In this engaging and wide-ranging discussion of fertility, infertility and the role of hormone testing, Dr. Alison McAllister, lead clinical consultant at ZRT, shares her considerable knowledge about the challenges of infertility and the heartbreak of those struggling to have a baby of their own.
Sadly, it is a growing problem that affects 1 in 8 couples and millions of people around the world. As a naturopath who looks at all aspects of infertility — physical, mental and emotional — McAllister aims not only to help couples become pregnant, but stay pregnant for the 9 months until a healthy baby is delivered into their arms.
Infertility Is Not Just a Female Problem
Infertility is commonly defined as the inability to get pregnant within 1 year of unprotected intercourse, or within 6 months in women over 35, or 3 months in women after the age of 40. But infertility is not just an affliction of women: 30% of all cases are due to female factors, another 30% are linked to male factors, and the remaining 40% can be traced back to both.
Yet, despite the equal-opportunity nature of the problem, far fewer men than women in couples trying to get pregnant have ever had a workup.
“I see it all the time and it’s one of my biggest pet peeves. The women are out there getting invasive procedures, and even laparoscopic surgery, while their spouse hasn’t had a sperm count!” — Dr. McAllister
McAllister strongly advises patients in opposite-sex relationships to get both a female workup and a male workup to determine the cause of their reproductive difficulties. When a couple under the age of 35 has been trying for over a year (or 6 months over the age of 35), screening for hormonal causes is one of the first recommended steps — because even simple adjustments to thyroid and/or progesterone can sometimes result in fertility.
Key Hormonal Causes of Infertility
Structural and Functional Disorders
From faulty sperm and anatomical problems in men, to anovulation and pelvic factors in women: in men, the lack of an intact blood-testes barrier due to trauma or infection can trigger antibodies against his own sperm; in women, endometriosis, fallopian tube defects or fibroids can disrupt ovulation, foetal development in utero and/or successful delivery.
The Key Labs That Are Too Often Missed
McAllister highlights the importance of a thorough hormonal workup, including day 3 FSH levels and LH surges for ovarian assessment, hormone testing to rule out PCOS, estrogen/progesterone and cortisol imbalances, thyroid, iodine and vitamin D testing — and evaluation of heavy metal exposure.
Our Fertility Test (Saliva & Blood Spot) measures the key reproductive hormones — including estradiol, progesterone, testosterone, DHEA, FSH and LH — providing a comprehensive hormonal picture for women and couples investigating the causes of infertility.
Thyroid and Iodine: The Most Commonly Missed Fertility Factors
McAllister feels strongly that women should be allowed a period of at least 3 months to identify silent conditions undermining fertility — such as undetected TSH levels over 2.5, or low iodine. The ovaries actually have the second highest level of iodine content in the body, and low iodine is associated with a dramatic drop in fertility rates. Conditions like these, if unrecognised and left untreated, make it much less likely that patients will be able to become pregnant with IVF, and also more prone to miscarrying once pregnant.
Our Thyroid & Iodine Test Kit measures TSH, Free T4, Free T3, TPO antibodies and urinary iodine — covering the full thyroid and iodine picture that is so often overlooked in standard fertility workups.
Environmental Toxins and Heavy Metals
Environmental toxins — cadmium, lead, arsenic, mercury — and xenoestrogens such as BPAs and plasticisers disrupt egg development and increase miscarriage recurrences. Heavy metal exposure is an important but frequently missed component of a thorough fertility investigation.
For women wanting the most comprehensive picture — combining hormone testing with toxic and essential elements analysis — our Advanced Female Wellness Test measures key female hormones alongside heavy metals and essential nutrients from a simple at-home blood spot collection, with a specialist doctor report included.
Optimising the Body Before IVF
PCOS and Fertility
Women with PCOS (associated with 70% of all cases of infertility) are all too often told they will not be able to have a child — but “nothing could be further from the truth,” says McAllister. These women often have plenty of eggs, and 80% of them can get pregnant — especially with complementary care to balance the diet, blood sugars and insulin levels.
Complementary Therapies That Support Fertility
McAllister shares some of her favourites for restoring normal cycles and ovulation: Vitex, the “natural version of Clomid”, an herb used for centuries by women to regulate periods; Inositol (“follicle studies show that the best eggs have higher inositol levels”); and adequate progesterone to “make the endometrium work.”
“Our aim should be to generally optimise her body for health and fertility, then use oral medications or IVF, knowing that success rates are going to be much higher per cycle.” — Dr. McAllister
Fertility is a multi-generational phenomenon that will always keep providers and researchers guessing to some extent — but there are many answers here, and a world of practical information that providers can use to assist patients in the successful creation of their own little miracle.
Originally by Candace Burch, ZRT Laboratory. Reproduced with permission. Last reviewed: May 2026.