Abstract
BackgroundEarly life exposure to arsenic is associated with decreased birth weight in highly exposed populations but little is known about effects of low-level arsenic exposure on growth in utero.MethodsUsing a sample of 272 pregnancies from New Hampshire we obtained biometric measurements directly from fetal ultrasound reports commonly found in electronic medical records. We used information extraction methods to develop and validate an automated approach for mining biometric measurements from the text of clinical reports. As a preliminary analysis, we examined associations between in utero low-level arsenic exposure (as measured by maternal urinary arsenic concentration) and fetal growth measures (converted to Z-scores based on reference populations for estimated fetal weight, head, and other body measures) at approximately 18 weeks of gestation.ResultsIn a preliminary cross-sectional analysis of 223 out of 272 pregnancies, maternal urinary arsenic concentration (excluding arsenobetaine) was associated with a reduction in head circumference Z-score (Spearman correlation coefficient, rs = -0.08, p-value = 0.21) and a stronger association was observed among female fetuses at approximately 18 weeks of gestation (rs = - 0.21, p-value < 0.05). Although, associations were attenuated in adjusted analyses — among female fetuses a 1 μg/L increase in maternal urinary arsenic concentration was associated with a decrease of 0.047 (95% CI: -0.115, 0.021) in head circumference and 0.072 (95% CI: -0.151, 0.007) decrease in biparietal head diameter Z-score.ConclusionsOur study demonstrates that useful data can be extracted directly from electronic medical records for epidemiologic research. We also found evidence that exposure to low-level arsenic may be associated with reduced head circumference in a sex dependent manner that warrants further investigation.Electronic supplementary materialThe online version of this article (doi:10.1186/1476-069X-14-12) contains supplementary material, which is available to authorized users.
Highlights
Life exposure to arsenic is associated with decreased birth weight in highly exposed populations but little is known about effects of low-level arsenic exposure on growth in utero
Among the ultrasound reports we identified, 42.6% of our sample of ultrasound reports were for current procedural terminology (CPT) code 76805 which corresponds to an initial fetal ultrasound examination, “Ultrasound pregnant uterus, fetal and maternal evaluation,” and 47.3% for CPT code 76816 that corresponds to a follow-up ultrasound, “Ultrasound pregnant uterus, follow-up evaluation” (Table 1)
Converted to gestational age specific Z-scores based on reference population, the mean Z-score for estimated fetal weight (EFW), head circumference (HC), biparietal diameter (BPD), abdominal circumference (AC), and femur length (FL) were 0.36 (SD: 1.5), 0.05 (SD: 0.8), -0.92 (SD: 1.00), -0.29 (SD: 0.82), and 0.03 (SD: 0.83) respectively
Summary
Life exposure to arsenic is associated with decreased birth weight in highly exposed populations but little is known about effects of low-level arsenic exposure on growth in utero. While previous studies have found effects on birth size [7] and growth into childhood [28] much less is known about effects on growth in the earliest stages of life [29]. To our knowledge only one study conducted in a highly exposed population has examined arsenic’s effects on intrauterine growth and found growth impairment in a sex-dependent manner [10]. One previous study from Bangladesh found that effects on human growth may occur at the lower end of the dose response curve (less than 100 ug/L as measured in urine) suggesting populations experiencing lower levels of exposure may be affected [7]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
