The frequency of deliveries among adolescents was 2.45%.

The mean age was 17.80 ± 1.20 years, with extremes of 13 and 19 years. Most participants were between 16 and 19 years old (94.10%). A large majority were enrolled in school (89%). Professionally, pupils/students and apprentices were predominant, with respective proportions of 37.90% and 29.30%. Regarding obstetric history, 91.30% were primigravidae and 93.70% were nulliparous. Only 38.87% had attended at least four antenatal care visits (ANC). The prenatal workup was fully completed in 31.62% of cases. However, 22% had not undergone any obstetric ultrasound. The main mode of admission was referral (67.20%). Sociodemographic and clinical characteristics are presented in Table 1.

Table 1. Sociodemographic characteristics and obstetric history of adolescents who delivered at CNHU-HKM, Cotonou, 2018-2022.

¹Paucigravida: women with 2 or 3 previous pregnancies, ²Multigravida: women with 4 or more previous pregnancies, ³Pauciparous: women with 2 or 3 previous deliveries.

Preterm delivery occurred in 36.53% of cases. The cesarean section rate was 41.69%.

The main indications for cesarean section were severe preeclampsia and eclampsia (24.70%), and acute fetal distress (18.50%). Onset of labor was most often spontaneous (90.30%). Delivery characteristics are presented in Table 2.

Table 2. Distribution of adolescents according to delivery characteristics at CNHU-HKM, Cotonou, 2018-2022.

Preterm delivery¹: From 22 weeks of gestation to 36 weeks + 6 days; Term delivery²: From 37 weeks to 41 weeks of gestation ; Post-term delivery³: After 41 weeks of gestation.; SVD⁴ (Spontaneous Vaginal Delivery): Vaginal delivery.

Maternal Mortality

Among 427 cases of early motherhood and 385 live births (LB), 14 maternal deaths were recorded, corresponding to a maternal mortality rate of 3.28% and a maternal mortality ratio (MMR) of 3636 deaths per 100,000 LB. The causes of death were eclampsia (35.70%), severe anemia (28.60%), and immediate postpartum hemorrhage (14.30%).

Maternal Complications During Pregnancy and Delivery

Pregnancy was complicated in 54.30% of cases. The main conditions identified were hypertensive disorders of pregnancy (15%), eclampsia (13.10%), and anemia (7.30%).

Complications of vaginal delivery included cervical lacerations (2.40%) and perineal tears (2.40%). In the postpartum period, the conditions identified were hypertensive disorders and eclampsia (18.90%), severe anemia (3.40%), and immediate postpartum hemorrhage (IPPH) (3.10%). Complications related to pregnancy and delivery are presented in Table 3.

Table 3. Distribution of adolescents who delivered at CNHU-HKM, Cotonou, 2018-2022, According to maternal complications.

IPPH⁵: Immediate postpartum hemorrhage.

Stillbirth

Out of 439 births, 54 stillbirths were recorded, corresponding to a stillbirth rate of 12.30%.

Perinatal Morbidities

Fetal asphyxia was observed in 18.68% of cases. Preterm newborns accounted for 36.50%, 5.50% had an Apgar score at one minute ≤ 3, and 31.70% had a birth weight below 2500 grams. Table 4 presents the main perinatal morbidities.

Table 4. Perinatal morbidities of adolescent mothers at CNHU-HKM, Cotonou, 2018-2022.

The frequency of deliveries among adolescents was 2.45%. This rate is lower than those reported by other authors in sub-Saharan Africa. Hamidou S reported a rate of 3.06% at the Issaka Gazobi Maternity in Niamey; Prosper found 7.7% in Lubumbashi; and Samaké reported 19.61% at the Reference Health Center of Commune VI in the Bamako district [4]-[6]. Tebeu noted a prevalence of 26.5% in northern Cameroon in rural area [7]. Some studies have reported lower rates than ours, notably in Enugu, Nigeria (1.67%), and Kuala Lumpur, Malaysia (1.1%) [8][9]. In France, the overseas departments record variable rates of adolescent maternity: 6.2% in French Guiana, 3.8% in Réunion, and 4.2% in Guadeloupe [4][10]. Although sub-Saharan Africa has experienced a general decline in the number of births per woman, adolescent fertility rates remain high in many countries. Each year, children born from girls aged 15 to 19 years account for 16% of all births, according to an UNFPA report [11]. Globally, one in five girls gives birth to her first child before the age of 18 [12].

