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J R Soc Med. 2001 June; 94(6): 282–285. | PMCID: PMC1281523 |
Copyright © 2001, The Royal Society of Medicine Design or accident? The natural history of teenage pregnancy Clare Seamark, MPhil MRCGP The Surgery, Marlpits Road, Honiton, Devon EX14 2NY, UK The UK has the highest rate of teenage pregnancy in Western Europe. A
retrospective record-based study was conducted in an East Devon general
practice to gain greater understanding of the outcome of first teenage
pregnancy and subsequent reproductive history. The comparison group was women
who had first conceived between the ages of 25 and 29 years. 149/673 women born between 1968 and 1977 became pregnant when teenagers. Of
these, 70 (47%) had the baby, 67 (45%) had a termination and 10 (7%) had a
spontaneous miscarriage; 2 others experienced fetal loss. Of the women aged
25-29 at first conception, 127 (92%) had the baby, 6 (4%) had a termination
and 5 (4%) had a miscarriage. 40 (27%) of the teenage group went on to have a
second teenage pregnancy, including 12 of the 67 who had their first pregnancy
terminated. Although teenage pregnancy is often viewed as unplanned and unwanted, the
reality is more complex. Among this group, many first pregnancies were
desired. Even among those whose first pregnancy was terminated, 18% went on to
have a baby while still a teenager. Teenage pregnancy is a cause for concern in the UK, and halving of the rate
in under-16s is an unmet target of The Health of the
Nation1. It is
also the subject of a recent report from the Social Exclusion
Unit 2. However,
there is still much we do not know or understand about the subject. Although
the UK does have the highest rate of teenage pregnancy in Western Europe, the
rate was even higher in the
past 3,4.
In England and Wales at least 94 377 teenagers became pregnant in 1996 and 38%
of these pregnancies were
terminated 4.
Miscarriage is not included in the nationally collected data, which
concentrate on conceptions leading to maternities and terminations of
pregnancy. Very little is known about what happens after the first teenage
pregnancy. Was it an isolated event or the beginning of a complex reproductive
history? East Devon has a relatively low rate of teenage pregnancy—5.3 per
1000 women under 16 years, compared with 9.4 per 1000 for England and Wales in
1996 4. Nevertheless,
at least 1 in 5 women born between 1955 and 1977 and registered with our
Honiton Practice were to experience a teenage pregnancy. This new study seeks to look at teenage pregnancy from a primary care
perspective. The advantages are that all pregnancies, including miscarriages,
can be studied, women can be followed up for repeat pregnancies and women from
different age groups can be compared. The study was conducted in the Honiton Group Practice, which serves a
population of 15 300 in the East Devon market town and surrounding rural area.
The Townsend score of the town varies from -1 to +1. The study is part of a
larger research project on teenage pregnancy, which has received ethical
approval. The practice uses the Exeter Computer System and has been fully
computerized since 1990. All consultations and significant events, such as
pregnancies, are recorded. The database was searched for women born between
1968 and 1977 who were registered on 1 January 1998 and were still registered
at the end of 1999. The records of these women were searched to see if they
had had a teenage pregnancy, for the outcome of such pregnancies and for
subsequent reproductive histories. The practice database was also searched for women who had conceived when
aged between 25 and 29 years and completed their first pregnancy by the end of
1997. The outcome of these pregnancies and follow-up over at least 2 years was
also recorded. First pregnancies Of 638 women in the teenage study group, 149 had experienced at least one
teenage pregnancy. The age at conception and the outcome of these first
pregnancies are contrasted in with data for women aged 25-29. Only 14 girls conceived before
the age of 16 (9% of teenage pregnancies). Younger teenagers are more likely
to have a termination (83% of 15-year-olds) than older teenagers (34% of
19-year-olds). Over 95% presented within the first trimester. 2 girls
concealed their pregnancies until 28 weeks and term, respectively. 2 babies
were adopted—one with a teenage mother, the other with a mother aged
29. | Table 1Outcome of pregnancies for teenagers and women aged 25-29 years |
Subsequent reproductive history By the end of 1999, when the teenage pregnancy group were aged 22-31 years,
108 (73%) had had a second pregnancy, 40 (27%) when still teenagers. Of those
whose first pregnancy resulted in a baby 54/70 (77%) became pregnant again.
shows the gaps between
end of first pregnancy and next conception in the two groups of women. In both
groups the gap tended to be longest among those whose first pregnancies were
terminated. Of the women whose first teenage pregnancy resulted in a baby, 46%
were pregnant again within 2 years compared with 27% of those who had a
termination first. | Table 2Gap between end of last pregnancy and next conception in teenagers and
women aged 25-29 |
Of the 40 women who became pregnant a second time as teenagers, 28 had the
baby, 6 had a termination and 6 miscarried. A total of 88 girls (59%) had
babies as teenagers despite 12 of their first pregnancies (and in 2 cases
first and second pregnancies) being terminated and 6 first pregnancies ending
in miscarriage or fetal loss. Of the 41 women who had had only one pregnancy by the end of 1999, 3
miscarried the first pregnancy and one is now trying to become pregnant by use
of in-vitro fertilization; 16 have one child and 22 had one
termination. Amongst these 149 women there have been a total to date of 351 pregnancies.
