Risk of preterm delivery after medically indicated termination of pregnancy with induced vaginal delivery: a case-control study

We investigated whether nonsurgical termination of pregnancy after 14 weeks of gestation increases the risk of preterm delivery in a subsequent pregnancy. We conducted a two-centre retrospective case-control study. Patients who underwent non-surgical termination of pregnancy after 14 weeks of gestation between 2012 and 2015 and who gave birth after 14 weeks of gestation to a live-born singleton infant were included. Control patients were those who gave birth after 37 weeks of gestation (the same month as a case patient) and had a second delivery of a singleton foetus after 14 weeks of gestation. The primary outcome was preterm delivery during the second pregnancy period. We included 151 cases and 302 controls and observed 13 (8.6%) preterm births during the second pregnancy in the case group versus 8 (2.6%) (odds ratio: 3.62; 95% confidence interval: 1.40-8.65, p < .001) in the control group. This result remained significant after multivariate analysis. Impact statementWhat is already known about this topic? Many studies have evaluated the association between first-trimester surgical or non-surgical termination of pregnancy and the risk of preterm birth in the subsequent pregnancy. However, no study has evaluated the association between second- or third-trimester non-surgical termination of pregnancy due to foetal disease and the risk of preterm birth in the subsequent pregnancy. A small number of studies have included a small proportion of patients who previously underwent non-surgical termination of pregnancy after 14 weeks of gestation and later experienced first-trimester termination during their second pregnancy. These studies focussed on the impact of the interpregnancy interval or pharmacological induction of labour on the risk of preterm delivery in the subsequent pregnancy.What did the results of this study add? This is the first study to specifically evaluate the association between second- and third-trimester non-surgical terminations of pregnancy and the risk of preterm birth in the subsequent pregnancy. When compared with term birth, nonsurgical termination of pregnancy was associated with the risk of spontaneous preterm birth and hospitalisation in the neonatal intensive care unit in the subsequent pregnancy.What are the implications of these findings for clinical practice and further research? Further studies are required to confirm our results, but information delivered to patients with a late termination of pregnancy and during their pregnancy follow-up for the subsequent pregnancy could be modified to provide this information.

The duration of gestation at previous induced abortion and its impacts on subsequent births: A nationwide registry-based study

INTRODUCTION

Previous induced abortions have been associated with adverse birth outcomes. However, only a few studies have considered the possible influence of gestational age at induced abortion. Therefore, this study aimed to identify the impacts of gestational age during prior induced abortion(s) on subsequent births among first-time mothers in Finland.

MATERIAL AND METHODS

First-time mothers (n = 418 690) with singleton births between 1996 and 2013 were identified from the Finnish Medical Birth Register and linked to the Abortion Register. Logistic regression analysis was used to estimate the risk (odds ratio [OR] and 95% confidence interval [CI]) of birth outcomes such as prematurity, low birthweight, perinatal death and small for gestational age (SGA).

RESULTS

Higher risk was determined for extremely preterm birth (OR 2.28; 95% CI 1.53-3.39) and very low birthweight (OR 1.62; 95% CI 1.22-2.16) in women having had late-induced abortion(s) (≥12 gestational weeks) compared with women having had early-induced abortion(s) (<12 gestational weeks); after adjusting for women's background characteristics, abortion method and interval between the pregnancies. When the analysis was limited to a single abortion, an increased risk was found for extremely preterm birth (OR 1.71; 95% CI 1.02-2.81). Higher risks were found for extremely preterm (OR 4.09; 95% CI 2.05-8.18) and very low birthweight (OR 2.65; 95% CI 1.61-4.35) among women with two or more late-induced abortions compared with those with two or more early-induced abortions. Worse outcomes were seen after a late-induced abortion compared to an early-induced abortion for both medically and surgically induced abortion.

CONCLUSIONS

The risk of subsequent adverse birth outcomes is very small if any, but the risk is higher with increasing gestational age at the time of induced abortion. Our study supports reduction of unintended pregnancy and offering abortion services without delay and as early in gestation as possible.

Risks of Adverse Perinatal Outcomes after Repeat Terminations of Pregnancy by their Methods: a Nationwide Register-based Cohort Study in Finland 1996-2013

BACKGROUND

Repeat terminations of pregnancy (TOPs) are associated with an increased risk of adverse outcomes in the subsequent birth. The perinatal outcomes after repeat TOPs by their methods have not yet been properly studied. This study aimed to examine perinatal outcomes in subsequent pregnancy among the women with a singleton birth and a history of TOPs.

METHODS

All the first-time mothers (n = 419 879) with a singleton birth during 1996-2013 in Finland were identified from the Medical Birth Register and linked to the Abortion Register. Adjusted multivariable logistic regression analysis was used to estimate risks of adverse perinatal outcomes.

RESULTS

The increased incidence of adverse perinatal outcomes was found with increasing number of surgical TOPs. After adjusting for confounders, the women with one surgical TOP had slightly increased but significant odds of 1.07 (95% CI 1.02, 1.13) for being small for gestational age compared with the women having no TOP. A significantly high risk for extremely preterm birth (OR 1.51, 95% CI 1.03, 2.23) was found among the women having had repeat surgical TOPs when compared to the women with no TOP. Non-significant risks were found for adverse perinatal outcomes after women's repeat surgical TOPs than repeat medical TOPs.

