Results
Study Population
There were 421 women undergoing fertility treatment (IVF or ICSI) at the Hamilton and Auckland clinics over the study period who met the inclusion criteria and were invited to participate; 164 declined so that 257 women were interviewed. Subsequently, data from seven women who did not start fertility treatment were excluded.
The studied cohort was demographically similar to the remainder of Fertility Associates clinics' population (Table I). The two groups had similar causes of infertility, except that a lower proportion of interviewed women had endometriosis as an underlying cause (P = 0.010; Table I). Our cohort consisted of well-educated women (with 60.3% holding a university degree or higher qualification). 4.4% of the study sample had a history of a previous eating disorder.
Interviews for this study were carried out 35 days (SD = 22) from fertility treatment initiation (median 32 days). However, 6 of the 250 women were interviewed >90 days prior to treatment.
Lifestyle and Lifestyle Changes
Most women (82.8%) stated that they had made at least one lifestyle change in preparation for their fertility treatment. These changes consisted mostly of eliminating or reducing alcohol and/or caffeinated beverage consumption ( Table II ).
Only a small minority of studied women smoked (2%; Table II ). Half of the women (50.8%) drank alcohol regularly prior to fertility treatment, with 4.4% reporting binge drinking (defined as consuming more than four alcohol drinks in a single session) ( Table III ). Among women who consumed alcohol, less than half either reduced their intake (20.4%) or abstained (24.8%) for treatment ( Table II ). One participant reported the consumption of as many as 18.5 standard drinks per week.
The majority of women (86.8%) consumed caffeinated beverages before fertility treatment ( Table II ), with 36.4% of women drinking caffeinated herbal tea (regular green tea). Less than half reduced (21.6%) or abstained (18.0%) for treatment, so that 60.4% of women did not change their consumption of caffeinated beverages prior to fertility treatment ( Table II ).
Similarly, the majority of women did not make any lifestyle changes aimed at reducing BMI or exercise levels (83.6 and 64.4%, respectively) ( Table II ). No women reported increasing tobacco, alcohol or caffeinated beverage consumption ( Table II ). There were no associations between lifestyle changes and ethnic group or level of education (data not shown).
Use of Medications, Dietary Supplements and Alternative Medicine
Approximately 25% of the study cohort took additional medications unrelated to fertility treatment, mainly asthma inhalers, antihistamines, metformin and thyroid medication. Almost all women were taking some form of dietary supplement (94.0%; Table III ), which is considerably more than the percentage of women aged 31–50 years taking supplements in the general New Zealand population (University of Otago and Ministry of Health, 2011) (34.7%; P < 0.0001). The majority of participants were taking some form of folic acid (93.2%), although 16.8% were taking either no folic acid or an inadequate amount ( Table III ).
Overall, 52.0% of the study group used at least one nutritional supplement other than folic acid; the most common additional supplements were fish oil, vitamin C and iron, with nearly 12.0% of women also reporting the intake of botanical/herbal supplements ( Table III ).
Women about to undergo fertility treatment consumed more bee products (such as propolis and royal jelly) (3.2 versus 0.5%; P = 0.003), similar amounts of oil supplements (19.2 versus 17.9%; P = 0.71), but considerably less botanical/herbal products (12.0 versus 27.3%; P < 0.0001) than women in the general New Zealand population (University of Otago and Ministry of Health, 2011). Alternative therapists were seen by 36.8% of women in the 3 months prior to the recruitment interview, most commonly acupuncturists and naturopaths.
Treatment Outcome
Exploratory analyses suggested that women who consumed caffeinated herbal tea had half the odds of becoming pregnant than women who did not consume it (OR: 0.52, 95% CI (0.28–0.97); P = 0.041). However, there was no significant association between coffee intake and treatment outcome. Among lifestyle changes, women who abstained from drinking or reduced alcohol intake had twice the odds of becoming pregnant than those who maintained their drinking habits prior to fertility treatment (OR: 2.27, 95% CI (1.01–5.15); P = 0.049). In addition, women who held a university degree or higher qualification had twice the odds of becoming pregnant as women with lower levels of education (OR 2.08, 95% CI (1.14–3.80); P = 0.017). There were no observed associations with other dietary and lifestyle habitats, including folic acid intake or smoking.