The goal of this project is to investigate factors predicting a couples natural fertility, as well as their response to environmental exposures. The emphasis is on applying innovative statistical methods to detailed data on the timing of menstrual bleeding, intercourse, and ovulation collected prospectively in non-contracepting menstrual cycles. Surprisingly little is known about the basics of human reproduction, such as the relationship between male and female age and fecundity. We have utilized data from Allen Wilcox's North Carolina Early Pregnancy Study in the past, and have recently focused on data from a multinational European fecundability study of users of natural family planning methods. Work has progressed in several areas: (1) the development of improved methods for assessing factors predictive of the day-specific probabilities of conception in the menstrual cycle; (2) the application of these methods to investigate the impact of cervical mucus and age; and (3) the development of methods for analysis of menstrual cycle data on hormones and cervical mucus. Using the European data base and a new Italian data base, we have demonstrated that cervical mucus secretions play a prominent role in the regulation of the fertile interval and the day-specific probabilities of conception. We hypothesize that sperm with lowered motility, either due to the natural process of male aging or to environmental exposure, may be less capable of survival and transport in the female reproductive tract unless high levels of estrogenic-type mucus are present. A striking interaction between mucus and the association between male age and fertility provides support for this hypothesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Intramural Research (Z01)
Project #
1Z01ES040011-06
Application #
7168271
Study Section
(BB)
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
2005
Total Cost
Indirect Cost
Name
U.S. National Inst of Environ Hlth Scis
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Scarpa, Bruno; Dunson, David B; Giacchi, Elena (2007) Bayesian selection of optimal rules for timing intercourse to conceive by using calendar and mucus. Fertil Steril 88:915-24
Stanford, Joseph B; Dunson, David B (2007) Effects of sexual intercourse patterns in time to pregnancy studies. Am J Epidemiol 165:1088-95
Bigelow, Jamie L; Dunson, David B (2007) Bayesian adaptive regression splines for hierarchical data. Biometrics 63:724-32
Scarpa, Bruno; Dunson, David B (2007) Bayesian methods for searching for optimal rules for timing intercourse to achieve pregnancy. Stat Med 26:1920-36
Stanford, Joseph B; Dunson, David B (2006) Foreword. Expanding Methodologies for Capturing Day-Specific Probabilities of Conception. Paediatr Perinat Epidemiol 20 Suppl 1:1-2
Scarpa, Bruno; Dunson, David B; Colombo, Bernardo (2006) Cervical mucus secretions on the day of intercourse: an accurate marker of highly fertile days. Eur J Obstet Gynecol Reprod Biol 125:72-8
Scarpa, Bruno; Dunson, David B (2006) Bayesian selection of predictors of conception probabilities across the menstrual cycle. Paediatr Perinat Epidemiol 20 Suppl 1:30-7
Dunson, David B; Bigelow, Jamie L; Colombo, Bernardo (2005) Reduced fertilization rates in older men when cervical mucus is suboptimal. Obstet Gynecol 105:788-93
Dunson, David B; Stanford, Joseph B (2005) Bayesian inferences on predictors of conception probabilities. Biometrics 61:126-33
Longnecker, Matthew P (2005) Invited Commentary: Why DDT matters now. Am J Epidemiol 162:726-8

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