Comparison of Ultrasonography and Amniotic Fluid Cytology in Screening for Suspected Neural Tube Defects in Intrauterine Fetal Demise at Kenyatta National Hospital
Abstract
Background: Neural tube defects are a cause of intrauterine fetal demise or stillbirth globally.
Ultrasonography screening for NTDs in IUFDs poses limitations as non-diagnostic sonogram
yields have been shown from studies among macerated IUFDs in screening for brain and heart
defects. Amniotic fluid cytology is inexpensive, rapid, and complements ultrasonograms on
screening for open NTDs and would improve the sensitivity and specificity of screening. The
amniocentesis procedure is safe and feasible, carrying low risks or complications for mothers.
Studies have been performed on intrauterine fetal demise in various populations, but few in
Kenya. There are limited facts on the frequency of neural tube defects in Kenya and studies
have recommended more studies and surveillance monitoring systems.
Objective: To detect exfoliated neural cells from suspected amniotic fluid smears, to identify
positive IHC-stained amniotic fluid cellblocks as confirmatory for open NTDs, and to compare
suspected fetal anatomy sonograms for NTDs with their amniotic fluid cytology results.
Methodology: This was a cross-sectional descriptive study. Ultrasonograms and amniotic fluid
samples were collected from 77 pregnant women with confirmed IUFDs over four months (Dec
2021 – Mar 2022) by purposive sampling method. Clinical and socio-demographic data was
collected using a structured questionnaire. Amniotic fluid samples were processed using
manual liquid-based cytology, routine staining, and immunohistochemistry staining. Kappa
statistical analysis and cross-tabulation were used to check the level of agreement and
significance between the diagnostic methods respectively. Results were presented as tables,
figures, bar graphs, and pie charts.
Results: A total of 77 gravid mothers with IUFDs were recruited and out of these, 26 had a
complete dataset. Multiple imputation analysis was done to replace the missing data with
substitute values to retain information about the dataset. Out of the 77 ultrasonograms and
amniotic fluid samples, 20 ultrasonographic scans showed abnormal fetal anatomy of the
IUFDs and 29 amniotic fluid samples were positive for neural tube defects respectively. The
prevalence of neural tube defects among IUFDs was 26%. There was a significant difference
between ultrasonography and amniotic fluid cytology (p = 0.003), and a comparability of 0.82
kappa statistic.
Conclusion: The study provides essential information comparison between ultrasonography
with amniotic fluid cytology for screening pregnant women with IUFDs. The data showed a
significant difference between ultrasonography and amniotic fluid cytology screening for
NTDs, with cytology performing better. Amniotic fluid cytology in this study complements
ultrasonography in the detection of neural tube defects in IUFDs
Publisher
University of Nairobi
Rights
Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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