Iodine-containing disinfectants in preparation for caesarean section: impact on thyroid profile in cord blood.
BACKGROUND
Iodine-containing disinfectants are widely used for skin preparation before caesarean section. Current evidence suggests that maternal exposure to these disinfectants results in thyroid dysfunction in the newborns, but its extent is not known.


OBJECTIVE
The purpose of this study was to explain the quality of the effect of these disinfectants on the thyroid function of newborns.


METHODS
This cohort study was performed on all the healthy mothers with a term pregnancy who underwent caesarean section in the obstetrics emergency department of an educational hospital affiliated with Tehran University of Medical Sciences from December 2013 to December 2014. We divided this 12-month period into two consecutive 6 months. Povidone-iodine 10% (PVP-I) and chlorhexidine gluconate 4% (CHX) were used in the first and second 6 months, respectively, for skin preparation before caesarean section and also for umbilical cord disinfection. Cord blood thyroid stimulating hormone (TSH) and thyroxine (T4) were assayed by the ELISA method.


RESULTS
We included 326 cases in this study, 153 in the PVP-I group and 173 in the CHX group. The incidence of cord blood TSH ≥ 10 mIU/L and T4 ≤ 7.3 µg/dL was significantly higher in the PVP-I than the CHX group. Cord blood TSH concentration showed a significant positive correlation with cord blood T4 concentration in the CHX group. Through selection of cases with cord blood T4 < 13 µg/dL, we found a negative correlation between cord blood TSH and T4 concentration in the PVP-I group.


CONCLUSIONS
It seems that PVP-I has the potential to cause false-positive screening-test results and increase recall rates, which should be evaluated in further studies.


BACKGROUND
Iranian Registry of Clinical Trials (IRCT) number IRCT201204289568N1.
Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Firoozeh
F
Nili
Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Sedigheh
S
Hantoushzadeh
Tehran University of Medical Sciences, Tehran, Iran.
Afsaneh
A
Alimohamadi
Family Health Institute, Maternal, Fetal and Neonatal Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Mamak
M
Shariat
Family Health Institute, Maternal, Fetal and Neonatal Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Golnaz
G
Rezaeizadeh
D000328:Adult; D000891:Anti-Infective Agents, Local / Q000009:adverse effects / Q000494:pharmacology*; D002585:Cesarean Section / Q000379:methods*; D002710:Chlorhexidine / Q000009:adverse effects / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D007037:Hypothyroidism / Q000139:chemically induced*; D007231:Infant, Newborn; D007492:Iran / Q000453:epidemiology; D018811:Maternal Exposure / Q000009:adverse effects*; D011206:Povidone-Iodine / Q000009:adverse effects / Q000494:pharmacology*; D011247:Pregnancy; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D000891:Anti-Infective Agents, Local; D011206:Povidone-Iodine; D013972:Thyrotropin; D013974:Thyroxine; D002710:Chlorhexidine
NEONATOLOGY