Pregnancy in teenagers under 16 years old: perinatal
adversities
Gravidez em adolescentes menores de 16 anos: adversidades perinatais
José Ricardo Dias Bertagnon1, Ana Carolina Daloia Ruzzante2, Juliana Cristina da Costa Santos3, Letícia Ferreira de Souza4, Olívia Capela Grimaldi Oliveira5, Ricardo Sestito Proto6
ABSTRACT
Objectives: To verify the prevalence of pregnancy among adolescents under 16 years of age, the risk of pregnancy-induced hypertension and neonatal complications in the population attend at the Hospital Geral do Grajaú. Methods: Data related to every delivery performed at the Hospital Geral do Grajaú (HGG) from January 1st, 2000 to April
30th, 2004 were collected. The sample was divided into two groups
of pregnant women: one consisting of adolescents aged under 16 years, and the other comprising all other pregnant women attended at the Institution. Maternal age, prevalence of pregnancy-induced hypertension, number of prenatal visits, mode of delivery, gestational age, birth weight and one-minute Apgar score were analyzed. For statistical analysis the t test was used considering p<0.05. Data regarding pregnant teenagers were compared to those related to the general patient population of the Obstetrics Clinic of the HGG. These data were obtained from the HGG’s Hospital Records Department. Results: Two hundred and thirty-one pregnant teenagers under 16 years of age were analyzed. This corresponds to 2.61% of the total obstetric population studied in this Institution. Among them, 53,2% did not attend prenatal care visits adequately, that is, they attended less than 5 visits. The prevalence of pregnancy-induced hypertension among these teenagers was 3.46%. Cesarean section was performed in 22% of the teenagers studied. There were 12.1% of low-birth weight newborns and 23.8% preterm infants, of whom 6.4% had a one-minute Apgar score = 3, and 17.7% had an Apgar score = 7. A statistically significant difference was observed regarding inadequate prenatal care, one-minute Apgar score = 3 and prematurity, compared to the data from the total pregnant population of the Institution. Conclusions: A higher risk of pregnancy-induced hypertension among pregnant adolescents aged under 16 years compared to the general population of patients of the Institution was not observed. However, the age range studied proved to be a risk factor for neonatal morbidity.
Keywords: Teenage pregnancy; Pregnancy complications; High-risk pregnancy
ORIGINAL ARTICLE
RESUMO
Objetivos: Verificar a prevalência de gravidez em adolescentes menores de 16 anos, o risco de doença hipertensiva específica da gravidez e as complicações neonatais na população atendida no Hospital Geral do Grajaú. Métodos: Foram colhidos dados referentes a todos os partos realizados no Hospital Geral do Grajaú no período de 1º de janeiro de 2000 a 30 de abril de 2004. Foram separados dois grupos de gestantes: um deles de adolescentes com idade menor que 16 anos e o outro englobando a população geral atendida na Instituição. Idade materna, prevalência de doença hipertensiva específica da gravidez, número de consultas de pré-natal, tipo de parto, idade gestacional, peso do recém-nascido e índice de Apgar de primeiro minuto foram analisados. Para análise estatística foi utilizado o teste t considerando p<0,05 e a seguir os dados referentes às gestantes adolescentes foram comparados aos dados da população geral da Clínica Obstétrica do HGG, obtidos a partir do Serviço de Arquivo Médico (SAME) do próprio hospital. Resultados: Foram analisadas 231 adolescentes grávidas com menos de 16 anos de idade, correspondendo a 2,61% da população obstétrica total estudada nesta Instituição e 53,2% não fizeram acompanhamento natal adequado, pois tiveram menos de cinco consultas no pré-natal. A prevalência de doença hipertensiva específica da gestação nessas adolescentes foi de 3,46%. A freqüência de parto cesariano entre as adolescentes consideradas foi de 22%. Foram encontrados ainda 23,8% de recém-nascidos de pré-termo; 6,4% com índice de Apgar no 1º minuto igual ou menor que 3 e 17,7% com índice de Apgar menor ou igual a 7. O acompanhamento pré-natal inadequado, Apgar no 1o minuto igual ou menor que 3 e prematuridade mostraram
significância estatística, quando comparados aos dados do total de gestantes da Instituição. Conclusões: Não houve maior risco de doença hipertensiva específica da gravidez entre adolescentes grávidas menores de 16 anos em relação à população geral da Instituição. Entretanto, a faixa etária estudada mostrou-se como fator de risco para morbidade neonatal.
