Designing prospective cohort studies for assessing reproductive and developmental toxicity during sensitive windows of human reproduction and development - the LIFE Study.
Buck Louis-GM; Schisterman-EF; Sweeney-AM; Wilcosky-TC; Gore-Langton-RE; Lynch-CD; Barr-DB; Schrader-SM; Kim-S; Chen-Z; Sundaram-R
Paediatr Perinat Epidemiol 2011 Sep; 25(5):413-424
The relationship between the environment and human fecundity and fertility remains virtually unstudied from a couple-based perspective in which longitudinal exposure data and biospecimens are captured across sensitive windows. In response, we completed the LIFE Study with methodology that intended to empirically evaluate a priori purported methodological challenges: 1.) implementation of population-based sampling frameworks suitable for recruiting couples planning pregnancy; 2.) obtaining environmental data across sensitive windows of reproduction and development; 3.) home-based biospecimen collection; and 4.) development of a data management system for hierarchical exposome data. We used two sampling frameworks (i.e. fish/wildlife licence registry and a direct marketing database) for 16 targeted counties with presumed environmental exposures to persistent organochlorine chemicals to recruit 501 couples planning pregnancies for prospective longitudinal follow-up while trying to conceive and throughout pregnancy. Enrolment rates varied from <1% of the targeted population (n = 424 423) to 42% of eligible couples who were successfully screened; 84% of the targeted population could not be reached, while 36% refused screening. Among enrolled couples, ~85% completed daily journals while trying; 82% of pregnant women completed daily early pregnancy journals, and 80% completed monthly pregnancy journals. All couples provided baseline blood/urine samples; 94% of men provided one or more semen samples and 98% of women provided one or more saliva samples. Women successfully used urinary fertility monitors for identifying ovulation and home pregnancy test kits. Couples can be recruited for preconception cohorts and will comply with intensive data collection across sensitive windows. However, appropriately sized sampling frameworks are critical, given the small percentage of couples contacted found eligible and reportedly planning pregnancy at any point in time.
Biological-effects; Biological-factors; Biological-monitoring; Environmental-exposure Environmental-factors; Epidemiology; Mathematical-models; Pregnancy; Prenatal-exposure; Reproductive-system; Statistical-analysis; Women;
Author Keywords: cohort; environment; fecundity; fertility; LIFE Study; preconception; pregnancy; study design; enrolment
Dr Germaine M. Buck Louis, Division of Epidemiology, Statistics & Prevention Research, Eunice Kennedy Shriver National Institute of Child Health & Human Development, NIH, 6100 Executive Boulevard, Rockville, MD 20852
Paediatric and Perinatal Epidemiology