Cigarette smoking and hormonesMarom-Haham, Lilach; Shulman, AdrianCurrent Opinion in Obstetrics and Gynecology: August 2016 - Volume 28 - Issue 4 - p 230–235 doi: 10.1097/GCO.0000000000000283 REPRODUCTIVE ENDOCRINOLOGY: Edited by David L. Olive Abstract Author Information Purpose of review The purpose is to provide a summary of the effects of cigarette smoking on steroid hormone metabolism and how it affects female fertility. Recent findings Components of tobacco smoke such as polycyclic aromatic hydrocarbons lead to transcriptional upregulation of a number of genes, including members of the cytochrome P450 (CYP) family, in particular CYP1B1 and CYP1A1. In humans, CYP1A1 and CYP1A2 are the primary enzymes catalyzing the 2-hydroxylation of estradiol. This pathway shunts available estrogen away from the more estrogenically potent 16α-hydroxylation to the production of catechol estrogens, mainly 2 and 4 hydroxyestradiol. Summary Smoking has multiple effects on hormone secretion and metabolism. These effects are mainly mediated by the pharmacological action of tobacco alkaloids (nicotine and its metabolite cotinine). A strong body of evidence indicates that the negative effects of cigarette smoking on fertility compromises nearly every system involved in the reproductive process. IVF Unit, Department of Obstetrics and Gynecology, Meir Medical Center (affiliated with Sackler Medical School, Tel Aviv University), Kfar Sava, Israel Correspondence to Adrian Shulman, MD, IVF Unit, Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tschernichovsky St., Kfar Sava 44281, Israel. Tel: +972 9 7471848; fax: +972 9 7472465; e-mail: firstname.lastname@example.org Copyright © 2016 YEAR Wolters Kluwer Health, Inc. All rights reserved.