Descritores: Gravidez na adolescência; Complicações na gravidez; Gravidez de alto risco
1PhD in Perinatology from the Instituto de Assistência Médica ao Servidor Público Estadual - IAMSPE – São Paulo (SP) – Brazil. Lecturer of Pediatrics, Department of Neonatology, Faculdade de Medicina da Universidade de Santo Amaro – UNISA - São Paulo (SP) – Brazil.
2Medical student, Department of Neonatology, Faculdade de Medicina da Universidade de Santo Amaro – UNISA - São Paulo (SP) - Brazil. 3Medical student, Department of Neonatology, Faculdade de Medicina da Universidade de Santo Amaro – UNISA - São Paulo (SP) - Brazil. 4Medical student, Department of Neonatology, Faculdade de Medicina da Universidade de Santo Amaro – UNISA - São Paulo (SP) - Brazil. 5Medical student, Department of Neonatology, Faculdade de Medicina da Universidade de Santo Amaro – UNISA - São Paulo (SP) - Brazil. 6Medical student, Department of Neonatology, Faculdade de Medicina da Universidade de Santo Amaro – UNISA - São Paulo (SP) - Brazil.
INTRODUCTION
The importance of the issue related to teenage pregnancy is emphasized by data from the Ministry of Health showing that 681,290 deliveries occurred among women at this age range in the year 2000. This represents 27.13% of all deliveries occurring that year. The increase in the number of deliveries among teenagers aged 10-14 (32,489 deliveries in the year 2000) is particularly noteworthy. According to these data, there was a 22% increase in the number of deliveries
at this age range in the past decade(1).
In addition to these alarming figures, it is important to point out that the extremes of childbearing age also
coincide with the peaks of maternal mortality(2). A
maternal mortality risk higher than 60% is reported, and 6% of the children of these women die in the first year of life(3). When biological, psychological, and social sequelae are added to these data, many authors state that teenage pregnancy is of high risk, because it also encompasses a higher risk of perinatal morbidity and mortality(4-8).
Pregnancy in this stage of life would pose an increased obstetric risk, especially regarding the presence of pregnancy-induced hypertension (PIH), anemia, prematurity, low birth weight, intrauterine growth restriction, and, in the postpartum, a higher risk of hemorrhage, puerperal endometritis, and episiotomy(8).
The relation between perinatal intercurrences and the non-utilization of prenatal care services has been demonstrated in several studies, whether showing a relation with intrauterine malnutrition, or with perinatal
mortality itself(7-8). Among the factors that could
interfere with the failure of the prenatal care, we can mention the pregnant teenager herself, because the future mother frequently hides her pregnancy for a long period(9).
Another aspect to be considered is the mode of delivery, which may also be a parameter to quantify perinatal adversities, since normal delivery should always be the first option, being replaced by cesarean section only in the presence of any peripartum
complication(1,10). Among adolescents, this investigation
becomes appropriate because of the implications that the “first cesarean section” may have on their obstetric future.
The Hospital Geral do Grajaú (HGG) serves a population from the outskirts of Sao Paulo, which, among other aspects, is characterized by a high prevalence of teenage mothers and by a low utilization of prenatal care. Previous studies in this Institution have concluded that a higher morbidity and mortality risk in the group of teenagers was not observed. This is
probably related to the fact that the majority of the pregnant women studied were mainly concentrated in the teenage group of young adults, that is, the majority
was closer to 19 than to 12 years of age(10).
