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.

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).

Risk of spontaneous abortion following induced abortion is only increased with short interpregnancy interval

We set out to study the risk of spontaneous abortion following a first trimester induced abortion as a function of the interpregnancy interval between two pregnancies. The cohort study is based on the following databases: Danish national registries: the Medical Birth Registry (MBR), the Hospital Discharge Registry (HDR), and the induced Abortion Registry (IAR). All primigravid women in the time period from 1980 to 1982 were identified in the MBR, the HDR and the IAR. A total of 15 727 women who terminated the pregnancy with a first trimester induced abortion were selected as the induced abortion cohort, and 46 026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies which were not terminated by induced abortion were identified from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected. Women whose first pregnancy was terminated following a first trimester induced abortion had a risk of spontaneous abortion of 11.0% vs. 9.4% in the control cohort. This relative difference of 1.17 was not statistically significant in logistic regression analyses. An increased risk was only found for women who had an interpregnancy interval of less than 3 months (OR=4.06, 95% C.I.=1.98-8.31). The abortion method, vacuum aspiration with dilatation or evacuation with dilatation did not modify this elevated risk. Overall the study did not show an increased risk of spontaneous abortion following one or more induced abortions, except for women with a short interpregnancy interval between an induced abortion and a subsequent pregnancy. We recommend women who have a first trimester induced abortion be advised to wait at least 3-6 months before trying to become pregnant again.

Induced abortion and risk of small-for-gestational-age birth

OBJECTIVE

To investigate the possibility of an association between previous induced abortion and subsequent birth of a small-for-gestational-age (SGA) infant.

DESIGN

Case-control study.

SETTING

General and university hospitals.

METHODS

Cases were 555 women who delivered SGA babies. Controls were 1966 women who gave birth at term (>37 weeks of gestation) to healthy infants of normal weight on randomly selected days at the hospital where cases had been identified. All women in the case and control categories were interviewed on the obstetric wards by one of a team of six interviewers. During the interviews, information was obtained regarding general socio-demographic factors, personal characteristics and habits, gynaecological and obstetric history, general anamnesis, family history of obstetric and gynaecological diseases, and the age of the father of the child. Further information on current pregnancy and delivery was also collected. We used conditional multiple logistic regression (with age as the matching variable), with maximum likelihood fitting, to obtain odds ratios and their corresponding 95% CIs. Included in the regression equations were terms for education, plus terms significantly associated in this data set with the risk of SGA birth (smoking in pregnancy, history of SGA, gestational hypertension and parity).

POPULATION

Women admitted to a general and a university hospital.

RESULTS

No significant increase in the risk of SGA birth was observed in women with a previous induced abortion [odds ratio (OR) 1.0; 95% CI 0.6-1.7]. The OR for SGA birth was 1.2 (95% CI 0.7-2.1) for preterm and 1.0 (95% CI 0.7-1.4) for term SGA births.

CONCLUSION

This study found no association between risk of SGA birth and induced abortion.

Is previous aberrant reproductive outcome predictive of subsequently reduced fecundity?

BACKGROUND

Effect of past reproductive performance on subsequent fecundity is uncertain.

METHODS

A total of 2983 consecutive pregnant women self-completed questionnaires about time to pregnancy (TTP), pregnancy planning, previous pregnancies, contraceptive use, age, and individual/lifestyle variables. Outcome measures were: TTP, conception rates (CR) and, subfecundity odds ratio (OR; with 95% confidence intervals) before and after each outcome of last pregnancy.

