Table 1.

Phases of ultrasound training in GRAPHS^a.

Phase of training	Trainer	Participants	Length of training	Topics covered
Phase 1	Trial obstetrician-perinatologist	All midwives (15) performing antenatal care at study district hospitals	1 week	Didactics: Basic obstetric ultrasound including assessment of viability, location of the pregnancy, placental location, plurality of the gestation, introduction to fetal biometry
				Hands-on: viability, pregnancy location, plurality, placental location
Phase 2	US-based registered diagnostic medical sonographer	5 midwives and 1 medical assistant, selected after Phase 1 for demonstration of ultrasound aptitude	2 weeks	Didactics: Focus on fetal biometry (CRL, BPD, FLb), appropriate landmark identification, adequate image magnification, correct caliper placement
				Hands-on: Fetal biometry all trimesters
Phase 3	US-based maternal-fetal medicine fellows	4 midwives selected after Phase 2 for aptitude and interest in ultrasound plus anticipated availability for trial duration	3 months	Hands-on: Fetal biometry <20 weeks gestation; practice scanning in 1000 subjects enrolled into separate maternal child health study
Phase 4	Trial obstetrician-perinatologist	4 study sonographers trained in Phase 3	6 months	Hands-on: Image acquisition of pilot GRAPHS participants; image review and written feedback by study obstetrician-perinatologist

^aGRAPHS: Ghana Randomized Air Pollution Health Study

^bCRL: crown-rump length; BPD: biparietal diameter; FL: femur length