For the reasons shown, the importance of studying the repercussions of pregnancy in adolescence becomes very clear, especially when considering a needy population.
OBJECTIVES
1. To verify the prevalence of pregnancy in teenagers under 16 years of age in a public hospital serving a needy population from the outskirts of the city of Sao Paulo.
2. To verify whether an increase in the incidence of PIH occurs in the group studied.
3. To study which are the complications related to the newborns of these teenage mothers, and to verify if a higher risk of neonatal morbidity occurs in this group.
METHODS
Data related to every delivery of teenage mothers aged 15 or under were obtained in a retrospective study,
between January 1st, 2000 and April 30th, 2004, from
the data entry book of the HGG’s Obstetric Center (OC), in a total of 231 cases. Every delivery is registered in this book, from which data are copied in the medical record that goes with the patient when she leaves the OC, so that no delivery fails to be registered. Data related to the number of prenatal visits, maternal age, occurrence of PIH, mode of delivery, gestational age, birth weight, and one-minute Apgar score were obtained.
A comparison between the variables selected from the sample and from the HGG’s general obstetric population was made using the chi-square method. Values of p<0.05 were considered significant.
RESULTS
A 2.1% prevalence of pregnant women under 16 years of age was verified, as shown in table 1.
Table 1. Prevalence of pregnant teenagers under 16 years of age at the HGG
Pregnant women population N FR%
Teenagers <16 years of age 231 2.1%
Total of deliveries 10,669 100.0%
N = absolute number FR% = frequency
In the general population, 10 to 15% of the nulliparas presented with pregnancy-induced hypertension, according to data obtained in a previous
study conducted in the same Institution(10).
The relation between the variables studied and teenagers under the age of 16 is shown in table 2.
Table 2. Relation between the variables studied and teenagers under the age of 16
Variable Teenage mothers<16 General population p value
years of age of mothers
N FR% N FR% Adequate 108 46.8 5,889 55.2 <0.05 prenatal care Surgical delivery 55 22.0% 2,716 25.4 >0.05 Low birth Weight 28 12.1% 1,585 14.9% >0.05 Preterm 55 23.8 1,686 15.8 <0.05 Apgar ≤ 3 15 6.4 369 3.5 <0.05* Apgar ≥ 7 41 17.7 1,931 18.1 >0.05 *RR=1.91 (1.1-3.26)
Among the teenagers, 46.8% attended prenatal care visits adequately (number of visits = 5), compared to 55.2% of the total number of pregnant women. A statistically significant difference was observed.
The rate of cesarean sections among the teenagers studied was 22%, whereas this rate in the HGG’s obstetric population aged 16 years or above was 25.5%, in the same period. No statistically significant difference was observed.
The percentage of low birth weight infants, that is, less than 2500g, among teenage mothers was 12.1%, and 14.86% in the HGG’s general population. No statistically significant difference was observed (p>0.05). In the group studied, there were 23.8% of premature infants (less than 37 weeks gestation) versus 15.8% in the general population. A statistically significant difference was observed (p<0.05).
Considering the infant’s first minute of life, a 6.4% frequency of an Apgar score = 3 in the infants of teenage mothers was found, versus a 3.45% frequency in the general population. A statistically significant difference [p<0.005 with RR 1.91 – (1.1 – 3.26)] was observed. For an Apgar score = 7, the frequency found was 17.7%, versus 18.1% in the general population, no statistically significant difference was observed.
DISCUSSION
The population included in this study, living in the outskirts of a large city, and with countless needs, had a frequency of pregnant women under 16 years of age that enabled this study, although comparisons with literature data are not easy because frequently the
division in age groups is different from the one used in the present study, that is, with a cut point at 15 years of age.
In relation to the number of prenatal care visits, in a study conducted among pregnant teenagers in the
city of São Marcos, State of Rio Grande do Sul(9), the
author verified that 71% of them attended six or more visits. This was not observed among the patients studied here in São Paulo: most of the pregnant teenagers did not attend prenatal care visits adequately, a datum similar to that previously found in the same
Institution(10). The high prevalence of inadequate
attendance of prenatal care visits is a characteristic of the low income population of the suburb of São
Paulo(11), which would reflect a regional behavior.
