Impact of spontaneous abortion history and induced abortion history on perinatal outcomes of singleton pregnancies

BACKGROUND

At present, there are several studies on abortion history and perinatal outcomes, but there is no unified conclusion whether the history of abortion and different types of abortion are related to perinatal complications of subsequent pregnancy. We aim to study the impact of different types of abortion history on perinatal outcomes of singleton pregnancies.

METHODS

This was a retrospective study from a maternity and infant hospital in Shanghai, China from 2016 to 2020. Pregnant women who gave birth to live singleton infant were included (n = 75,773). We classified abortion into spontaneous abortion (SAB) and induced abortion (IA). We compared the perinatal outcomes of singleton pregnancies with different abortion histories and used Logistic regression analysis to evaluate the associations between pre-pregnancy abortion history with perinatal outcomes.

RESULTS

We observed that pregnant women with a history of abortion were more likely to have a premature delivery (0.99% VS 0.45%), gestational diabetes mellitus (GDM) (13.40% VS 10.29%), placenta abnormality (8.16% VS 5.06%), placenta previa (5.65% VS 3.75%), placenta accreta (0.18% VS 0.04%), and placenta adhesion (2.79% VS 1.03%) than those who obtained singleton pregnancies without a history of abortion. When confounding factors were adjusted, differences in placenta abnormality still existed (excluding placenta abruption). The odds ratios and 95% confidence interval of placenta previa, placenta accreta, and placenta adhesion in pregnant women with only SAB history, only IA history, and both abortion history were 1.294(1.174-1.427), 1.272(1.159-1.396), and 1.390(1.188-1.625), 2.688(1.344-5.374), 2.549(1.268-5.125), and 5.041(2.232-11.386), 2.170(1.872-2.515), 2.028(1.738-2.366), and 3.580(2.917-4.395), respectively.

CONCLUSIONS

Our research showed that pregnant women who have a history of abortion before pregnancy were more likely to have premature birth, GDM, placenta previa, placenta accreta, and placenta adhesion. After adjusting for confounding factors, we found that the history of SAB, IA, and both SAB and IA history were related to the increased risk of placenta previa, placenta accreta, and placenta adhesion.

Subsequent placenta accreta after previous mifepristone-induced abortion: A case report

BACKGROUND

Mifepristone-induced abortion (MIA) has been used worldwide to terminate pregnancies. However, the association between placenta accrete (PA) and MIA has seldom been reported.

CASE SUMMARY

A 26-year-old pregnant woman presented with painless vaginal bleeding at 35 wk of gestation. She had a medical abortion (mifepristone followed by misoprostol) 1 year ago at the sixth week of gestation. Her personal history for previous surgery was negative. Abdominal ultrasonography showed a normal foetus with complete placenta previa. The foetal membrane ruptured with massive vaginal bleeding and severe abdominal pain. An emergency Caesarean section was performed, and the newborn was delivered. The placenta failed to expel and manual extraction was carried out. A large defect was noted in the uterine fundus and repair of the uterine rupture was conducted immediately. The postoperative pathology report showed placenta accreta.

CONCLUSION

The evidence suggests a possible etiologic role of MIA in PA, as the incidence of PA after MIA is much higher than general population. Millions of pregnancies are complicated by PA each year, some of which result in fatality. To prevent subsequent placental complications after MIA, hormonal supplementation might be a promising therapeutic options. However, further studies are needed to identify the high-risk factors and to confirm the effectiveness of estrogen supplement therapy.

No. 360-Induced Abortion: Surgical Abortion and Second Trimester Medical Methods

OBJECTIVE

This guideline reviews evidence relating to the provision of surgical induced abortion (IA) and second trimester medical abortion, including pre- and post-procedural care.

INTENDED USERS

Gynaecologists, family physicians, nurses, midwives, residents, and other health care providers who currently or intend to provide and/or teach IAs.

TARGET POPULATION

Women with an unintended or abnormal first or second trimester pregnancy.

EVIDENCE

PubMed, Medline, and the Cochrane Database were searched using the key words: first-trimester surgical abortion, second-trimester surgical abortion, second-trimester medical abortion, dilation and evacuation, induction abortion, feticide, cervical preparation, cervical dilation, abortion complications. Results were restricted to English or French systematic reviews, randomized controlled trials, clinical trials, and observational studies published from 1979 to July 2017. National and international clinical practice guidelines were consulted for review. Grey literature was not searched.

VALUES

The quality of evidence in this document was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology framework. The summary of findings is available upon request.

