Baby Aspirin for IVF and Pregnancy: Secret Pill or False Hope?

Can baby aspirin help you get pregnant or prevent a miscarriage – when trying naturally or via IVF? Sometimes, yes, But the medical evidence is clear: not always. 

Baby aspirin can reduce the risk of pre-eclampsia. It’s sometimes prescribed alongside Clexane to guard against negative outcomes associated with antiphospholipid syndrome. But as a routine IVF add-on, or as a general implantation booster? Few studies endorse it.   

So, should you use baby aspirin when trying to conceive? Only your doctor or clinic can tell you. Don’t just head to your pharmacy and buy the pills over the counter (which is very easy to do). They’re not vitamins. Don’t self-prescribe.

What is baby aspirin?

Baby aspirin is the same as low-dose aspirin. However, it’s not aspirin for babies. It refers to the smaller dosage per pill than standard aspirin.    

In the UK, baby aspirin is mainly available as 75-mg pills – much lower than the 300-mg ones taken for pain relief and other aspirin-friendly  symptoms. Your doctor or clinic may prescribe one baby aspirin pill dally, or perhaps two, but there needs to be a good medical reason to take it.           

Aspirin reduces the activity of platelets – the blood cells involved in clotting. At low doses, it may improve placental blood flow and reduce the risk of any abnormal placental development. IVF patients, with a close eye on successful treatment, have always been interested in it.

Assuming they’re right for you, the dose matters. High-dose aspirin (the 300-mg pills) is generally not recommended during pregnancy. However, the NHS advises taking baby aspirin in pregnancy only when medically approved. Caution is key. 

Can baby aspirin improve IVF success?

The theory is reasonable: reduce clots, improve blood flow to the uterus, boost embryo implantation. But, as discussed, a reality check is needed. Let’s look at two specific studies.    

A 2017 review into low dose aspirin and IVF/ICSI did see an improvement in clinical pregnancy rates for ICSI patients who took 100 mg of low-dose aspirin daily. The study reassessed 13 earlier studies, which followed over 3,000 fertility patients.

But, disappointingly, there was no significant improvement in implantation rates or live birth rates. Nor a decline in the miscarriage rate. The conclusion? Larger trials were needed to assess if baby aspirin really helps with IVF or not.           

A later study from 2021 looked at aspirin’s effect on endometrial preparation during IVF. It reported higher live birth rates. But, by their own admission, the researchers said further studies were needed. Most clinics aren’t thinking about baby aspirin and womb-lining formation anyway.               

Here’s the lowdown. Routine use of baby aspirin isn’t proven to boost IVF live birth rates. Rather like Prednisolone, baby aspirin sits in the “maybe” category of IVF extras. Only your clinic can decide if the rewards of adding it to your protocol outweigh the risks.         

Does baby aspirin help with frozen embryo transfers?

Low-dose aspirin is sometimes added to frozen embryo transfer protocols. Usually, the patient might have had a previously unsuccessful fresh cycle using donor eggs or their own. The baby aspirin is therefore a “tweak” to their medication.        

The research on low-dose aspirin and FETs is inconclusive. Some studies show better pregnancy outcomes; others see no benefit. A randomised trial in 2020 into low-dose aspirin during  FETs found that baby aspirin didn’t boost implantation or clinical pregnancy rates. (It was a small trial: only 128 women too part.)

This aligns with a major Cochrane review into aspirin and assisted reproduction from 2016. It found no evidence that aspirin improves IVF pregnancy rates. The key phrase it used was “the general IVF population”. That keeps the door open for specific cases. 

If your FET protocol includes baby aspirin, ask your clinic which risk factors it‘s addressing. Be wary of vague answers.    

Can baby aspirin prevent miscarriage?

Some studies suggest baby aspirin can improve pregnancy rates for patients with a miscarriage history. An interesting study into low-dose aspirin and miscarriage found that taking baby aspirin before conception and in early pregnancy could boost pregnancy rates for women who had or two miscarriages previously. However, that study didn’t focus on IVF patients.                   

