Introduction

Question 1

what are the known causes of birth defects?

Answer 1

• Teratogens
• Genetic abnormality
• Chromosomal abnormality
• Twinning
• 70-75% unknown cause (2-5% births have recognizable birth defects)

Question 2

what percentage of neonatal deaths and infant deaths are due to birth defects?

Answer 2

70% neonatal deaths ( before 1 month)

22% infant deaths (up to 15 months)

Question 3

what is the risk of birth defects altered by?

Answer 3

maternal age

increased age= increased risk

Question 4

how does cancer occur?

Answer 4

Normal processes of developmental biology -> unrestrained developmental processes underpin pathophysiology of cancer

• Proliferation -> limitless replicative potential, self-sufficiency to growth signals
• Apoptosis -> evading apoptosis
• Migration -> tissue invasion & metastasis
• Responsiveness to local signals and neighbouring cells -> sustained angiogenesis, insensitivity to anti-growth signals

Question 5

what are the stressors for foetal origins of adult disease?

Answer 5

• Endocrine (cortisol)
• Nutritional
• Extrinsic toxicants (e.g smoking)
  
  • Male births= lower sperm counts
  • Mother= less eggs and earlier death age
  • Female birth= reduction oocytes and lower rate of egg development

Question 6

what are the effects of maternal or placental stress?

Question 7

how is DNA arranged?

Answer 7

• DNA wrapped around histones
• Histones contain chemical groups which can be changed
• DNA methyl group can influence whether genes on or off

Question 8

what factors are monitored in child developmental tracking?

Answer 8

1. Gross motor control
2. Fine motor control
3. Cognitive development
4. Language development
5. Social and emotional development

Question 9

what occurs in fertilisation?

Answer 9

• Occurs within fallopian tube
• Triggers cortical reaction
• Cortical granules release molecules which degrade zona pellucida (ZP2 and 3)
  
  • Prevents f urther sperm binding as no receptors
• Haploid -> diploid

Question 10

how does the conceptus develop?

Answer 10

• Continues to divide as it moes down fallopian tube to uterus (3-4 days)
• Receives nutrients from uterine secretions
• This free-living phase can last 9-10days

Question 11

what are the phases of implantation?

Answer 11

attachment phase

decidualisation phase

Question 12

what happens in the attachment phase?

Answer 12

• Outer trophoblast cells contact uterine surface epithelium
• Leukaemia inhibitory factor (LIF) from endometrial cells stim adhesion of blastocyte to endometrial cells
• Interleukin-11 (IL11) from endometrial cells is released into uterine fluid, may be involved
• Many other molecules involved (HB-EGF)

Question 13

what happens in the decidualization phase?

Answer 13

• Changes in underlying uterine stromal tissue (within few hours)
• Requires progesterone domination in presence oestrogen
• Endometrial changes due to progesterone
  
  • Glandular epithelial secretion
  • Glycogen accumulation in stromal cell cytoplasm
  • Growth of capillaries
  • Increased vascular permeability -> oedema
• Factors involved
  
  • Interleukin-11, histamine, certain prostaglandins & TGFb (promotes angiogenesis)