Mother and Baby

Chemical pregnancy: Symptoms, signs, information and support

Section: Pregnancy
Chemical pregnancy

A chemical pregnancy, also known as biochemical pregnancy, is defined as a very early miscarriage that happens before 5 weeks pregnant.

What happens during a chemical pregnancy?

After conception takes place following ovulation, the embryo implants in the womb as normal.

As these miscarriages are early on in a pregnancy and occur before anything can be seen in the womb during an ultrasound, the only evidence confirming the pregnancy is from a positive home pregnancy test or blood test.

It has been reported that in cases where a woman has a positive blood test of pregnancy test, but then starts bleeding soon afterwards, more blood tests may be taken.

These further blood tests can determine if a woman's pregnancy hormones are decreasing, which will most probably mean the woman is experiencing a chemical pregnancy. 

How common is it?

Most miscarriages happen in the first 12 weeks, with one study showing that once a pregnancy gets past 6/7 weeks and has a heartbeat, the risk of miscarriage drops to around 10 per cent.

Miscarriages are more common than most people realise and it's estimated that 1 in 8 pregnancies end in miscarriage. During the first 0-6 weeks age can play a factor in an early pregnancy loss with another study showing that women aged 35-39 have a 75 per cent risk and women aged 40+ are 5 times that risk.

The symptoms

  • Light spotting or heavier bleeding with or without cramps
  • Clots 

According to the NHS, during the first 12 weeks of pregnancy vaginal bleeding can be a sign of miscarriage or ectopic pregnancy, so it is also best if you have any concerns to speak with your GP or midwife. 

How long does the bleeding last?

The type of bleeding you may experience completely depends, as it's different for everyone. It could last for a couple of hours, or you could experience bleeding for up to a week. 

Causes of a chemical pregnancy

Chemical pregnancies occur when the egg becomes fertilised but the implantation hasn't been completed. Tommys, who has plenty of support for women going through baby loss, states that 'chemical pregnancies happen because of chromosomal abnormalities with baby developing'. 

Other causes can be:

  • Infections including chlamydia or syphilis
  • Implantation outside the uterus - ectopic pregnancy 
  • Uterine abnormalities
  • Untreated thyroid disease
  • Abnormality in hormone levels
  • Thin uterine lining
  • Being over the age of 35 also increases the risk of a chemical pregnancy

Treatment for a chemical pregnancy

Most women don't know they've had this type of miscarriage as it can often be mistaken as a late period. And while this type of miscarriage means you will recover quickly and in a more natural way, your GP can help advise you if you're thinking about trying to conceive in the future. If you are thinking about trying to conceive soon after an early miscarriage, the GP may also recommend that you wait before trying again, until after your next period.

Miscarrage at any stage can be difficult and if you are in need of support please reach out to your GP or midwife. You can also contact a Tommy's midwife for free here, by calling 0800 0147 800 or email

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While training as a journalist at the University of Gloucestershire for 3 years, she was nominated for the Best Feature Category at the Midlands Student’s Media Awards this year, and Head of News and Social Media for the university’s radio station, Tone Radio. Ellie has been published by the likes of Heatworld, Heart, Gloucestershire Live, and ITV West Country. 

Other contributors

Maria Martin - Digital Group Editor - Mother&Baby and Yours

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