FETAL MALNUTRITION AND MATERNAL SERUM LEVELS OF ZINC AT IDO-EKITI, SOUTHWESTERN NIGERIA

Abstract

Zinc is an essential micronutrient for normal fetal growth. Zinc deficiency is one of the
commonest micronutrient deficiencies in the developing countries probably because pregnant
women consume diets low in minerals and vitamins compared to those in developed countries.
Maternal zinc deficiency is associated with fetal growth retardation and fetal malnutrition (FM)
is common in developing countries. This study aimed to determine the association between the
maternal serum zinc levels and the prevalence of FM among term babies in Ido-Ekiti.
This cross-sectional study was conducted at the labour, post-natal and neonatal wards of
Federal Medical Centre, Ido-Ekiti. Consecutive mother-infant pairs at term were studied. Each
baby was examined within 24 hours of life for evidence of FM using the Clinical Assessment of
Nutritional Status (CANS) and the score (CANSCORE) as described by Metcoff. Babies with
CANSCORE below 25 were diagnosed as having FM. Anthropometric measurements obtained
were used to derive the ponderal index (PI) and mid arm circumference to head circumference
ratio (MAC/HC) of the babies. Maternal and cord blood samples were taken at delivery for
serum zinc analysis using Atomic Absorption Spectrophotometry. Zinc levels in babies with FM
and their mothers were compared with those without FM.
Three hundred and eighty-six mother-infant pairs were studied. PI and MAC/HC gave
prevalent rates of fetal malnutrition as 16.6% and 14.5% respectively while CANSCORE
identified ninety (23.3%) babies with malnutrition. The mean (SD) maternal serum zinc
concentration was 9.0 (6.1) µmol/L. One hundred and eighty-seven (48.4%) mothers had
hypozincaemia (serum zinc concentration < 7.6 µmol/L). The mean (SD) serum zinc levels of
mothers of babies with FM was 7.4 (5.3) µmol/L compared to 9.5 (6.2) µmol/L for the mothers
of babies without FM (p = 0.003). Fifty-eight (64.4%) mothers of the 90 babies with FM had
hypozincaemia compared with 129 (43.6%) of the 296 mothers of babies without FM. The
difference was statistically significant (p = 0.001).
The mean (SD) cord serum zinc concentration was 13.1 (7.8) µmol/L. One hundred and
fifty-three (39.6%) babies had hypozincaemia (cord serum zinc concentration < 9.9 µmol/L). The
mean cord serum zinc concentration was significantly higher than the mean maternal serum zinc
concentration (p = 0.000). Maternal serum zinc levels had positive correlation with cord serum
zinc levels (r = 0.403, p = 0.000). One hundred and seventeen (62.6%) babies of 187 mothers
with hypozincaemia had hypozincaemia while 36 (18.1%) babies of the 199 mothers with normal
serum zinc levels had hypozincaemia (p = 0.000).
The findings of the present study confirmed that there is a high prevalence of FM in the
study environment. The study also revealed a high prevalence of both maternal and cord serum
hypozincaemia. The higher prevalence of FM among babies of mothers with hypozincaemia
would suggest a causal relationship between low maternal zinc and FM. Community-based
studies on the prevalence of maternal hypozincaemia and its impact on FM and neonatal outcome are needed.

FETAL MALNUTRITION AND MATERNAL SERUM LEVELS OF ZINC AT IDO-EKITI, SOUTHWESTERN NIGERIA