Data presented in the literature are quite controversial as to incidence of severe PIH among the teenage
population(12). Very high rates are reported: 42% of the
teenagers aged under 13 presented the disease. This figure drops to 16.1% when pregnant women under 16
years of age are studied(13). A five-fold higher incidence
of PIH has already been reported among pregnant
women under 16 years of age(14). However, these finding
have not been confirmed in later studies(7, 15).
In Brazil, some studies have also demonstrated high rates of preeclampsia among the teenage population,
with figures ranging from 19.2% to 31%(16-18). The
authors related the presence of this complication to the patients’ primiparity. Data obtained in 1991 reported a 15% frequency of preeclampsia among the pregnant teenagers followed in the multidisciplinary program of the Hospital das Clínicas da FMUSP, and a 21.97% frequency among those who gave birth in the Institution,
but did not attend a specialized prenatal care(19). In
2000, a study including 258 teenagers under 18 years of age, in the same hospital, found a 9.3% rate of preeclampsia. The authors of this study related the development of preeclampsia to a positive family history for the disease, marital status (patients with no support from their partners), overweight when becoming pregnant, weight gain above 12 kg during prenatal care, and rise in the levels of uric acid measured between 32 and 36 weeks.
In 2002, a study including 456 teenagers reported a 6.14% preeclampsia rate, although more than 13% of them had presented with hypertension, with no confirmation of eclampsia. Therefore, the total frequency of hypertension during pregnancy was
19.14%(20). The present study demonstrated a low
It is important to notice that the incidence of pregnancy-induced hypertension could be minimized if teenagers were provided with a comprehensive, specific and multidisciplinary care(19).
A higher frequency of cesarean sections was not observed among teenagers under 16 years of age compared to older pregnant women, as also reported in several studies in the literature(8,20).
Considering cesarean section as a factor indicating probable perinatal complication, however, this type of delivery is less frequent among teenage mothers and no statistically significant difference was found regarding the mode of delivery compared to the respective control groups(8,10,20), one could conclude that the obstetric risks would not be increased among these teenagers. On the other hand, it is important to mention that the lower frequency of surgical deliveries could be attributed to a higher number of low birth weight
infants in this group(21), which, however, did not occur
in the present study.
It is also important to point out that some of the results reported showed a more than 55% prevalence
of cesarean sections among teenage mothers(9-10).
Perhaps this difference could be explained by the fact that deliveries occurring in the private health care network were also evaluated in these studies, and the frequency of elective cesarean sections is known to be higher in these health care services(9).
Many are the causes alleged to explain the indication of surgical deliveries for teenagers. They include from the outdated idea of an inadequate hip development, which would cause whether a pelvic defect, or cephalo-pelvic disproportion, to the currently more accepted
idea of fetal distress as the main determinant(22-24). In
the Obstetrics Clinic of Faculdade de Medicina da Universidade de São Paulo (FMUSP), fetal distress was reported in 32.2% of the cesarean sections in teenagers, representing the most frequently reported indication. The presence of meconium ranked second (19.35%), justifying the surgical procedure. These two conditions together, indicating confirmed or suggested fetal distress, account for 51.61% of the cesarean sections. The third most common indication for cesarean section is functional dystocia (12.9%)(25).In this study, the most frequent indication was fetal distress. It is important to emphasize that the beneficial action of a multidisciplinary prenatal care could decrease the rates
of cesarean sections among pregnant teenagers(26-27).
When low birth weight is analyzed, several studies
confirm its prevalence among teenagers(7,9,20). A previous
study conducted at HGG, which also studied a group of adolescents aged under 16 years, reports a 16% rate of low birth weight infants, whereas in the general
population this rate was 23.6%, indicating a 1.51% relative risk for low birth weight among non-teenage
mothers (95% CI: 1.07 – 2.14)(10).
