Table 7.

Description of included studies— travel time

Author, year, country	Study designandsetting	Study objectives	Study period	Eligibility criteria	Participant characteristics	Description of exposures travel distance	Services context information	Review outcomes
								Perinatal	Maternal
UK Studies
Dummeret al 29, 2004, UK	Retrospective population-based cohort study, Cumbria	To investigate whether geographical accessibility to hospitals affected SB rates and infant mortality	1950–1993 grouped: 1950–1959 1960–1969 1970–1979 1980–1993	Included: All births Excluded: Women with missing postcodes	n=283 668 births Other characteristics: NR	Travel time (mins): <17 18–35 >35	Universal state provision of maternity care. 1950–1993: 4 hospitals opened, 2 closed	NM; Early NM; Post NM	NR
Paranjothyet al 30 31, 2013, 2014, UK (abstract& full paper)	Retrospective cohort study, All Wales Perinatal SurveyandNational Community Child Health Database	To study the association between travel time from home to OU on intrapartum stillbirth (SB)andNM	1995–2009	Included: All registered birth >23 wks GA Excluded: Antepartum SB, lethal congenital anomalies, multiple pregnancies, invalid or missing GA, missing maternal age/postcode/hospital of birth or baby’s gender	n=466 255 singleton births Maternal age yrs %<20 90.7 20–34 76.5 34–44 13.8 45+0.1 Parity: Nullips 44.9% Social deprivation quintile %: 1 (least depr) 16.7 2–4 57.8 5 (most depr) 25.6 Ethnicity, education: NR	Travel time (mins): <15 15–29 30–44 >45	Universal state provision of maternity care. 50 hospitals (16 outside Wales)	Intrapartum SB; Early NM; Late NM	NR
Other European Studies
Combieret al 32, 2013, France	Retrospective cohort study, based on hospital discharge summaries, Burgundy	To analyse the effect of travel time to closest OU on pregnancy outcomeandprenatal management in Burgundy	2002–2009	Included: Singleton births >21 wks GA Excluded: Medical ToP, multiple pregnancy, births outside Burgundy, births in 2002 and 2008 due to closure of 3 units	n=111 001 births Other characteristics=NR	Travel time (mins): ≤15 16–30 31–45 ≥46	2000–2001: 2 private maternity units closed 2002–2009: 3 public maternity units closed. Units(n): 2000 (20) 2009 (15)	SB; PM; BBA	NR
Renesmeet al 34, 2013, France	Case–control, multicentre study, 8 units, Finistere District, Brittany	To evaluate the social- geographical factors associated with BBAs	2007–2009	Included cases: BBA of live birth Included controls: 2 controls for each case irrespective of delivery mode. Excluded: GA <22 weeks, BW <500 g, planned home birth	n=225 Cases vs controls n=76 vs 149 Age (median, range) yrs: 30 (16–41) vs 30 (16-41) Parity (median, range): 2 (1–6) Maternal INSEE code n (%): 1, 2, 3 or 4=15 (23.8) vs 56 (43.4); five or 6: 20 (31.8) vs 55 (42,6); 8=28 (44.4%) vs 18(14) Ethnicity, education: NR	Travel time (mins): 15 15–29 30–44 >45	9700 births/year in Finistere In 2012 units with <300 births/yr were closed. Universal state provision of maternity care	BBA	NR
Nguyenet al 33, 2016, France	Case–control study, university hospital in Caen	To estimate the incidence of BBA during the study period	2002–2009	Included cases: Unplanned BBA Included controls: Next spontaneous birth in hospital Excluded: NR	n=188Casesn=94 Mean age: 28.9 years Parity: 1.8 SES: 73.4% no profession/student Control n=94 Mean age: 29.2 years Parity: 0.9 SES: 47.9% no profession/student Ethnicity, education: NR	Travel time (mins): ≤20 mins >20 mins	University Hospital with neonatal care facilities. Universal state provision of maternity care	BBA	NR
