Childbearing dynamics among married women of reproductive age in Nigeria: re-affirming the role of education

Nigeria ranks among the high-fertility countries in sub-Saharan Africa. Studies that examine relationship between fertility dynamics and education are important to improving maternal and child health. This study uses 2008 NDHS dataset on births history of married women of childbearing age. Data were analysed using ANOVA, Kaplan-Meier and Cox-proportional hazard models. Mean CEB were 6.72 and 4.31 among women with no formal education and higher education respectively. Majority (38.6%) of the women left 24-35 months births-interval. Women with lower education exhibited shorter births-interval and higher completed fertility than more educated women. The Births Progression Hazard Rate from marriage to 1 birth was higher among highly educated women than those with no education, but reverse pattern was observed at higher order births. This pattern barely changes after controlling for other socio-demographic variables. Education remains an important factor in fertility dynamics in Nigeria; therefore, existing policies addressing female education should be sustained

Determinants of Unmet Need for Modern Contraception and Reasons for Non-use among Married Women in Rural Areas of Burkina Faso

Burkina-Faso (TFR=6.0) is among the top-ten high fertility countries world-wide and CPR (15%) among women is low. This study examined the factors associated with non-use of modern contraception among married women residing in the rural areas of Burkina-Faso. The study used 2010 Burkina Faso Demographic and Health Survey data-set and focussed on married women aged 15-49 years (n=7,191). Chi-square and logistic regression techniques were used for the analysis (a=5%). Mean number of living children was significantly higher among women who have UNMC (3.92) than those with met need (3.01). Modern CPR and UNMC among married women was 12.7% and 40.7% respectively. The multivariate analysis reveals that being married more than once increases the likelihood of UNMC (OR=1.304; C.I=1.0821.571, p<0.05). Husbands’ approval of FP is a protective factor of UNMC (OR=0.858; C.I=0.7560.975, p<0.05). Husbands’ approval and health education on benefits of FP are important factors to consider in strategies aimed at reducing UNMC in Burkina-Faso.

Contraceptive use among Nigerian women with no fertility intention: interaction amid potential causative factors

High fertility (HF) remains a public health problem and intention to reduce fertility is a global phenomenon. The health hazards and economic burden of HF on women are enormous. Contraceptive is widely known as a fertility reduction method. Achieving desirable MDGs and PoA of 1994 ICPD will be an illusion if research on the relationship between fertility intention and contraceptive use is neglected. The study which focused on 2,257 women of childbearing age who do not have any intention to bear more children utilized Nigeria Demographic Health Survey, 2008 dataset. Data was analysed using Chi-square, binary and multinomial logistic regression (=5.0%). Mean age of the women and children ever born were 40.91±5.73 years and 6.28±2.62 respectfully. The prevalence of Current Use of Any Contraceptive Method (CUACM) was 37.6% with 12.4% and 25.2% currently using natural and modern family planning methods respectively. About 7.0% of women in poorest wealth quintile are CUACM compared to 61.8% of those in richest wealth quintile. Current use of modern contraceptive prevalence rate was strikingly higher among Yorubas (41.8%) than the Hausas (3.6%). Multivariate analysis identified age, region, residence, education, ethnicity and family planning media exposure as significant predictors of CUACM. In addition; religion and decision on how to spend family income were identified as predictors of current use of modern contraceptive method (p<0.05). The use of contraceptive is not adequately practiced in Nigeria. The identified predictors of contraceptive use in this study should be considered while designing strategies to improve contraceptive prevalent rate in Nigeria

Variations in modern contraceptive uptake and its correlates in South West and North East Nigeria: a comparative analysis

