How likely are you to get pregnant according to these tests?
Couples who face any glitch, even a delay of a few months after beginning the journey “trying to conceive” start exploring reasons and solutions. Advances in reproductive science and infertility treatments have opened floodgates of information on topics relating to conception and pregnancy.
Technically, successful conception involves fertilization of an oocyte (egg) by a sperm followed by implantation of the embryo on the endometrial lining of the uterus. This is one of nature’s most amazing and extremely intricate process orchestrated by a number of hormones in a timely fashion. The physiological and structural status of gametes (oocyte and sperm) is a major determinant for successful conception and issues like sub-optimal sperm morphology, motility and oocyte quality may delay or hinder conception. Women’s ovaries produce a number of follicles (immature oocytes) every menstrual cycle and one or two of these become lead follicles, finally released as mature oocyte. The quality or the reproductive viability of this egg is generally evaluated by hormonal estimations in a blood sample. The key hormonal markers used to predict the egg quality, ovarian reserve and reproductive potential are Follicle-stimulating hormone (FSH), Anti Mullerian Hormone (AMH) and Estradiol.
Follicle Stimulating Hormone (FSH)
FSH is secreted by the pituitary gland and it functions by signalling ovaries for the maturation of the resting follicles. Estradiol released by the developing healthy follicles regulates the production of FSH from the pituitary. Women with a diminished ovarian reserve have fewer healthy follicles and the brain gets tricked to produce higher amounts of FSH in order to boost the development of follicles. The oocytes produced from a diminishing reserve are generally not of good quality with morphological and chromosomal aberrations. Day 2 or 3 (of the menstrual cycle) basal FSH and Estradiol levels are routinely evaluated in women seeking medical help for conceiving and higher FSH value ( > 9mIU/ml) is considered as a warning sign indicating aging ovaries. However, interpretation of the FSH values has to be done with immense care as low values are not always a guarantee of good quality eggs and high ovarian reserve. Tests can vary depending on your cycle and depending on the lab. According to scientists, the ovarian reserve cannot be changed. In my clinical experience, I have seen FSH levels change dramatically, which leads me to believe that it can be changed or that the blood tests are not very accurate.
Anti Muellerain Hormone (AMH)
AMH is a glycoprotein produced by the immature ovarian follicles and it's level declines as the follicles mature finally leading to no AMH production. The normal range is 14 – 30 pmol/L. Interestingly as AMH is produced by small immature follicles, the values of AMH are directly proportional to the follicles present in ovarian reserve. Women with advanced age generally in the late reproductive years have low AMH values because they have fewer small follicles and it indicates a diminished ovarian reserve. However, women with polycystic ovarian syndrome show higher AMH values due to numerous small follicles in their ovaries. AMH levels in case of such women are analyzed along with the ultrasound information to avoid the risk of misinterpretation.
Based on my own clinical experience and some studies on the subject, it seems that interpretation of AMH levels in relationship to the likelihood of conception is quite misleading. In one study two women had a spontaneous ongoing pregnancy despite undetectable AMH levels. In another study, AMH levels were 65% lower in obese women compared to non-obese women. Obviously AMH levels can be influenced by weight loss and a healthy lifestyle.
As useful as these tests may be, they can also have a very detrimental emotional effect on the couple trying to conceive. It adds a lot of stress, urgency and desperation as time seems to be running out and women may feel pressured into taking some drastic steps to conceive.
Timothée Fraisse, Victoria Ibecheole, Isabelle Streuli, Paul Bischof, Dominique de Ziegler: Undetectable serum anti-Müllerian hormone levels and occurrence of ongoing pregnancy. Fertility and Sterility, Volume 89, Issue 3, March 2008, Pages 723.e9-723.e11 Association of anti-mullerian hormone levels with obesity in late reproductive-age women. Ferti and Sterility Vol. 87, Issue 1, January 2007, Pages 101-106