Placental, Fetal and New born Physiology

1. Current research is placing the etiology of certain complications of pregnancy on the formation of a good placenta. To this end, the placental cotyledons are formed primarily by which of the following?

2. Because the fetus is growing rapidly, its need for nutrients and energy exceeds the mother’s on a gramfor-gram basis. Often, the placental transport will achieve a fetal concentration greater than maternal,but occasionally the converse occurs. Which of the following has a lower concentration in the fetus than in the mother?

3. The placenta is supplied by two umbilical arteries that carry deoxygenated fetal blood. This blood flows into intervillous capillaries and back to the fetus in the single umbilical vein. The maternal circulation is designed to bathe the placental villi to optimize transport across the placenta of nutrients, oxygen, and metabolic wastes. Which of the following best describes the path of the maternal blood flow?

4. The human placenta is a complex structure that serves as the interface between the fetus and maternal circulation to allow excretory, respiratory, and nutritional functions for the fetus. It does which of the following?

5. A chronic hypertensive patient presents with complaints of decreased fetal movement. Her prenatal care has been sporadic but it appears that she is at 37 weeks’ gestation with an estimated fetal weight of 2,200 g. Concerns are raised regarding placental reserves for oxygenating the fetus. This can be most directly assessed by which of the following?

6. Labor is induced at 38 weeks due to severe oligo-hydramnios. The infant is born with a congenital absence of the left hand. This is likely due to which of the following?

7. A poorly controlled class D diabetic patient desired a repeat cesarean section. An amniocentesis to verify pulmonary maturity was done prior to scheduled surgery at 37 weeks’ gestation. The L/S ratio was 2:1 and phosphatidyl-glycerol was absent. An infant was delivered who developed infant respiratory distress syndrome (IRDS). What was the most likely reason?

8.  A patient presents to labor and delivery complaining of regular uterine contractions. Upon reviewing her gestational dating criteria, the following is determined: Last menstrual period (LMP) places her at 36 weeks’ estimated gestational age (EGA). Her clinical sizing at her initial obstetrical visit places her at 41 weeks. Ultrasound done at 10 weeks places her at 38 weeks. Ultrasound done at this presentation places her at 35 weeks. Clinical size at presentation places her at 34 weeks. You determine that she is how many weeks’ EGA?

9. The fetal head is usually the largest part of the infant. Depending on the positioning of the head as it enters the pelvis, labor will progress normally or experience a dystocia due to cephalopelvic disproportion. The smallest circumference of the normal fetal head corresponds to the plane of which diameter?

10. A patient at her 34-week prenatal visit inquires as to the estimated fetal weight. When told it is likely 4 pounds she gets worried that with only a few more weeks that her fetus is too small and there is a problem. While reassuring her, she is told that most of the growth of an infant is in the last month or two of the pregnancy. During the last month of normal pregnancy, the fetus grows at a rate of approximately which of the following?

11. A patient is found to be blood type A negative during her first pregnancy. She receives antenatal RhoGAM at 28 weeks. At 32 weeks she develops severe preeclampsia and is induced, resulting in an uncomplicated vaginal delivery. The infant does well and is found to be A positive. The mother is found to have anti-D immunoglobulin at a titer of 1:1. Which of the following best describes how much RhoGAM the patient should receive?

12. A patient has an emergent cesarean section for an abruption. Because of a large anterior placenta, the placenta was entered during the surgery. The mother is Rh-negative. The infant appears anemic and is Rh-positive. To determine the amount of RhoGAM that needs to be given to prevent sensitization, an estimate of the amount of fetal red blood cells (RBCs) in the maternal circulation is necessary. Fetal RBCs can be distinguished from maternal RBCs by which of the following?

13. The oxygen dissociation curve of fetal blood lies to the left of the curve of maternal blood. Which of the following is implied?

14. In utero, the fetus exists in a “water”-filled environment. Oxygen is derived from the placenta. The fetal lungs are filled with amniotic fluid. Given the lower oxygen tension of the fetal blood, the circulation through the heart and lungs is altered to allow optimal oxygen delivery to the most critical structures. Yet this unique circulation must convert in minutes upon delivery to a typical adult circulatory flow. Oxygenated blood from the umbilical vein enters the fetal circulation via which of the following?

