What is hCG?

by Carolyn Salafia, MD, Ph.D.

Lately, the infertility grapevine has been buzzing with reports of previously infertile women delivering healthy babies thanks to hCG injections. I've received numerous e-mails from infertile women asking, "What is it about hCG that makes the difference?"

hCG is the abbreviation for the hormone "human chorionic gonadotropin." It is secreted by the placenta and causes the fertilized egg to release estrogen and progesterone. Home pregnancy tests screen for it and doctors send pregnant women for weekly blood tests to check that their HCG levels are properly increasing as their pregnancies develop. For infertile women, non-rising hCG levels are often the first marker that something is going wrong with their pregnancies. Yet often, women with perfectly normal hCG levels lose their pregnancies for no documented reason. Some doctors (myself among them) believe that even when hCG levels are normal, problems occur when the molecular structure of the hCG is somehow impaired. This improperly functioning hCG may cause the placenta to develop in such a way that blood flow to the uterus is restricted. This abnormal blood flow results in lost pregnancies.

Since administering hCG to women with abnormal blood flow to the uterus is a cutting edge treatment for pregnancy loss, you may be hard-pressed to convince your doctor that it works. To date, the success of hCG in salvaging pregnancies has not been documented in a clinical study, although various studies are underway. The success rate--which is high in instances where abnormal blood flow to the uterus has been documented--has only been established anecdotally.

My own research has led me to believe strongly in the potential efficacy of hCG. After graduating medical school I worked for twelve years at a hospital trying to understand why low-risk pregnancies went wrong. I found that the single most common problem in people with no clinical "good reason" for a complicated pregnancy (such as a chromosomally abnormal fetus or a documented progesterone defect) was an abnormality in how the maternal blood vessels were able to carry blood, nutrients and oxygen to the placenta. Before this time, the only proposed causes of most serious pregnancy complications were infection as well as preeclampsia/toxemia. Our pioneering work showed that many women who never were toxemic had the same blood flow problems as toxemic women. The idea that preeclampsia anatomy could be present--and cause problems like fetal loss, preterm birth and growth restriction--in women who had normal blood pressure changed the obstetric world view of maternal blood vessels.

As my career progressed, I moved to the National Institutes of Health; to Montefiore Medical Center; and then to Columbia University where I was a professor of pathology and pediatrics. As my research continued, it became clear to me that the knee-jerk treatment for blood vessel problems--giving a woman the blood thinner heparin--was not a cure-all. In short, heparin did not correct blood flow abnormalities in some of the women and their pregnancies failed.

Looking for answers on how to make their pregnancies succeed, I delved deeply into the literature on cardiology. Unlike the obstetrical field--where examining blood vessel function is still considered cutting edge--in cardiology researchers have been examining how blood vessels function for decades. Cardiologists have found that heparin treats problems with veins very well but is much less effective in treating problems with arteries. I then began researching possible non-toxic treatments for arterial vascular dysfunction in pregnancy. Since many drugs are risky in pregnancy, we kept examining what treatment we could administer to the mother that would not pose a risk to the baby.

Then, in 1997 researchers at the University of Louisville established that hCG has a direct relaxing effect on uterine arteries. After speaking with the Louisville researchers, and taking the clinical protocol currently in use in Europe, I began recommending to a number of pregnancy loss specialists that they select patients for this new treatment based on my identification of "bad blood vessels" on the patients' miscarried tissues. To date, because of my colleagues' recommendation for hCG treatments, almost 100 women whose abnormal blood flow was corrected have delivered healthy babies and many more women are currently pregnant.

In order to bring the treatment to more women we need to develop a better understanding of how the hCG treatment works. I am continuing to research the role hCG plays in preventing recurrent early pregnancy loss. Without this research the success of hCG will remain only anecdotal and, therefore, many physicians will therefore not prescribe it for their patients.

Carolyn Salafia, M.D., Ph.D., is board certified in Anatomic and Clinical Pathology and in Pediatric Pathology.

 Note: This communication is for educational purposes only and should not be used as a substitute for a consultation with your physician.