Prematurity has a higher incidence in the group of
pregnant teenagers(7-8), with rates that may range from
10% to 26.3%(23,25,28), the latter being closer to that found in the teenage population of the Institution studied, which could mean a higher risk of neonatal morbidity. Many causes may justify this increase in prematurity rates, such as low socioeconomic level, stress, anxiety, excess physical activity, poor hygiene, higher incidence of vaginal and urinary infections, in addition to poor nutrition(29). It must be pointed out that teenagers prove to have a poor perception of their pregnant bodies, which could delay a possible diagnosis of premature labor. Thus, they seek medical help in a late irreversible phase. All these factors must be approached in a proper prenatal care aiming to reduce the incidence of prematurity and low birth weight, thus improving
perinatal outcomes(17,26). In the present study, higher
frequencies for prematurity than for low birth weight were observed. The fact that non-low birth weight premature infants were found leads to the conclusion that they were borderline premature infants, with no intrauterine growth restriction. The low frequency of PIH observed among the teenagers analyzed in this study could explain this finding to a certain extent, otherwise this population is different from those referred to in other studies in the literature, a fact that would demand further studies.
Birth conditions, assessed by the Apgar score, have also been studied among teenagers. A 3% frequency
of one-minute Apgar score ≤ 3 (severe anoxia) in infants
of teenage mothers under 17 years of age was
reported(20). This finding is different from that obtained
in the present study, that is, a higher prevalence of
one-minute Apgar score ≤ 3, and, compared to the
Apgar score results ≤ 7 found in the infants of the teenage population analyzed did not show a statistically significant difference compared to the total obstetric population. This fact demonstrates that teenage pregnancy is not a risk factor for mild to moderate neonatal anoxia.
CONCLUSIONS
1. The prevalence of pregnancy among teenagers under the age of 16 in the HGG was 2.1%.
2. The age range analyzed is not a risk factor for pregnancy-induced hypertension.
3. The age range analyzed proved to be a risk factor for neonatal morbidity.
REFERENCES
1. Galleta MK. Investigação dos fatores associados à pré-eclâmpsia em gestantes adolescentes [tese].São Paulo: Faculdade de Medicina da Universidade de São Paulo; 2002.
2. Siqueira AA, Tanaka AC, Santana RM, Almeida PA. Mortalidade materna no Brasil. Rev Saúde Pública. 1984;18(6):448-65.
3. Tyrer LB. Complications of teenage pregnancy. Clin Obstet Gynecol. 1978; 21(4):1199-213.
4. Battaglia FC, Frazier TM, Hellegers AE. Obstetric and pediatric complications of juvenile pregnancy. Pediatrics. 1963;32:902-10.
5. Papiernik E, Centene J. Dèpistage du grossesses à haut risque. Étude préliminaire rètrospective. Bull Fed Soc Gynécol Obstet Lang Fr. 1970;22: 413-7.
6. Mehra S, Agrawal D. Adolescent health determinants for pregnancy and child health outcomes among the urban poor. Indian Pediatr. 2004;41(2):137-45. 7. Gortzak-Uzan L, Hallak M, Press F, Katz M, Shoham-Vardi I. Teenage pregnancy: risk
factors for adverse perinatal outcome. J Matern Fetal Med. 2001;10(6):393-7. 8. Conde-Agudelo A, Belizan JM, Lammers C. Maternal-perinatal morbidity and
mortality associated with adolescent pregnancy in Latin America: cross-sectional study. Am J Obstet Gynecol. 2005;192(2):342-9.
9. Chemello CS. Perfil epidemiológico das adolescentes grávidas na cidade de São Marcos, RS [tese]. São Paulo: Faculdade de Saúde Pública da Universidade de São Paulo;1999.
10. Torres MS, Bertagnon, JR, Carignani A, Staveropoulos RG. Estudo perinatal das adolescentes no Hospital Geral do Grajaú, São Paulo,SP [abstract]. In: 29º. Congresso Brasileiro de Neonatologia. Florianópolis (SC); 2001. Anais. Florianópolis; 2001.
