What is a Chemical Pregnancy?

A chemical pregnancy is when you have got a positive pregnancy test at home but as soon you visit your obstetrician for confirmation, your sonography shows no sign of pregnancy.

Yes, it does sound a bit baffling at first, but once you try to understand it, the reason is pretty simple. Pregnancy can be confirmed using sonography earliest by the 5th week of gestation and if there is a spontaneous abortion (miscarriage) before that, it leads to what is known as a chemical pregnancy.

What are the signs of a chemical pregnancy?

Chemical pregnancy presents like any other miscarriage occurring at a later period. There is light to moderate bleeding, somewhat resembling a menstrual bleeding. It can also be accompanied by lower abdominal cramps of moderate severity.

If someone takes a pregnancy test following such a bleeding, it will yield negative result. Further, if a woman is not aware of her pregnancy, she may take this bleeding as any other menstrual period, and will remain oblivious of the whole scenario.

How can you differentiate between implantation bleeding and chemical pregnancy?

Implantation bleeding is light bleeding or spotting in the early months of pregnancy. This just another symptom of pregnancy and no harm is done to the growing fetus.

While implantation bleeding strictly coincides with expected date of periods, bleeding due to chemical pregnancy can occur anytime. In the latter condition, bleeding is darker and heavier. A sonography can help to distinguish more correctly.

What can be the cause behind it?

Genetic anomalies of the developing fetus are accountable for more than 50% of miscarriages taking place within first 12 weeks of pregnancy (first trimester). Most commonly encountered genetic abnormality is the presence of an abnormal number of chromosomes in the fetus, called aneuploidy.

Diabetes, if poorly controlled, may lead to miscarriages. Other hormonal disorders like Polycystic Ovarian Syndrome (PCOS), Luteal Phase Defect (LPD) or thyroid abnormalities (both hypothyroid as well as hyperthyroid states) may lead to the same fate.

If the mother is infected by certain microorganisms, those may get transmitted to the baby inside uterus via the placenta. This process has a fancy name in medical literature – vertical transmission. Rubella is the most common viral infection to cause an early miscarriage. Malaria, chlamydiasis, AIDS are other diseases, which when transmitted vertically, can also end up in a chemical pregnancy.

Wastage of pregnancy can occur if the mother’s blood group is incompatible with that of the fetus. In particular, Rh antigen mismatch can be a reason for late abortions. Male partner having blood type ‘A’ and female partner having type ‘O’ possess a higher risk of experiencing an abortion.

Conception through Assisted Reproductive Technology (ART) also has a high risk of abortion in the early weeks. Careful monitoring and care should be observed to ensure successful progression of that pregnancy. Moreover, presence of contraceptive intrauterine devices (IUDs) inside the uterus may lead to complications for the maintenance of pregnancy.

Finally, habits like smoking, alcohols, exposure to radiations pose threats to the fetus too.

Why was pregnancy test positive?

Pregnancy tests, conducted with your urine or blood as sample relies on the presence of a hormone, Human Chorionic Gonadotropin (hCG). This hormone is responsible for the maintenance of pregnancy for the early few weeks till the placenta (tissue connecting maternal tissue with the growing fetus) is fully developed for transferring the nourishment from mother to the child.

hCG is secreted by the tissues of developing embryo as soon as the fertilized egg gets implanted in the uterus. So a positive pregnancy test can be obtained earliest by 7-10 days following fertilization. Hence, this test can confirm pregnancy even before the symptoms begin to show. Sonography can detect pregnancy only when the woman is already 5 weeks pregnant.

If it’s a case of chemical pregnancy, then miscarriage occurs in between these two events in the timeline. As only testing of chemicals confirmed the pregnancy, it is called chemical pregnancy.

Can you have a normal pregnancy after that?

Chemical pregnancy doesn’t interfere with one’s fertility. You can try to conceive anytime after the miscarriage without waiting for any specific time period. Having said that, you must keep in mind that most early abortions are due to anomalies in the genetic makeup and there may be a recurrence of the mishap. To ensure an uneventful pregnancy, it is always advisable to assess the cause of previous miscarriage before planning another pregnancy.