DETERMINATION OF LEAD LEVELS IN MATERNAL AND UMBILICAL CORD BLOOD AT BIRTH AT THE LAGOS UNIVERSITY TEACHING HOSPITAL, LAGOS

Abstract

The harmful effects of varying concentrations of lead on body organs and systems have been
widely studied in both children and adults. Furthermore, lead has been shown to cross from the
mother to the fetus via the placenta and levels as low as 5µg/dl may have a profound effect on
the neurological status of the newborn. Evidence abounds of high lead contamination in the
Nigerian environment mainly from continued use of leaded gasoline amongst other factors;
therefore there is the possibility of high lead levels in the newborns of women living in this
environment. This cross sectional study aimed to determine maternal and umbilical cord blood
lead levels at birth, and to assess the relationship between these levels and the socio
demographic factors and anthropometry of the newborns.
A total of four hundred mother-newborn pairs were enrolled for the study. Blood samples were
obtained from the mothers and umbilical cord of the newborns at delivery and analysed by
atomic absorption spectrophotometry. Socio-demographic and obstetric data was obtained by
questionnaires administered to the mothers. The anthropometric measurements of the babies
were taken at birth and clinical data recorded.
The results from this study showed that median maternal blood lead level was 64.3µg/dl and that
of the umbilical cord was 39.2µg/dl. The levels were above 5µg/dl in 75.6% and 66.8% of
mothers and umbilical cord respectively. There was a strong positive correlation between the
maternal and umbilical cord blood lead levels (rs= 0.80). Use of calcium supplements during
pregnancy was shown to be significantly associated with a lower lead level in the maternal blood
(p=0.010) while recent painting and renovation of residential accommodation were associated
with a higher lead concentration in the umbilical cord blood (p=0.025). There were no
statistically significant associations between the maternal and umbilical cord blood lead levels
and the gestational age and anthropometry of the newborns at birth.
The findings of the study support the hypothesis of the possibility of elevated lead levels in
newborns of women residing in Lagos. There is therefore a crucial need to intensify measures
aimed at reducing lead exposure which should incorporate sensitization of the general public and
policy makers, ensure clear policy direction complementative on lead content of items such as
paints, gasoline etc. routine education of mothers in our ante-natal classes, and mandatory lead
screening in our antenatal care programme.

DETERMINATION OF LEAD LEVELS IN MATERNAL AND UMBILICAL CORD BLOOD AT BIRTH AT THE LAGOS UNIVERSITY TEACHING HOSPITAL, LAGOS