Differences in perinatal outcomes in teenage mothers with their first and third pregnancies and predictors of adverse neonatal events: A cross-sectional study

Abstract Background Repeated teenage pregnancy is a major burden on the healthcare system worldwide. Objective We aimed to compare teenagers with their first and third pregnancies and to evaluate the likelihood of neonatal complications. Materials and Methods This cross-sectional study was performed on female teenagers (aged ≤ 19 yr) with singleton pregnancies. The subjects (n = 298) were screened over 12 months. Ninety-six women were excluded, based on the exclusion criteria. The remaining subjects (n = 202) were divided into two groups: teenagers with first pregnancy (n = 96) and teenagers with third pregnancy (n = 47). The subjects were observed throughout pregnancy and delivery. The final sample size of the first and third pregnancy groups was 96 and 47, respectively. Results There was a significant risk of preeclampsia in the first pregnancy group (p = 0.01). Low birth weight, five-min Apgar score < 7, and neonatal intensive care unit admission were the most significant neonatal outcomes in the first pregnancy group. In the third pregnancy group, significant predictors of neonatal complications included very young age in the first pregnancy ( ≤ 15 yr), an inter-pregnancy interval < 2 yr, current anemia, and history of obstetric and/or neonatal complications in previous pregnancies. Conclusion Based on the results, teenagers with their first pregnancy had comparable obstetric outcomes (except for preeclampsia) as teenagers with their third pregnancy, whereas neonatal complications occurred more frequently in the first pregnancy group. Overall, we can predict high-risk neonates in the third pregnancy, based on the abovementioned parameters.


Introduction
Teenage pregnancy occurs when women aged ≤ 19 yr become pregnant. The frequency of this phenomenon has increased in different parts of the world and is no longer limited to developing countries, as high rates have also been reported in developed countries, including the United States (1,2). Teenage pregnancy has been discussed in many previous studies, and its causes and complications have been investigated as major issues in health policymaking and programs throughout the world (3,4).
The impact of teenage pregnancy is variable in different communities. In developed countries, lack of common sexual health education programs and contraceptive measures has contributed to this phenomenon, which occurs mostly outside marriage (5). Nonetheless, these countries have a better status than developing countries in terms of teenage pregnancy. This may be due to the fact that in developing countries, the public accepts the idea of teenage marriage because of the cultural background and traditions (5,6).
At a social level, teenage pregnancy imposes significant pressure on new couples with poor academic performance and a low socioeconomic status.
Moreover, many adverse events may occur during or after gestation, such as anemia, preeclampsia, obstructed labor, preterm delivery, postpartum depression, and even maternal death, which has been shown to be five times more likely than in older women (7,8). The newborns are also more likely to be exposed to several complications, such as prematurity and low birth weight (LBW), which can have acute and remote effects on the newborn and family. Almost 15% of delivered newborns in the Persian Gulf area of the Middle East are born to teenage mothers.
However, in Iraq, a country with a similar culture and belief system to other Persian Gulf countries, there is no precise estimation or evidence regarding pregnancy during adolescence (6,9,10).
Since in Iraq, adolescents may marry and conceive at a very young age (starting from 11 yr), and it is socially advised to have multiple pregnancies within short intervals (6,11)      The level of statistical significance was set at p < 0.05.

Results
The rate of third pregnancy in our sample of teenage mothers was 22.93% (61/266), while the rate of first pregnancy was 53.00% (141/266). The first and third pregnancy groups consisted of 141 and 61 women, respectively. However, only 96 and 47 women were included, respectively, as 45 and 14 women were excluded, respectively, because of missing data or lack of regular followups ( Figure 1). Maternal anemia had a high prevalence in both groups (higher in the first pregnancy group), without any significant difference between the groups. Other parameters showed no significant differences between the groups.

Neonatal complications
Neonatal outcomes, including LBW, five-min Apgar score < 7, and neonatal intensive care unit (NICU) admission, were significantly more common in the first pregnancy group, as shown in table III.

Predictors of neonatal outcomes
The odds ratios and 95% confidence intervals were calculated by performing a logistic regression analysis to identify the significance of possible etiological factors in influencing neonatal complications of the third pregnancy group (Table IV)

Discussion
While teenage pregnancy is a common problem in developing countries, it is also not uncommon in developed regions. This phenomenon imposes a significant burden on the healthcare systems of all countries due to its associated complications during pregnancy and after delivery. Therefore, major attempts have been made for better identification and management of these complications (12,13). To the best of our knowledge, this is the first study to discuss these adverse events in teenagers with three pregnancies during adolescence.
In the present study, teenagers with their first and third pregnancies had comparable sociodemographic characteristics, unlike a previous Japanese study, which compared junior teenagers (< 16 yr) with senior teenagers (16)(17)(18)(19) yr), regardless of parity or gravidity, and found that younger teenagers were thinner and shorter and had more smoking habits (7). In our study, the first pregnancy group, which was the younger age group, had a lower mean weight and a higher smoking rate, compared to the older group with the third pregnancy, although these differences were not significant; these findings could be partly in agreement with the Japanese study results.
Maternal anemia was slightly more prevalent in our first pregnancy group, although the difference was not significant. Despite the high rate of maternal anemia in both groups, it was close to the local maternal anemia estimates (14). Overall, increased rates of anemia have been reported in teenage pregnant women as compared to older adults. According to some studies, the younger a teenage pregnant woman is, the lower her hemoglobin level will be (15,16). In the present study, lower rates of delivery by cesarean section (CS) were observed in the first pregnancy group, which is in line with previous studies, suggesting the decreased frequency of CS in teenage pregnant women (17,18). Also, the rates of CS delivery were lower in both groups as compared to the national Iraqi CS rates for all age groups (19). On the other hand, Turkish researchers documented higher rates of CS in teenagers due to the immaturity of pelvic organs, leading to possible disproportions (8); this discrepancy between the results might be related to racial differences.
The frequency of preeclampsia was significantly higher in the first pregnancy group as compared to the third pregnancy group (p = 0.01).
Many previous studies have also suggested that preeclampsia, eclampsia, and pregnancyinduced hypertension occur more frequently among teenagers (17,18,20,21

Conclusion
Teenage mothers with their first pregnancy had comparable obstetric complications as teenage mothers with their third pregnancy, except for preeclampsia, which was significantly more likely in the first pregnancy group. Regarding the neonatal outcomes, LBW, five-min Apgar sore < 7, and NICU admission were significantly more common in the first pregnancy group. Other neonatal outcomes were also more frequent in the first pregnancy group as compared to the third pregnancy group, although these differences were not significant. Maternal age ≤ 15 yr, rapid repeated pregnancies (inter-pregnancy interval < 2 yr), maternal anemia in the current pregnancy, and the presence of obstetric and/or neonatal complications in previous pregnancies were possible predictors of future neonatal adverse events in the third pregnancy.