Assessment of the Third Trimester

Question 1

fetal growth

Answer 1

• interval fetal growthcan be determined with ultrasound examinations a minimum of 3 weeks apart
• in the last 3 months of pregnancy, the fetus will grow an additional 4 inches in length and gain an additional 2000-2800g in weight at 100-200g per week
• distal femoral epiphysis seen around 32 wks
• proximal tibial epiphysis seen around 35 wks

Question 2

frank breech

Answer 2

• fetal buttocks are presenting with the feet near head
• both hips and knees are extended
• most common

Question 3

macrosomia

Answer 3

• fetal weight above 4000g or above the 90th percentile for gestational age
• fetuses of diabetic mothers are likely to display organomegaly whereas fetuses of nondiabetic mothers will demonstrate normal growth
• fetuses of diabetic mothers demonstrate a higher mortality rate.

Question 4

symmetric IUGR

Answer 4

• result of embryologic insult
• small for dates
• symmetrically small head and abdomen circumference
• oligo

Question 5

amniotic fluid

Answer 5

• early in gestation, the major source of amniotic fluid is the amniotic membrane
• as the embryo and placenta develop, fluid is produced by the placenta and fetus
• after 16 gestational weeks, the fetus is the major producer of amniotic fluid

Question 6

vernic caseosa

Answer 6

fatty material found on the fetal skin and amniotic fluid late in pregnancy

Question 7

causes of polyhydramnios

Answer 7

fetal

• CNS
• GI travt
• abd wall defects
• cardiac defects

maternal

• diabetes mellitus
• cardiac disease
• preeclampsia
• idiopathic

Question 8

function of amniotic fluid

Answer 8

• maintains intrauterine temperature
• allows fetus free movement within the amniotic cavity
• protects the developing fetus from injury
• prevents adherence of the amnion to the fetus
• allows symmetric growth

Question 9

asymmetric IUGR

Answer 9

• causes: placental insufficiency, chromosomal abnormality, or infection
• FIndings: small for dates, low maternal weight gain, hypertension
• maternal risk factors: hypertension, poor nutrition, alcohol and drug abuse

Question 10

hypertension

Answer 10

systolic pressure > 140 mm Hg or a diastolic pressure > 90 mm Hg

Question 11

complete breech

Answer 11

• fetal buttocks are presenting with the knees bent and feet down
• both hips and knees are flexed
• least common

Question 12

incomplete breech

Answer 12

• footling breech
• fetal foot is the presenting part
• one or both hips and knees are extended
• greatest risk for prolapsed cord

Question 13

causes of oligohydramnios

Answer 13

fetal

• genitourinary tract abnormality
• IUGR

maternal

• poor nutrition
• placenta insufficiency
• premature rupture of membranes

Question 14

intrauterine growth restriction

Answer 14

• results from insufficient fetal nutrition
• fetal weight at or below the 10th percentile for gestational age
• associated with maternal hypertension
• evaluation of AFI, estimated fetal weight, and maternal blood pressure results in the most accurate diagnosis
• liver is the most severly affected fetal organs