Question special

In their systematic review and meta-analysis Maheshwari et al (Fertil Steril 2012;98:368-77) used the following internationally accepted indicators of perinatal health as preterm birth, small for gestational age, low birth weight and perinatal mortality. We (Helmerhorst et al. BMJ 2004;18:485) used the following internationally accepted definitions: “International definitions were followed for preterm ( < 37 weeks), very preterm ( < 32 weeks), low birth weight ( < 2500 g), very low birth weight ( < 1500 g), small for gestational age (birth weight < 10th centile for gestation), and perinatal mortality (stillbirths and deaths in first week ≥ 500 g per 1000 total births ≥ 500 g).”