Background: Family planning programs are implemented specifically to address the sexual and reproductive health challenges of women of childbearing age but these interventions are yet to address regional differences in modern contraceptive usage in Nigeria. Hence, this study aimed to examine correlates of modern contraceptive uptake in South West and North Eastern, Nigeria.Methods: A cross-sectional survey data for women aged 15-49 years was extracted from Nigeria demographic and health surveys 2018 (NDHS). Data analyses were based on a weighted sample of 10,907 (North East= 5406 and South West = 5501) women of reproductive age. The outcome variable was modern contraceptive use. The main explanatory variables were age, employment status, religion, Number of living children, education, and marital status. Frequency distribution, Chi-square test, and binary logistic regression were used for data analysis (α=0.05).Results: The result showed the mean age of women of reproductive age in South West and North East to be 32years and 30 years respectively. More women in South West used modern contraceptive than women in North East. About 91.5% and 75.8% of women in North East and South West respectively did not used any modern method. The result showed that, in the South West, number of living children (OR:4.06, CI: 2.794-5.921), education (OR:1.35, CI: 1.045-1.754) and wealth index (OR:1.77, CI: 1.053-2.973) increased the odds of contraceptive uptake, while maternal age (OR:0.52, CI: 0.282-0.965), religion (OR:0.25, CI: 0.184-0.347) and place of residence (OR:0.68, CI: 0.504-0.916) significantly reduced the odds of modern contraceptive uptake in North East.Conclusions: This study concludes that there are regional variations in uptake and predictors of modern contraceptives use in Nigeria. Therefore, sexual and reproductive health interventions that considers the study’s significant variables should be put in place to increase uptake

The African Genome Variation Project shapes medical genetics in Africa.

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa

Identification, Replication, and Fine-Mapping of Loci Associated with Adult Height in Individuals of African Ancestry

Adult height is a classic polygenic trait of high heritability (h2 ∼0.8). More than 180 single nucleotide polymorphisms (SNPs), identified mostly in populations of European descent, are associated with height. These variants convey modest effects and explain ∼10% of the variance in height. Discovery efforts in other populations, while limited, have revealed loci for height not previously implicated in individuals of European ancestry. Here, we performed a meta-analysis of genome-wide association (GWA) results for adult height in 20,427 individuals of African ancestry with replication in up to 16,436 African Americans. We found two novel height loci (Xp22-rs12393627, P = 3.4×10−12 and 2p14-rs4315565, P = 1.2×10−8). As a group, height associations discovered in European-ancestry samples replicate in individuals of African ancestry (P = 1.7×10−4 for overall replication). Fine-mapping of the European height loci in African-ancestry individuals showed an enrichment of SNPs that are associated with expression of nearby genes when compared to the index European height SNPs (P<0.01). Our results highlight the utility of genetic studies in non-European populations to understand the etiology of complex human diseases and traits

Genetic Association for Renal Traits among Participants of African Ancestry Reveals New Loci for Renal Function

Chronic kidney disease (CKD) is an increasing global public health concern, particularly among populations of African ancestry. We performed an interrogation of known renal loci, genome-wide association (GWA), and IBC candidate-gene SNP association analyses in African Americans from the CARe Renal Consortium. In up to 8,110 participants, we performed meta-analyses of GWA and IBC array data for estimated glomerular filtration rate (eGFR), CKD (eGFR <60 mL/min/1.73 m2), urinary albumin-to-creatinine ratio (UACR), and microalbuminuria (UACR >30 mg/g) and interrogated the 250 kb flanking region around 24 SNPs previously identified in European Ancestry renal GWAS analyses. Findings were replicated in up to 4,358 African Americans. To assess function, individually identified genes were knocked down in zebrafish embryos by morpholino antisense oligonucleotides. Expression of kidney-specific genes was assessed by in situ hybridization, and glomerular filtration was evaluated by dextran clearance. Overall, 23 of 24 previously identified SNPs had direction-consistent associations with eGFR in African Americans, 2 of which achieved nominal significance (UMOD, PIP5K1B). Interrogation of the flanking regions uncovered 24 new index SNPs in African Americans, 12 of which were replicated (UMOD, ANXA9, GCKR, TFDP2, DAB2, VEGFA, ATXN2, GATM, SLC22A2, TMEM60, SLC6A13, and BCAS3). In addition, we identified 3 suggestive loci at DOK6 (p-value = 5.3×10−7) and FNDC1 (p-value = 3.0×10−7) for UACR, and KCNQ1 with eGFR (p = 3.6×10−6). Morpholino knockdown of kcnq1 in the zebrafish resulted in abnormal kidney development and filtration capacity. We identified several SNPs in association with eGFR in African Ancestry individuals, as well as 3 suggestive loci for UACR and eGFR. Functional genetic studies support a role for kcnq1 in glomerular development in zebrafish

Discovery and fine-mapping of adiposity loci using high density imputation of genome-wide association studies in individuals of African ancestry: African Ancestry Anthropometry Genetics Consortium