BENEFITS, HARMS, AND/OR COSTS

IA is safe and effective. The benefits of IA outweigh the potential harms or costs. No new direct harms or costs identified with these guidelines.

Prevalence of abnormally invasive placenta among deliveries in mainland China: A PRISMA-compliant Systematic Review and Meta-analysis

BACKGROUND

Abnormally invasive placenta (AIP) or placenta accreta (PA) is considered numerous adverse maternal and fetal-neonatal complications. There has been no detailed study to characterize the prevalence of AIP among deliveries in mainland China.

OBJECTIVES

We aimed to fill this gap and obtained overall and regional estimates of AIP prevalence via a systematic review and meta-analysis.

METHODS

This systematic review and meta-analysis was totally performed following the Meta-analysis of Observational Studies in Epidemiology guidelines for systematic reviews of observational studies, and the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement for reporting systematic reviews and meta-analysis.

RESULTS

A total of 23 articles (including 350,939) were included. Most studies (22) focused on the placenta increta (PI), only 2 articles in PA, and none in placenta percreta (PP). In this meta-analysis, the overall prevalence of AIP was 0.22% (95% confidence interval 0.18%-0.27%) in a heterogeneous set of studies (I = 93.5%). In a subgroup, the prevalence of PA and PI was 0.48% and 0.23%, respectively. Stratified analyses of PI found that the prevalence was similar in North (0.23% [0.14%-0.32%]) and South (0.23% [0.15%-0.32%]), and lower in Central (0.20% [0.09-0.31%]); the inlanders (0.17% (0.12%-0.23%]) had a lower prevalence of PI than those living in coastal areas (0.24% [0.35%-0.63%]). As time goes on, the prevalence, from 0.03% (0.02%-0.04%) in 1970 to 1979 to 0.48% (0.30%-0.66%) in 2010 to present, was higher and higher. The different prevalence was also found in different in maternal age groups.

CONCLUSIONS

This first systematic review and meta-analysis found that the prevalence differed among different geographic areas and maternal age groups. The results would be useful for the design of abnormally invasive placenta planning and implementation adequate health care systems and treatment programs in mainland China.

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.

Adverse pregnancy outcomes among women with prior spontaneous or induced abortions

OBJECTIVE

The aim of the article is to determine whether prior spontaneous abortion (SAB) or induced abortion (IAB), or the interpregnancy interval are associated with subsequent adverse pregnancy outcomes in nulliparous women.

METHODS

We performed a secondary analysis of data collected from nulliparous women enrolled in a completed trial of vitamins C and E or placebo for preeclampsia prevention. Adjusted odds ratios (ORs) for maternal and fetal outcomes were determined for nulliparous women with prior SABs and IABs as compared with primigravid participants.

RESULTS

Compared with primigravidas, women with one prior SAB were at increased risk for perinatal death (adj. OR, 1.5; 95% CI, 1.1-2.3) in subsequent pregnancies. Two or more SABs were associated with an increased risk for spontaneous preterm birth (PTB) (adj. OR, 2.6, 95% CI, 1.7-4.0), preterm premature rupture of membranes (PROM) (adj. OR, 2.9; 95% CI, 1.6-5.3), and perinatal death (adj. OR, 2.8; 95% CI, 1.5-5.3). Women with one previous IAB had higher rates of spontaneous PTB (adj. OR, 1.4; 95% CI, 1.0-1.9) and preterm PROM (OR, 2.0; 95% CI, 1.4-3.0). An interpregnancy interval less than 6 months after SAB was not associated with adverse outcomes.

CONCLUSION

Nulliparous women with a history of SAB or IAB, especially multiple SABs, are at increased risk for adverse pregnancy outcomes.

Risk of retained placenta in women previously delivered by caesarean section: a population-based cohort study

OBJECTIVE

To evaluate whether women with a caesarean section at their first delivery have an increased risk of retained placenta at their second delivery.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

All women with their first and second singleton deliveries in Sweden during the years 1994-2006 (n = 258,608). Women with caesarean section or placental abruption in their second pregnancy were not included in the study population.

METHODS

The risk of retained placenta at second delivery was estimated for women with a first delivery by caesarean section (n = 19,458), using women with a first vaginal delivery as reference (n = 239,150). Risks were calculated as odds ratios by unconditional logistic regression analysis with 95% confidence intervals (95%) after adjustments for maternal, delivery, and infant characteristics.

MAIN OUTCOME MEASURES

Retained placenta with normal (≤1000 ml) and heavy (>1000 ml) bleeding.

