Teen Pregnancy

Introduction

This report examines teen pregnancies between 2003 and 2012.  Teen pregnancies include all live births, stillbirths, and therapeutic abortions in those under 20 years of age.  For comparison purposes, this report defines the teen pregnancy rate as the number of pregnancies per 1,000 females aged 15 to 19.  Between 2001 and 2010, teen pregnancy rates decreased in eight of the thirteen Canadian provinces and territories, including Ontario.1  The teen pregnancy rate has also decreased in KFL&A.2;3

Although the teen pregnancy rate is declining, live births to teen mothers account for about 4.4% of all live births in Ontario.4  There are several biological and sociodemographic risk factors that may contribute to an increased risk of adverse maternal and infant outcomes for teenage mothers.  Biologically, teenage mothers are still growing, and may not have developed adequate fat stores or uterine and cervical blood supplies in order to support a healthy pregnancy.5  This can mean increased infections for the mother which may predispose them to preterm births.5  Many teen mothers are socioeconomically disadvantaged, live in neighbourhoods with lower family income and education, and experience other factors, such as smoking and substance misuse, that increase their risk of adverse outcomes.6 They are also less likely to complete their education, and subsequently, may not be earning high wages.7  Aboriginals are also twice as likely to experience teenage pregnancy.7  The pattern of teenage pregnancy may also be a repetitive cycle, with teenagers mothers being more likely to have had a teenage mother herself.7

According to a study conducted with birth data the Better Outcomes Registry & Network (BORN) database, teenage mothers are more likely to experience adverse birth outcomes, even after controlling for potentially confounding socioeconomic factors.4  Newborn outcome data from the BORN database found that infants born to teenage mothers have significantly higher risks of being born very preterm (before 32 weeks gestation), and being admitted to the neonatal intensive care unit (NICU).4  Other studies have also found teenage mothers were at higher risk of preterm delivery, low birth weight, maternal anemia, postpartum depression, eclampsia and pre-eclampsia, and neonatal mortality.5;8-10  Children of teenage mothers may also be more likely to have developmental problems, learning difficulties, hearing and visual impairments, chronic respiratory problems and to become teen parents themselves.6

Teenage mothers were also found to have significantly lower rates of prenatal class attendance, prenatal visits in the first trimester, intention to breastfeed, and exclusive breastfeeding upon discharge from the hospital;4 all of which may have a negative impact on infant health and well-being.

Despite some concerns of adverse birth outcomes among teens, Fleming and colleagues found that teenage mothers had a significantly lower risk of gestational hypertension, gestational diabetes, placental abruption, placenta previa, and premature rupture of membrane (PROM).4 They also found that teenage mothers were less likely to have a caesarean section (CS), assisted vaginal delivery, and use epidural analgesia.4 Despite being less likely to have a CS, teen mothers were reported to have a significantly higher risk of unplanned emergency CS's - mostly due to dystocia or non-reassuring fetal status.4 A summary of health, labour and birth outcomes are summarized in Table 1.

Interpretation for Figure 1

Figure 1 shows the teen pregnancy rates in both KFL&A and Ontario from 2003 to 2012.  In KFL&A in 2012, there were 26.4 pregnancies, including total births and therapeutic abortions, per 1,000 females age 15 to 19.  Teenage pregnancy rates are comparable between KFL&A and Ontario, and rates in both areas have declined over the years.

Figure 2. Proportion of births (live births and stillbirths) and therapeutic abortions for mothers aged 15 to 19, KFL&A, 2012(2,3)

Interpretation for Table 2 and Figure 2

Table 2 provides a breakdown of the number of live births, stillbirths, therapeutic abortions and pregnancies occurring in teens aged 15 to 19 in KFL&A, from 2003 to 2012.  Figure 2 provides the proportions of all births (including live births and stillbirths) and therapeutic abortions for mothers aged 15 to 19 in the KFL&A area.  For most years, the proportion of teenage mothers obtaining therapeutic abortions is slightly higher than the proportion of births.  No notable increase or decrease in the proportion of teenage mothers obtaining therapeutic abortions is observed.

Figure 3. Proportion of mother's aged 15 to 19 at infant's birth (both live and stillbirths), KFL&A, 1986-2013(2,3)

Interpretation for Figure 3

Figure 3 shows the proportion of mothers aged 15 to 19 at infant's birth in KFL&A from 1986 to 2013. Since 1995, the proportion of mothers aged 15 to 19 years has decreased by 2.4 times; the proportion in 1995 was 7.4% and was 3.1% in 2010. In recent years, the proportion of teenage mothers has fluctuated around 3 or 4%.

References

1. McKay A. Trends in Canadian national and provincial/territorial teen pregnancy rates: 2001-2010. The Canadian Journal of Human Sexuality 2012; 21(3-4):161-176.
2. Hospital and Medical Services Data (Calendar years: 2000-2012). Ontario Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO. 2014 [extracted 2014 Oct 6]
3. Ontario Vital Statistics Live Birth Data (Calendar years 1986-2011). Ontario Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO. [extracted 2014 Oct 6]
4. Fleming N, Ng N, Osborne C, Biederman S, Yasseen AS, III, Dy J et al. Adolescent pregnancy outcomes in the province of Ontario: a cohort study. J Obstet Gynaecol Can 2013; 35(3):234-245.
5. Shrim A, Ates S, Mallozzi A, Brown R, Ponette V, Levin I et al. Is young maternal age really a risk factor for adverse pregnancy outcome in a canadian tertiary referral hospital? J Pediatr Adolesc Gynecol 2011; 24(4):218-222.
6. Ministry of Health and Long-Term Care. Initial Report on Public Health. MOHLTC 2009; [cited 2014 Nov. 27]; Available from: http://www.health.gov.on.ca/en/public/publications/pubhealth/init_report/index.html
7. Luong M. (2014) Life after teenage motherhood. Statistics Canada
8. Chen XK, Wen SW, Fleming N, Demissie K, Rhoads GG, Walker M. Teenage pregnancy and adverse birth outcomes: a large population based retrospective cohort study. Int J Epidemiol 2007; 36(2):368-373.
9. Kawakita T, Wilson K, Grantz KL, Landy HJ, Huang CC, Gomez-Lobo V. Adverse maternal and neonatal outcomes in adolescent pregnancy. J Pediatr Adolesc Gynecol 2015.
10. Jeha D, Usta I, Ghulmiyyah L, Nassar A. A review of the risks and consequences of adolescent pregnancy. J Neonatal Perinatal Med 2015.
11. Fleming NA, Tu X, Black AY. Improved obstetrical outcomes for adolescents in a community-based outreach program: a matched cohort study. J Obstet Gynaecol Can 2012;34:1134-1140.