Also known as a very early miscarriage, chemical pregnancies often happen without any visible signs or symptoms.

Many people will know what a spontaneous miscarriage a pregnancy loss within the first 20 weeks. However, many would not be familiar with chemical pregnancies, even though these are believed to account for 50 to 70 per cent of all miscarriages.

“A chemical pregnancy may be defined as an early pregnancy loss, usually within the first few weeks of conception,” explains Dr Christopher Ng, a gynaecologist and obstetrician at GynaeMD Women's & Rejuvenation Clinic. “It usually happens because of implantation failure.”

He adds that it is referred to as “chemical” because a urine pregnancy test and pregnancy hormone test (Beta HCG) would be positive at this stage, given that HCG levels are elevated enough. “However, the gestation sac (pregnancy sac) would not be reflected on the ultrasound scan as it is too early.”

Since the baby is lost at such an early stage, how would you actually know if you’ve experienced a chemical pregnancy? Dr Ng lists essential facts to know about such miscarriages.

1. You may not know that you have conceived

Dr Ng notes, “Most women don’t even realise that they have conceived or had a very early miscarriage, especially if they have not done a urine pregnancy test.”

A chemical pregnancy doesn’t have a definitive time frame as the clearest indication is a positive urine pregnancy test, which then becomes negative shortly after. 

“It is officially diagnosed with a positive urine pregnancy test and ultrasound scan (which doesn't reveal the presence of an intrauterine gestational sac). We would then observe HCG hormone levels decreasing over a few days,” Dr Ng elaborates.

A chemical pregnancy may be defined as an early pregnancy loss, usually within the first few weeks of conception. It usually happens because of implantation failure.”

2. Symptoms vary from woman to woman

The signs of a chemical pregnancy may vary. Some women have no pregnancy symptoms at all, and have no awareness of their miscarriage unless they have had a previous positive urine pregnancy test.

“For others, they may experience a delayed menses,” Dr Ng observes. “And when it comes, it may be heavier than usual and often accompanied with menstrual pain.”

Other possible symptoms include mild pelvic cramping, abdominal cramping, vaginal bleeding or mild spotting a week before an expected menses.

However, mild spotting or bleeding after a positive pregnancy result doesn’t always indicate a chemical pregnancy. It may in fact be implantation bleeding, bleeding that occurs between six and 12 days after conception. In contrast to chemical pregnancies, implantation bleeding is usually the first sign of pregnancy ― it happens when a fertilised egg attaches to the interior lining of the uterus.

3. Chromosomal abnormalities are a common cause

“The causes of chemical pregnancies are similar to that of spontaneous miscarriages, with chromosomal abnormalities and other unexplained factors being the cause in most cases,” Dr Ng says.

Chromosomal irregularities occur when there are too many or not enough chromosomes. This may give rise to the improper implantation and development of an embryo.  Unfortunately, it’s hard to identify who exactly is at risk of developing chromosomal abnormalities as these often occur randomly and can affect anyone.

Risk factors such as advanced maternal age (being 35 or older), uterine fibroids or undiagnosed medical issues like thyroid or blood-clotting disorders may also increase the likelihood of chemical pregnancies. 

 

4. It’s hard to pinpoint percentages

Dr Ng notes that it’s difficult to indicate accurately what percentage of pregnancies are chemical as many cases are unreported, since most women are unaware it’s happened to them.

He adds, “Having said that, the risk of a spontaneous miscarriage happening is one in four to six pregnancies, so the percentage of chemical pregnancies would probably be higher.”

Just as in spontaneous miscarriages, a chemical pregnancy may also recur, he points out. This is especially so if the main cause of the chemical pregnancy has not been detected or treated. 

5. Prevention: A healthy lifestyle is important

To avoid losing your baby, the same advice applies for both spontaneous miscarriages and chemical pregnancies, Dr Ng notes.

He recommends that women who plan to conceive continue adopting a healthy lifestyle. This includes regular exercise, maintaining a well-balanced diet, avoid smoking and alcohol, consuming preconception folic acid and multivitamins and making efforts to reduce stress.

Some may also have heard about the benefits of taking a low-dose aspirin in prevent miscarriage. Aspirin is thought to reduce the likelihood of blood clots as these potentially restrict the flow of nutrients to a developing baby.

However, Dr Ng advises that women exercise caution with aspirin. “Whether a low-dose aspirin has a role in preventing a chemical pregnancy is debatable,” he notes. “It has only shown to be beneficial to women with recurrent spontaneous miscarriages (three miscarriages in a row) due to antiphospholipid syndrome.”

He recommends that women who plan to conceive continue adopting a healthy lifestyle. This includes regular exercise, maintaining a well-balanced diet, avoid smoking and alcohol, consuming preconception folic acid and multivitamins and making efforts to reduce stress.

6. Some women will be more emotionally affected than others

“For the majority of women who have experienced a chemical pregnancy, they generally take it in their stride and are less emotionally affected,” Dr Ng observes. “This is because it happens so early that the pregnancy cannot even be seen on an ultrasound scan.”

But for women who have had high hopes of starting a family, early miscarriages are no less painful than late ones. The difficulty in identifying a chemical pregnancy’s exact cause makes the loss even harder to accept. 

Women who have been trying to conceive either via through intercourse or artificially assisted techniques (SO-IUI or IVF) will understandably need more time to recover, and may need more emotional support and counselling,” Dr Ng acknowledges.

7. Women should take heart even after the loss

“Physically speaking, most women recover quickly after a chemical pregnancy as it happens so early,” Dr Ng notes. “Fertility should return shortly after as well.”

Also, suffering a chemical pregnancy won’t increase your risk of having another in the future. So, take heart and don’t be discouraged!

“The good news is that most women who have suffered such a loss go on to have successful pregnancies, just by heeding precautions and advice like maintaining a healthy lifestyle,” reassures Dr Ng.

Photos: iStock

Like us on Facebook and check SmartParents regularly for the latest reads!

Check out these stories, too…

What does your period blood tell you about your health [Photo Gallery]

EXPERT ADVICE: When should I try for a rainbow baby?

What to eat for a healthy pregnancy