This study aimed to assess the prevalence and associated factors of teenage pregnancy in high-fertility countries in sub-Saharan Africa. Accordingly, one in four adolescent girls experiences pregnancy. Factors such as women’s education, occupation, marital status, wealth quantile, knowledge about modern contraceptive methods, unmet needs for family planning, and country were independently associated with teenage pregnancy.
In this study, the overall prevalence of teenage pregnancy was 24.88%, which is higher than the studies conducted in Ethiopia 23.59% , Cameroon 8.7% , Kenya 23.3% , Nigeria 22.9%  and South Africa 19.2% . This might be because of the large sample size and the fact that we included participants from different countries with a wide variety of socioeconomic status and cultural norms. Besides, the possible justification might be that in high fertility countries, there is a high proportion of early sexual initiations and early marriages [26, 27]. These factors may contribute to the high prevalence of teenage pregnancy in the present study as compared to the previous one.
However, the current finding is lower than studies conducted in East Africa 54.6% . The possible justification for this difference might be due to differences in socio-demographic characteristics among participants. For instance, the proportion of adolescent girls who had no formal education in this study was 28.21%. Whereas in the East Africa study, the figure was 8.28%. Moreover, the proportion of adolescent girls who were married in the current study was 27%, while in the previous study it was 46.46%. In this regard, previous research has documented that educational status has a negative association with teenage pregnancy, whereas marital status has a positive association with teenage pregnancy [6, 18, 29, 30]. Hence, preventing early marriage and having a large proportion of adolescents with secondary education or higher may reduce the odds of teenage pregnancy.
This study showed an association between education and teenage pregnancy. The odds of teenage pregnancy was 1.39 and 1.45 times higher among adolescents who had no formal education and primary education compared to secondary/ higher education levels, respectively. This is in line with studies conducted in East Africa  and sub-Saharan Africa . The possible reason could be that education enhances women’s autonomy and decision-making power to negotiate with their partners about sexual and reproductive rights. It also enhances economic independence, leading to the postponement of early marriage and a reduction of fertility . This indicates that educational status has a great impact on preventing teenage pregnancy.
In the current study, adolescent girls who have no work had higher odds of teenage pregnancy compared with those who had work. This finding is in line with a study conducted in Nepal . This might be explained by the fact that adolescents with no work might have no opportunity to access contraceptives and might be engaged in early sexual intercourse for the purpose of their economic benefit. Furthermore, adolescent girls who had work can financially support a poor family and stay in the family for a longer period without marrying. However, this finding is inconsistent with study done in sub-Saharan Africa .
Married adolescent girls had higher odds of being pregnant compared to their counterparts, which is supported by studies done in East Africa  and sub-Saharan Africa . This might be as adolescent girls married, being more likely to be exposed to frequent and unprotected sexual activity, often leading to an early and risky first birth. In developing countries, fertility was proved within a year of marriage . Furthermore, their husband's influence on them not to use contraception may be a factor . The finding of this study suggest that investment in ending early marriage is crucial to reducing teenage pregnancy and its complications.
This multilevel analysis found that household economic status significantly influenced the odds of teenage pregnancy in which the odds of teen age pregnancy was significantly higher among adolescents from poor and middle class households compared to the rich household class, which is in line with a study done in East Africa . This could be because adolescent girls from higher poverty may be exposed to early marriage and sexual initiation and can not afford the cost of sexual and reproductive health services, including contraceptives . Moreover, adolescent girls from poor households may be involved in transactional sex as an economic survival strategy, and this leads to pregnancy at a younger age .
Adolescent girls who had higher knowledge of contraceptive methods were more likely to have teenage pregnancies compared to their counterparts. Despite being counter-intuitive. This might be due to adolescent girls’ being aware of modern contraceptive methods after pregnancy occurs. Another possible reason could be that pregnancy might have occurred despite knowledge of family planning because of social pressure or desire to become pregnant and was not mitigated by outside incentives to delay pregnancy . Studies from the SSA have found that higher knowledge of modern contraceptive methods, particularly among adolescents, does not always lead to higher contraceptive use [37, 38]. Adolescent girls from Angola, Chad, the Demographic Republic of Congo, and Mali had a higher chance of being pregnant early.
Furthermore, the unmet need for family planning was significantly associated with teenage pregnancy. Women with unmet needs for family planning had higher odds of experiencing teenage pregnancy than those who met their family planning needs. The possible justification might be that the unmet need for family planning exposes adolescents to the risk of unintended pregnancy [39, 40]. Hence, these findings indicate that addressing the unmet need for family planning among adolescents is a good opportunity to reduce teenage pregnancy in the study areas so far.
Strength and limitation of the study
The study's main strength was that it used a large sample size of nationally representative survey data from high fertility countries in SSA. We employed multilevel analysis (an advanced model) to accommodate the hierarchical nature of the data and to get a reliable estimate and standard error. However, the data used in this study were cross-sectional, and we were unable to reveal the temporal relationship between teenage pregnancy and explanatory variables. Moreover, DHS surveys are based on self-reported information, and they might have the possibility of recall bias.