Obstetric outcome in women with subfertility
Fiona Thomson, Smrutha Shanbhag, Allan Templeton, Siladitya Bhattacharya
Background It has been suggested that a history of subfertility is associated with increased obstetric and
perinatal risks. It is unclear if the cause is inherent characteristics in the women or the fertility treatment.
Objectives To compare the obstetric and perinatal risks of singleton pregnancies in women with a history of
subfertility in comparison with the general population.
Design Population cohort.
Setting Aberdeen, Scotland.
Population Cases were women attending the Fertility Clinic between 1989 and 1999 who subsequently went
on to have singleton pregnancies. Controls included the general population of women who delivered
singletons over the same period.
Methods We performed a retrospective cohort study to investigate the obstetric outcome of singleton
pregnancies in women with subfertility. The general population of women who delivered singletons over the
same period served as controls.
Main outcome measures Obstetric and perinatal complications in singleton pregnancies.
Results Maternity records were available for a total of 1437 subfertile women and 21,688 controls.
Subfertile women were older [mean (SD) age: 31 (4.7) years vs 27 (5.4) years, P < 0.01] and more
likely to be primiparous (70% vs 65%, P < 0.001). After adjusting for age and parity, subfertile women
were at increased risk of pre-eclampsia (OR 1.9, 95% CI 1.5–2.5), placenta praevia (OR 3.9, 95% CI
2.2–7.0) and placental abruption (OR 1.8, 95% CI 1.1–3.0), and more likely to undergo induction of
labour (OR 1.5, 95% CI 1.3–1.6), caesarean section (OR 2.1, 95% CI 1.8–2.4) and instrumental
delivery (OR 2.2, 95% CI 1.8–2.6), and deliver low birthweight (OR 1.4, 95% CI 1.3–1.7) and preterm
(OR 1.7, 95% CI 1.2–2.2) infants. There were no differences between treatment-related and treatment-
Conclusion Subfertile women are at higher risk of obstetric complications, which persist after adjusting for
age and parity.
Approximately one in seven couples experience a period
of subfertility during their reproductive life.1Half of
these couples can conceive spontaneously2–4with the
remainder requiring some form of fertility treatment.2In
comparison with women who have no trouble conceiving,5,6
pregnancy in this population is believed to be associated
with increased obstetric and perinatal risks. Maternal
complications reported include pre-eclampsia, antepartum
haemorrhage (APH) and caesarean section (CS),4,6,7while
perinatal problems include low birthweight (LBW),8,9
prematurity8,10and increased perinatal mortality.9Although
initially attributed to the greater number of iatrogenic
multiple pregnancies, a higher incidence of LBW and
preterm labour have been noted among singletons con-
ceived using fertility treatment.11–13A recent study from
Finland found that in vitro fertilisation (IVF) pregnancies
were associated with higher rates of APH, but no other
The true extent of these associations has yet to be de-
termined. Previous studies have examined small cohorts of
subfertile women, which limit generalisability and interpre-
tation of findings. It is unclear if the increased risks are a
consequence of certain inherent characteristics5in women,
treatment-related15or due to some unknown factor linked
to subfertility. Knowledge of any potentially avoidable or
treatable factors in the genesis of obstetric complications
associated with subfertility is important as it may influence
the planning and delivery of maternity care for affected
couples. In order to determine the true risks attributable to
subfertility, what is required is a study involving a large
group of subfertile women which is capable of adjusting for
We aimed to examine the obstetric and perinatal risks
associated with subfertility by comparing: (1) the outcome
BJOG: an International Journal of Obstetrics and Gynaecology
May 2005, Vol. 112, pp. 632–637
D RCOG 2004 BJOG: an International Journal of Obstetrics and Gynaecology
Department of Obstetrics and Gynaecology, University of
Aberdeen, Aberdeen Maternity Hospital, UK
Correspondence: Dr S. Bhattacharya, Department of Obstetrics and
Gynaecology, University of Aberdeen, Aberdeen Maternity Hospital,
Foresterhill, Aberdeen, AB25 2ZD UK.
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by gestational age. Am J Epidemiol 2002;155:203–209.
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Do obstetric complications explain high caesarean section rates
among women over 30? A retrospective analysis. BMJ 2001;322:
20. Rizk B, Doyle P, Tan SL, et al. Perinatal outcome and congenital
malformations in IVF babies from Bourn Hallam Group. Hum Reprod
21. Hill GA, Bryan S, Herbert III CM, Shah DM, Wentz AC.
Complications of pregnancy in infertile couples: routine versus
assisted reproduction. Obstet Gynecol 1990;75:790–794.
22. Frydman R, Belaisch-Allart J, Fries N, Hazout A, Glissant A, Testart
J. An obstetric assessment of the first 100 births from the in vitro
fertilisation program at Clamant, France. Am J Obstet Gynecol 1986;
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follow up. Acta Obstet Gynecol Scand 1997;76:238–243.
Accepted 28 July 2004
OBSTETRIC COMPLICATIONS IN SUBFERTILE WOMEN 637
D RCOG 2004 BJOG: an International Journal of Obstetrics and Gynaecology 112, pp. 632–637