RESULTS

The overall rate of retained placenta was 2.07%. In women with a previous caesarean section and in women with previous vaginal delivery, the corresponding rates were 3.44% and 1.96%, respectively. Compared with women with a previous vaginal delivery, women with a previous caesarean section had an increased risk of retained placenta (adjusted OR 1.45; 95% CI 1.32-1.59), and the association was more pronounced for retained placenta with heavy bleeding (adjusted OR 1.61; 95% CI 1.44-1.79).

CONCLUSIONS

Our report shows an increased risk for retained placenta in women previously delivered by caesarean section, a finding that should be considered in discussions of mode of delivery.

Repeated abortion affects subsequent pregnancy outcomes in BALB/c mice

AIM

In this study, we aimed to establish a mouse model of repeated medical termination of pregnancy in order to determine subsequent outcomes.

METHODS

A model of mifepristone (RU 486)-induced medical abortion was established in BALB/c mice to facilitate the investigation of the impact of medical abortion on subsequent pregnancies, including litter sizes and newborn birth weights. Pregnant mice were sacrificed to examine midterm pregnancy status, investigate the frequency of fetal resorption, and measure placental function gene expression by real-time PCR and immunohistochemistry. Offspring liver mRNA was harvested for real-time PCR to determine gene expression and assess the effects of abortion on offspring development.

RESULTS

Mice subjected to 2 previous medical abortions experienced spontaneous abortions in subsequent pregnancies. Medical abortion caused reduced reproductive capacity and affected placental dysfunction, with reduced expression of tissue factor (TF) and genes encoding proteins involved in metabolic functions relevant to pregnancy, such as 11β-hydroxysteroid dehydrogenase 1/2 (11β-HSD1/2) and glucocorticoid receptor (GR). Reduced expression was also observed for platelet endothelial cell adhesion molecule-1 (CD31) and vascular endothelial growth factor (VEGF). In offspring from subsequent pregnancies, genes involved in lipid metabolism, which may enhance key lipid transcription factors, such as PPARA and PPARG, as well as GR/11β-HSD1, were downregulated in the liver. In addition, the sperm motility of the F1 males reduced.

CONCLUSION

Repeated medical abortion impaired the reproductive function of female mice, significantly affecting the outcomes of subsequent pregnancies. The impact of repeated abortions on the offspring of subsequent pregnancies was also noteworthy and deserves further exploration. Thus, this model provides a useful means to study the mechanisms underlying the above phenomena, which will ultimately benefit the health of women and their children.

Reproductive outcomes following induced abortion: a national register-based cohort study in Scotland

OBJECTIVE

To investigate reproductive outcomes in women following induced abortion (IA).

DESIGN

Retrospective cohort study.

SETTING

Hospital admissions between 1981 and 2007 in Scotland.

PARTICIPANTS

Data were extracted on all women who had an IA, a miscarriage or a live birth from the Scottish Morbidity Records. A total of 120 033, 457 477 and 47 355 women with a documented second pregnancy following an IA, live birth and miscarriage, respectively, were identified.

OUTCOMES

Obstetric and perinatal outcomes, especially preterm delivery in a second ongoing pregnancy following an IA, were compared with those in primigravidae, as well as those who had a miscarriage or live birth in their first pregnancy. Outcomes after surgical and medical termination as well as after one or more consecutive IAs were compared.

RESULTS

IA in a first pregnancy increased the risk of spontaneous preterm birth compared with that in primigravidae (adjusted RR (adj. RR) 1.37, 95% CI 1.32 to 1.42) or women with an initial live birth (adj. RR 1.66, 95% CI 1.58 to 1.74) but not in comparison with women with a previous miscarriage (adj. RR 0.85, 95% CI 0.79 to 0.91). Surgical abortion increased the risk of spontaneous preterm birth compared with medical abortion (adj. RR 1.25, 95% CI 1.07 to 1.45). The adjusted RRs (95% CI) for spontaneous preterm delivery following two, three and four consecutive IAs were 0.94 (0.81 to 1.10), 1.06 (0.76 to 1.47) and 0.92 (0.53 to 1.61), respectively.

CONCLUSIONS

The risk of preterm birth after IA is lower than that after miscarriage but higher than that in a first pregnancy or after a previous live birth. This risk is not increased further in women who undergo two or more consecutive IAs. Surgical abortion appears to be associated with an increased risk of spontaneous preterm birth in comparison with medical termination of pregnancy. Medical termination was not associated with an increased risk of preterm delivery compared to primigravidae.