title: Does maternal exposure during pregnancy to higher ambient temperature increase the risk of hypospadias?
abstract: BACKGROUND
  The association between ambient temperature that the mother is exposed to during pregnancy and hypospadias has not been investigated by the studies, although the recent studies showed the correlation between some congenital malformations (congenital heart disease, neural tube defect, etc.) and ambient temperature.
  
  
  OBJECTIVE
  The aim was to investigate the relation between hypospadias and the ambient temperatures that the mother is exposed to during her pregnancy.
  
  
  METHODS
  The data of patients with hypospadias that had their gestational periods in Ankara and Istanbul regions, and had other urological treatments (circumcision, urinary tract infection, pyeloplasty, nephrolithotomy, etc.) between January 2000 and November 2015 were analyzed retrospectively. The ambient temperature at 8-14 weeks of gestation was investigated for each patient by reviewing the data of the General Directorate of Meteorology, since this period was risky for development of hypospadias. The data including ambient temperature that the pregnant mother was exposed to, maternal age, parity, economical status, gestational age at birth, and birth weight were compared between two groups. The retrospective nature of the study may be a potential source for selection bias.
  
  
  RESULTS
  The data of 1,709 children that had hypospadias repair and 4,946 children that had other urological treatments between 2000 and 2015 were retrospectively analyzed. There were no differences between the groups for maternal age, parity, economical status, gestational age at birth, and birth weight (Table). Analysis of exposed maximum and average ambient temperatures at 8-14 weeks of gestation revealed that July and August, hot periods in summer time, were more prevalent in the hypospadias group (p = 0.01). The average and maximum monthly ambient temperatures during summer increased the risk for hypospadias (OR, 1.32; 95% CI, 1.08-1.52; and OR, 1.22; 95% CI, 0.99-1.54, respectively.
  
  
  CONCLUSIONS
  In this paper, we evaluated the relation between hypospadias and the ambient temperatures that the mother is exposed during her pregnancy. The results of this study indicated that the high ambient temperatures the mother and fetus are exposed to at 8-14 weeks of gestation increased the risk of hypospadias in the offspring.
authors: Department of Urology, Ankara Training and Research Hospital, Ankara, Turkey. Electronic address: mdfatihkilinc@yahoo.com.
authors: Muhammet Fatih
authors: MF
authors: Kilinc
authors: Department of Urology, Sisli Etfal Training and Research Hospital, Istanbul, Turkey.
authors: Sedat
authors: S
authors: Cakmak
authors: Department of Urology, Ankara Training and Research Hospital, Ankara, Turkey.
authors: Demirhan Orsan
authors: DO
authors: Demir
authors: Department of Urology, Ankara Training and Research Hospital, Ankara, Turkey.
authors: Omer Gokhan
authors: OG
authors: Doluoglu
authors: Department of Urology, Ankara Training and Research Hospital, Ankara, Turkey.
authors: Yildiray
authors: Y
authors: Yildiz
authors: Department of Urology, Sisli Etfal Training and Research Hospital, Istanbul, Turkey.
authors: Kaya
authors: K
authors: Horasanli
authors: Department of Urology, Sisli Etfal Training and Research Hospital, Istanbul, Turkey.
authors: Ayhan
authors: A
authors: Dalkilic
mesh_terms: D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D007021:Hypospadias / Q000453:epidemiology* / Q000209:etiology*; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D012189:Retrospective Studies; D018570:Risk Assessment
keywords: Ambient temperature; Hypospadias; Urogenital malformations