15. In utero, the fetus exists in a “water”-filled environment. Oxygen is derived from the placenta. The fetal lungs are filled with amniotic fluid. Given the lower oxygen tension of the fetal blood, the circulation through the heart and lungs is altered to allow optimal oxygen delivery to the most critical structures. Yet this unique circulation must convert in minutes upon delivery to a typical adult circulatory flow. In the fetus, the most well-oxygenated blood is allowed into the systemic circulation by which of the following?

16. In utero, the fetus exists in a “water”-filled environment. Oxygen is derived from the placenta. The fetal lungs are filled with amniotic fluid. Given the lower oxygen tension of the fetal blood, the circulation through the heart and lungs is altered to allow optimal oxygen delivery to the most critical structures. Yet this unique circulation must convert in minutes upon delivery to a typical adult circulatory flow. In the fetal circulation, the highest oxygen content occurs in which of the following?

17. In utero, the fetus exists in a “water”-filled environment. Oxygen is derived from the placenta. The fetal lungs are filled with amniotic fluid. Given the lower oxygen tension of the fetal blood, the circulation through the heart and lungs is altered to allow optimal oxygen delivery to the most critical structures. Yet this unique circulation must convert in minutes upon delivery to a typical adult circulatory flow. In systemic circulation of the fetus, the highest oxygen content occurs in which of the following?

18. A couple bring their newborn to the pediatrician with concerns regarding possible bruises on the infant’s leg. There is no evidence of trauma or violence. The couple had an uncomplicated home birth. Concerns are raised regarding the infant’s coagulation status. Which of the following best describes typical fetal coagulation at birth?

19. The fetus can produce immune antibodies during development. Also there is some transport of immune antibodies across the placenta. In the fetal blood at birth (compared to maternal blood), there is/are generally which of the following?

20. A 21-year-old patient who is a G3P0111 at EGA of 33 weeks presents with preterm labor. She had a prior preterm infant at 28 weeks who still has pulmonary dysplasia, so she is very concerned about the pulmonary development of this fetus. Lung surfactant is critical to pulmonary functioning by keeping surface tension in the alveoli low and thereby decreasing the occurrence of atelectasis and atrioventricular (AV) shunting. Surfactant is formed in which of the following?

21. A 21-year-old patient who is a G3P0111 at EGA of 33 weeks presents with preterm labor. She had a prior preterm infant at 28 weeks who still has pulmonary dysplasia, so she is very concerned about the pulmonary development of this fetus.The presence of which of the following substances is most reassuring that fetal lungs will be mature?

22. A 21-year-old patient who is a G3P0111 at EGA of 33 weeks presents with preterm labor. She had a prior preterm infant at 28 weeks who still has pulmonary dysplasia, so she is very concerned about the pulmonary development of this fetus. Fetal breathing movements can be an indicator of fetal well-being in utero and should occur in what interval of time?

23.  A patient presents for her routine prenatal visit at 32 weeks’ EGA. Her pregnancy up to now has been uncomplicated. Her BMI is 25. Her laboratory testing is normal including a 1-hour glucose screen. An anatomic ultrasound done at 22 weeks was normal and confirmed her dating. Her fundal height is 37 cm today. A brief bedside ultrasound reveals an amniotic fluid index (AFI) of 30 cm. Which of the following situations is most likely to be the etiology of polyhydramnios?

24. A fetus has an infection that is causing acute hemolysis. At birth, the infant is not jaundiced though the liver is enlarged. The lack of fetal jaundice is because of which of the following?

25. Which of the following best describes the fetal kidneys?

26. A woman presents for her new obstetrical visit at 12 weeks’ EGA. Her medical history is complicated by Graves thyroiditis that has been treated with radioactive iodine a few years prior. The patient is currently being maintained on thyroid replacement. She is worried that this will compromise the fetus. She is told that the interaction between maternal and fetal physiology relative to thyroid function is complex. Which of the following is an accurate description of this interaction?

27. A fetus has genotype 46,XY. Early in embryoge-nesis, the right testis does not form (dysgenesis). What will be the resulting developments?

28. A female fetus has partial fusion of the two Müerian ducts and complete failure of septal resorption. What is the resulting uterine anomaly called?