Topic 5 Part 2 Preterm birth

Question 1

Preterm birth is defined as birth prior to _ of gestation.

Answer 1

37 weeks.

Question 2

Preterm birth peaked around 2006, possibly due to _

Answer 2

Increased use of in vitro fertilization.

Question 3

The national average preterm birth rate is around _

Answer 3

12%.

Question 4

Individuals of _ ethnicity are at the highest risk for having preterm birth.

Answer 4

Black/African.

Question 5

Major categories of risk for preterm birth

Answer 5

1. Extremes of maternal age (less than 17 or greater than 35).
2. Unintended pregnancy.
3. Late PTB (34, 35, 36, 37 weeks).
4. Maternal race (black race - highest risk).
5. Multiple gestation - #1 risk factor.
6. Cesarean section.

Question 6

The two best predictors of having a preterm birth are _

Answer 6

Multifetal gestation and/or a history of preterm labor/delivery.

Question 7

Preterm birth can be conceptualized as a _

Answer 7

Common complex disorder.

Question 8

Factors involved in complex disorders

Answer 8

1. Genetic contribution (familial aggregation, recurrence of preterm birth, racial disparity).
2. Environmental influences (smoking, infection - especially bacterial vaginosis, stress - may cause vasoconstriction around the uterus).
3. Gene-environment interactions (example: maternal infection can be affected by genes that regulate the response to the infection).

Question 9

Genes that influence _ activity probably play a role in preterm birth.

Answer 9

Cytokine/inflammatory.

Question 10

Single nucleotide polymorphisms (SNPs)

Answer 10

1. One nucleotide within a coding region of the sequence is changed, such as guanine (G) being substituted for cytosine (C).
2. A DNA sequence variation that is common in the population (1% of people) and may or may not affect coding for a significant protein.
3. A SNP can be present in one or both alleles; this may effect expression of the phenotype.

Question 11

Several studies have reported associations of single nucleotide polymorphisms (SNPs) in _ genes with preterm delivery.

Answer 11

TNF-α and IL-6.

Question 12

Human Microbiome Project

Answer 12

1. The human body has 10 times as many microbial cells as human cells; these bacteria have their own DNA that interacts with our own in various ways.
2. The Human Microbiome Project takes a metagenomic approach and seeks to study these microbial communities.