Ravelli Study
Ravelli et al 35–37, 2011, Netherlands (full papers & abstract)	Retrospective population-based cohort study, rural and urban areas, 12 provinces	To study the effect of travel time from home to OU on mortality and other adverse outcomes in pregnant women at term in primary and secondary care	2000–2006	Included: Singleton term births Excluded: Antepartum deaths, congenital anomalies, invalid/missing postcodes or outpatient codes, or births from Wadden islands, home deliveries, hospitals participated for 1–2 years	n=751 926 singleton births Age yrs, % <20, 2 20–34, 78.3 35–39, 17.2≥40, 2.4 Parity: Nullips: 49.9% Ethnicity: White 81.7% SES % : high 25.2, medium 48.2, low 26.7 Education: NR	Travel time (mins): <20≥20	Universal state provision of maternity care. 99 OUs including tertiary perinatal centres	NM (Combined intrapartum & early & late NM up to 28 days) NM (0–24 hours) NM (0–27 days) NM(8–27 days); Combined (mortality and/or Apgar<4 at 5 min, and/or NNU admission)	NR
Ravelli et al 38, 2012, Netherlands	Retrospective cohort study in nine regions	To investigate provincial differences in perinatal mortality (PM) and to determine the influence of different risk factors, including travel time from home to the OU during labour	2000–2006	Included: Singleton births Excluded: Women with incorrect post codes	n=1 242 725 singletons Age yrs, % <20, 1.8>35, 19.5 Parity, % Nullips, 46.3 Ethnicity, % Non-western 16.2 SES low (10th centile): 10% Education NR	Travel time(mins): <20≥20	Universal state provision of maternity care	PM	NR
Stolp et al 39, 2015, Netherlands	Prospective cohort study, rural & urban areas	To assess whether the limit of 45 mins is met for ambulance transfer of women with PPH after home birth	2008–2010	Included: Women with PPH after MW supervised home birth Excluded: Cases of PPH with missing data	n=72 (54 analysed) Age median (range) yrs: 31 (23-41); Parity (n, %): Primip 27%–50% Ethnicity, Education, SES: NR	Travel time (mins): <45 >45	Home birth for low risk women and hospital birth. Universal state provision of maternity care	NR	Maternal admission to intensive care; (ICU); Blood transfusion; Postpartum haemorrhage (PPH)
Egjom Study
Engjomet al 40 41, 2017 & 2015, Norway (full paper & abstract)	Retrospective population-based cohort study, Medical Birth Registry of Norway and Statistics Norway, 19 counties	To assess peripartum mortality associated with place of birth and availability of obstetric units.	1999–2009	Included: All births in Norway with GA ≥22 wks or BW ≥500 g Excluded: Lack of address and municipality, antepartum SB, planned home births	n=646 898 960.4% singletons. Age yrs, % <20 20.4 20–35, 80.7>35, 16.9%; Multips 58.7%; Education >11 y 77.2 Ethnicity: Western 90.7%	Travel time (hrs):<1 1–2 >2	Basic obstetric care for normal delivery; Emergency obstetric care <1500 births/yr. Universal state provision of maternity care	BBA	NR
Canadian Studies
Grzybowskind Stroll Study
Grzybowski et al 43, 2011, Canada	Retrospective cohort study, rural areas of British Columbia	To document newborn and maternal outcomes in relation to travel time to the nearest OU with CS capability	2000–2004	Included: All deliveries>20 weeks’ GA Excluded: Multiple birth, congenital anomalies or late ToP, core urban areas	n=35 426 birthsGroups:<1 hour, 1–2, 2–4,>4 hours Group N: 32 814, 1359, 747, 506 Mean maternal age yrs: 28.7, 28.67, 27.25, 27.2 Parity % primips: 42.6, 38.6, 36.7, 36.8 SES*: 0.12, 0.10, 0.30, 0.33, first Nations % 0.05, 0.30, 0.23, 0.42 Education: NR	Travel time (hrs): <1 1–2 2–4 >4	Universal medical coverage for core healthcare, 13 NNUs, 42 000 births /year	PM (SB & early NND); BBA; NNU admission	CS
