We identified data through 2 sources: (1) systematic review of the published literature and (2) reviews of online policies and an online survey submitted to clinicians, researchers, and relevant professionals worldwide.

We undertook systematic literature searches of Medline, Embase, Literature in the Health Sciences in Latin America and the Caribbean (LILACS), Scopus, and the World Health Organization library database (WHOLIS). The literature search was updated on 20 January 2017. We used the search terms “antibiotics,” “intrapartum,” “group B Streptococcus,” and “colonization” with no date or language restrictions (full search terms are listed in Supplementary Table 1). We additionally searched the China Academic Journals Full-Text Database (with a time restriction of 3 years), and a Russian online database (Cyberleninka) with no date restrictions, as these data are often not present on classical database searches. We abstracted the data from articles in foreign languages alongside translators where available and used automatic translation if native speakers were unavailable.

We searched for online policies of all 130 countries listed on the International Federation of Gynecology and Obstetrics (FIGO) website [26] to identify the latest policies. In addition, we designed an online survey (Supplementary Materials 2) and approached the World Health Organization (WHO) Safer Childbirth Group, FIGO, the Royal College of Obstetricians and Gynaecologists, and the European Society for Paediatric Infectious Diseases to disseminate to their members.

Two authors (K. L. D. and K. T.) independently abstracted data onto standard Excel data entry forms. Policies were reviewed according to the inclusion and exclusion criteria below. For any discrepancies, a third researcher (M. O.) was consulted. We included any document detailing IAP policy and strategy: microbiological screening (including sample site of swab and gestation of screening), clinical risk factors, the type and route of antibiotic administered, and an estimate of IAP coverage within that country. We excluded any policy that had been revoked or was under review (Supplementary Table 2).

To ensure results were current, we selected the latest available policy from each country. The hierarchy of policy documents, based on their likely accuracy, was as follows: (1) national policy document available from relevant national association; (2) national policy available from published literature; (3) national policy available from survey participant.

We categorized countries into 4 groups: (1) no IAP policy or low implementation (0%); (2) microbiological screening policy with limited implementation (defined as <50% of eligible women receiving IAP); (3) clinical risk factor–based screening with high implementation (defined as >50% of eligible women receiving IAP); (4) universal microbiological screening policy with high implementation (defined as ≥50% of eligible women receiving IAP). We did an ecological analysis comparing country IAP policy by category with EOGBS disease incidence as a scatterplot.

We identified 853 articles, of which we retained 60 after title and abstract screening for review of full texts (Figure 2). We excluded a further 15 articles after full-text review as these either presented duplicate data (n = 7), did not have policy data in the main text (n = 3), or did not make full text available (n = 5), leaving 45 articles for inclusion in the analysis. Of these, details of policy were already available from 30 national policy documents, leaving 15 articles containing additional policy information.

Using the international list of obstetric and gynecological societies listed on the FIGO website, we identified online policy documents from 42 countries and received responses that there was no national policy from 19 countries through FIGO. Of the remaining 71 countries, either there was no society website or no working email address, or the contacts did not reply to the FIGO email, despite receiving a read-receipt.

We received responses from 265 participants to our survey (Figure 2). We excluded 238 due to duplicate entries with identical responses from participants in the same country (n = 142), incomplete responses (n = 32), or because policy documents had already been received from the country’s obstetric association and survey responses matched the country policy (n = 72), leaving 19 unique survey responses. Details are reported in Supplementary Table 3. The final dataset included policies from 95 countries (FIGO = 61; original articles = 15; survey = 19)

Sixty of 95 countries had a national IAP policy. The strategies used varied: 25 of 60 (42%) used a risk factor–based approach and 35 of 60 (58%) used both microbiological screening and risk factor approaches. Thirty-five of 95 (37%) countries had no national policy. Within these, there were reports of policies from hospitals or localities in 9 countries. Of these, 5 of 35 used rapid screening at point of labor only and 4 of 35 used risk factor approaches. Figure 3 shows countries where IAP policies were identified and Figure 4 shows IAP policy type globally.

We received responses concerning IAP policy from all regions. All developed region countries had an IAP policy (34/34). Other regions varied with the majority of countries in sub-Saharan Africa (3/20) and East Asia (1/3) reporting no IAP policy (Table 1).

The majority of countries reporting no policy came from low and lower-middle–income countries (25/33 [76%]). Two countries had limited IAP strategies, reported as risk-based screening in hospitals run by the charitable organization Médecins sans Frontières. Of countries reporting any IAP policy, 4 of 16 (25%) were from lower-middle–income countries (all risk-based screening policies). In upper-middle–income countries, 8 of 20 reported microbiological policy and 6 of 20 risk-based policy, whereas in high-income countries, 24 of 44 had microbiological and 16 of 44 risk-based policies. (Supplementary Table 3).

For countries with an IAP policy, implementation varied both within and between countries. Implementation was more frequently reported as high in countries with microbiological screening (median, 80% [range, 20%–95%]) compared to countries with clinical risk factor–based approaches (29% [range, 10%–50%]). Policy documents estimating implementation varied from estimates based on clinician reporting, especially in countries using clinical risk factor–based approaches, where clinician reporting was lower than that reported in policy documents.

In 35 countries reporting microbiological screening (30 national screening, 5 hospital-level screening), women were usually screened at 35–37 weeks’ gestation. Two countries (Bulgaria and Japan) offered additional microbiological screening at 20 weeks’ gestation. In 5 countries (Poland, Bangladesh, Iran, Thailand, and Trinidad and Tobago), individual hospitals offered point-of-care screening using polymerase chain reaction when women presented in labor, in addition to screening at 35–37 weeks’ gestation. The estimated coverage of these guidelines varied greatly and ranged from 20% in Brazil to 89% in the United States and Belgium (median, 80%). Where microbiological screening methods were reported (n = 35), 21 reported sampling both the rectum and vagina either with separate (n = 2) or combined (n = 19) swabs, and 14 used only vaginal swabs.

Twenty-five countries reported IAP based on clinical risk factors (14 national, 11 regional/hospital). There was little variation in risk factors used to determine the need for IAP. All recommended IAP use if a previous infant had GBS disease; the majority (23/25) also recommended IAP for preterm prolonged rupture of membranes, premature rupture of membranes >18 hours (PROM), or maternal GBS bacteriuria. The clinical risk factors are listed in Table 2.

Two middle-income countries reported IAP administration based on clinical risk factors (Kenya and South Africa). However, responses from the online survey suggest that coverage of this policy in these countries was low.

There was considerable variation in the survey responses between countries concerning the question “Does your country have a national policy for intrapartum antibiotics to prevent neonatal group B streptococcal disease?” In countries with risk-based screening policies, one-third of respondents answered “no,” although their obstetric societies have published national guidance. There was no discrepancy in countries reporting microbiological screening approaches.

The majority of policies (50/60) recommended intravenous penicillin–based antibiotics (38/50 penicillin, 12/50 ampicillin) and clindamycin in cases of confirmed penicillin allergy. Six countries recommended a cephalosporin rather than penicillin and 4 countries in South America and 2 in Asia recommended additional vancomycin because of concerns about a theoretical risk of developing antibiotic resistance in their populations in patients with penicillin allergy.

EOGBS incidence data were available for 32 countries: 12 reporting a microbiological and risk-based strategy, 15 reporting a clinical risk factor strategy, and 5 reporting no national policy. The results are presented in Figure 5. Broadly, EOGBS incidence was lower in countries with a microbiological and clinical risk–based policy [1].