Chemical pregnancy

A chemical pregnancy is when a pregnancy sadly ends in miscarriage before five weeks of pregnancy.  

On this page

What is a chemical pregnancy?

Signs of a chemical pregnancy

What causes a chemical pregnancy?

Treatment for chemical pregnancy

Chemical pregnancy and fertility treatment

Support for you

What is a chemical pregnancy?

A chemical pregnancy (sometimes called a biochemical pregnancy) is a very early miscarriage that usually happens around 5 weeks. A pregnancy test detects an increase in pregnancy hormones, but the embryo is lost before it can be seen on an ultrasound scan. It is different to a ‘clinical’ pregnancy which is one that can be seen on an ultrasound scan. It can still be very hard to cope with.

Signs of a chemical pregnancy

You may not even realise you have had a chemical pregnancy if you do not miss a period or take a pregnancy test.

Now home pregnancy tests can detect pregnancy hormones before your period is due, you may be more aware of a chemical pregnancy or very early loss. If your hormone levels are being monitored as part of fertility treatment, you may see them rise and then decrease again.

Signs of a chemical pregnancy might include:

  • A positive pregnancy test at first, but then a negative one soon after.
  • Mild cramping.
  • A bleed like a period even after a positive pregnancy test.
  • Low, or decreasing levels of pregnancy hormone (hCG) on a blood test.

What causes a chemical pregnancy?

Chemical pregnancies are likely to be caused by problems with chromosomes. Chromosomes are blocks of DNA, which contain instructions for your baby’s development.

If your baby’s embryo has the wrong number of chromosomes, it can’t develop, and the pregnancy ends almost immediately. Some chemical pregnancies may happen because the lining of the womb has not developed in the right way at the right time. If this happens, an embryo cannot embed properly.

You can see more about causes and risk factors for miscarriage here.

Tommy’s is conducting research into the causes of miscarriage. You can see more about this research here:

Treatment for a chemical pregnancy

You do not need treatment for a chemical pregnancy.

Even if you’ve had a positive pregnancy test, the bleed will probably be similar to a normal period. You may also have stomach cramps.

You can try again for a baby straight away if you want to, but your doctor will usually recommend waiting until after your next period. This is to avoid uncertainty about dates and the size of any future pregnancies. Some people may not be worried about this. If you have had miscarriages in the past, you may find uncertainty around early scans harder to deal with.

Find out more about trying again after a miscarriage.

Chemical pregnancy and fertility treatment

If you have been going through fertility treatment and have a chemical pregnancy, it can feel very upsetting. It may help to know that women and birthing people who have an early pregnancy loss after IVF are more likely to have successful IVF cycle in the future when compared with patients who did not conceive at all.

Support for you

It can be hard to recover from a miscarriage. No matter when in your pregnancy you lose your baby, you may need support to help you come to terms with what’s happened. Tommy’s is here to help you. You can talk to a Tommy’s midwife for free, Monday-Friday, 9am-5pm. You can call them on 0800 0147 800 or email [email protected] 

Annan JJ, Gudi A, Bhide P, Shah A, Homburg R. (2013). ‘Biochemical pregnancy during assisted conception: a little bit pregnant’. J Clin Med Res. 2013 Aug;5(4):269-74. doi: 10.4021/jocmr1008w. Epub 2013 Jun 21. PMID: 23864915; PMCID: PMC3712881. 

Dickey RP, Olar TT, Taylor SN, Curole DN, Harrigill K. (1993). ‘Relationship of biochemical pregnancy to pre-ovulatory endometrial thickness and pattern in patients undergoing ovulation induction’. Hum Reprod. 1993 Feb;8(2):327-30. doi: 10.1093/oxfordjournals.humrep.a138045. PMID: 8473442. 

Bates GW Jr, Ginsburg ES. ‘Early pregnancy loss in in vitro fertilization (IVF) is a positive predictor of subsequent IVF success’. Fertil Steril. 2002 Feb;77(2):337-41. doi: 10.1016/s0015-0282(01)02988-0. PMID: 11821093.

Miscarriage Association (nd) Chemical pregnancy. Available at (Accessed 23 January 2024) 

Review dates
Reviewed: 14 February 2024
Next review: 14 February 2027