Pregnancy may, at times, be difficult to attain for some couples. In such scenarios, couples may consider IVF and also hear of the term chemical pregnancy. It may lead you to wonder about the differences between a chemical pregnancy and IVF.
Those couples with concerns about infertility can go for in vitro fertilization (IVF) and intrauterine insemination (IUI), two medically approved techniques that assist in artificial conception. However, chemical pregnancy after IVF and IUI is common. A positive pregnancy test can be an instant source of joy in most families. Unfortunately, many couples suffer from infertility issues that compel them to resort to medical assistance to fulfill their dream of having a baby.
These processes are often tedious and involve an array of diagnostic tests, different hormonal medications, or surgical interventions. However, in the end, these medical techniques may not be a fool-proof solution to a successful pregnancy and come with their own share of adversities. One such phenomenon is referred to as “Chemical Pregnancy.” Continue reading this post as we tell you in detail about this condition, what may cause it, the diagnosis and how it can be prevented.
What Is IVF?
Before we tell you about chemical pregnancy, let’s understand IVF a little better.
IVF or In Vitro Fertilization is the process involving hormone therapy, which encourages the development of numerous eggs in a woman’s ovaries.
These eggs are then collected and fertilized in a test tube using healthy sperm received from a man. These fertilized eggs make embryos that are allowed to grow for 2-5 days. The most vigorous of these embryos are transferred to the uterus. Pregnancy typically begins when these embryos nestle nicely in the uterus (implantation) (1).
What Is A Chemical Pregnancy?
Now that you know, in brief, what IVF is, let’s move on to a chemical pregnancy. What exactly is a chemical pregnancy? How is it different from a miscarriage?
A chemical pregnancy is a practical name given to a pregnancy loss. Here’s a brief account of what a chemical pregnancy entails (2):
- A chemical pregnancy is an early miscarriage, a rather early miscarriage. In fact, more women than you can imagine have a chemical pregnancy but don’t even know about it.
- It usually occurs around the time or a little after your period is due. That is when you are technically four to five weeks pregnant.
- A chemical pregnancy implies that your body did make the hCG hormone, a sure shot indicator of pregnancy.
- Most women experience their periods within days of a positive pregnancy test when they have a chemical pregnancy.
- A chemical pregnancy usually does not have differentiating symptoms. It feels like a period that came a little late.
Women who suffer from infertility, especially those undergoing IVF, experience a chemical pregnancy more often than others. Women who conceive naturally, in most cases, treat a chemical pregnancy as a late period because they have no clue they were even pregnant in the first place! On the other hand, women using artificial reproductive techniques like IUI and IVF, test (whether HPT or a blood test) a maximum of 14 days after transfer, which allows them to realize an early pregnancy.
Chemical Pregnancy And IVF – Causes
Many women experience chemical pregnancy while undergoing IVF. Here are the major causes of a chemical pregnancy after IVF:
1. Embryo Abnormalities:
The biggest cause of a chemical pregnancy and miscarriage is embryo abnormality. What exactly does embryo abnormality mean? Well, a normal embryo consists of many chromosomes. But an abnormal embryo contains a disproportionate number of chromosomes. Other factors that can cause the growth of abnormal embryos include structural, chromosomal, epigenetic, and metabolic factors. Older women and women with PCOS (polycystic ovarian syndrome) are more likely to experience embryo abnormalities during IVF too (3).
2. Implantation Dysfunction:
Several chemical pregnancies occur due to implantation issues. Some of the causes of implantation dysfunction include (4)
- Endometrial polyps
- Surgical scarring
- Advanced maternal age
3. Autoimmune Issues:
Sometimes, a woman’s immune cells are wired in such a way that they attack a growing embryo instead of nurturing it. This happens because the immune system is unable to differentiate between embryo cells and disease-causing cells (5).
4. Other Issues:
Other causes of chemical pregnancy can include (2):
- Infections (especially sexually transmitted infections)
- Thyroid issues
- Abnormal hormone levels
- Unbalanced embryo chromosomal translocations
Testing To Avoid A Chemical Pregnancy
If you are experiencing repeated chemical pregnancies, it may be time to dig a little deeper.
