Table 1 Description of included studies

Alonso CP, Maresca MI, Oritz TA, & Serrano MM. (2006) (Spanish)

Local, hospital records, 2000-2002

Spain (Madrid)

2759 African, American, European, & Oriental "immigrants" vs. 3990 Spanish women.

L & ND overall (not statistically tested)

Fair

Aurelius G, & Ryde-Blomqvist E. (1978) (English)

Local, hospital records, 1968-1969

Sweden (Stockholm)

1235 “Immigrants” from Scandinavia, West, South, & East Europe, & “other countries” vs. 412 Swedish women. Only singleton births included.

H & ND overall (unadjusted)

Fair

Barron SL, & Vessey MP. (1966) (English)

Local, hospital records, 1958-1960

UK (South London)

1563 West Indian & Irish “immigrants” vs. 3891 British women. Only singleton births.

H overall (not statistically tested; W Indian: primips H, multips ND; Irish: primips ND, multips H)

Fair

Berger C, Liska G, Gallier J, & Soutoul JH. (1973) (French)

Local, hospital records, 1970-1972

France (Tours)

800 Portuguese/Spanish, North African, Yugoslavia, “other” “migrants” vs. 2655 French women.

M overall (not statistically tested)

Fair

Berger C, Laugier J, & Soutoul JH. (1974) (French)

Bona G, Zaffaroni M, Cataldo F, Sandri F, & Salvioli GP. (2001) (English)

National, population-based hospital data, 1996-1997

Italy

3347 “Legal immigrants from developing countries” (Latin America, North Africa, Sub Saharan Africa, Middle East, Indian Sub-continent, Far East, Oceania, Eastern Europe, & Gipsies) vs. 6694 Italians.

ND overall (all immigrants combined; unadjusted; Variation by groups but not statistically tested)

Fair

Braveman P, Egerter S, Edmonston F, & Verdon M. (1995) (English)

Regional, population-based registry, 1991

US (California)

81,445 Asian and Latina “foreign born” vs. 93,685 “Whites”. Only singleton primiparous women.

L & ND overall (adjusted)

Good

Cassell E. (1995) (English) Thesis

Regional, population-based registry, 1982-1992

Australia (Victoria)

5268 Filipino-born vs. 507,457 Australian-born.

H overall (stratified by parity and age caesarean rates consistently H) H emerg (unadjusted) H elect (unadjusted)

Good

Chan A, Roder D, & Macharper T. (1988) (English)

Regional, population-based registry, 1981-1983

Australia (South Australia)

5675 “Non-English speaking countries” (includes Italy, Holland, Germany, Vietnam, Greece, Yugoslavia, Philippines, & “other”) vs. 2894 Australian-born.

H overall (all immigrants combined; unadjusted; Variation by groups but not statistically tested) H emerg (all immigrants combined; unadjusted) H elect (all immigrants combined; unadjusted)

Fair

Comas M, Català L, Sala M, et al. (2011) (English)

Local, hospital records, 2006-2007

Spain (Barcelona)

564 Foreign-born (includes women from South America, Asia and North Africa- Morocco, Pakistan and Ecuador most represented) vs. 462 Spanish-born women. Only women who lived in hospital catchment area were included.

ND overall (all immigrants combined; unadjusted)

Fair

Delvaux T, Buekens P, Thoumsin H, Dramaix M, & Collette J. (2003) (English)

Local, research study, 1997-1998

Belgium (Liege)

89 North-African nationality vs. 184 Belgian nationality women. Singleton live births, excluded women with gestational diabetes & malformed babies at birth.

ND overall (unadjusted)

Fair

Diani F, Zanconato G, Foschi F, Turinetto A, & Franchi M. (2003) (English)

Local, hospital records, 1992-2001

Italy (Verona)

1014 “Non-EU women” (including Central Africa, Northern Africa/Middle East, Eastern Europe, Asia, & Latin America) vs. 12,931 Italians.

