148 6 CHAPTER 6 Supplement Supplement 1. Invitational e-mail. The original e-mail was in Dutch, this is a translated version. Dear… We invite you to participate in a study of variation in protocol for neonatal referral. (For detailed information about this study, please see the end of this e-mail.) For this study, we would like to receive the following protocols for neonatal referral: o Large for gestational age/macrosomia; o Small for gestational age/fetal growth restriction; o Meconium stained amniotic fluid; o Vaginal instrumental birth; o Caesarean birth; You can send us the protocols in two ways: 1. E-mail, replaying to this e-mail (e-mail address). 2. Post (postal address). Detailed information about the study This study is carried out by researchers of the department of Midwifery Science, Amsterdam UMC, location VUmc in cooperation with a multidisciplinary research team*. Ethical approval was requested from the Medical Ethics Review Committee of VU University Medical Centre. The committee confirmed that ethical approval was not required, because the Medical Research involving Human Subjects Act did not apply to this study (nr. 2019.549). Studies have shown large regional variation in neonatal referral. This large variation could not be explained by maternal characteristics, indicating unwarranted variation due to underuse or overuse of care. To reduce unwarranted variation, it is necessary to study underlying factors contributing to regional variation. A possible explanation for variation is the variation in protocols used for neonatal referral. The aim of this study is to gain more insight to variation between regional protocols used for neonatal referral. To gain a complete picture of the protocols used for neonatal referral, all obstetric and neonatal department in the Netherlands are invited to participate in this study.