Ellen Knox, Perinatal Institute  May 2002

The West Midlands has the highest teenage pregnancy rate in the UK, which in turn has the highest rate in Western Europe.

As a result the Social Exclusion Unit were asked to develop a strategy to reduce teenage pregnancy rates. They identified two main goals:

1. To halve the rate of teenage conceptions among the under 18s by 2010.
2. To reduce the long term risk of social exclusion by getting more teenage parents into education, training or employment.

As health care professionals largely involved with the care of teenagers who are already pregnant we are still in a position to improve their care. It is first important to review the evidence for the risks they face.

Many adverse outcomes have been associated with teenage pregnancy including: premature delivery (1,2), small for gestational age infants (1), low birthweight infants (1,3), increased neonatal mortality (4), anaemia (2,5) and pregnancy induced hypertension (2,5). However, the evidence for some is more robust than for others. In addition, many studies do not adjust for the confounding variables of socio-economic status and adverse lifestyle factors that are more prevalent in this group and can independently affect outcome (6). It is therefore not clear from the literature whether teenagers are at increased risk of adverse outcome because of biological immaturity, a combination of gynaecological immaturity and the fact that they may not have reached her growth potential and there may be nutritional competition between fetus and mother. Indeed prepregnancy weight and weight gain during pregnancy appears to have more of an impact on pregnancy outcome in the teenage than the adult population (7,8).

In an attempt to adjust for biological immaturity, a cohort study in Sweden examined outcomes from women having first live singleton births in the teenage period and second consecutive births after age 20 (9). At first birth the risk of prematurity increased with decreasing maternal age. At second birth the risk of prematurity decreased for all age groups but the greatest reduction was amongst those who had been <17 at first birth. As the investigators had previously found teenage pregnancy to increase the risk of adverse social situations, they concluded that the reduced risk of premature delivery in the second pregnancy was secondary to relative biological maturity.

However, a Scottish cohort study examined first and second births within the teenage years adjusting for smoking status and socio-economic deprivation (10). They found no increased risk of adverse outcome in first pregnancies but an increase in prematurity and stillbirth during second pregnancies. Although this examined population first and second births rather than consecutive births within the same woman, the study concluded that background factors in the first pregnancy were the cause of adverse outcome.

Conflicting results were found in a study in Utah, which adjusted for marital status, educational attainment and antenatal care provision (1). They found increased risks of low birthweight, prematurity and small for gestational age infants amongst teenage mothers. However, after adjusting for smoking status the only significant difference was an increased risk of low birthweight amongst younger teenagers (<17 years).

Increased risks of neonatal and postneonatal mortality have been described amongst teenage births (4). However this was almost entirely accounted for by the high rates of prematurity within the group.

In conclusion, the literature is in general agreement with an increased risk of premature birth, especially amongst those in the very young (aged 13-16) age group (1,11). This may represent the intrinsic risk of biological immaturity although this has yet to be proven. Other adverse outcomes may result partly from infant prematurity or the background socio-economic risk factors. Regardless of the effect of adjustment for background factors, the fact remains they are more prevalent in teenage pregnancy.

This was highlighted in the last Confidential Enquiry into Maternal Deaths 1997-99 (12). There were 14 deaths of mothers aged< 18, 5 of which were < 16. 13/14 were socially excluded, 50% had disclosed domestic violence (compared to 12% of the entire cohort of mothers who died) and 50% were poor attenders at antenatal clinic (compared to 20% of the total cohort who were poor attenders or booked late). In addition, 4 women were homeless at the time of death despite the fact that 3 were <16 and under the care of social services at the time.

The prevalence of sexually transmitted diseases is increasing and is a particular problem in the teenage age group. The incidence of gonorrhoea increased 35% between 1997-99 in the United Kingdom and the group in the female population most at risk were aged 16-19 (13). A recent study in the United States revealed 1 in 5 teenagers to have an undiagnosed STD (14). In addition 1 in 8 teenagers attending a family planning clinic in Nottingham had an STD.

"In a single act of unprotected intercourse with an infected partner, a teenage girl has a 1% risk of contracting HIV, a 30% chance of contracting genital herpes and a 50% chance of contracting gonorrhoea. (15)"

This must be accessible and the advice delivered in an appropriate manner. Contrary to popular belief, many teenagers do seek advice. In a recent case controlled study, of 240 teenagers who conceived, 94% had consulted a health care professional in the year prior to conceiving (16). 71% had consulted specifically about contraception and 50% had been prescribed the oral contraceptive pill. Those who had conceived were far more likely to have consulted than those (controls) who had not.

There is some evidence that teenage mothers are more likely to suffer from postnatal depression than older mothers (17). In addition, one study reported a 37-54% reduction in milk production 6 months after childbirth in adolescents compared to older mothers (18). There were some differences in breastfeeding behaviour between the two groups which may have contributed to the result, but it appears that teenagers may need extra support with breastfeeding.