H overall (all immigrants combined; unadjusted)

Fair

Fedeli U, Alba N, Lisiero M, Zambon F, Avossa F, & Spolaore P. (2010) (English)

Regional, population-based registry, 2006-2007

Italy (Veneto region)

20,332 Regular and Irregular foreign born/migrants vs. 73,098 Italian women.

L overall (unadjusted; when stratified by age for regular migrants ND across strata except ages 30-34 years H)

Fair

Forna F, Jamieson DJ, Sanders D, & Lindsay MK. (2003) (English)

Local, hospital records, 1991-2001

US (Atlanta)

13,465 Africa, Asia, Caribbean, Europe, Central & South America, Middle East & “other” foreign-born vs. 36,439 US born (mostly Black women). Excluded women with no prenatal care.

H & ND overall (unadjusted)

Fair

Gagnon AJ, Dougherty G, Platt RW, et al. (2007) (English) and Gagnon AJ, Van Hulst A, Merry L, et al. (2012) (English) Unpublished when review of literature was conducted, 2007 reference describes original study; 2012 reference is publication of caesarean results (after review of literature was completed)

Local, research study, 2003-2004

Canada (Montreal, Toronto, Vancouver)

1018 “Recently arrived migrants (≤ 5 years)” and defined by UN Macro Region (Europe, Latin America, Africa, West Asia/North Africa, & South-Central Asia), migration status (refugee, asylum seeker, non-refugee immigrant) and length of time (≤ 2 years vs. > 2 years) vs. 2482 Canadian-born. Only low-risk (≤ 35 years, gestational age ≤ 42 weeks) primiparous women.

H & ND overall (unadjusted but restricted to low-risk population) ND emerg (unadjusted but restricted to low-risk population) ND elect (not statistically tested)

Good

Gagnon AJ, Wahoush O, Dougherty G, et al. (2006) (English) Unpublished, 2006 reference describes study

Local, research study, 2006-2009

Canada (Montreal, Toronto, Vancouver)

1025 “Recently arrived migrants” (≤ 5 years) defined by migration status: refugee, asylum seeker, non-refugee immigrant vs. 514 Canadian-born.

ND overall (unadjusted) ND emerg (unadjusted) ND elect (unadjusted)

Fair

Gann P, Nghiem L, & Warner S. (1989) (English)

Local, hospital records, 1981-1987

US (Lowell)

310 Cambodian refugees vs. 110 low income Whites. Only singleton births included. Primary caesareans only.

L overall (unadjusted; ND primips, L multips)

Fair

Gayral-Taminh M, Arnaud C, Parant O, Fournie A, Reme JM, & Grandjean H. (1999) (French)

Local, hospital records, 1988-1994 (excl 1990)

France (Toulouse)

2636 “Black Africa” & Maghreb vs. 3172 French women. Only singleton births included.

H & ND overall (unadjusted; results consistent when stratified by parity) ND during labour caesarean (unadjusted) ND pre-labour caesarean (unadjusted)

Fair

Giani U, Bruzzese D, Pugliese A, Saporito M, & Triassi M. (2011) (Italian, used English abstract)

Regional, population-based registry, 2005

Italy (Campania)

1709 Foreign-born women vs. 28,557 Italian women. Excluded repeat caesareans.

L elect (adjusted)

Good

Harlap S, Kaufman R, Prywes R, Davies AM, Sterk VV, & Weiskopf P. (1971) (English)

Local, research study, 1964-1967

Israel (West Jerusalem)

13,112 Asian, North African, & Western countries (based on birth place) vs. 7635 Israeli women. Only singleton births.