RESULTS

After miscarriage, TTP was longer than before miscarriage [2.1 (1.4-3.0), P < 0.001] and than TTP after livebirth [OR = 2.1 (1.6-2.6), P < 0.001]. Also subfecundity OR after miscarriage increased [1.7 (1.2-2.4), 1.8 (1.2-2.5), P = 0.001, 0.002 respectively]. This effect was more evident in older and obese women. Compared with livebirth, time to ectopic pregnancy (EP) was longer [OR = 13.8 (1.8-108.5), P = 0.001] but TTP after EP was not significantly different. Subfecundity OR relative to livebirth were 12.8 (3.6-45.0) (P<0.001) before, and 3.9 (1.4-11.0) (P=0.01) after, EP. The CR after EP increased 3-fold (1.1-8.3) over those prior to EP. Time to the terminated pregnancies even without contraceptive failures was shorter than that to livebirth [OR = 0.5 (0.3-0.7), P = 0.001] and than TTP after termination [0.35 (0.1-0.8), P = 0.001]. Also subfecundity OR increased after termination [7.2 (1.8-29.7), P = 0.02].

CONCLUSIONS

Miscarriers should be counselled about short-term reduction in subsequent fecundity, and earlier investigations should be considered in those who have other potential risk factors for reduced fertility. Further studies are required to clarify the relatively favourable effect on fecundity following EP and the relative reduction in fecundity after termination of pregnancy.

Mifepristone-induced early abortion and outcome of subsequent wanted pregnancy

Follow-up information on subsequent pregnancies after mifepristone (RU486)-induced abortion is scarce. The authors examined whether one mifepristone-induced first-trimester abortion affects the outcome of a subsequent wanted pregnancy. In a study conducted in 1998-2001 at antenatal clinics in Beijing, Chengdu, and Shanghai, China, the authors enrolled 4,925 women with no history of induced abortion, 4,931 women with one previous mifepristone-induced abortion, and 4,800 women with one previous surgical abortion and followed them through pregnancy and childbirth. The adjusted odds ratio for preterm delivery in women with one mifepristone abortion compared with women with no abortion was 0.77 (95% confidence interval: 0.61, 0.98). Although the mean birth weight of infants born to women with mifepristone abortion was 33 g (95% confidence interval: 17, 49) higher than that of infants born to women with no abortion, the frequencies of low birth weight and mean lengths of pregnancy were similar. There were no significant differences in risk of preterm delivery, frequency of low birth weight, or mean infant birth weight in the comparisons of women with previous mifepristone abortion and women with surgical abortion. This study suggests that one early abortion induced by mifepristone in nulliparous women has no adverse effects on the outcome of a subsequent pregnancy.

Induced abortion and risk of subsequent miscarriage

BACKGROUND

To evaluate the impact of surgically induced first-trimester abortion on the risk of miscarriage in a subsequent pregnancy.

METHODS

The study is a pregnancy cohort study. It was conducted among 15 general hospitals or maternity and infant health institutes in Shanghai, China from November 1993 to March 1998. The abortion cohort consisted of pregnant women whose previous pregnancies were terminated by vacuum aspiration (98%). The reference cohort consisted of primigravidae. Subjects were recruited at 35-63 days of gestational age. A total of 2953 pregnant women were enrolled; 1502 in the abortion cohort, 1451 in the reference cohort.

RESULTS

There were only 62 women lost to follow-up. The remaining 2891 women had 2732 live births, and 137 miscarriages. About 5.5% of pregnancies in the abortion cohort were miscarried and 4.0% in the reference cohort. Once potential confounders were controlled for by logistic regression, odds ratio (OR) of miscarriage between the abortion cohort and the reference cohort was 1.55 (95% CI: 1.08-2.23). The adjusted OR were 2.44 (95% CI: 1.16-5.15) among women who were recruited within 49 days of gestational age, and 1.72 (95% CI: 1.09-2.72) for the first-trimester miscarriage.

CONCLUSIONS

Induced abortion by vacuum aspiration is associated with an increased risk of first-trimester miscarriage in the subsequent pregnancy.

