Optimising Women's Health
Before Trying to Conceive

The three to six months before conception are arguably the most impactful window in your future child's life — long before a positive test. Oocyte maturation, uterine lining quality, and hormonal milieu are all modifiable. Here's what the evidence says.

Body Weight & Composition

BMI is one of the strongest modifiable predictors of fertility. Both extremes are harmful:

• Underweight (BMI <18.5): Associated with hypothalamic anovulation, irregular cycles, and increased miscarriage risk.
• Overweight/Obese (BMI >25–30): Excess adipose tissue increases peripheral aromatisation of androgens to oestrogen, disrupting the HPO axis. Linked to PCOS, anovulation, implantation failure, and gestational diabetes.

A 5–10% weight loss in overweight women with anovulatory infertility has been shown to restore ovulation in a significant proportion without medical intervention (NICE Guideline CG156, 2013, updated 2023).

Physical Activity

Moderate-intensity aerobic exercise (150 minutes/week) improves insulin sensitivity, reduces androgen excess in PCOS, and supports a healthy BMI — all beneficial for fertility. However, excessive high-intensity exercise (particularly in lean women) can suppress the HPO axis and cause luteal phase defects or amenorrhoea. If you're training intensively and cycles are irregular, this warrants evaluation.

Menstrual Cycle Assessment

Before trying, understand your cycle. A regular 21–35 day cycle with ovulation is the baseline. Red flags worth investigating:

• Cycles <21 or >35 days
• Intermenstrual or post-coital bleeding
• Significant dysmenorrhoea (consider endometriosis)
• Oligomenorrhoea or amenorrhoea (consider PCOS, hypothalamic dysfunction, thyroid disease)

Nutritional Foundations

Mediterranean Diet Pattern

The most robustly studied dietary pattern for female fertility. High in vegetables, legumes, whole grains, olive oil, fish, and nuts — and low in processed foods and red meat. Associated with improved IVF outcomes and reduced time-to-pregnancy in observational studies (Chavarro et al., Fertility and Sterility, 2018).

Folate

Begin 400–800 mcg daily at least 3 months before conception. Folate is critical in the first 28 days post-conception — before most women even know they are pregnant — for neural tube closure.

Iron

Iron-deficiency anaemia impairs ovulation. Dietary haem iron from lean meats is well absorbed; non-haem iron from plant sources is enhanced by concurrent vitamin C intake. Check FBC before supplementing — excessive iron is not benign.

Lifestyle Modifications

Smoking Cessation

Smoking accelerates ovarian ageing, reduces oocyte quality, and increases miscarriage risk. The toxins in cigarette smoke cause direct DNA damage to oocytes. Cessation benefits are measurable within 3 months — the average oocyte maturation cycle.

Alcohol

No safe threshold for pre-conception alcohol use has been established. Current ACOG guidance recommends abstinence once you are trying to conceive, given alcohol's known teratogenic potential in early implantation.

Stress & Sleep

Chronic psychological stress elevates cortisol and prolactin, both of which can interfere with GnRH pulsatility and ovulation. This is difficult to quantify but clinically real. Prioritising 7–9 hours of sleep and building in stress-reduction strategies (exercise, mindfulness) is evidence-supported.

When to Seek Further Evaluation

ACOG and NICE guidelines recommend seeking fertility evaluation after:

• 12 months of unprotected intercourse (women <35)
• 6 months (women ≥35)
• Immediately if known risk factors exist (irregular cycles, prior pelvic surgery, endometriosis, male factor concerns)