H overall (not statistically tested)

Fair

Hazekamp JT. (1982) (English)

Local, hospital records, 1978

Norway (Oslo)

51 Wives of Pakistani migrant workers vs. 51 Norwegian women matched for age and parity.

ND overall (not statistically tested)

Fair

Helsel D, Petitti DB, & Kunstadter P. (1992) (English)

Regional, population-based registry, 1985-1988

US (Merced & San Joaquin counties, California)

1937 Hmong refugees vs. 3776 non-Hispanic Whites. Mixed marriages excluded. Only singleton births included.

L overall (results consistent across different age and parity strata)

Good

Henry OA, Guaran RL, Petterson CD, & Walstab JE. (1992) (English)

Local, hospital records, 1979-1988

Australia (Melbourne)

1123 Vietnamese (likely refugees) vs. 35,373 Australian born women.

ND overall (adjusted)

Good

Holan S, Vangen S, Hanssen K, & Stray-Pedersen B. (2008) (Norwegian)

Local, research study, 1993-1998

Norway (Oslo)

220 Asian/African women combined (including women from Pakistan, Sri Lanka, India, Vietnam, Morocco, & Somalia) immigrants with diabetes vs. 262 Norwegian women with diabetes. Only singleton births included.

L overall (unclear if statistically significant; results similar when just primips) ND emerg (not statistically tested) ND elect (not statistically tested)

Fair

Howell R. (1989) (English)

Local, hospital records, 1980-1984

Australia (Brisbane)

338 Vietnamese refugees and Filipino women (most married to Caucasian men) vs. 14,790 Australian-born women.

ND overall (unadjusted; ND for primips, L & ND for multips) H emerg (not statistically tested), H (primips) & ND (multips) emerg (unadjusted) L & ND elect (unadjusted but consistent results by parity)

Fair

Ismail KI, Marchocki Z, Brennan DJ, & O’Donoghue K. (2011) (English)

Local, hospital records, 2009

Ireland (Cork)

867 Eastern European women (refers to women from Belarus, Bulgaria, Czech Republic, Hungary, Moldova, Poland, Romania, Russia, Slovakia, & Ukraine); nationality used to categorize; most would be economic migrants. Multiple, breech and elective or pre-labour caesareans were excluded vs. 5550 Irish women.

ND caesareans during labour (unadjusted) L (primips, unadjusted but results consistent when stratified by age) & ND (multips, unadjusted) caesareans during labour

Good

Ismail KI, Marchocki Z, Brennan DJ, & O’Donoghue K. (2010) (English) Conference abstract

Janevic T.(2011)^† (English) Conference abstract

Local, population-based registry, 1995-2003

US (New York)

511,564 “Foreign-born and ethnicity/region of origin” : North Africa, Sub-Saharan Africa, Africa unspecified, Non-Hispanic Caribbean, Hispanic Caribbean, Mexico, South America, Central America, East Asia, South East Asia/Pacific Islands, & South Central Asian vs. 449,817 US born women. Singleton births only.

M overall (adjusted)

Good

Johnson EB, Reed SD, Hitti J, & Batra M. (2005) (English)

Regional, population-based registry, 1993-2001

US (Washington)

579 Somali immigrants vs. 4837 US-born Whites & Blacks. Only singleton births.

H (compared to US Whites) & ND (compared to US Blacks) (not statistically tested) H (primips) & ND (multips) overall; (adjusted)

Good

Kaminski M. (1975) (French)

Local, research study, 1963-1969

France (Paris)

1795 Migrants from North Africa, South Europe & the Antilles (only women whose husbands were also born outside of France were considered migrants) vs. 5774 French women.

H& ND overall (unadjusted)

Fair

Kingston D, Heaman M, Chalmers B, Kaczorowski J, et al. (2011) ^† (English)

National, Population-based survey, 2006

Canada

16,040 “Landed immigrants” (residents) (including North America, Central America, Caribbean/Bermuda, South America, West Europe, East Europe, North Europe, South/unspecified Europe, East Africa, North Africa, West/Central Asia/Middle East/Kurdistan, East Asia, South East Asia/Asia/East Timor, South Asia/Asia non-specified) defined as recent (≤ 5 years) and non-recent arrival (> 5 years) vs. 57,800 Canadian-born. Only singleton births. Weighted numbers.