Early surgical abortion: an alternative to and backup for medical abortion

Surgical abortion by vacuum aspiration is one of the most commonly reported surgical procedures in the United States. The developments of highly sensitive urinary pregnancy tests and transvaginal ultrasonography have encouraged the application of surgical abortion methods at earlier gestational ages. Manual vacuum aspiration with a handheld syringe safely accomplishes early abortion in a variety of settings, from elective abortion in the office or clinic setting to emergency care of a patient with an incomplete abortion. As a wider range of clinicians expresses interest in offering medical abortion, the appropriate use and technique of surgical backup are crucial in safely providing medical abortion. This article reviews vacuum aspiration during the first few weeks of pregnancy, with special attention to manual vacuum aspiration, both for elective surgical abortion and when intervention is required after medical abortion.

Induced abortion and low birthweight in the following pregnancy

BACKGROUND

To examine whether induced abortion increases the risk of low birthweight in subsequent singleton live births.

METHODS

Cohort study using the Danish Medical Birth Registry (MBR), the Hospital Discharge Registry (HDR), and the Induced Abortion Registry (IAR). All women who had their first pregnancy during 1980-1982 were identified in the MBR, the HDR, and the IAR. We included all 15,727 women whose pregnancy was terminated by a first trimester induced abortion in the induced abortion cohort and 46,026 women whose pregnancy was not terminated by an induced abortion were selected for the control cohort. All subsequent pregnancies until 1994 were identified by register record linkage.

RESULTS

Low birthweight (<2500 g) in singleton term live births occurred more frequently in women with one, two, three or more previous induced abortions, compared with women without any previous induced abortion of similar gravidity, 2.2% versus 1.5%, 2.4% versus 1.7%, and 1.8% versus 1.6%, respectively. Adjusting for maternal age and residence at time of pregnancy, interpregnancy interval, gender of newborn, number of previous spontaneous abortions and number of previous low birthweight infants (control cohort only), the odds ratios (OR) of low birthweight in singleton term live births in women with one, two or more previous first trimester induced abortions were 1.9 (95% CI: 1.6, 2.3), and 1.9 (95% CI: 1.3, 2.7), respectively, compared with the control cohort of similar gravidity. High risks were mainly seen in women with an interpregnancy interval of more than 6 months.

CONCLUSIONS

The findings suggest a positive association between one or more first trimester induced abortions and the risk of low birthweight in subsequent singleton term live births when the interpregnancy interval is longer than 6 months. This result was unexpected and confounding cannot be ruled out.

Abortion and maternal health

Since the beginning of recorded history, women have attempted to terminate unwanted pregnancies. Despite the safety of modern techniques of abortion, many women throughout the world still have to resort to unsafe abortions, placing themselves at considerable risk. The World Health Organization estimates that there are approximately 20 million unsafe abortions performed each year, and estimates of maternal deaths as a result of abortion range between 60,000 and 100,000 per year. With free and legal access to safe abortions, rates of complications and mortality drop dramatically. There is an urgent need for efforts to prevent unwanted pregnancies in order to reduce the need for abortion; for the early identification of abortion complications and easy access to treatment for women suffering those complications; for expansion of safe abortion availability; and for proper training and resources for providers of abortion services.

Multiple induced abortions: Danish experience

Experience with 50 first time aborters, 50 second time aborters, and 50 third time aborters residing in an urban area of Copenhagen suggests that women having a repeat abortion are more similar than dissimilar to women having a first induced abortion. There were no differences in socioeconomic status, educational level, or stated reasons for choosing abortion (usually socioeconomic and family considerations). Though similar to first and second time aborters in their life situations and greater contraceptive risk-taking, third timers seemed to become pregnant more readily. They were also less willing to be interviewed. Related studies and suggestions for postabortion counseling are discussed.

