(Ref. 3, p. 226). This means that they tried without birth control methods to get a child, but were not successful after 2 years.
There can be various causes of infertility as is explained below, but essentially infertility occurs when fertilization process does not work. This can happen, because no sperm is there (azoospermia), no ovulation takes place to release an egg (anovulation) or because there is a fallopian tube blockage making it impossible for sperm to reach an egg. A review of several studies showed that in about 27% of infertile couples the reason for infertility was an ovulatory problem, in 22% there was a tubal blockage, in 5% there was endometriosis infertility, in 25% there was a male factor infertility, in 4% there were other factors and in 17% the cause was unknown (Ref. 3, p. 327). Below I have listed the common causes of infertility in more detail. This is explained further in links under the various headings.
26. Dr. John R. Lee, David Zava and Virginia Hopkins: “What your doctor may not tell you about breast cancer – How hormone balance can help save your life”, Wellness Central, Hachette Book Group USA, 2005. Page 29 – 38 (Chapter 2): Risk factors for breast cancer. Page 360 to 374 explains about xenohormones and how they cause estrogen dominance. Pages 221 to 234 (chapter 12) explains why Tamoxifen is not recommended and bio-identical progesterone is more powerful in preventing breast and uterine cancer.