ND overall (all countries combined & stratified by time since arrival; adjusted; Variation by country but not statistically tested)

Good

Lansakara N, Brown SJ, & Gartland D. (2010) (English)

Local, research study, 2003-2005

Australia (Melbourne)

212 Mothers born overseas of non-English speaking background- needed to be fluent in English to participate; included women from 53 different countries, largest group were from South Asia, Sri Lanka and India vs. 1074 Australian-born mothers. Primiparous women only.

ND overall (all countries combined; unadjusted) ND emerg (all countries combined; unadjusted) ND elect (all countries combined; unadjusted)

Fair

LeRay C, Carayol M, Zeitlin J, Breart G, & Goffinet F. (2006) (English)

National, research study, 2001-2002

France

618 “Origin abroad” (including North Africa, North European, South European, African & Asian) vs. 2797 French. Only low risk primiparous, singleton, cephalic presentation, no induction, Birthweight 2500-4500 g babies, included.

H caesarean during labour (all migrants combined; adjusted; Variation by groups but not statistically tested)

Good

Loew D, & Schrank P. (1966) (German)

Local, hospital records, 1956-1965

Germany (Russelheim)

398 “Foreigners” (including Southern Europe, East Europe & “other”) vs. 6602 German women.

H overall (all foreigners combined; unadjusted)

Fair

Ma J, & Bauman A. (1996) (English)

Regional, population-based registry, 1990-1992

Australia (New South Wales)

64,922 Immigrant women from Europe, Asia, Africa, New Zealand/Oceania, Middle East, America vs. Australian (non-Aboriginal).

M overall (unadjusted)

Fair

Malin M, & Gissler M. (2009) (English)

National, population-based registry, 1999-2001

Finland

6532 Migrants from Latin American/Caribbean, Somali, African, Vietnamese, South East Asian, Iran/Afghan/Iraq, Chinese, South Asian, Middle East, Baltic, Soviet Union, Eastern Europe, Western Europe, & Nordic (only those with resident status) vs. 158,469 Finnish women. Only singleton births.

M overall (unadjusted but results presented by parity)

Fair

Maslovitz S, Kupferminc MJ, Lessing JB, & Many A. (2005) (English)

Local, hospital records, 2001-2002

Israel (Tel Aviv)

721 Non-resident foreign labourers [mostly Eastern Europe, also included women from Africa (Kenya, Nigeria, Ghana) and Asia (Thailand, Philippines, China)] vs. 16,012 Israeli residents.

H overall (all migrants combined; unadjusted) H emerg (all migrants combined; unadjusted) L elect (all migrants combined; unadjusted)

Fair

Merten S, Wyss C, & Ackermann-Liebrich U. (2007) (English)

National, population-based hospital data, 2000-2002

Switzerland

24,284 Migrants based on nationalities from various regions &/or countries of birth: Africa, Latin America, Asia, Balkan/Turkey, EU/USA; Angola, DR Congo, Morocco, Somalia, Tunisia, Brazil, Dominican Republic, Peru, Philippines, Sri Lanka, Thailand, Vietnam, Albania, Bosnia, Croatia, Kosovo, Macedonia, Serbia, Turkey, Austria, France, Germany, Italy, Netherlands, Poland, Portugal, Russia, Spain, UK, & USA vs. 7500 Swiss women.

M overall (adjusted)

Good

Moscioni P, Romagnoli C, Pomili G, & Gilardi G. (1995) (Italian)

Local, hospital records, 1992-1994

Italy (Perugia)

186 “Immigrant/foreign women” vs. 1716 Italian women.

L overall (unadjusted)

Fair

Mossialos E, Allin S, Karras K, & Davaki K. (2005) (English)

Local, hospital records, 2002

Greece (Athens)

181 “Immigrants” (majority from Albania, also included other Balkan countries and India/Philippines/Pakistan) vs. 259 Greek women. Only singleton births.