Fertility after contraception or abortion

There is a very small correlation, if any, between the prior use of OCs and congenital malformations, including Down's syndrome. There are few, if any, recent reports on masculinization of a female fetus born to a mother who took an OC containing 1 mg of a progestogen during early pregnancy. However, patients suspected of being pregnant and who are desirous of continuing that pregnancy should not continue to take OCs, nor should progestogen withdrawal pregnancy tests be used. Concern still exists regarding the occurrence of congenital abnormalities in babies born to such women. The incidence of postoperative infection after first trimester therapeutic abortion in this country is low. However, increasing numbers of women are undergoing repeated pregnancy terminations, and their risk for subsequent pelvic infections may be multiplied with each succeeding abortion. The incidence of prematurity due to cervical incompetence or surgical infertility after first trimester pregnancy terminations is not increased significantly. Asherman's syndrome may occur after septic therapeutic abortion. The pregnancy rate after treatment of this syndrome is low. The return of menses and the achievement of a pregnancy may be slightly delayed after OCs are discontinued, but the fertility rate is within the normal range by 1 year. The incidence of postpill amenorrhea of greater than 6 months' duration is probably less than 1%. The occurrence of the syndrome does not seem to be related to length of use or type of pill. Patients with prior normal menses as well as those with menstrual abnormalities before use of OCs may develop this syndrome. Patients with normal estrogen and gonadotropin levels usually respond with return of menses and ovulation when treated with clomiphene. The rate for achievement of pregnancy is much lower than that for patients with spontaneous return of menses. The criteria for defining PID or for categorizing its severity are diverse. The incidence of PID is higher among IUD users than among patients taking OCs or using a barrier method. The excess risk of PID among IUD users, with the exception of the first few months after insertion, is related to sexually transmitted diseases and not the IUD. Women with no risk factors for sexually transmitted diseases have little increased risk of PID or infertility associated with IUD use. There appears to be no increased risk of congenital anomalies, altered sex ratio, or early pregnancy loss among spermicide users. All present methods of contraception entail some risk to the patient. The risk of imparied future fertility with the use of any method appears to be low.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of pregnancy termination on future reproduction

A variety of conditions have been anecdotally ascribed to induced abortion, including subsequent reproductive complications. Since most women obtaining induced abortions are at the beginning of their reproductive life, the effect of induced abortion on subsequent reproduction becomes a very significant one. Our review of the literature confirms findings reported previously. First, except in the case where an infection complicates induced abortion, there is no evidence of an association between induced abortion and secondary infertility or ectopic pregnancy. Second, the risk of midtrimester abortion, premature delivery and low birthweight in women whose first pregnancy is terminated by vacuum aspiration is not higher than that in women in their first pregnancy or women in their second pregnancy whose first pregnancy was carried to term. However, the risk of having a premature delivery or a low birthweight baby tends to be higher (but not significantly) among women whose first pregnancy is terminated by induced abortion when compared with women in their second pregnancy than when compared with women in their first pregnancy. This suggests that an induced abortion does not protect a women against the known risk of low birthweight for first-born offspring. Finally, women whose pregnancy is terminated by dilatation and evacuation may have an increased risk of subsequent premature delivery and a low birthweight baby. Very little has been published and no conclusions can be made regarding the effects of instillation procedures and repeat abortions on future reproduction. In conclusion, except for the association between pregnancies following dilatation and evacuation procedures and premature delivery and low birthweight, no significantly increased risk of adverse reproductive health has been observed following induced abortion.

Age and infertility

Direct evidence on age patterns of infecundity and sterility cannot be obtained from contemporary populations because such large fractions of couples use contraception or have been sterilized. Instead, historical data are exploited to yield upper bounds applicable to contemporary populations on the proportions sterile at each age. Examination of recent changes in sexual behavior that may increase infecundity indicates that sexually transmitted infections, the prime candidate for hypothesized rises in infertility, are unlikely to have added to infecundity to any great extent. These results imply that a woman in a monogamous union faces only moderate increases in the probability of becoming sterile (or infecund) until her late thirties. Nevertheless, it appears that recent changes in reproductive behavior were guaranteed to result in the perception that infecundity is on the rise.