Abstract:
Introduction: Neural tube defects (NTDs) are preventable birth anomalies of the spine
and brain that occur in the first trimester of pregnancy, leading to increased morbidity
and mortality in children <5 years. Globally an estimated 300,000 cases of NTD occur,
where 276,000 die during infancy, majority in low income countries. In Kenya World
Health Organization (WHO) estimates prevalence of NTDs at 6/10,000 live births as at
2013. NTDs account for 0.5-2.0/1000 pregnancies annually and is as high at 10.0/1000
in certain geographical locations.
Objective: Determine factors associated with NTDs among infants attending Kijabe
Hospital and affiliated satellite clinics.
Methods: Matched case-control study conducted between July and November 2017.
Cases were infants diagnosed with NTD at Kijabe Hospital and its affiliated satellite
clinics, controls were infants with no history of hospitalization, not known /or
diagnosed with any congenital anomaly. Controls were selected randomly from
Maternal Child Health Clinics in County and Sub-County Hospitals proximal to the
satellite clinics. Controls were matched to cases for -age, -sex and -geographical
location. Maternal risk factor information collected included, maternal socio-
demographic information, maternal Health, Obstetric, and nutrition information.
Neonates information collected were Age, sex, weight, length, type of NTD, gestation
age at birth, birth order. Risk factor information were FA supplementation,
consumption of FA fortified foods, folate rich foods, drug use, alcohol use, medication
in pregnancy, smoking, previous family history of NTDs/ or birth defects. Principal
Components Analysis (PCA) was used to generate wealth index for the respondents
based on a set of household characteristics, and asset ownership. Conditional logistic
regression was used to evaluate risk factors for NTDs.
Results: A total of 60 cases and 120 controls were enrolled. Of 60 cases, 59 (98.3%)
had spinabifida and 1 (1.7%) encephalocele. Among spinabifida cases, 29 (48%) were
meningoceles, 29 (48.0%) myelomeningocele and 25 (41.7%) spina bifida occulta
5(8.4 %). Median age of infant- participants was 5.5 (range 3 -52) weeks, median
gestational age at birth was 39 (range 34-42) weeks. Infant gender 111(61.7%) were
boys of whom 37 were cases, and 69 (38.3%) girls with 23 being cases. Mothers with
unplanned pregancy were 101 (55.2%) and 166 (92.2%) attended antenatal clinic
(ANC). Mothers tested for HIV were 158 (87.8%) of whom 12 (6.6%) were on
antiretrovirals, with only one being a case. Factors associated with increased risk of
NTD were history of pregnancy loss (aOR=6.4, 95% CI 2.4-17.4), multiparity
(aOR=6.59, 95% CI 2.16-20.1), periconception consumption of folic acid fortified flour
(aOR=6.9, 95% CI 1.61-29.6), use/contact with pesticides (aOR=6.4, 95% CI 1.3-13.9).
Preconception folic acid supplementation was protective (aOR 0.13, 95% CI 0.045-
0.5).
Conclusions: Risk factors associated with NTDs identified were multiparity, previous
pregnancy loss, use/ contact to pesticides. Folic acid supplementation before conception
was protective. Periconceptional consumption of folic acid fortified flour 3 times/week
was not protective against NTDs.
Recommendations: Use of personal protective gear, contact to pesticides was
associated with increased NTDs risk. Encourage periconceptional FA supplements to
women of reproductive age and post market surveillance of levels of FA in fortified
flour.