L overall (all immigrants combined; adjusted)

Good

Oliva GC, Zannella MP, Filidi C, Cavaliere AF, Casarella L, & Mancuso S. (2007) (Italian)

Local, hospital records, 2000-2004

Italy (Rome)

2628 “Foreign women based on nationality” vs. 11,976 Italian women.

L overall (unadjusted) H during labour caesarean (unadjusted) L pre-labour caesarean (unadjusted)

Fair

Panagopoulos P, Tsoukalos G, Economou A, et al. (2005) (English)

Local, hospital records, 2000-2004

Greece (Piraeus)

1990 “Immigrants” (according to nationality) vs. 1081 Greek women.

ND overall (unadjusted)

Fair

Parsons L, Macfarlane AJ, & Golding J. (1993) (English)

National, population-based registry, 1982-1985

UK

Mediterranean, African (excluding East Africa), Bangladeshi, & Pakistani vs. UK women.

M overall (+ variation by parity; unclear if statistically significant)

Fair

Press F, Katz M, Leiberman JR, Shoham I, & Glezerman M. (1993) (English)

Local, hospital records, 1988-1991

Israel (Be’er Sheva)

431 Ethiopian Jewish immigrants vs. 20,047 Israeli Jewish women.

ND overall (unadjusted)

Fair

Richman D, & Dixon S. (1985) (English)

Local, research study, 1980-1981

US (San Diego)

50 Hmong and Cambodian refugees vs. 25 Caucasian (non-Spanish, non-Oriental surnames).

L overall (unadjusted)

Fair

Rio I, Castelló A, Barona C, et al. (2010) (English)

Regional, population-based registry, 2005-2006

Spain (Catalonia & Valencia)

34,746 Latin America, Eastern Europe, & Maghreb vs. 180,633 Spanish women. Only singleton births.

M overall (adjusted for age but not parity)

Fair

Rizzo N, Ciardelli V, Gandolfi-Colleoni G, et al. (2004) (English)

Local, hospital records, 1997-2001

Italy (Bologna)

510 Immigrant women from non-EU countries vs. 510 Western world (Italy, other EU, Australia, Canada, US). Only singleton births.

ND overall (unadjusted) ND emerg (unadjusted) L elect (unadjusted)

Fair

Roman H, Blondel B, Bréart G, & Goffinet F. (2008) (English)

National, population-based survey, 2003

France

585 Africa (excluding North Africa), North Africa, Europe, & “other” nationalities vs. 4658 French women. Only included low risk, singleton births, with no previous caesarean or medical indications for caesarean.

H & ND overall (not statistically tested) H & ND caesareans during labour (adjusted) H & ND caesareans pre-labour (adjusted)

Good

Rudman A, El-Khouri B, & Waldenström U. (2008) ^† (English)

National, population-based survey, 2000

Sweden

236 Swedish-speaking Foreign-born vs. 2472 Swedish women.

ND overall (unadjusted) ND emerg (unadjusted) ND elect (unadjusted)

Fair

Rumbaut RG. (1996) (English)

Local, hospital records, 1989-1991

US (San Diego)

1211 “Foreign-born & ethnicity”: defined as White, Asian, Hispanic, & Black; Europe/Canada, Middle East, Indo-Chinese, East Asian, Mexican, Central America & Sub-Saharan Africa vs. 253 US born.

L & ND overall (unadjusted)

Fair

Saurel-Cubizolles M-J, Saucedo M, Drewniak N, Blondel B, & Bouvier-Colle M-H. (2012) (French)

National, Population-based survey, 2010

France

1864 Foreign-born (based on nationality) who could complete the survey in French: European (including Turkey), North-African, Sub-Saharan African, & other; 13% arrived in 2009/2010 and 36% between 2005-2008. vs. 12,125 French women.