Genome-wide association studies (GWAS) have identified >300 loci associated with measures of adiposity including body mass index (BMI) and waist-to-hip ratio (adjusted for BMI, WHRadjBMI), but few have been identified through screening of the African ancestry genomes. We performed large scale meta-analyses and replications in up to 52,895 individuals for BMI and up to 23,095 individuals for WHRadjBMI from the African Ancestry Anthropometry Genetics Consortium (AAAGC) using 1000 Genomes phase 1 imputed GWAS to improve coverage of both common and low frequency variants in the low linkage disequilibrium African ancestry genomes. In the sex-combined analyses, we identified one novel locus (TCF7L2/HABP2) for WHRadjBMI and eight previously established loci at P < 5×10−8: seven for BMI, and one for WHRadjBMI in African ancestry individuals. An additional novel locus (SPRYD7/DLEU2) was identified for WHRadjBMI when combined with European GWAS. In the sex-stratified analyses, we identified three novel loci for BMI (INTS10/LPL and MLC1 in men, IRX4/IRX2 in women) and four for WHRadjBMI (SSX2IP, CASC8, PDE3B and ZDHHC1/HSD11B2 in women) in individuals of African ancestry or both African and European ancestry. For four of the novel variants, the minor allele frequency was low (<5%). In the trans-ethnic fine mapping of 47 BMI loci and 27 WHRadjBMI loci that were locus-wide significant (P < 0.05 adjusted for effective number of variants per locus) from the African ancestry sex-combined and sex-stratified analyses, 26 BMI loci and 17 WHRadjBMI loci contained ≤ 20 variants in the credible sets that jointly account for 99% posterior probability of driving the associations. The lead variants in 13 of these loci had a high probability of being causal. As compared to our previous HapMap imputed GWAS for BMI and WHRadjBMI including up to 71,412 and 27,350 African ancestry individuals, respectively, our results suggest that 1000 Genomes imputation showed modest improvement in identifying GWAS loci including low frequency variants. Trans-ethnic meta-analyses further improved fine mapping of putative causal variants in loci shared between the African and European ancestry populations

Genome-Wide Association of Body Fat Distribution in African Ancestry Populations Suggests New Loci

Central obesity, measured by waist circumference (WC) or waist-hip ratio (WHR), is a marker of body fat distribution. Although obesity disproportionately affects minority populations, few studies have conducted genome-wide association study (GWAS) of fat distribution among those of predominantly African ancestry (AA). We performed GWAS of WC and WHR, adjusted and unadjusted for BMI, in up to 33,591 and 27,350 AA individuals, respectively. We identified loci associated with fat distribution in AA individuals using meta-analyses of GWA results for WC and WHR (stage 1). Overall, 25 SNPs with single genomic control (GC)-corrected p-values<5.0×10−6 were followed-up (stage 2) in AA with WC and with WHR. Additionally, we interrogated genomic regions of previously identified European ancestry (EA) WHR loci among AA. In joint analysis of association results including both Stage 1 and 2 cohorts, 2 SNPs demonstrated association, rs2075064 at LHX2, p = 2.24×10−8 for WC-adjusted-for-BMI, and rs6931262 at RREB1, p = 2.48×10−8 for WHR-adjusted-for-BMI. However, neither signal was genome-wide significant after double GC-correction (LHX2: p = 6.5×10−8; RREB1: p = 5.7×10−8). Six of fourteen previously reported loci for waist in EA populations were significant (p<0.05 divided by the number of independent SNPs within the region) in AA studied here (TBX15-WARS2, GRB14, ADAMTS9, LY86, RSPO3, ITPR2-SSPN). Further, we observed associations with metabolic traits: rs13389219 at GRB14 associated with HDL-cholesterol, triglycerides, and fasting insulin, and rs13060013 at ADAMTS9 with HDL-cholesterol and fasting insulin. Finally, we observed nominal evidence for sexual dimorphism, with stronger results in AA women at the GRB14 locus (p for interaction = 0.02). In conclusion, we identified two suggestive loci associated with fat distribution in AA populations in addition to confirming 6 loci previously identified in populations of EA. These findings reinforce the concept that there are fat distribution loci that are independent of generalized adiposity