11. SINASC: Coordenadoria de Saúde da Capela do Socorro. Recém-nascido de baixo peso. Prefeitura do Município de São Paulo;1999-2002.
12. Velasco, Victor Israel Pastrana. Estudo epidemiológico das gestantes adolescentes de Niterói. [tese]. Fundação Oswaldo Cruz, Escola Nacional de Saúde Pública; 1998.
13. Marchetti AA, Menaker JS. Pregnancy and the adolescent. Am J Obstet Gynecol. 1950;59(5):1013-20.
14. Clark JF. Toxemia is major complication in teen pregnancy. Ob-Gyn News. 1970;5:35-8.
15. Hamada H,Zaki A, Nejjar H, Filali A, Chraibi C, Bagad R et al. A profile of pregnancy and delivery in adolescents: 311 cases. J Gynecol Obstet Reprod. 2004;33(7):607-14.
16. Correa MD. Riscos Obstétricos. In: Maakaroun MF, Souza RP, Cruz AR editores. Tratado de adolescência: um estudo multidisciplinar. Rio de Janeiro: Cultura Médica; 1991. p. 380-9.
17. Oliveira FC Jr, Gildemeister SB, Sprengel CA, Henriques DC, Souza GL Jr. Gestação na adolescência. J Bras Ginecol. 1989;99(4):161-3.
18. Pinto e Silva JL. Contribuição ao estudo da gravidez na adolescência. [tese] Campinas: Faculdade de Ciências Médicas da UNICAMP; 1982.
19. Bittar RE, Bortolotto MR, Bracher ES, Motta EV, Zugaib M. Gestação na adolescência: resultados maternos e perinatais [abstract]. In: 44º Congresso Brasileiro de Ginecologia e Obstetrícia. Brasília (DF); 1991. Anais. Brasília (DF); 1991.
20. Connolly G, Kennelly S, Conroy R, Byrne P. Teenage pregnancy in the Rotunda Hospital. Ir Med J. 1998;91(6):209-12.
21. Verma V, Das KB. Teenage primigravidae: a comparative study. Indian J Public Health. 1997;41(2):52-5.
22. Moerman ML. Growth of the birth canal in adolescent girls. Am J Obstet Gynecol. 1982;143(5):528-32.
23. Coates V, Correa MM. O atendimento de adolescentes grávidas. In: Maakaroun MF, Souza RP, Cruz AR. Tratado de adolescência: um estudo multidisciplinar. Rio de Janeiro: Cultura Médica;1991. p. 390-406.
24. Maia Filho NL. A adolescente precoce: aspectos relacionados ao parto, puerpério imediato e recém-nascido, comparativamente às não-precoces e às gestantes adultas [tese] Campinas: Faculdade de Ciências Médicas da UNICAMP; 1993. 25. Galleta MK, Lippi AT, Giribola A, Migueles J, Zugaib M. Fatores associados com a pré-eclâmpsia na gestação de adolescentes. In: 6º. Congresso Paulista de Obstetrícia e Ginecologia [abstract]. São Paulo (SP): SOGESP;2000. Anais. São Paulo(SP): SOGESP; 2002. p. 35.
26. Scholl TO, Hediger ML, Belsky DH. Prenatal care and maternal health during adolescent pregnancy: a review and meta-analysis. J Adolesc Health. 1994;15(6):444-56.
27. Chalem E, Silva MG, Correa SR, Teles ACP, Moron AF. Repercussões da abordagem multiprofissional em gestantes adolescentes. In: Anais da 3a. Jornada Paulista de Obstetrícia e Ginecologia. São Paulo, SP. SOGESP, nov,dez;1995.
28. Lins RC, Medeiros Filho JG, Batista SS, Barbosa MM, Nunes Maia HG. Avaliaçào epidemiológica da gestação em adolescentes de João Pessoa- Paraíba, Brasil. Rev Bras Cienc Saúde. 2001;5(1):131-40.