H & ND overall (unadjusted) H & ND caesarean during labour (unadjusted) H & ND caesarean pre- labour (unadjusted)

Fair

Saurwein A. (1969) (German)

Local, hospital records, 1964-1968

Germany (Cologne)

297 “Foreigners” from Southern Europe (including Turks, Greeks, Italian, & Spanish women) vs. 7465 German women.

H overall (all immigrants combined; unadjusted)

Fair

Schliemann F, & Schliemann G. (1975) (German)

Local, population-based registry, 1969-1973

Germany (Hamburg)

1217 “Foreigners/Guest workers” from Spain, Italy, Portugal, Yugoslavia, Greece, Turkey & “others” vs. 5112 German women.

H & ND overall (unadjusted)

Fair

Schultze-Naumburg R, & Scholtes G. (1976) (German, used English abstract)

Local, hospital records, 1968-1973

Germany (Berlin)

1941 “Foreign women” vs. 9009 German women.

L overall (not statistically tested)

Fair

Shah D, Tay A, Desai A, Parikh M, Nauta M, & Yoong W. (2011) (English)

Local, hospital records, 2006-2008

UK (North London)

125 First generation Chinese immigrant women (born in China). Economic migrants most likely and mean length of time in UK =3.2 years. vs. 125 British Caucasian women matched for age and parity.

L overall (unadjusted but matched by age and parity)

Good

Shah RR, Ray JG, Taback N, Meffe F, & Glazier R. (2011) (English)

Local, hospital records, 2002-2006

Canada (Toronto)

3672 "Foreign born" based on country and region of birth using World Bank classification: Latin America/Caribbean, Western Europe/USA/Japan/Australia/New Zealand, Eastern Europe/Central Asia, Middle East/North Africa, Sub-Saharan Africa, South Asia, East Asia/Pacific. Asylum seekers examined based on health insurance. < 5years & ≥ 5years also examined. Women with multiple gestation removed. vs. 1435 Canadian-born.

H & ND overall (adjusted)

Good

Shah RR. (2007) (English) Thesis

Sletten K. (2011) (English) Thesis unpublished

Local, hospital records, 2009-2010

Norway (Baerum)

803 Immigrants from Latin America, Africa, Asia, Eastern Europe, & Western Europe vs. 1634 Norwegian women. Low risk women (35 weeks or greater gestational age, no diabetes, singleton births) only.

H & ND overall (unadjusted) H & ND emerg (adjusted) L & ND elect (adjusted)

Good

Small R, & Lumley J. (2007) ^† (English) Conference abstract

Regional, population-based registry, 1999-2007

Australia (Victoria)

70,417 Women from Non-English-speaking countries (only countries w >1000 births were included): Vietnam, China, Former Yugoslavia, Philippines, Lebanon, India, Sri Lanka, Somalia, Ethiopia, Eritrea, Sudan, Turkey, Malaysia, Iraq, Cambodia, Indonesia, Greece, Germany, Poland and Italy vs. 444,175 Australian-born.

M overall (+ variation by parity; not statistically tested)

Fair

Small R, Gagnon A, Gissler M, et al. (2008) (English)

Regional & National, population-based registries, 1997-2004

Australia (New South Wales, Victoria), Belgium (Flanders, Brussels), Canada (Ontario, Quebec), Finland, Norway, Sweden

10,431Somali women vs. 2, 168, 891 receiving-country-born women.

H overall [Belgium- Flanders (primips & multips) & Belgium -Brussels]; H (primips) & ND (multips) overall (Australia- Victoria, Finland, Norway, & Sweden); ND overall [Australia -New South Wales (primips & multips) & Canada] (unadjusted)

Fair

Stray-Pedersen B, & Austveg B. (1996) (Norwegian)

Local, hospital records, 1993

Norway (Oslo)

734 "Immigrants" (including Asia/Africa/South America/East Europe and Turkey) vs. 3188 Norwegians.

