Factors associated with adolescent pregnancy and public health interventions to address in Nigeria: a scoping review

Papers on adolescent pregnancy in Nigeria published between January 2007 and December 2022 were searched. The choice to include papers from the past fifteen years reflects the urgent requirement for recent data to support advocacy for the domestication and use of WHO guidelines to reduce adolescent pregnancy and enhance adolescent sexual reproductive and mental health in Nigeria. This review used the population, Concept and Context (PCC) approach when formulating the review question.; the population are teenage girls, the concept of Teenage Pregnancy, and the context in Nigeria.

A spreadsheet in Microsoft Excel was used to extract information from the full texts. Information extracted included the author's name, the title of the study, the publication year, the design of the study, the sample size, the prevalence of adolescents' pregnancy, observed factors, and the key messages derived from the results, and interventions to reduce teenage pregnancy if used in the study.

The reviewers used the socioecological model to report the factors mentioned in the articles. The data were organised into common categories and summarised in a table. The results were then reviewed in connection to the general review question through a narrative summary included with the tabulated results. The reviewers used the socioecological model to map Nigeria's factors affecting teenage pregnancy. This model was adopted by [24].

This model describes factors on different levels individual, interpersonal, organisation, community, and policy. This model is used widely to map better factors considering individual factors, social, cultural, policy and systems-related factors [25, 26, 28].

The initial comprehensive search yielded 241 articles, of which 229 were identified through the databases, and 12 were identified through hand search. After removing 43 duplicates, a total of 201 publications were screened for eligibility based on their titles and abstracts. After reviewing their titles and abstracts, a full-text review of 96 papers was conducted. We removed 68 after doing a thorough text analysis since they did not fit our inclusion criteria for various reasons. Using review article references as a guide, we could not locate any additional articles to include. In the end, 28 publications were included in our scoping review after meeting all inclusion criteria (Fig. 1).

Table 1 presents the characteristics of the included articles. A total of 28 studies were included in the study. Twenty-two quantitative studies: 9 descriptive cross-sectional studies out of the 28 included studies [19, 32, 33, 52, 60, 72], 13 comparative cross-sectional studies [1, 6, 18, 34, 45, 57, 58], [8, 10, 21, 36, 62, 63], five qualitative studies :1 focus group discussions [13] and four key informant interviews [11, 35, 48, 64] and one retrospective study [42]. In addition, out of the 28 included studies, 10 were studies that used only the Demographic Health Survey in "Nigeria" [6, 8, 10, 11, 18, 21, 36, 45, 62].

In terms of the geographical location of the studies, six studies were conducted in South-west Nigeria [1, 35, 48, 60, 63, 72], while five were conducted in South-south [14, 32, 52].On the other hand, few studies (4) were conducted in the Southeast [19, 33, 57, 58], and finally, only two studies were conducted in North Central [33, 62].

Fourteen out of the twenty-eight studies included in the analysis reported adolescent pregnancy prevalence. In Nigeria, the prevalence of adolescent pregnancy, as recorded by researchers, was 7.5%, 19%, 23%, 7.5–24%, 30%, and 49.50% [6, 8, 35, 36, 45, 58]. The regional prevalence, as reported by researchers in South-south, was 1.5%, 12% and 77% [14, 52], South-west 1.1%, 5.60% and 43.50% [48, 63, 72], Southeast 45% and 49% [32, 55] and North 14.30% and 8.2% [33, 62] (Table 1).

Twenty-eight studies were included in the study. Twenty-two studies were quantitative (9 descriptive cross-sectional and 13 comparative cross-sectional studies), while five were qualitative studies and one retrospective study (Table 1).

The factors were categorised using the social-ecological model [24] into the individual level, interpersonal level factor, organisational level and community-level factors were identified as correlate/putative risks for adolescent pregnancy in Nigeria (Table 2).

Six out of the twenty-eight studies included in the analysis reported interventions of adolescent pregnancy in Nigeria [11, 19, 35, 58, 72]. The interventions are grouped into individual level which include abstinence from sexual activities, self-discipline, preventive health strategies and avoidance of bad friends [11, 35, 72] governmental level which include government awareness , regulation of social media, banning of blue film etc [11, 19, 35, 72] interpersonal level which includes adequate financial support , Proper parental upbringings and guidance and cordial relationships between parents and children etc [11, 19, 35, 72] organisational level which include distribution of condoms in schools, joining religious groups and religious upbringing [11, 19, 35] ) and educational levels reported as sex education [11, 19, 35, 58, 72] (Table 3).

The prevalence of adolescent pregnancy in Nigeria ranged from 7.5% to 49.5%. The prevalence was found to vary by region, with the Northcentral region having the highest prevalence of 14.3% and the South-south region having the lowest prevalence of 5.2%. These findings are consistent with previous studies that have shown regional differences in adolescent pregnancy rates in Nigeria [73]. This prevalence is higher than other SSA, which ranged from 7.2% in Rwanda to 44.3% in Congo [5]. The attitudes and beliefs of individuals and society towards the education of the female child, public health campaigns and the promotion of contraceptive uptake, as well as religious and cultural norms, can significantly impact the prevalence of adolescent pregnancy. For instance, in some parts of Nigeria, the education of the female child is not prioritized, and girls may have limited access to information about sexual and reproductive health. Furthermore, some religious and cultural practices may discourage the use of contraceptives, leading to a higher risk of unintended pregnancy. [5]. To further support this finding, a study by Ilene S Speizer et al. [73] revealed that in northern Nigeria, girls have lower levels of education, are more likely to be married early, and have less access to healthcare and family planning services, compared to their southern counterparts. On the other hand, in the southern region, where there is generally more education and access to healthcare, adolescent pregnancy prevalence is lower.

This review has revealed some factors associated with adolescent pregnancy in Nigeria and identified some intervention strategies for curbing this issue. These strategies can be grouped into individual, governmental, interpersonal, organisational, and educational levels.

Our review has several strengths, including the use of a rigorous methodology to address the research questions. However, it is important to note that only studies published in English were included, which may have limited the scope of our findings. Some studies included in our review had small sample sizes, which could have led to an underestimation of the prevalence of adolescent pregnancy in Nigeria. Additionally, our review did not examine the subcomponents of the interventions to better understand the causal pathways to the impact of the studies that recorded successful interventions. Therefore, the replication or scaling up of these successful interventions should be done with caution. Lastly, our focus on research conducted solely among adolescents in Nigeria may have excluded potentially successful interventions recorded in other settings that could be adapted to Nigeria.

To effectively leverage international attention and improve interventions against adolescent pregnancy in Nigeria, it is essential to consider the empirical evidence from this scoping review on the prevalence, associated factors, policies, and interventions for preventing adolescent pregnancy. This evidence can inform the development and investment in Adolescent Sexual and Reproductive Health and Rights (ASRHR) policies and programs in Nigeria. Implementing evidence-based interventions is expected to yield a high return on investment and positively impact the sexual and mental health of adolescents. Policymakers, researchers, and stakeholders should use the findings from this review to inform policy decisions, design effective interventions, and conduct further research to strengthen the evidence base on interventions against adolescent pregnancy in Nigeria.