Robert Krajina

Relationship between the prenatal exposure to low-level of mercury and the size of a newborn’s cerebellum

Exposure to methylmercury at any stage of central nervous system development could induce alterations and result in severe congenital abnormalities. Total mercury level in maternal hair during pregnancy correlates well with blood levels of methylmercury and with total mercury levels in fetal brain. A prospective study has been conducted and a total of 137 childbearing women living at the coastal region with term, normal pregnancies were included and their newborns evaluated by ultrasonography. Mothers and their newborns are divided in two groups according to their hair mercury levels; examined group with high body levels of mercury (≥ 1 μg/g) and control group with low body levels of mercury (<1 μg/g). Neurosonographic examination was conducted to all newborns. Two dimensions of cerebellum in the sagital-medial plane have been measured: maximum height and width starting from the roof of the fourth chamber. Majority of mothers had hair mercury levels lower than 1 μg/g (N = 107). Mean value was 0.88 μg/g (SD 1.24), ranging from 0.02 to 8.71 μg/g. There was no significant difference between the two groups when it comes to the width of cerebellum (Mann-Whitney test: Z = 1471; p = 0.141). However, comparison related to the length of cerebellum shows statistically significant smaller cerebellum in newborns whose mother had hair mercury levels higher than 1 μg/g (Mann-Whitney test: Z = 2329; p = 0.019). Our results lead to a conclusion that prenatal exposure to, what we consider to be, low-levels of methylmercury does influence fetal brain development detected as decreased size of newborns cerebellum. From a clinical point of view, a question related to the influence of prenatal low-level methylmercury exposure on fetal neurodevelopment remains open. Our further objectives are to direct the research towards performing detailed neuropshychological tests on children at the age of 18 months. Such tests could indicate the presence of subtle neurological or neuropsychological deficits.

The influence of pre-eclampsia on fetal lung maturity

To use amniotic fluid (AF) lamellar body count (LBC) to assess the influence of pre‐eclampsia and associated pathologic conditions on fetal lung maturity (FLM).

Lamellar body count as a diagnostic test in predicting neonatal respiratory distress syndrome

Aim To determine the lamellar body count (LBC) cutoff value for fetal lung maturity and to evaluate the clinical usefulness of LBC in predicting the severity of neonatal respiratory distress syndrome (RDS). Methods A prospective study was conducted from 2002 until 2010. LBC was estimated in uncentrifugated amniotic fluid samples using Cell-Dyn 1800 analyzer. Amniotic fluid samples were obtained by amniocentesis or by puncturing embryonic membranes during cesarean section. The presence of mild, moderate, and severe RDS was assessed by neonatologist. Results A total of 313 patients with singleton pregnancies (24-41 weeks) were included in the study and 294 met the inclusion criteria. RDS was diagnosed in 28 neonates – mild in 8, moderate in 10, and severe in 10. In premature neonates (<37 gestational weeks), significant differences in LBC were only found between the subgroup without RDS and the group with moderate and the group with severe RDS (P < 0.001). In all neonates, significant differences were found between neonates without RDS and neonates with RDS. Using LBC cutoff value of ≥20,000/µL, sensitivity, specificity, and positive and negative predictive values of LBC in determining mature fetal lungs were 96%, 88%, 45.6%, and 99.5%, respectively. Conclusion This study suggests that LBC cutoff value of ≥20,000/µL can predict pulmonary maturity and reduce the risk of neonatal respiratory distress syndrome.

Fetal ultrasound biometry for pregnant population in the County of Primorje-Gorski Kotar (Croatia)

Objective. To create curves of three most commonly used biometric parameters for singleton pregnancies from 22 to 41 weeks of gestation in the County of Primorje-Gorski Kotar (Croatia) and to compare results with other studies. Methods. From January 2002 to December 2009, ultrasound examination was performed on fetuses of 1248 pregnant women with uncomplicated pregnancy. Values for biparietal diameter, femur length, and fetal abdominal circumference were measured. Results were compared with studies pertaining to European and North American population. Mean, percentile scale, and Wilcoxons matched pairs test were used. Regression analysis was applied to analyze data correlation and to determine correlation quotients. Results. Total of 2178 measurements for fetal biometry charts were performed. Established mean and centile values for fetal biometry parameters are reported numerically and graphically. Comparison of obtained values with values of identical fetal biometric parameters of other world populations has revealed statistically significant differences (p < 0.01). Conclusion. Normal fetal biometry charts for population of pregnant women in the northern coastal region of Croatia were constructed. Due to existence of statistically significant differences in ultrasound fetal biometry values among various populations under comparison, construction of own charts and their implementation in routine obstetrical work are justified.

Effects of prenatal exposure to low-level methyl-mercury on fetal brain development: A preliminary report

Istraživani su ucinci niske razine metil-žive na razvoj fetalnog mozga. Nije nađena statisticka znacajnost razlike neurorazvojnih karakteristika mozga djece prenatalno izložene razinama metil-žive vece i manje od 1mcg/g.