Some tests that can help unearth the real cause of repeated chemical pregnancies are:
1. Sonohysterogram, Hysteroscopy Or A Pelvic MRI:
Any of these tests can help evaluate the condition of your uterus and pinpoint any abnormalities. It makes sense to undergo these tests before you embark on IVF so that you can avoid chemical pregnancies and early pregnancy losses (6).
2. Ultrasound Scan:
An ultrasound scan determines the thickness of your endometrial wall lining. If your lining measures less than 8mm, it makes sense to wait till it is thicker before embryo transfer.
3. Natural Killer Cell aActivity (NKa) Test:
This primary immune test can help your doctor to find out if it is your immune system that is causing the chemical pregnancies.
4. Blood Tests:
If you are undergoing IVF, the chances are high that you would have undergone a plethora of blood tests already. But something may have changed in your body since your last series of tests. So, it is better to take new tests to learn more about your recurring chemical pregnancies.
5. Molecular And Biochemical Testing:
Your doctor can also check the molecular and biochemical factors in your endometrium. These tests can help discover your chances of implantations.
6. Chromosome Testing:
Thanks to the development of medical science, your doctor can now choose the healthiest embryo to transfer! Tests like using Comparative Genomic Hybridization (CGH) can help identify chromosomally healthy and normal embryos (7).
IVF And Chemical Pregnancy – Prevention
Once the exact cause is clear, your doctor can go on to treat the condition. Some of the treatment options for recurrent chemical pregnancies are:
2. Baby Aspirin:
Baby Aspirin acts as a blood thinner and can help prevent chemical pregnancy in certain women (9).
If an infection is causing you to lose your pregnancies, a course of antibiotics can do the trick.
As mentioned above, abnormalities in the uterus can in many cases cause chemical pregnancies. In such a case, your doctor may prescribe surgery to fix the problem.
Frequently Asked Questions
1. When does a chemical pregnancy happen in IVF?
Chemical pregnancy may happen anytime after IVF, and the elapsed time may vary case-to-case basis. Speak to your doctor to understand the phase when you may be at a high risk of experiencing a chemical pregnancy after an IVF (10).
2. What causes early miscarriage in IVF?
Advanced maternal age and atypical uterus shape may increase the risk for early miscarriage followed by IVF. Thyroid disorders, polycystic ovarian syndrome (PCOS), diabetes, sexually transmitted infection (STI), and high or low hormone levels are some other risk factors (10).
Chemical pregnancy and IVF are common concerns for anyone undergoing assisted reproductive technologies to conceive. Chemical pregnancy indicates an early miscarriage where a positive hormone test is the only evidence. Usually, the chemical pregnancy is detected after IVF since the early hormone tests are conducted to determine the procedure’s success. Ultrasound imaging and other tests can be normal. Early pregnancy loss can be like a normal period, and often there can be a slight delay, such as one or two days. Abnormalities of the embryo, issues in the procedure, infections, hormonal issues, and autoimmunity can cause chemical pregnancy. It may go unnoticed, and the hormone levels can be normal while the time most seek testing.
Infographic: What You Should Know About A Chemical Pregnancy?
A chemical pregnancy is early pregnancy loss that occurs even before a woman knows she is pregnant. It is not possible to prevent chemical pregnancy in most cases when the causes are not known. Go through the infographic to learn more facts about a chemical pregnancy.
- Chemical Pregnancy: Here Are The Facts.
- In Vitro Fertilization (IVF).
- Recurrent pregnancy loss.
- Assessment and treatment of repeated implantation failure (RIF).
- Types of autoimmune diseases in pregnancy.
- Chromosome Analysis Test.
- Arri Coomarasamy et al.; (2020); Progesterone to prevent miscarriage in women with early pregnancy bleeding: the PRISM RCT.
- Anticoagulant drugs for the prevention of recurrent miscarriage in women with antiphospholipid antibodies.
- Chemical Pregnancy.
- Miscarriage – Prenatal Genetics.
- John Jude Kweku Annan et al.; (2013); Biochemical Pregnancy During Assisted Conception: A Little Bit Pregnant.