title: Dairy intake in relation to in vitro fertilization outcomes among women from a fertility clinic.
abstract: OBJECTIVE
  Is dairy food consumption associated with live birth among women undergoing infertility treatment?
  
  
  CONCLUSIONS
  There was a positive association between total dairy food consumption and live birth among women ≥35 years of age.
  
  
  BACKGROUND
  Dairy food intake has been previously related to infertility risk and measures of fertility potential but its relation to infertility treatment outcomes are unknown.
  
  
  METHODS
  Our study population comprised a total of 232 women undergoing 353 in vitro fertilization (IVF) treatment cycles between February 2007 and May 2013, from the Environment and Reproductive Health study, an ongoing prospective cohort.
  
  
  METHODS
  Diet was assessed before assisted reproductive technology (ART) treatment using a validated food frequency questionnaire. Study outcomes included ovarian stimulation outcomes (endometrial thickness, estradiol levels and oocyte yield), fertilization rates, embryo quality measures and clinical outcomes (implantation, clinical pregnancy and live birth rates). We used generalized linear mixed models with random intercepts to account for multiple ART cycles per woman while simultaneously adjusting for age, caloric intake, BMI, race, smoking status, infertility diagnosis, protocol type, alcohol intake and dietary patterns.
  
  
  RESULTS
  The age- and calorie-adjusted difference in live birth between women in the highest (>3.0 servings/day) and lowest (<1.34 servings/day) quartile of dairy intake was 21% (P = 0.02). However, after adjusting for additional covariates, this association was observed only among women ≥35 years (P, interaction = 0.04). The multivariable-adjusted live birth (95% CI) in increasing quartiles of total dairy intake was 23% (11, 42%), 39% (24, 56%), 29% (17, 47%) and 55% (39, 69%) (P, trend = 0.02) among women ≥35 years old, and ranged from 46 to 54% among women <35 years old (P, trend = 0.69). There was no association between dairy intake and any of the intermediate outcomes.
  
  
  CONCLUSIONS
  The lack of a known biological mechanism linking dairy intake to infertility treatment outcomes calls for caution when interpreting these results and for additional work to corroborate or refute them.
  
  
  CONCLUSIONS
  Dairy intake does not appear to harm IVF outcomes and, if anything, is associated with higher chances of live birth.
  
  
  BACKGROUND
  This work was supported by NIH grants R01-ES009718 and R01ES000002 from NIEHS, P30 DK046200 from NIDDK and T32HD060454 from NICHD. M.C.A. was supported by a Ruth L. Kirschstein National Research Service Award T32 DK 007703-16 from NIDDK. She is currently employed at the Nestlé Research Center, Switzerland and completed this work while at the Harvard School of Public Health. The other authors declare no conflicts of interest.
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA mafeiche@hsph.harvard.edu.
authors.forename: M C
authors.initials: MC
authors.lastname: Afeiche
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chiu
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Gaskins
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: P L
authors.initials: PL
authors.lastname: Williams
authors.affiliation: Vincent Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: I
authors.initials: I
authors.lastname: Souter
authors.affiliation: Vincent Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Wright
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Vincent Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: R
authors.initials: R
authors.lastname: Hauser
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Chavarro
mesh_terms: D000328:Adult; D003611:Dairy Products; D004032:Diet; D004435:Eating; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007246:Infertility / Q000628:therapy*; D016014:Linear Models; D011247:Pregnancy; D018873:Pregnancy Rate; D012307:Risk Factors; D016896:Treatment Outcome
keywords: assisted reproductive technology; dairy; diet; in vitro fertilization outcomes; live birth rate