Looking at the ESHRE guidance on recurrent pregnancy loss, low-dose aspirin can be added to IVF treatment plans for some blood disorders. But not routinely for miscarriage patients. We see a similar approach in the ASRM’s view on recurrent pregnancy loss: baby aspirin (and/or Clexane) for APS patients and other specific blood disorders may be acceptable.

But previous miscarriages on their own aren’t a good enough reason to take baby aspirin. 

Does baby aspirin help with Factor V Leiden and thrombophilia?

Thrombophilic conditions, including Factor V Leiden, are not the same as antiphospholipid syndrome (APS). Can baby aspirin help here?        

Although Factor V Leiden, an inherited genetic condition, can increase the blood-clot risk, medical evidence doesn’t support routine use of baby aspirin (with or without a stronger blood thinner, like Clexane) to improve pregnancy rates.

A study of aspirin and the Factor V mutation, looking specifically at recurrent pregnancy loss, failed to see any effectiveness in prescribing baby aspirin to Factor V Leiden patients. But the use of Clexane (or LMWH) did see the pre-eclampsia rate drop. Read on.            

Baby aspirin and pre-eclampsia

Many fertility patients worry about pre-eclampsia. It’s generally accepted that donor-egg recipients have a higher chance of getting it. And for frozen embryo transfers, whether using own eggs or donor eggs, there’s a pre-eclampsia risk too. So, the case for baby aspirin is stronger here.

Pre-eclampsia is a serious pregnancy issue, characterised by high blood pressure and, often, early delivery. Pregnancy monitoring is therefore important – particularly for fertility patients.    

In the UK, NICE recommends 75 mg to 150 mg of aspirin daily from 12 weeks until birth for pregnant women with a risk factor for pre-eclampsia.

Those factors include:

• Previous hypertensive disease during pregnancy
• Chronic kidney disease
• Autoimmune disease (including APS)
• Type 1 or type 2 diabetes
• Chronic hypertension
• A BMI of 35 or higher

For fertility patients over 40, the pre-eclampsia risk is also higher. And since many IVF patients are that age, or close to it, clinics should assess the use of baby aspirin carefully. In the US, general IVF is seen as a moderate risk factor for pre-eclampsia and baby aspirin use is often supported.   

So, speak to your doctor or clinic about baby aspirin and whether it’s right for you. The evidence tilts in favour of its use for certain fertility patients. Ask if you’re one of them.          

Aspirin and prednisone: a fertility combination?

Aspirin is sometimes prescribed with prednisone (or prednisolone – a very similar medication) in fertility treatment protocols. The efficacy of this union – a steroid and a mild anticoagulant – is far from clear.

A number of small trials have been done. None are conclusive. One found an increased pregnancy rate in a small number of IVF patients. Another saw no pregnancy bounce, but found the combination might help with OHSS. 

The HFEA – the UK’s fertility watchdog – says there’s a lack of strong evidence to support steroids in fertility cycles. Nor does it show much enthusiasm for baby aspirin, or mixing the two.        

Only your doctor or clinic can tell you if they’re worth trying together. It could be argued that a lack of strong evidence isn’t a deal breaker. Fertility protocols often include preventative medications. If the risks are managed, and the benefits possible, there’s a case for their inclusion in some protocols, even in the absence of large-scale trial endorsements.              

Is baby aspirin safe during pregnancy?

Baby aspirin is widely used during pregnancy and is generally safe to take. But every patient is different. Its usage, pros and cons need to be expertly considered.   

Possible side effects from baby aspirin are indigestion, stomach irritation, allergic reactions and bleeding. Aspirin use may be unwise if you’re intolerant of it, have asthma, stomach ulcers or certain liver or kidney conditions.

Your doctor must assess you carefully. If you’re a fertility patient, ensure you complete the clinic’s pre-treatment questionnaire accurately, stating all previous or current medical conditions.             

In summary: should IVF patients take baby aspirin?

Baby aspirin must be given for a reason. It’s most effective at reducing the risk of pre-eclampsia and for certain blood disorders. 

For routine IVF cycle (fresh or frozen), recurrent implantation failure cases, or for women with a miscarriage history, the evidence for using baby aspirin doesn’t stack up. Baby aspirin is not a go-to pregnancy pill for everyone. Tread carefully.