CONCLUSION

Information regarding the consequences of repeat induced TOPs will be significant in sexual health education as well as counselling women after first termination.

Perinatal outcomes after induced termination of pregnancy by methods: A nationwide register-based study of first births in Finland 1996-2013

Background

Women with previous terminations of pregnancy (TOPs) before their first birth have been associated with poorer perinatal outcomes. However, previous studies on the perinatal outcomes by the method in previous TOPs are inconsistent.

Objective

To examine the perinatal outcomes of the first-time mothers with singleton births, by the method of previous TOP (medical and surgical vs no TOP, and surgical vs medical).

Method

This is a nationwide register-based study including 419,879 first-time Finnish mothers with singleton birth during the time period 1996–2013. Mothers having their first birth were identified from the Medical Birth Register and linked to the Abortion Register by their identification numbers. Multinomial logistic regression analysis was performed to examine the risk for preterm birth, low birth weight, small for gestational age and perinatal death by the method in previous TOPs.

Results

Among the first-time mothers, 87.0% had no history of TOPs, 3.2% had a history of medical TOP(s), 9.2% had a history of surgical TOP(s) and 0.6% had a history of both (medical and surgical) TOP(s). No significant differences in perinatal outcomes were found among the women with surgical TOPs, compared to the women with no TOPs. In unadjusted analysis, increased odds for preterm birth and low birth weight were found when comparing women having previous surgical TOPs with medical TOPs. Even after the adjustment of potential confounders, odds for preterm birth < 37 weeks (OR = 1.19, 95% CI = 1.04–1.36) and low birth weight < 2500 g (OR = 1.16, 95% CI = 1.00–1.35) remained significant. After restricting data to the single TOP, the results were similar; OR for both preterm birth and low birth weight was 1.18 (95% CIs = 1.02–1.36 and 1.01–1.38).

Conclusion

Perinatal outcomes did not differ among the mothers with surgical TOPs compared to the mothers with no TOPs, while the outcomes were poorer after surgical TOP(s) than after medical TOP(s).

Prior uterine evacuation of pregnancy as independent risk factor for preterm birth: a systematic review and metaanalysis

BACKGROUND

Preterm birth (PTB) is the number one cause of perinatal mortality. Prior surgery on the cervix is associated with an increased risk of PTB. History of uterine evacuation, by either induced termination of pregnancy (I-TOP) or spontaneous abortion (SAB), which involve mechanical and/or osmotic dilatation of the cervix, has been associated with an increased risk of PTB in some studies but not in others.

OBJECTIVE

The objective of the study was to evaluate the risk of PTB among women with a history of uterine evacuation for I-TOP or SAB.

DATA SOURCES

Electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, EMBASE, and Sciencedirect) were searched from their inception until January 2015 with no limit for language.

STUDY ELIGIBILITY CRITERIA

We included all studies of women with prior uterine evacuation for either I-TOP or SAB, compared with a control group without a history of uterine evacuation, which reported data about the subsequent pregnancy.

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary outcome was the incidence of PTB < 37 weeks. Secondary outcomes were incidence of low birthweight (LBW) and small for gestational age (SGA). We planned to assess the primary and the secondary outcomes in the overall population as well as in studies on I-TOP and SAB separately. The pooled results were reported as odds ratio (OR) with 95% confidence interval (CI).

RESULTS

We included 36 studies in this metaanalysis (1,047,683 women). Thirty-one studies reported data about prior uterine evacuation for I-TOP, whereas 5 studies reported data for SAB. In the overall population, women with a history of uterine evacuation for either I-TOP or SAB had a significantly higher risk of PTB (5.7% vs 5.0%; OR, 1.44, 95% CI, 1.09-1.90), LBW (7.3% vs 5.9%; OR, 1.41, 95% CI, 1.22-1.62), and SGA (10.2% vs 9.0%; OR, 1.19, 95% CI, 1.01-1.42) compared with controls. Of the 31 studies on I-TOP, 28 included 913,297 women with a history of surgical I-TOP, whereas 3 included 10,253 women with a prior medical I-TOP. Women with a prior surgical I-TOP had a significantly higher risk of PTB (5.4% vs 4.4%; OR, 1.52, 95% CI, 1.08-2.16), LBW (7.3% vs 5.9%; OR, 1.41, 95% CI, 1.22-1.62), and SGA (10.2% vs 9.0%; OR, 1.19, 95% CI, 1.01-1.42) compared with controls. Women with a prior medical I-TOP had a similar risk of PTB compared with those who did not have a history of I-TOP (28.2% vs 29.5%; OR, 1.50, 95% CI, 1.00-2.25). Five studies, including 124,133 women, reported data about a subsequent pregnancy in women with a prior SAB. In all of the included studies, the SAB was surgically managed. Women with a prior surgical SAB had a higher risk of PTB compared with those who did not have a history of SAB (9.4% vs 8.6%; OR, 1.19, 95% CI, 1.03-1.37).

CONCLUSION

Prior surgical uterine evacuation for either I-TOP or SAB is an independent risk factor for PTB. These data warrant caution in the use of surgical uterine evacuation and should encourage safer surgical techniques as well as medical methods.