Risk factors associated with neural tube defects among infants attending Kijabe Hospital and the affiliate six Satellite Clinics

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.