Phthalates in Medications and Risk of Male Genital Defects

This study aims to evaluate whether the risk of two male genital malformations are increased after maternal exposure to large amounts of phthalates that may be contained in certain medicine.

Hypospadias (urethral opening on the ventral surface of the penis) and cryptorchidism (undescended testis) are the most common congenital malformations of the male genital system, but we know little about possible causes. It has been suggested that chemicals contained in certain plastics (called phthalates) may increase the risk of these malformations, but evidence supporting this suggestion is not very strong. While humans can be exposed to phthalates from many sources, we have pointed out that phthalates can be contained in certain medications, and when they are, the amounts absorbed can be far greater than what we encounter in everyday living.

In this study, we will identify which drugs taken by study subjects contained phthalates as inactive ingredients, and then determine whether taking these medications during pregnancy increases the risk of having an infant with hypospadias and cryptorchidism.

We will gather data from a large ongoing surveillance program of birth defects in North America, the Slone Epidemiology Center Pregnancy Health Invertiew Study (Birth Defects Study), and plan to include around 675 infants with cryptorchidism and 1100 with hypospadias; the phthalate exposures from medications in the mothers of these infants will be compared with mothers’ exposures among over 10,000 infants without these conditions.

Findings from this effort will contribute to our understanding of the role, if any, played by certain maternal phthalate exposures in male genital malformations. They will also help health professionals provide better advice to women, either in the form of reassurance, if no associations are found, or if some risks are identified, they can offer specific recommendations to minimize those risks.


Sonia Hernández-Díaz, M.D., Dr.P.H., Principal Investigator
Allen A. Mitchell, M.D., Co-Principal Investigator
Carol Louik, Sc.D., Co-Investigator
Martha M. Werler, Sc.D., Co-Investigator

Study Staff:

Dawn Jacobs, R.N., M.P.H., Project Coordinator
Fiona Rice, M.P.H., Program Coordinator
Nastia Dynkin, Computer Programmer
Christina Coleman, P.A., Research Coordinator

Nurse Interviewers:

Clare Coughlin, R.N.
Moira Quinn, R.N.
Kathleen Sheehan, R.N.
Laurie Cincotta, R.N.
Susan Littlefield, R.N.
Laine Fletcher, Interpreter
Ileana Gatica, Interpreter
Monica Martinez-Dale, Interpreter

Research Assistants:

Joan Shander
Julia Venanzi, Senior Research Assistant
Mark Abcede
Gabrielle Fortier
Michelle Eglovitch

Source of Funding:

National Institute of Child Health and Human Development

Study Period:

September 2009 to 2014

Dawn Jacobs, R.N., M.P.H., Project Coordinator
(617) 734-6006

Participant Information:

(866) 896-1097 (toll free-bilingual English/Spanish line)