Definitions And Epidemiology ✅ Flashcards
How is a babys due date traditionally calculated?
Asking the mother about the first day of the last menstrual period, and relying on this
When is a baby’s due date not based on the mothers LMP?
When there is a discrepancy with USS dates of more than 10 days
What do some think should be used to determine a babies due to?
USS biometry alone, when available
What is the problem with the potential difficulties in accurately determining gestational age?
Obtaining accurate data relating to stillbirths and mortality/survival rates in extremely preterm infants is difficult
Why is comparing data on stillbirths/extremely preterm infants from different countries difficult?
Due to variation in legislation, regulation, and practices of registration of stillbirth, live birth, and death
In what respects is there wide variation between different countries with regard to stillbirths?
Gestational age at which fetal deaths are registered as stillbirths (which influences decision whether extremely preterm births are registered as live birth or miscarriage)
How is gestational age in completed weeks calculated?
From the first day of the last menstrual period to the date of birth
What is a neonate defined as?
Infant 28 days or younger
What is preterm defined as?
Gestation <37 weeks of pregnancy
What is preterm often subclassified into?
- Extreme preterm
- Very preterm
- Moderate preterm
- Late preterm
What is considered to be extreme preterm?
<28 weeks
What is considered to be very preterm?
28-31 weeks
What is considered to be moderate preterm?
32-33 weeks
What is considered to be late preterm?
34-36 weeks
What is considered a term pregnancy?
37-41 weeks
What is considered post term pregnancy?
42 or more weeks gestation
What is stilbirth defined as?
Fetus delivered at or after 24+0 weeks gestational age showing no signs of life
What is neonatal death defined as?
A live born baby (born at 20+0 weeks gestational age or later, or with birth weight of 400g+ where accurate gestation not available), who died before 28 completed days after birth
How is the perinatal mortality rate calculated?
Stillbirths + deaths within the first week per 1000 live births and stillbirths
How is the neonatal mortality rate calculated?
Deaths of live-born infants within the first 4 weeks after birth per 1000 live births
What is the postneonatal mortality rate?
The number of deaths aged 28 days+, but under 1 year, per 1000 live births
What is the infant mortality rate?
The number of deaths under 1 year of age per 1000 live births
What is low birth weight defined as?
<2500g
What is very low birth weight defined as?
<1500g
What is extremely low birth weight defined as?
<1000g
What is small for gestational age defined as?
Birth weight <10th centile for gestational age
What are the maternal risk factors for poor fetal outcomes in the UK?
- Coexisting medical conditions
- Parity
- Socio-economic status
- Age
- Nutrition
- Antenatal service provision and their utilisation
What has improved the perinatal mortality rate in the past 30 years?
- Improved maternal health and nutrition
- Improved socio-economic conditions
- Better antenatal and perinatal care
- High antenatal steroid uptake
- Improved survival of preterm infants
What % of neonatal deaths occur in low and middle-income countries?
99%
What are the main causes of neonatal deaths?
- Preterm birth
- Infection
- Perinatal asphyxia