H overall (all immigrants combined; unadjusted)

Fair

Teixeira C, Correia S, & Barros H. (2010) (English) Conference abstract

Geographical coverage not indicated, research study, years not indicated

Portugal

743 European/North American, African, & South American (based on country of birth) vs. 6692 Portuguese-born. Singleton births only.

H & ND overall (adjusted but variables included not indicated)

Fair

Triantafyllidis G, Tziouva K, Papastefanou I, Samolis S, Katsetos C, & Panagopoulos P. (2010) (English) Conference abstract

Local, hospital records, 2007

Greece (Pireaus)

657 "Immigrants" (based on nationality) (mostly Albanians) vs. 304 Greek women. Only term deliveries (gestational age 37-40 weeks).

ND overall (unadjusted)

Fair

Van Enk A, Doornbos HP, & Nordbeck HJ. (1990) (English)

Local, hospital records, 1972-1982

Holland (Amsterdam)

1614 Non-European immigrants defined by ethnic origin: "Blacks" (Surinam & Dutch Antilles), Mediterranean (Turks & Moroccans), Asians [West Indian Asians (Hindustani from Surinam), Chinese & some Indonesians] vs. 6234 Dutch Caucasian.

H & ND overall (unadjusted; results consistent when stratified by parity)

Fair

Van Enk WJ, Gorissen WH, & Van Enk A. (2000) (English)

National, population-based registry, 1990-1993

Holland

5841Migrant teenagers (15-19 years old) defined by ethnic and geographical background: Mediterranean [Turkish & North African (mainly Moroccan)], Black (Surinam & Dutch Antilles), Hindustani (West Indian-Asian from Surinam & Dutch Antilles), Asian (Chinese, Malaysian & Malaccan); non-Dutch European (West & East Europe & American), & "others" (mixed, unknown or other ethnicity) vs. 45,570 Dutch (born in Netherlands and West European origin, includes teenagers and 20-24 yr olds). Singleton, primiparous pregnancies.

M overall (when compared to Dutch teens); L & ND overall (when compared to 20-24 yr old Dutch); (unadjusted but restricted to primips and defined age groups)

Fair

Vangen S, Stoltenberg C, & Schei B. (1996) (English)

Local, hospital records, 1992

Norway (Oslo)

67 Pakistani vs. 70 Norwegian women.

ND overall (unadjusted) ND emerg (unadjusted) ND elect (unadjusted)

Fair

Vangen S, Stoltenberg C, Skrondal A, Magnus P, & Stray-Pedersen B. (2000) (English)

National, population-based registry, 1986-1995

Norway

17,891 Immigrants from Turkey/Morocco, Pakistan, Sri Lanka/India, Vietnam, Philippines, Somalia/Eritrea/Ethiopia, Chile/Brazil vs. 535,600 Norwegians

M overall (adjusted) H & ND emerg (not statistically tested) M elect (not statistically tested)

Good

Vangen S, Stoltenberg C, Johansen RE, Sundby J, & Stray-Pedersen B. (2002) (English)

National, population-based registry, 1986-1998

Norway

1733 Somali vs. 702,192 Norwegians.

H overall (adjusted) H emerg (adjusted) L elect (not statistically tested)

Good

Vangen S, Stray-Pedersen B, Skrondal A, Magnus P, & Stoltenberg C. (2003) (English)

National, population-based registry,1986-1998

Norway

2408 Filipino mother/Filipino father and mixed= Filipino mother/Norwegian father vs. 615,063 Norwegian women.

H overall (adjusted) H emerg (not statistically tested) H & ND elect (adjusted)

Good

Vangen S, Stoltenberg C, Holan S, et al. (2003) (English)

National, population-based registry, 1988-1998

Norway

10,908 "Immigrants" (some had Norwegian citizenship): included countries in North Africa (Morocco, Algeria and Tunisia), South Asia (Pakistan, Sri Lanka, India/Bangladesh) vs. 601,785 Norwegian women. Women with and without diabetes included.