Several factors contribute to the high rates of pregnancy and childbirth among adolescents, including socioeconomic vulnerability, low levels of education, lack of information and sexual education, forced and early marriages, sexual violence, cultural taboos, stigmatization of girls using contraceptive methods, and difficulties in accessing contraception [12]-[14].

In Cotonou, early motherhood primarily affects older adolescents, with a mean age of 17.80 ± 1.20 years, most of whom are enrolled in school (89%). Antenatal care was limited, with an insufficient number of prenatal visits and incomplete biological and ultrasound assessments. Among the 63.50% who delivered at term or post-term, only 38.87% attended at least four antenatal care visits. Several factors may explain this finding, including lack of financial resources, unawareness of the importance of prenatal care, insufficient family support, and fear of stigmatization by healthcare staff [15]. In the literature, the mean age of adolescents experiencing early motherhood varies but generally ranges between 15 and 19 years [4]-[6][16]. In many societies, a considerable proportion of girls over 15 years are married, with pregnancy occurring as a consequence of marriage or prompting the union. Consequently, at least 90% of adolescent mothers are married, highlighting the close link between adolescent pregnancy and child marriage [17][18].

Insufficient prenatal care has been reported by several authors in both developed and developing countries [5][6][10][15][19]. Poor quality of prenatal follow-up exposes pregnant adolescents to missed identification of pregnancy risk factors, inadequate delivery planning, and an increased risk of obstetric complications, which may adversely affect maternal and perinatal outcomes.

Most of the patients were referred (67.20%). Referrals were due to pregnancy-related complications such as hypertensive disorders, dystocia, and in utero transfer in cases of risk of prematurity, regardless of the specific reason. The center off the study is indeed a level III referral maternity hospital, handling a high proportion of high-risk pregnancies and delivery.

It provides comprehensive emergency obstetric and neonatal care

Pregnancy-related complications among adolescents are numerous. The most frequent maternal conditions include anemia, hypertensive disorders of pregnancy and their complications, and threatened preterm labor. Perinatally, low birth weight associated with prematurity and intrauterine growth restriction (IUGR), as well as acute fetal asphyxia, are most commonly reported [5][6]. Uterine hypovascularization in adolescents, as suggested by some authors, maternal anemia, hypertensive disorders of pregnancy, and smoking may partially explain intrauterine growth restriction and prematurity [16][20][21]. Analytical studies have confirmed an increased risk of anemia among adolescents compared with adult pregnant women, plausibly linked to iron deficiency in this population [22]. Puberty, physical growth, and menstrual blood loss increase iron requirements, which are not always met through diet. In adolescents, the nutritional needs of pregnancy are compounded by those of ongoing growth. Regarding hypertensive disorders of pregnancy, a contrast exists between developed and developing countries. In some industrialized countries, the risk of hypertensive disorders in adolescents is not higher compared with adult pregnant women [16][23], whereas a higher risk is reported in developing countries [5][24][25][26].

Psychologically, the prevalence of depression among adolescent mothers is twice as high as in adult mothers, ranging from 26% to 68% within three months postpartum [27]. Concerning delivery, most analytical studies conclude an increased risk of cesarean section and episiotomy among adolescents compared with adult parturients. In our series, the cesarean rate appears high (41.69%) compared with other reports, which range from 11.4% to 39.36% [5][6][16][21].

The maternal mortality rate was 3.28%, with a maternal mortality ratio (MMR) of 3636 deaths per 100,000 live births among adolescents. The causes of death were eclampsia (35.70%), severe anemia (28.60%), and immediate postpartum hemorrhage (14.30%). Maternal mortality rates were lower in other series, and several comparative studies did not find a statistically significant difference compared with adult women [4]-[6][10][16]. The high rate of severe obstetric complications, particularly hemorrhagic complications combined with inadequately met transfusion needs, insufficient prenatal care, and critical condition at admission, may explain the elevated hospital maternal mortality observed in our series. The stillbirth rate of 12.30% observed at CNHU-HKM in Cotonou is comparable to that reported by Tebeu at the University Hospital of Yaoundé among mothers under 17 years (11.88%). The influence of maternal age on perinatal mortality risk is variable in the literature. Several studies reported an increased risk of perinatal death in cases of early motherhood [5][28], whereas others found no significant difference compared with adult parturients [21][29]. Although the etiology of stillbirth is often undetermined, the high rates of acute fetal asphyxia, post-term delivery, and prematurity among adolescent mothers in various series may explain the increased perinatal mortality risk. Similarly, low socioeconomic status, insufficient prenatal care, maternal anemia, and frequent parasitic and bacterial infections in low-income countries may contribute to stillbirth [29].