Perinatal epidemiology

Question 1

what is meant by perinatal

Answer 1

around the time or birth
ICD10 definition = 22 completed weeks of gestation to 7 completed days after birth

Question 2

when does WHO say the perinatal period ends

Answer 2

28 weeks of gestation or when the fetus weighs 1000g to the end of the 7th completed day

Question 3

how does the NHS define perinatal

Answer 3

the time between conceiving a baby until the end of the first postnatal year

Question 4

what is the importance of perinatal epidemiology

Answer 4

identifying effects of events during pregnancy, outcome, maternal fetal and neonatal health outcomes
can identify harmful exposures during pregnancy, diet, genetic constitution, the effects of illness and medications
increased evidence that adverse experiences during pregnancy can impact childhood and adult health

Question 5

what is the fetal origins hypothesis

Answer 5

Barkers 1995
says undernutrition in the womb during middle-late pregnancy causes improper fetal growth and so predisposition to diseases in adulthood

Question 6

what is meant by fetal programming

Answer 6

events occurring during critical points of pregnancy may cause permanent effects on fetus and infant long after birth

Question 7

what are methodological challenges to consider when using randomised control trial in perinatal research

Answer 7

randomising women
recruitment
factors like age, ethnicity, genetic constitution
inclusion of multiple births and subsequent births from the same mother

Question 8

how do calculate perinatal prevalence rates

Answer 8

total birth prevalence = no. cases / no. births (live and still

Question 9

how to find number of births for calculating prevalence

Answer 9

LB + FD + IA
live born
fetal deaths from 20 weeks gestation
IA - induced abortion or termination of pregnancy

Question 10

what is perinatal mortality

Answer 10

number of stillbirths and deaths in the first week of life per 1000 live births

Question 11

what is a stillbirth

Answer 11

a baby born dead after 24 completed weeks of pregnancy
before this is a miscarriage
5 in 1000 births in the Uk are still
stillbirth rates in most industralised countries have declined over the past 20 years

Question 12

outline neonatal death

Answer 12

deaths among live born infants prior to first 28 days of life, per 1000 live births

Question 13

what is ENMR

Answer 13

early neonatal mortality = deaths 0-6 days

Question 14

what is LNMR

Answer 14

late neonatal mortality
= deaths 7-28 days

Question 15

what is post neonatal mortality

Answer 15

deaths among live born infants between 29 days of life to the end of the first year of life per 1000 live births

Question 16

what did Shenyang show for neonatal death between 1997 and 2014

Answer 16

urban neonatal mortality rate was lowest compared to rural neonatal mortality rate which was highest
per 1000 live births

Question 17

what can perinatal mortality be used as

Answer 17

a public health indicator to assess the populations health status
effective way to compare public health between populations and over time
compare perinatal and antenatal health care between countries

Question 18

what are factors undepinning perinatal death burden

Answer 18

genetics
environment
diagnostic services
methods of data collection
termination of pregnancy

Question 19

what are some health and survival challenges to the fetus

Answer 19

abnormal placentation
poor nutrition
multiple births
congenital abnormalities
infection
these can lead to stillbirth

Question 20

why is the rate of twins increasing

Answer 20

due to increasing maternal age and assisted reproductive technologies

Question 21

outline the global burden of congenital abnormalities

Answer 21

2-3% of babies born with significant congenital anomaly
major cause of stillbirth, infant mortality, childhood morbidity and long term disability

Question 22

outline genetics as a cause of congenital anomaly

Answer 22

abnormalities of large portion or entire chromosome
inheritance of abnormal genes
sporadic mutations in one of the germ cells contributing to fetus

Question 23

outline teratogenic exposure as a cause of congenital anomaly

Answer 23

in intrauterine environment of fetus
- dietary deficiency e.g maternal folic acid associated with increased risk of spina bifida
- toxic effects - exposure to harmful substance during pregnancy e.g thalidomide, mercury
- maternal infection e.g rubella and syphilis

Question 24

what can the zika virus cause

Answer 24

microcephaly
below average head size of baby, often caused by failure of brain to grow at normal rate
affects 25,000 babies in US each year

Question 25

what was the rate of stillbirths in 2020

Answer 25

3.8 stillbirths per 1000 births - unchanged since 2019

Question 26

what is the reason for lack of decline in stillbirth rates

Answer 26

unknown but may be related to changes in the distribution of risk factors e.g greater numbers of births to very young and older women, increase in obesity and diabetes

Question 27

how many neonatal deaths are there worldwide

Answer 27

4 million

Question 28

what are the main causes of neonatal death

Answer 28

preterm birth - 28% infections - 26% asphyxia - 23% tetanus - 7%

Question 29

what are some consequences of challenges to the fetus

Answer 29

premature delivery low birth weight cerebral palsy gastroschisis neonatal death

Question 30

what are common infectious diseases associated with fetus

Answer 30

respiratory tract infection adenovirus pneumonia

Question 31

what is the rate of preterm birth

Answer 31

5-7% large ethnic variation interventions have limited success genetic suscpetibility factors believed to be important

Question 32

what are the consequences of preterm birth

Answer 32

patent ductus arteriosus (PDA) - delay of closure to blood vessel diverting blood from lungs developmental delay respiratory distress neonatal mortality importance of nutrition to catch up growth

Question 33

what is the leading cause of illness and death in mothers and new born babies

Answer 33

late pregnancy 19% of all first pregnancies affected

Question 34

what are 3 diseases of late pregnancy

Answer 34

- pre-eclampsia - severe high BP, risk of stroke and seizure - 5% of first time mothers - fetal growth restriction - due to placenta problems leading to inadequate nutrition - 1 in 10 pregnancies - pre-term labour - long term disability, high morbidity and mortality

Question 35

what are causes of low birth weight

Answer 35

alcohol consumption increased chorioaminonitis cocaine use increased multiple births preterm induction of labour

Question 36

what is cerebral palsy

Answer 36

group of non-progressive neurological disabilities in development of human movement and posture arises from disturbance in fetal brain development no decline over past 60 years

Question 37

what are the 2 types of cerebral palsy

Answer 37

congenital - during pregnany - 75% acquired - after birth - 25%

Question 38

what is the incidence of cerebral palsy

Answer 38

2.5 per 1000 live births

Question 39

what are some known causes of cerebral palsy

Answer 39

80% of cases have unknown aetiology infections, malnutrition, head injury in early childhood

Question 40

what is gastroschisis

Answer 40

opening in abdominal wall causes bowel to develop outside of babys stomach occurs during 4th week of development due to lack of meeting between lateral body and walls of embryo associated with young maternal age

Question 41

what is the prevalence of gastroschisis

Answer 41

4 in 1000 new borns

Question 42

what are risk factors associated with gastroschisis

Answer 42

low social class smoking alcohol consumption medications use of recreational drugs like cocaine opioid use

Question 43

in summary what are the causes of neonatal death

Answer 43

birth outcomes obsteric and neonatal complications (injury, asphyxia, hypothermia) maternal health preceding and during pregnancy bacterial and viral infections