These have resulted in 92 terminations, 227 babies (including one set of
twins), 1 stillbirth, 2 intrauterine deaths, 2 medical terminations for fetal
abnormality and 28 miscarriages. By the end of 1999, 118/149 (79%) had at
least one baby (range of 1-4) and 77/149 (52%) women had had at least one
termination of pregnancy, 13 two terminations and one three. 24 (16%) women
had experienced spontaneous miscarriage, 4 having had two miscarriages. One woman had been referred to a fertility clinic after trying to conceive
for over 3 years. She actually conceived at the age of 19.9 years just before
attending. 3 women experienced secondary fertility problems. Among women aged 25-29 years at first conception, 85/138 (62%) had a second
pregnancy. The gaps are shown in . By the end of 1999 these women had had a total of 248
pregnancies, median 2 (range 1-5). 9 women had had difficulty conceiving and
one had used clomiphene, one in-vitro fertilization and one
artificial insemination by donor to conceive. The teenagers who had a baby from their first conception were more likely
to get pregnant again than women in the 25-29 year group (χ2
with Yates correction =4.81, P<0.05). The teenagers who had a
termination first were not significantly more likely to get pregnant again
than the older women. In each group the median number of pregnancies at the
end of the study was 2, range 1-6 in the teenagers, 1-5 in the older
women. Although the teenage pregnancy rate in East Devon is well below the
national average, 1 in 5 girls still conceive as teenagers. Of the teenage
pregnancies recorded in this study, half were terminated, with highest
termination rates in the very young. Over a quarter of the girls went on to
have further teenage pregnancies, including 18% of those who had their first
pregnancy terminated; but those whose first pregnancies were terminated tended
to wait longer before becoming pregnant again than those who kept their
babies. At the close of the study, the median number of pregnancies in the
teenage group did not differ from that in the group who first became pregnant
at age 25-29. The strengths of this study come from the comprehensive nature of the
computerized general practice record. Pregnancies were unlikely to be missed,
and the follow-up data in this population are good. However, the results may
not be typical of the rest of the country for several reasons. First,
termination of pregnancy is readily available in East Devon, 95% being
provided by the National Health Service; the 49% termination rate in our
teenage group must be compared with 38% for England and
Wales 4. Other
workers have reported highest termination rates in affluent areas and where
the overall pregnancy rate is
low 5. Moreover, we
already know that high teenage pregnancy rates are associated with low
socioeconomic
status 5,6,7,
with maternal history of teenage
conception 8,9,
with poor educational achievement and with family
disruption 6,7,
none which could be adjusted for here. The findings in this study suggest that many of the teenagers became
pregnant by design rather than by accident. In the UK, the Social Exclusion
Unit report stated that about 10% of 16-19-year-olds whose pregnancy is
terminated have already undergone one abortion and 2% have had both an
abortion and a
baby 2. A study in
East Anglia of pregnant girls aged 13-16 indicated that 11/98 (12%) had been
pregnant before 6. In
the United States researchers have tended to focus on girls whose first
pregnancy produced a baby, and some 30-50% conceived again within 24
months 10. The
corresponding figure in Honiton was 46%. Can we identify the individuals most likely to have a rapid repeat
pregnancy? Suggested risk factors include young age at first pregnancy, low
socioeconomic status, low educational achievement in the teenager and head of
household, married status, intended or desired first pregnancy, and use of
contraception other than
Norplant 11. But
there is no consensus. In one American study the main risk factor seemed to be
a lack of motivation not to have a second
pregnancy 12. Second
pregnancies in American teenagers are more likely to be desired than first
pregnancies. This seems to be true also in Honiton, even though a rapid repeat
pregnancy is associated with negative short-term consequences in terms of
education, employment and welfare dependency. Those whose first pregnancy
produced a baby were particularly likely to become pregnant again as
teenagers. In the 1970s it was observed that women who started childbearing in their
teens had more children, closer together, than women who delayed
childbearing 13.
This we have not yet found in Honiton, though the younger group in our study
still have many remaining years of fertility. Thanks are due to the partners and staff of the Honiton Group Practice,
especially Dr David Seamark. The author received the 1998-2000 Research
Training Fellowship from the RCGP/BUPA. The Honiton Group Practice is a NHS
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