BSNC 5000 - OB Exam Questions &
Answers (Grade A+)
Uteroplacental circulation -
correct answer ✅- uterine arterial blood supply shown at right
- both the ovarian and uterine arteries supply the myometrium
- spiral arteries elongate as the endometrium cyclically thickens to
accommodate the possibility of implantation of a blastocyst
Intervillous space -
correct answer ✅- the space in the placenta in which maternal
blood bathes chorionic villi, allowing the exchange of materials
between the fetal and maternal circulations.
Divided into 3 parts:
- arterial circulation
- circulation in the intervillous space
- venous drainage
Hemodynamics of uteroplacental circulation -
correct answer ✅Volume of placental blood flow - 600-700mL/min
Pressure in supplying uterine artery - 80-100 mmHg
,BSNC 5000 - OB Exam Questions &
Answers (Grade A+)
Pressure in spiral arteries - 70mmHg
Pressure in draining uterine vein - 10mmHg
Maternal intravascular volume changes -
correct answer ✅- plasma volume increases by up to 1L
- rise in #rbc/blood volume but to lesser extent (placental lactogen
stimulates production of erythropoietin)
- dilutional gap causes physiological anemia
Blood pressure change in normal pregnancy -
correct answer ✅- progesterone relaxes smooth muscle in the wall
of blood vessels
- relaxin increases systemic arterial compliance (vasodilation) to
reduce peripheral resistance
- decreases the effective circulating volume (same volume but
larger space to fill)
, BSNC 5000 - OB Exam Questions &
Answers (Grade A+)
- effects of vasodilation:
•non-osmotic release of vasopressin/ADH
•activation of SNS and RAAS increases plasma volume for adequate
organ perfusion
Maternal cardiovascular changes -
correct answer ✅- increasing volume -> increase in preload ->
increased contractility.
- decrease in vascular resistance reduces afterload which increases
cardiac output by nearly 50% thereby increasing the efficiency of
the heart.
Risk of thrombosis during pregnancy -
correct answer ✅- increase in clotting factors increases risk of
thrombosis about 2x
- platelet count decreases as pregnancy progresses
- diulutional effects
- sequestering in the intervillous spaces of the placenta
Answers (Grade A+)
Uteroplacental circulation -
correct answer ✅- uterine arterial blood supply shown at right
- both the ovarian and uterine arteries supply the myometrium
- spiral arteries elongate as the endometrium cyclically thickens to
accommodate the possibility of implantation of a blastocyst
Intervillous space -
correct answer ✅- the space in the placenta in which maternal
blood bathes chorionic villi, allowing the exchange of materials
between the fetal and maternal circulations.
Divided into 3 parts:
- arterial circulation
- circulation in the intervillous space
- venous drainage
Hemodynamics of uteroplacental circulation -
correct answer ✅Volume of placental blood flow - 600-700mL/min
Pressure in supplying uterine artery - 80-100 mmHg
,BSNC 5000 - OB Exam Questions &
Answers (Grade A+)
Pressure in spiral arteries - 70mmHg
Pressure in draining uterine vein - 10mmHg
Maternal intravascular volume changes -
correct answer ✅- plasma volume increases by up to 1L
- rise in #rbc/blood volume but to lesser extent (placental lactogen
stimulates production of erythropoietin)
- dilutional gap causes physiological anemia
Blood pressure change in normal pregnancy -
correct answer ✅- progesterone relaxes smooth muscle in the wall
of blood vessels
- relaxin increases systemic arterial compliance (vasodilation) to
reduce peripheral resistance
- decreases the effective circulating volume (same volume but
larger space to fill)
, BSNC 5000 - OB Exam Questions &
Answers (Grade A+)
- effects of vasodilation:
•non-osmotic release of vasopressin/ADH
•activation of SNS and RAAS increases plasma volume for adequate
organ perfusion
Maternal cardiovascular changes -
correct answer ✅- increasing volume -> increase in preload ->
increased contractility.
- decrease in vascular resistance reduces afterload which increases
cardiac output by nearly 50% thereby increasing the efficiency of
the heart.
Risk of thrombosis during pregnancy -
correct answer ✅- increase in clotting factors increases risk of
thrombosis about 2x
- platelet count decreases as pregnancy progresses
- diulutional effects
- sequestering in the intervillous spaces of the placenta
