like PCOS or underactive thyroid are likely to gain more weight during a controlled ovarian stimulation. This weight gain is in the region of 3kg (6.6lb) or more. 


Women who start the IVF treatment at a higher weight or BMI (Body Mass Index) are also likely to gain more weight during treatment.

2. Environmental and Emotional Factors 

Lower physical activity levels

Many women report uncertainty about what exercise they can do during IVF and naturally significantly reduce the amount of their daily physical activity during treatment. Weight gain due to low or no exercise during IVF may be anecdotal, but perhaps if the level of activity is low and there is increase in appetite, then this can tip the balance on the scale. 


There is some indication that fertility drugs can cause mood swings and psychological distress particularly drugs like gonadotropins. Yet, any kind of physical and mental stress in your body will activate hormonal responses that lead to weight gain around the waistline.

Emotional eating

Weight gain as a result of emotional eating is very common and it depends on your individual coping mechanisms to stress. You can feel emotionally drained and stressed after an egg retrieval or embryo transfer. It is worrying to not know how many eggs were retrieved, how many eggs were fertilised, how many embryos reached day 5 and so on, and whether you need to go through this all over again. So in that tense period of time your stress turns to an emotional eating response. Emotional eating can drive you to gain weight because of the amount and type of foods you are eating during your IVF cycle. 

woman touching her tummy feeling bloated after IVF

When do you need to be alert about too much weight gain? 

If you experienced rapid weight gain after egg retrieval or feel very bloated during IVF stimulation, then it’s likely you experienced Ovarian Hyperstimulation Syndrome (OHSS) as a result of taking IVF medications. 

OHSS is a potentially serious complication following hormonal injections (gonadotropins) to help the ovaries to produce more eggs than normal. If you develop OHSS, then this can be mild to severe and can last from 7 days up to a few weeks. 

You may experience abdominal pain, nausea/ vomiting, thirst and shortness of breath. If you are experiencing any of the symptoms above, you should seek medical help from your GP, fertility clinic or A&E. 

How to avoid weight gain during IVF?

The majority of the weight gained during an ovarian stimulation is due to fluid retention and feeling bloated. So you can expect to lose this weight once the treatment ends. 

But there are simple steps to take for when feeling bloated or if you want to avoid the weight slowly creeping up the scale during stimulation, egg retrieval and embryo transfer. Below you will find a simple guide on how to avoid bloating and weight for each scenario. 

How to avoid bloating during IVF? 

Bloating following ovarian stimulation is common. Here are some helpful tips to manage this, so that you feel like yourself again. 

  • Eat plenty of fibre from fruit, vegetables and wholegrains.

  • If you’re feeling constipated then try to eat 1-2 Kiwi fruits per day.

  • Reduce salt intake in foods and avoid salty foods and snacks to minimise fluid retention.

  • Drink at least 2Lt  of water (and other fluids) per day but avoid carbonated drinks.

  • Avoid sugar alcohols like sorbitol, maltilol, mannitol, xylitol, erythritol, isomalt, polydextrose and hydrogenated starch. Sugar alcohols are not well absorbed in the gut, so eating too much of these can make the bloating worse and may increase fluid retention.

  • If bloating is uncomfortable, incorporate some gentle movement like yoga and walking.

  • If your pants don’t fit, wear loose clothes like yoga pants, stretchy sweatpants/ tracksuit bottoms.

  • Apply a heat pack or massage gently your tummy area.

IVF iinjection on yellow background referring to how to avoid IVF weight gain

How to avoid weight gain after egg retrieval and before fresh embryo transfer?

If you’re overweight, you may be concerned about the impact of IVF injections on your body weight. Even if you are someone who puts on weight easily, now is not the time to start a crash diet. 

Losing weight during or shortly after egg retrieval lowers your egg quality and impacts the outcome of your IVF. Instead, try to do the following to keep the weight off:

  • Eat regular small meals (especially if you are feeling bloated).

  • Pay attention to the types and amounts of food you’re eating. Eat lots of fruit and vegetables (use the rainbow colours as a guide) and limit highly processed foods.

  • Eat mindfully by checking your hunger and fullness cues.

  • Focus on staying hydrated by drinking plenty of fluids (up to 2 litres).

  • Increase your physical activity levels. Contrary to common belief, women who regularly engage in moderate -intensity exercise during IVF, like brisk walking, dancing, gardening, swimming, tennis and so on, can improve fertility, insulin sensitivity (for those with PCOS or diabetes) and increase chance of implantation and pregnancy. Vigorous activity is more risky for fertility and pregnancy.

  • Manage the stress with some gentle movement like yoga and breathing exercises so that you don’t overeat, even if you’re not an emotional eater.  

woman's feet on a weight scale referring to how to lose IVF weight gain

How to lose the “IVF weight gain” after IVF (and before the next cycle)?

A lot of women will undergo more than one cycle of IVF. The time frame between one IVF cycle to the next cycle depends on the individual’s circumstances. As discussed above, most women will gain weight (not fluid) after egg retrieval and before IVF transfer. They may also gain weight after each subsequent cycle. 

If you have experienced weight gain after an unsuccessful IVF and you’re preparing your body for another cycle (ovulation induction or frozen embryo transfer), then there are some key areas to look at, so that you can lose the weight you gained: 

  • Understand the evidence of weight loss and IVF success.

  • Prioritise making small changes to your eating patterns and eating habits so that you lose weight in a sustainable way. If you’re uncertain where to start, then consult an expert fertility weight loss dietitian.

  • Explore if there are any medical underlying issues that caused the weight gain. Blood tests for fertility may be the first step to take. This would help to manage or prevent further weight gain in your future IVF cycle or embryo transfer. 

  • Explore and manage your relationship with food, especially if you’re someone who turns to food for comfort. Going through IVF is such a rollercoaster that leaves you mentally and physically drained. So take some time to identify what’s triggering you and how to cope with the uncertainty of undergoing IVF.

booklets for sustainable weight loss stratgies for fertility to download

How to manage weight, now you’re pregnant after IVF?

If you have just gone through a successful IVF and you're starting off your pregnancy at a higher weight than the weight before your IVF cycle, it can feel really hard.

You can use your pregnancy as an opportunity to change your lifestyle, eat balanced meals and get the nutrients you and your baby need, so you can support your body and grow a healthy baby.

Do you want my expert guidance during your pregnancy to gain a healthy weight and feel certain that you are doing the best you can for you and your baby?

Check out the Healthy Weight Gain in Pregnancy programme and take the first step towards a healthier you.

Dr Katie Psarou, Fertility and Maternal Dietitian

Dr Katie Psarou, PhD, MSc, BSc (Hons) RD MBDA

UK Registered Fertility and Maternal Health Dietitian

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