Whilst there is no evidence to date of medical interventions that can specifically improve pregnancy outcome, we must ensure that teenage mothers receive supportive care and are directed towards the social support they need. Smoking cessation should be targeted and attendance at antenatal clinic encouraged. In addition post natal contraception can help prevent second teenage pregnancy and sexually transmitted diseases.

There are many initiatives already in the West Midlands area addressing these issues. We await the results of the research being conducted in Coventry and Walsall examining the antenatal and postnatal experiences of young women who became pregnant under the age of twenty. This will be released shortly and will provide a valuable insight into how services can be improved.

In addition, the midwifery project, “Teenage pregnancy-improving service delivery” aims to optimise maternity and community links within the West Midlands. This is a 12 month project run jointly by the West Midlands Perinatal Institute (Cynthia Folarin, Public Health Specialist) and the Regional Teenage Pregnancy Coordinator (Alice Cruttwell). It aims to map the current delivery of maternity care offered to pregnant teenagers identifying any gaps that exist, increase early entry into prenatal care, identify first point of contact and identify the need for teenage pregnancy specific maternity services. In addition it will work towards the development of minimum standards of practice and a resource pack for professionals.

References

1. Fraser AM, Brockert JE, Ward RH. Association of young maternal age with adverse reproductive outcomes NEJM 1995; 332: 1113, Abstract

2. Scholl TO, Hediger ML, Belsky DH. Prenatal care and maternal health during adolescent pregnancy: a review and meta-analysis. Journal of Adolescent Health 1994; 15:444-456, Abstract

3. Miller HS, Lesser KB, Reed KL. Adolescence and very low birthweight infants: a disproportionate association. Obstet Gynecol 1996; 87: 83-88, Abstract

4. Olausson PO, Cnattingius S, Haglund B. teenage pregnancies and risk of late fetal death and infant mortality. Br J Obstet Gynaecol 1999; 106: 116-121, Abstract

5. Knoje JC, Palmer A, Watson A et al. Early teenage pregnancy in Hull. Br J Obstet Gynaecol 1992; 99: 969-973, Abstract

6. Nebot M, Borrell C, Villalbi JR. Adolescent motherhood and socio-economic factors. An ecological approach. European Journal of Public Health 1997; 7: 144-148.

7. Haiek L Lederman SA. The relationship between maternal weight for height and term birth weight in teens and adult women. J Adolesc Health Care 1989; 10: 16-22, Abstract

8. Hediger ML, scholl TO, Belsky DH, Ances IG, Salmon RW. Patterns of weight gain in adolescent pregnancy: effects on birthweight and preterm delivery. Obstet Gynecol 1989; 74: 6-12, Abstract

9. Olausson PO, Cnattingius S, Haglund B. Does the increased risk of preterm delivery in teenagers persist in pregnancies after the teenage period? Br J Obstet Gynaecol 2001; 108: 721-725, Abstract

10. Smith GCS, Pell JP. Teenage pregnancy and risk of adverse perinatal outcomes associated with first and second births: population based retrospective cohort study. BMJ 2001; 323: 476-9, Abstract

11. Satin AJ, Levano KJ, Sherman ML et al. Maternal youth and pregnancy outcomes: Middle school versus high school age groups compared with women beyond the teen years. Am J Obstet Gynecol 1994; 171: 184-187, Abstract

12. Why Mothers Die 1997-1999 the Confidential Enquiries into Maternal Deaths in the United Kingdom.RCOG Press 2001, http://www.cemd.org.uk

13. Martin IMC, Ison CA. Rise in gonorrhoea in London, UK. Lancet 2000; 355: 623, Abstract

14. Wiesenfeld HC. Lowry DL. Heine RP. Krohn MA. Bittner H. Kellinger K. Shultz M. Sweet RL. Self-collection of vaginal swabs for the detection of Chlamydia, gonorrhea, and trichomoniasis: opportunity to encourage sexually transmitted disease testing among adolescents. Sexually Transmitted Diseases. 2001; 28(6): 321-5, Abstract

15. Alan Guttmacher Institute, ibid, 1998.

16. Churchill R, Allen J, Pringle M et al. Consultation patterns and provision of contraception in general practice before teenage pregnancy: case-control study. BMJ; 321: 461-520 Abstract

17. Deal L, Holt V. Young maternal age and depressive symptoms: results from the 1988 national maternal and infant health survey. American Journal of Public Health 1998; 88: 266-270, Abstract

18. Motil KJ, Kertz B, Thota thuchery M. Lactational performance of adolescent mothers shows preliminary differenes from that of adult women. J. Adolesc Health 1997; 20: 442-449, Abstract