OBJECTIVE: To assess the extent to which lubricant use during intercourse is associated with time to pregnancy (TTP).
DESIGN: Prospective cohort study.
SETTING: Denmark and North America.
POPULATION: A total of 6467 women aged 18-49 years who were not using contraception or fertility treatment.
METHODS: We pooled data from two continuing prospective cohort studies of pregnancy planners in Denmark (2011-2017) and North America (2013-2017). Female participants completed bimonthly questionnaires for 12 months or until they reported pregnancy. After restricting the study to women without a history of infertility who had been trying to conceive for six or fewer cycles at enrollment, 6467 women were retained for analysis. Self-reported lubricant use was categorised as water-based/not pH balanced, water-based/pH balanced 'fertility friendly', silicone-based, oil-based, or a combination of these. We used proportional probability models to calculate fecundability ratios (FRs) and 95% confidence intervals (95% CIs) for the association between lubricant use and fecundability, after adjusting for cohort and sociodemographic and lifestyle factors.
MAIN OUTCOME MEASURE: Fecundability.
RESULTS: At baseline, 17.5% of participants reported the use of lubricants, most commonly water-based/not pH balanced (11.4%). Compared with non-use of lubricants, FRs were 1.02 (95% CI 0.93-1.11) for water-based/not pH-balanced lubricant use, 1.01 (95% CI 0.86-1.18) for water-based/pH balanced 'fertility friendly' lubricant use, 1.23 (95% CI 0.94-1.61) for oil-based lubricant use, and 1.27 (95% CI 0.93-1.73) for silicone-based lubricant use. Associations between oil-based lubricant use and fecundability were inconsistent across subgroups of study cohort, age, parity, and intercourse frequency.
CONCLUSIONS: Lubricant use was not associated with reduced fecundability in the preconception cohorts of pregnancy planners studied.
TWEETABLE ABSTRACT: Lubricant use during intercourse was not associated with time to pregnancy in a study of pregnancy planners.