Grzybowskiet al 44, 2013, Canada	Retrospective cohort study, rural areas of British Columbia	To compare rural maternity care by level of services	2000–2007	Included: Singleton births Excluded: Women with residential postcode of large urban centres	n=4672 births; Mean age, yrs: 27.7 Parity: primips: 39.7% SES*: 0.22%; Ethnicity: first Nations 0.3% Education: NR	Travel time (hrs):<1 >1	Universal medical coverage for core healthcare	SB; NND (late<1 month); PM; IM; BBA; NNU admission	CS; Emergency CS; PPH
Grzybowskiet al 45, 2015, Canada	Retrospective cohort study, British Columbia (BC), Alberta, Nova Scotia (NS)	To examine the safety of rural Canadian maternity services	2003–2008	Included: Singleton deliveries Excluded: Multiple births, infants born with congenital anomalies, planned home births, accidental BBA	Alberta, BC, NS Age yrs (n %) <18: 1618 (2.3), 1256 (2.0), 413 (2.2) >35 yrs: 5127 (7.3), 8866 (14.3), 2387 (12.7) Multips n (%) 41 730 (59.6), 35 089 (56.6), 10 656 (56.8) Ethnicity, SES, education: NR	Travel time (hrs):<1 1–2 2–4 >4	Universal medical coverage for core healthcare, 20 small maternity closures since 2000	PM (SB & NND up to 7 days)	CS
Stoll et al 46, 2014, Canada	Retrospective cohort study, rural British Columbia	To report on characteristics and perinatal outcomes of rural women with only MW involved in care	2003–2008	Included: Women residing outside core urban areas, singletons >20 wk GAand care by a MW Excluded: Late ToP, congenital anomalies	<1 hour, 1–2 hours, >2 hours:n=3438, 124, 130 Mean age yrs: 29.78, 31.4, 30.5 Primips n (%) 1574 (45), 63 (50.8), 63 (48.5) Ethnicity, SES & Education: NR	Travel time (hrs):<1 1–2 >2	Universal medical coverage for core healthcare, closure of 22 rural maternity services	PM (SB & NND up to 7 days)	CS
Darling et al 42, 2019, Canada	Retrospective population-based cohort study, Ontario	Whether greater diving distances to OU associated with a higher risk of adverse neonatal outcomes	2012–2015	Included: Women who planned home births regardless of actual place of births Excluded: Multiple births, Preterm <37 wks	n=11 869 Age yrs, %:<25, 9.5 25–39,87.6≥40, 2.9 Primps n (%) 4208 (35.5) SES low, n(%) 2465 (20.8) Ethnicityandeducation: NR	Travel time (mins): ≤30 >30	Universal medical coverage for core healthcare	PM (PM); NNU admission; 5 mins Apgar<7	CS
Other countries
Aoshimaet al 47, 2011, Japan	Before and after study design, data from perinatal care centres	Whether reducing travel time influences the neonatal mortality rate (NM)	2002–2006	Included: All births Excluded: Municipalities consisting of isolated islands	Number of births: 2002=347 284 2006=322 514 Other characteristics: NR	Travel time (hrs): ≤1 >1	Universal healthcare insurance system, 346 perinatal care centres	NM	NR

INSEE: Institute National de la Statistique et des Etudes Economiques; INSEE codes: 1: farmer; 2: craftsperson, merchant or entrepreneur; 3: businessexecutive, intellectual occupation; 4: other professionals; 5: employee; 6: worker; 8: no occupation.

*SES: Catchment level Social vulnerability -1 to +1

†GPESS = general practitioner with enhanced surgical skills.

BBA, born before arrival; BW, birth weight; CS, caesarean section; GA, gestational age; ICU, intensive care unit; NNU, neonatal unit; NR, not reported; NS, not significant; OU, obstetric unit; RR, relative risk; SES, socioeconomic status; ToP, termination of pregnancy.