1. Culture techniques of included studies.

Trial	Culture technique day 2/3	Culture technique day 5/6
Aziminekoo 2015	Sydney IVF cleavage medium, Cook	Sydney IVF blastocyst medium
Brugnon 2010	G series™ medium (Vitrolife, Sweden)	G series™ medium (Vitrolife, Sweden)
Bungum 2003	Sequential G1 Vitrolife	Sequential G1/G2 Vitrolife
Coskun 2000	Sequential MediCult	Sequential G1/G2 Vitrolife
Devreker 2000	NS	NS
Elgindy 2011	NS	NS
Emiliani 2003	In‐house sequential (based on G1/G2)	In‐house sequential (based on G1/G2)
Fernandez‐Shaw 2015	Sequential G1 Vitrolife	Sequential G1/G2 Vitrolife
Fisch 2007	NS	NS
Frattarelli 2003	NS	NS
Gaafar 2015	NS	NS
Gardner 1998a	Single Ham's F10 In‐house	Sequential G1/G2 In‐house
Hatirnaz 2017	Standard culture medium	Sequential G1/G2 Scandinavian IVF Sciences
Hreinsson 2004	Vitrolife IVF	Sequential G1/G2 or CCM Vitrolife
Karaki 2002	MediCult	Sequential G1/G2 Vitrolife
Kaser 2017	Global total with HSA LifeGlobal	Global total with HSA LifeGlobal
Kaur 2014	Cleavage medium	G2 Plus media
Kolibianakis 2004	Sequential G1 Vitrolife	Sequential G1/G2 Vitrolife
Levi‐Setti 2018	NS	NS
Levitas 2004	NS	Sequential ‐ G1/G2 Vitrolife
Levron 2002	NS	NS
Livingstone 2002	Sequential ‐ Sydney IVF Cook	Sequential ‐ Sydney IVF Cook
Motta 1998	Sequential ‐ Irvines P1	Sequential ‐ Irvines P1 then Blast media
Pantos 2004
Papanikolaou 2005	Sequential ‐ Vitrolife G1/G2 GII or GIII	Sequential ‐ Vitrolife G1/G2 GII or GIII
Papanikolaou 2006	Assume sequential ‐ Vitrolife G1/G2	Assume sequential ‐ Vitrolife G1/G2
Rienzi 2002	Sequential G1 Vitrolife	Sequential G1/G2 Vitrolife
Schillaci 2002	NS	NS
Singh 2017	NS	NS
Ten 2011	NS	NS
Van der Auwera 2002	Sequential both Cook and Vitrolife	Sequential both Cook and Vitrolife
Yang 2018	Sequential media (G1.5, Vitrolife) in a Primo Vision time‐lapse system (Vitrolife)	Sequential G1/G2 Vitrolife

CCM: a Vitrolife trademarked medium for blastocyst culture
IVF: in vitro fertilisation
G1/G2:sequential media from Vitrolife
NS: not stated