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'Practice-changing' study on antibiotics given after assisted birth

NewbornThousands of women every year could be spared painful and occasionally life-threatening infections if doctors administered preventive antibiotics after every assisted childbirth, The Guardian reports a major trial has found. A single dose of antibiotics within six hours of childbirth nearly halved the number of infections in women whose babies were delivered with either forceps or ventouse suction cups, procedures that are used in one in eight UK births.

The report says the trial involving 3,420 women who gave birth in 27 units across Britain suggests that this could prevent 7,000 maternal infections in the UK, and more than 200,000 maternal infections worldwide annually.

The findings, described as “practice-changing” by doctors not involved in the trial, will be reflected in new advice to be published by the UK’s Royal College of Obstetricians and Gynaecologists this year.

“This will have a very big impact on women and not just in terms of the infection rate,” said Marian Knight, a professor of maternal and child population health at the University of Oxford in the report. “Those who received antibiotics were much less likely to have perineal pain, much less likely to have burst stitches, and they had fewer problems feeding their baby as a consequence of that pain.”

Forceps and ventouse suction cups can raise the risk of infection by introducing microbes into the genital tract. But women who have assisted childbirth also tend to be in labour longer, have more vaginal examinations, are fitted with urinary catheters more often, and have more tears and surgical cuts than those who give birth spontaneously.

The report says all can increase the risk of infection, which in rare cases can develop into life-threatening sepsis. In developed countries, infections account for about one in 20 maternal deaths. For every fatal infection, a further 70 women develop infections that are serious enough to cause long-term health problems.

Between March 2016 and June 2018, women who took part in the trial were randomly assigned to have either an antibiotic (amoxicillin and clavulanic acid), or a saline placebo, administered intravenously within six hours of childbirth. Overall, a third of the births were ventouse and two-thirds of the babies were delivered by forceps.

In the placebo group, 19% of women picked up an infection soon after childbirth, compared with 11% in the antibiotic group. More serious cases of sepsis, confirmed by a positive blood test, reached 1.5% in the placebo group, but only 0.6% in the antibiotic group, according to the study.

“I was surprised by the proportion of women who got an infection,” said Knight. “The majority are not serious, life-threatening infections, but they do need to be caught early to make sure they don’t progress to those major infections.”

The report says by protecting women against infections immediately after giving birth, overall antibiotic use fell, the doctors found. For every 100 doses of antibiotics given prophylactically, clinicians avoided the need to give 168 doses for infections that took hold after childbirth.

The lower rate of infections among the women given antibiotics had a knock-on effect on their broader recovery from childbirth, according to the trial. Compared with the placebo group, women who had antibiotics were less likely to be treated for burst stitches and perineal pain, and reported fewer outpatient appointments due to their wounds, or home visits from GPs, nurses or midwives.

In an accompanying editorial, Vincenzo Berghella of Thomas Jefferson University in Philadelphia described the findings as “practice-changing” and called for clinical guidelines for obstetricians to be updated.

Pat O’Brien, a consultant obstetrician and spokesperson for the Royal College of Obstetricians and Gynaecologists, said in the report: “This is a very interesting and well-conducted trial. Around 12% of women in the UK have an assisted birth and these results show that single dose antibiotic use could reduce infections by half – equivalent to around 7,000 infections every year.

“It is standard practice to provide single-dose antibiotic to all women who have a caesarean birth to reduce infection, and it follows that this should be considered for women following an assisted birth.

“Based on these findings alone, it does seem that routine use of a single dose of antibiotic following an assisted birth would help to reduce infections and ensure the best possible health outcomes for women, as well as reduce costs of complications for the health service.”

Background: Risk factors for maternal infection are clearly recognised, including caesarean section and operative vaginal birth. Antibiotic prophylaxis at caesarean section is widely recommended because there is clear systematic review evidence that it reduces incidence of maternal infection. Current WHO guidelines do not recommend routine antibiotic prophylaxis for women undergoing operative vaginal birth because of insufficient evidence of effectiveness. We aimed to investigate whether antibiotic prophylaxis prevented maternal infection after operative vaginal birth.
Methods: In a blinded, randomised controlled trial done at 27 UK obstetric units, women (aged ≥16 years) were allocated to receive a single dose of intravenous amoxicillin and clavulanic acid or placebo (saline) following operative vaginal birth at 36 weeks gestation or later. The primary outcome was confirmed or suspected maternal infection within 6 weeks of delivery defined by a new prescription of antibiotics for specific indications, confirmed systemic infection on culture, or endometritis. We did an intention-to-treat analysis. This trial is registered with ISRCTN, number 11166984, and is closed to accrual.
Findings: Between March 13, 2016, and June 13, 2018, 3427 women were randomly assigned to treatment: 1719 to amoxicillin and clavulanic acid, and 1708 to placebo. Seven women withdrew, leaving 1715 in the amoxicillin and clavulanic acid group and 1705 in the placebo groups. Primary outcome data were missing for 195 (6%) women. Significantly fewer women allocated to amoxicillin and clavulanic acid had a confirmed or suspected infection (180 [11%] of 1619) than women allocated to placebo (306 [19%] of 1606; risk ratio 0·58, 95% CI 0·49–0·69; p<0·0001). One woman in the placebo group reported a skin rash and two women in the amoxicillin and clavulanic acid reported other allergic reactions, one of which was reported as a serious adverse event. Two other serious adverse events were reported, neither was considered causally related to the treatment.
Interpretation: This trial shows benefit of a single dose of prophylactic antibiotic after operative vaginal birth and guidance from WHO and other national organisations should be changed to reflect this.

Marian Knight,Virginia Chiocchia, Christopher Partlett, Oliver Rivero-Arias, Xinyang Hua, Kim Hinshaw, Derek Tuffnell, Louise Linsell, Edmund Juszczak


But there are some limitations and concerns about antimicrobial resistance that would need to be thoroughly considered before there's a change to current guidelines. The UK's National Health Service (NHS) says this is because exposing people to a single dose of an antibiotic can lead to bacterial resistance.

In this case, this would mean giving a dose of antibiotics to around 77,511 women, according to 2017-18 figures for women requiring assisted vaginal delivery.

Some of these women would need antibiotics anyway because of a serious perineal tear or other complications, but this is still a substantial number of women.

Though the researchers say this would save 168 treatment doses of antibiotics per 100 women, these would have been indicated doses and so would be less likely to contribute to antimicrobial resistance.

The trial was robust, but it had some limitations: around 86% of women in the study were white, so it's not clear if similar results would be seen in people with more diverse ethnicity; 1 in 4 women did not complete the follow-up questionnaire, which may have affected the results; and the results of this trial will need to be carefully weighed up to determine if the reduced risk of infection outweighs the increased risk of antimicrobial resistance.

[link url=""]The Guardian report[/link]
[link url=""]The Lancet abstract[/link]
[link url=""]The Lancet editorial[/link]
[link url=""]NHS material[/link]

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