Association between gestational night blindness and serum retinol in mother/newborn pairs in the city of Rio de Janeiro, Brazil

OBJECTIVE

Gestational night blindness (XN) is associated with increased risk of reproductive morbidity and mortality. This study investigated the prevalence of gestational XN among postpartum women treated in a public maternity hospital in the city of Rio de Janeiro, Brazil and evaluated its association with maternal and neonatal (cord blood) serum retinol concentrations.

METHODS

XN was evaluated retrospectively, using an interview according to guidelines of the World Health Organization, in 222 postpartum women (< or = 6 h after delivery) after singleton births who had low obstetric risk. Serum retinol concentrations were measured according to the modified Bessey method, with a cutoff point lower than 1.05 micromol/L for inadequate serum retinol concentration.

RESULTS

Prevalence of gestational XN was 18%, and inadequate maternal and cord blood serum retinol concentrations were found in 24.4% and 45.5% of samples, respectively. The results associated gestational XN with inadequate maternal serum retinol concentration (P = 0.000), and an association was observed between maternal and neonatal serum retinol concentrations (P = 0.000). A poor association was observed between maternal XN and serum levels of retinol in newborn children (P = 0.06).

CONCLUSIONS

The results suggest that prevalence of gestational XN and inadequate serum retinol concentration among postpartum women and newborns is a concern, calling attention to the need for studies in other parts of Brazil. In addition, the risk of inadequate serum retinol in newborns was significantly higher among infants of postpartum women with serum retinol levels below 1.05 micromol/L. Gestational XN was associated with inadequate levels of maternal serum retinol, and the results suggest a poor relation between maternal XN and vitamin A nutritional status of newborns.

Gestational nightblindness among women attending a public maternity hospital in Rio de Janeiro, Brazil

This study evaluated the prevalence of gestational nightblindness among postpartum women seen at the University Maternal Hospital of the Federal University in Rio de Janeiro, Brazil and the association of this symptom with a biochemical indicator (serum retinol levels) and sociodemographic, anthropometric and antenatal care variables. In total, 262 postpartum women, who did not receive vitamin A supplementation during pregnancy, were interviewed. Gestational nightblindness was diagnosed through the standardized interview as proposed by WHO. Serum retinol levels were evaluated by spectrophotometry. Gestational nightblindness relating to low levels of serum retinol (<1.05 micromol/L, p = 0.000) was diagnosed in 17.9% of subjects interviewed. Less than five antenatal care appointments (odds ratio [OR] = 2.179; confidence interval [CI] 95% = 1.078 - 4.402) and a history of one or more miscarriage(s) (OR = 2.306; CI 95% = 1.185 - 4.491) were predictors for gestational nightblindness. These findings justify the need for nutritional counselling, aimed at improving the vitamin A nutritional status, especially among pregnant women with a history of previous miscarriages and poor antenatal care.