Preventive lymecycline therapy in women with a history of pelvic inflammatory disease undergoing first-trimester abortion: a clinical, controlled trial

Prophylactic antibiotics for preventing genital tract infection in women undergoing surgical procedures for incomplete abortion: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Findings about the effect of prophylactic antibiotics in preventing genital tract infection (GTI) associated with surgical procedures used for incomplete abortions are conflicting. Some reported a decrease in infection associated with the use of antibiotic prophylaxis, whereas others found no significant reduction in GTI.

OBJECTIVE

To synthesise systematically the evidence on the effect of prophylactic antibiotics compared with placebo in women undergoing surgical procedures for incomplete abortion.

SEARCH STRATEGY

In February 2020, PubMed, Embase and Cochrane Central for Register of Controlled Trials were searched for relevant published randomised controlled trials.

SELECTION CRITERIA

Randomised controlled trials reporting GTI following surgical procedures for incomplete abortion and comparing antibiotic prophylaxis with placebo.

DATA COLLECTION AND ANALYSIS

Meta-analysis using inverse variance heterogeneity model included subgroup and sensitivity analyses determined a priori were conducted. The quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

MAIN RESULTS

A total of 16 178 women who participated in 24 eligible randomised controlled trials published between 1975 and 2019 were included. Pooled estimates showed the risk of GTI following surgical procedures after incomplete abortion was significantly lower among those who had prophylactic antibiotics (relative risk [RR] = 0.72; 95% CI 0.58-0.90; I²  = 49%). There was no significant effect of antibiotics in women in low- and middle-income countries (three studies, 3579 participants, RR = 0.90; 95% CI 0.50-1.62; I²  = 63%), but it was clinically and statistically significant among women high-income countries (21 studies, 12 599 participants, RR = 0.67; 95% CI 0.53-0.84; I²  = 44%), with a strong level of evidence as assessed by GRADE.

CONCLUSION

This study provides evidence that antibiotic prophylaxis is beneficial in reducing post-abortion GTI among women undergoing surgical procedures for incomplete abortion. More studies are needed from low- and middle-income countries.

TWEETABLE ABSTRACT

Prophylactic antibiotics after incomplete abortion are effective in reducing GTI. More studies are needed from low- and middle-income countries.

Perioperative antibiotics to prevent infection after first-trimester abortion

BACKGROUND

There are two main strategies for the prevention of post-abortal upper genital tract infection: antibiotics given around the time of surgery for all women; and 'screen-and-treat', in which all women presenting for abortion are screened for genital infections and those with positive results are treated.

OBJECTIVES

To determine:1. the effectiveness of antibiotic prophylaxis in preventing post-abortal upper genital tract infection; 2. the most effective antibiotic regimen; 3. the most effective strategy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, POPLINE and LILACS. The search was last updated in May 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in any language including women undergoing induced first trimester surgical or medical abortion, comparing: 1) any antibiotic regimen to placebo, nothing, or another antibiotic; 2) screen-and-treat versus antibiotics. The primary outcome was the proportion of women diagnosed with post-abortal upper genital tract infection.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected references and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI). We used meta-analysis where appropriate and examined between trial heterogeneity using the I(2) statistic. In the presence of between trial heterogeneity we also estimated the 95% prediction interval (PI).

MAIN RESULTS

A total of 703 unique items was identified. We included 19 RCTs. There was evidence of small study biases (Egger test, P = 0.002). In 15 placebo-controlled RCTs there was an effect of antibiotic prophylaxis (pooled RR 0.59, 95% CI 0.46 to 0.75, 95% PI 0.30 to 1.14, I(2) = 39%). There were insufficient data (three trials) to determine whether one regimen was superior to another. In one trial, the incidence of post-abortal upper genital tract infection was higher in women allocated to the screen-and-treat strategy (RR 1.53, 95% CI 0.99 to 2.36).

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis at the time of first trimester surgical abortion is effective in preventing post-abortal upper genital tract infection. Evidence of between trial heterogeneity suggests that the effect might not apply to all settings, population groups or interventions.This review did not determine the most effective antibiotic prophylaxis regimen. Antibiotic choice should take into account the local epidemiology of genital tract infections, including sexually transmitted infections.Further RCTs comparing different antibiotics or combinations of antibiotics with each other would be useful. Such trials could be done in low and middle income countries and where the prevalence of genital tract infections in women presenting for abortion is high.

Antibiotic prophylaxis to prevent post-abortal upper genital tract infection in women with bacterial vaginosis: randomised controlled trial

OBJECTIVE

To determine the prevalence of bacterial vaginosis in women undergoing first trimester suction termination of pregnancy and to evaluate the efficacy of metronidazole in reducing the risk of post abortal pelvic infection in women with bacterial vaginosis.

DESIGN

Randomised double-blind placebo-controlled trial.

SETTING

Two teaching hospitals and one district general hospital.

SAMPLE

Two hundred and seventy-three women with bacterial vaginosis undergoing termination of pregnancy.

METHODS

Women with bacterial vaginosis, diagnosed using modified Spiegel's criteria, were individually randomised to receive either a 2 g metronidazole suppository or identical placebo per-operatively. Participants, doctors and investigators were blinded to treatment allocation. Participants were asked to complete a questionnaire about post-operative symptoms, visits to the general practitioner, antibiotic treatment, readmission to hospital, contraception and emotional response after one month.

RESULTS

The prevalence of bacterial vaginosis was 29.3% (326/1,111). Intention-to-treat analysis showed that post-operative upper genital tract infection developed in 12/142 (8.5%) women allocated to metronidazole and 21/131 (16.0%) women randomised to placebo, a difference of 7.6% (95% confidence intervals -15.4 to +0.2%; relative risk 0.53. 0.27 to 1.03, P = 0.055). The effect of prophylaxis was similar when the analysis was restricted to women receiving the allocated treatment and with complete follow up. There was no difference in the risk of readmission to hospital and the frequencies of self reported symptoms in the two groups were similar.

CONCLUSION

This randomised placebo-controlled trial among women with bacterial vaginosis provides weak evidence that metronidazole decreases the risk of upper genital tract infection after first trimester suction termination of pregnancy but a chance finding could not confidently be excluded. Large well-conducted randomised trials with long term outcome measures are now needed to determine the most effective antibiotic combinations and strategy for prevention of post-abortal pelvic infection.

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.