Table 2.

Periodontal examination, first trimester obstetric ultrasound, and fetal membrane sample training and continuous quality control procedures

Procedure	Initial training	Continuous quality control procedures
Periodontal examination	The UoN periodontist conducted an in-person training with the CPGH dentist that included teaching, observation and calibration.	Interexaminer calibration biannually—The UoN periodontist and a second UoN experienced periodontist conduct periodontal exams on a series of patients to compare results. The UoN periodontist serves as the gold standard comparator for the CPGH dentist. Intraexaminer calibration once per 50 examinations—Examination is repeated on one participant to compare results between the first and second examination.
First trimester obstetric ultrasound	All sonographers received a standardised refresher training on ultrasound determination of gestational age, early pregnancy complications and MPTB study specific procedures by the Kenyan study radiologist.	For each participant with a first trimester ultrasound, an image of the crown rump length is saved and quality is assessed by the study radiologist according to criteria developed for the International Fetal and Newborn Growth Consortium for the 21st century.59 (For participants with a crown rump length measurement of >84 mm, gestational age is assessed using biometric measurements.) Sonographers access the results of quality assessments for ongoing feedback. Annually, sonographers in Nairobi meet with the study radiologist to review quality metrics and receive refresher training on study procedures. The radiologist provides ongoing one-on-one support to the Mombasa sonographers by phone.
Fetal membrane sample	Initial training of labour and delivery nurses and KNH-based Kenyan obstetrician was performed by SL, who developed the fetal membrane collection technique.41 Trainees were required to demonstrate proficient sample collection technique and verbalise study procedures.	Subsequent trainings are conducted as needed and led by a Kenyan obstetrician-gynaecologist based at KNH who participated in the initial training.

CPGH, Coast Provincial General Hospital; KNH, Kenyatta National Hospital; MPTB, Microbiota and Preterm Birth Study; UoN, University of Nairobi, Nairobi.