Before revision: Classification of infant deaths and stillbirths Postnatally (after birth) to estimate various risk factors center| 700px| Timeline of pregnancy by gestational age Estimation of due date 280px| Distribution of gestational age at childbirth among singleton live births, given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period The mean pregnancy length has been estimated to be 283.4 days of gestational age as timed from the first day of the last menstrual period and 280.6 days when retrospectively estimated by obstetric ultrasound measurement of the fetal biparietal diameter (BPD) in the second trimester.
After revision: Classification of infant deaths and stillbirths Postnatally (after birth) to estimate various risk factors center| Timeline of pregnancy by gestational age Estimation of due date Distribution of gestational age at childbirth among singleton live births, given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period The mean pregnancy length has been estimated to be 283.4 days of gestational age as timed from the first day of the last menstrual period and 280.6 days when retrospectively estimated by obstetric ultrasound measurement of the fetal biparietal diameter (BPD) in the second trimester.