ND overall (all immigrants combined; not statistically tested) ND emerg (all immigrants combined; not statistically tested) ND elect (all immigrants combined; not statistically tested)

Fair

Versi E, Liu KL, Chia P, & Seddon G. (1995) (English)

Local, hospital records, 1987-1991

UK (East London)

6460 Bangladeshi vs. 7592 low-income Caucasian women.

ND overall (unadjusted; results consistent when stratified by parity) ND emerg (not statistically tested) H (multips) & ND (primips) emerg (unadjusted) L (primips & multips) elect (unadjusted)

Fair

Von Katterfeld B, Li J, McNamara B, & Langridge AT. (2011) (English)

Regional, population-based registry, 1998-2006

Australia (West Australia)

59,245 Foreign-born women as per mother's country of birth as declared in the birth register, ten regional categories as per Standard Australia Classification of countries: Oceania, North/West Europe, South/East Europe, North Africa/Middle East, Sub Saharan Africa, South East Asia, North East Asia, South/Central Asia, Americas vs. 149,737Australian-born (non-indigenous).

M overall (not statistically tested) H & ND emerg (unadjusted) M elect (unadjusted)

Fair

Walsh J, Robson M, & Foley M. (2009) (English) Conference abstract

Local, hospital records, 2008

Ireland (Dublin)

931 Eastern Europe, Africa, Britain, India, China vs. 2499 Irish women. Only primiparous women, and delivered singleton, term infants.

M caesarean during labour (unclear if statistically significant)

Fair

Walsh J, Mahony R, Armstrong F, Ryan G, O’Herlihy C, & Foley M. (2011) (English)

Local, hospital records, 2008

Ireland (Dublin)

552 Eastern European vs. 2449 Irish women. Primiparous, singleton, term deliveries for women who laboured.

ND caesarean during labourb (adjusted) ND caesarean pre-labour (excluded group from study)

Good

Ryan G, Armstrong F, Walsh J & Foley M. (2010) (English) Conference abstract

Walsh J, Mahony R, McAuliffe F, O'Herlihy C, Robson M, & Foley M. (2009) (English) Conference abstract

Yoong W, Wagley A, Fong C, Chukwuma C, & Nauta M. (2004) (English)

Local, hospital records, 2002

UK (North London)

61 Kosovo-Albanian vs. 61 British Caucasian.

ND overall (unadjusted)

Fair

Yoong W, Kolhe S, Karoshi M, Ullah M, & Nauta M. (2005) (English)

Local, research study, 2002

UK (North London)

69 Somali vs. 69 British Caucasian.

ND overall (unadjusted)

Fair

Zanconato G, Lacovella C, Parazzini F, Bergamini V, & Franchi M. (2011) (English)

Local, hospital records, 2005-2009

Italy (Verona)

2661 “Immigrants" defined as 5 ethnic minority groups based on geographical location: Sub-Saharan Africa, Central & Eastern Europe, Middle East & North Africa, Central and South America, South and East Asia vs. 6365 Italian women; singleton births only.

M overall (adjusted for age but not parity) H & ND caesarean during labour (adjusted for age but not parity) M caesarean pre-labour (not statistically tested)

Fair

Zlot AI, Jackson DJ, & Korenbrot C. (2005) (English)

Local, hospital records, 1994-1998

US (San Diego)

1789 Mexican-born (categorized into acculturation groups by language ability- English, Spanish and bilingual) vs. 313 US born Latina women. Only includes low-risk, low income women.

H & ND (primips) & L & ND (multips) overall; (adjusted)

Good

Zuppa AA, Orchi C, Calabrese V, et al. (2010) (English)

Local, research study, 2005

Italy (Rome)

585 “Immigrants” (includes women from Latin America, East Europe, West Europe, Russia, North America, Asia, Africa) vs. 2334 Italian-born.

L overall (all immigrants combined; unadjusted)

Fair