Impact of induced abortions on subsequent pregnancy outcome: the 1995 French national perinatal survey

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Abstract

Objective To study the impact of previous induced abortions on preterm delivery, small for gestational age and low birthweight in subsequent pregnancies.

Design Survey of a national sample of births in France in 1995.

Setting All public and private maternity hospitals in France.

Population 12,432 women who had a singleton live birth during one week.

Methods Data were collected during the women's postpartum stay in hospital, partly obtained by interview and partly abstracted from hospital medical records. Rates of preterm delivery, small for gestational age and low birthweight were compared according to existence and number of previous induced abortions. Maternal age, parity, history of previous adverse pregnancy outcome, maternal weight before pregnancy, marital status, educational level, maternal employment status during pregnancy, nationality, smoking during the third trimester of pregnancy and antenatal care were controlled for using multiple logistic regression and polytomous logistic regression.

Results Twelve percent of women reported one previous induced abortion, and 3% two or more. Previous induced abortion was associated with an increased risk of preterm birth (OR 1.4; 95% CI 1.1–1.8); the risk of preterm delivery increased with the number of previous induced abortions (OR 1.3; 95% CI 1.0–1.7 for one previous abortion and OR 1.9; 95% CI 1.2–2.8 for two or more). The relationship was the same for very preterm and moderately preterm deliveries and for spontaneous and indicated preterm deliveries. After controlling for potential confounders, the association between previous induced abortions and small for gestational age and low birthweight infants was no longer significant.

Conclusion This study suggests that a history of induced abortion increases the risk of preterm delivery, particularly for women who have had repeated abortions. The respective role of the surgical and medical techniques used for induced abortions needs to be explored.

Introduction

About 225,000 induced abortions are carried out in France each year. This figure, relatively stable from year to year, places France in an average position in Europe. Induced abortion in France (32 abortions per 100 live births)1is more frequent than in the United Kingdom (23 per 100 live births), in Germany (13 per 100) or in The Netherlands (11 per 100), similar to Sweden (30 per 100) and much less than in Eastern European countries (189 abortions per 100 live births in Russia and 212 per 100 in Romania)2. In the 1980s there was an increasing trend in repeated abortions; in 1993 in France 18% of women having an induced abortion had already had one previously3; this trend is now remaining stable.

About 60% of women having an induced abortion are less than 30 years old3. Therefore induced abortions mainly concern women who are at the beginning or middle of their reproductive life and who may want to have children in the future. Because of the number of induced abortions performed each year in France and with 15% of women giving birth having a history of previous induced abortion4, it is important to know whether previous abortions may have an impact on subsequent pregnancies and on the health of the newborn.

The international literature on induced abortions and the outcome of subsequent pregnancies is limited and without a clear conclusion. Reviews of earlier studies5., 6. showed inconsistent results, however were mostly negative regarding preterm delivery and low birthweight. Most studies were limited to induced abortions in nulliparous women only and did not consider the impact of repeated induced abortions. Many of the more recently published studies also rely on data collected in the 1970s or early 1980s7., 8., 9., 10., 11., 12., 13.. Together with more recent data14., 15., 16., these studies tend to show an increase in preterm delivery in women with previous induced abortions8., 9., 10., 12., 14., 15., 16., although this trend is not always statistically significant. For low birthweight7., 9., 11., 13.and intrauterine growth restriction8., 12., the evidence is more limited and inconsistent.

The present study was undertaken to estimate the risk of preterm, small for gestational age and low birthweight deliveries following first or repeated induced abortions in a large national sample of French women who had recently given birth. Because the factors by which induced abortions might affect the outcome of following pregnancies are expected to be mechanical or linked to infections17, our hypothesis was that there would be a stronger association of previous induced abortions with preterm delivery than with intrauterine growth restriction.

Section snippets

Methods

The study was undertaken using the data from the 1995 French National Perinatal Survey which included all births in France during one week, including live births and stillbirths of at least 22 weeks of gestation or weight of 500 grammes4. This study focused on singleton live births and included 12,885 women. Data were collected from medical records and by interviewing the women after the delivery during their stay in the maternity unit. Information on previous induced abortion was collected by

Results

Women with previous induced abortions differed from the others with regard to medical history and sociodemographic and behavioural characteristics (Table 1). Women who reported previous induced abortions were significantly older; they had a higher number of previous pregnancies and more often a history of previous adverse pregnancy outcome (stillbirth, preterm birth or small for gestational age infant). They were more often alone and unmarried, of foreign nationality, with a lower educational

Discussion

After controlling for confounders, a significant association between previous induced abortion and preterm delivery was observed, both for early and moderate preterm delivery, and for spontaneous and induced preterm delivery; odds ratios increased with the number of previous induced abortions. With small for gestational age and low birthweight, the adjusted association was not statistically significant, although odds ratios were consistently above 1.

The original sample was representative of

Conclusion

A significant association between previous induced abortions and preterm delivery in subsequent pregnancies was observed, the risk increasing with the number of previous induced abortions. Other studies, taking into account the techniques used for induced abortion and the gestational age at intervention, are necessary in order to better understand the pathophysiological mechanisms brought into play and to anticipate them better.

Acknowledgements

The 1995 French National Perinatal Survey was conducted by the Ministry of Health (the National Direction of Health and the Statistics Department), our research unit, and the Maternal and Child Health Services in each district. It was financially supported by a grant from the Fonds d'Intervention en Santé Publique. The authors would like to thank the heads of the maternity units for allowing the survey to be carried out in their wards and the investigators for the data collection, as well as Dr

References (31)

  • C.J.R Hogue et al.

    The effects of induced abortion on subsequent reproduction

    Epidemiol Reviews

    (1982)
  • D.S Seidman et al.

    Child-bearing after induced abortion: reassessment of risk

    J Epidemiol Comm Health

    (1988)
  • J.M Lang et al.

    A comparison of risk factors for preterm labor and term small-for-gestational-age birth

    Epidemiology

    (1996)
  • P.I Frank et al.

    Outcome of pregnancy following induced abortion

    Br J Obstet Gynaecol

    (1985)
  • W Zhou et al.

    Induced abortion and low birthweight in the following pregnancy

    Int J Epidemiol

    (2000)
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