ABSTRACT
We have previously reported that the fetal middle cerebral artery (MCA) peak systolic
velocity (PSV) increases in anemic fetuses and in fetuses with intrauterine growth
restriction (IUGR). We hypothesized that the pathophysiology for the increased MCA
PSV is different in anemic and IUGR fetuses. Thus the aim of this study was to determine
the factor(s) among fetal umbilical vein blood pH, Po
2, Pco
2, and hemoglobin that might affect the MCA PSV in fetuses with anemia and IUGR. This
study included two groups of fetuses. The first group included fetuses at risk for
anemia because of red cell alloimmunization, whereas the second group included IUGR
fetuses. For both groups of fetuses, we determined hemoglobin, umbilical vein blood
gases-at cordocentesis in anemic fetuses and immediately after cesarean delivery in
IUGR fetuses-and MCA PSV before cordocentesis, or before delivery. The relationship
between MCA PSV and the hemoglobin, Po
2, Pco
2, and pH values for the anemic and the IUGR fetuses were assessed by regression analysis
using multiples of the mean. There were 14 fetuses in the first group and 22 fetuses
in the second group. In the first group, the only parameter that was related to MCA
PSV was the fetal hemoglobin (R
2 = 0.34; p < 0.05); in fetuses with IUGR, the Pco
2 (R
2 = 0.36; p < 0.01) and the PO
2 (R
2 = 0.30; p < 0.01) correlated well with the MCA PSV, whereas no relationship was found between
the MCA PSV and the hemoglobin. The data indicate that the mechanism of high MCA PSV
is different in anemic and nonanemic IUGR fetuses, and suggest that the process of
cerebral autoregulation is present in the preterm IUGR fetus.
KEYWORDS
Fetal autoregulation cerebral blood flow - middle cerebral artery - peak systolic
velocity - anemia - intrauterine growth restriction (IUGR)
REFERENCES
- 1
Mari G, Deter R L, Carpenter R L et al..
Non-invasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal
red-cell alloimmunization. Collaborative Group for Doppler Assessment of the Blood
Velocity in Anemic Fetuses.
N Engl J Med.
2000;
342
9-14
- 2
Zimmerman R, Carpenter Jr R J, Durig P, Mari G.
Longitudinal measurement of peak systolic velocity in the fetal middle cerebral artery
for monitoring pregnancies complicated by red cell alloimmunisation: A prospective
multicentre trial with intention-to-treat.
BJOG.
2002;
109
746-752
- 3 Practice Bulletin ACOG .Management of Alloimmunization during Pregnancy (No. 75). Washington,
DC; American College of Obstetricians and Gynecologists 2006
- 4
Fan F C, Chen R Y, Schuessler G B, Chien S.
Effect of hematocrit variations on regional hemodynamics and oxygen transport in the
dog.
Am J Physiol.
1980;
238
H545-H552
- 5
Mari G, Hanif F, Cosmi E, Santolaya-Forgas J, Treadwell M C.
Middle cerebral artery peak systolic velocity: a new Doppler parameter in the assessment
of IUGR fetuses.
Ultrasound Obstet Gynecol.
2007;
29
310-316
- 6
Hanif F, Cosmi E, Mari G.
Hemoglobin concentration in IUGR fetuses with ductus venosus reversed flow delivered
at < 32 weeks' gestation.
Am J Obstet Gynecol.
2006;
195
S220
, (abst 737)
- 7
Hadlock F P, Harrist R B, Martinez-Poyer J.
In utero analsysis of fetal growth: a sonographic weight standard.
Radiology.
1991;
181
129-133
- 8
Soothill P W, Nicolaides K H, Rodeck C H, Campbell S.
Effect of gestational age on fetal and intervillous gas and acid-base values in human
pregnancy.
Fetal Ther.
1986;
1
168-175
- 9
Vyas S, Nicolaides K H, Bower S, Campbell S.
Middle cerebral artery flow velocity waveforms in fetal hypoxaemia.
Am J Obstet Gynecol.
1990;
97
797-803
- 10
Greisen G.
Autoregulation of cerebral blood flow in newborn babies.
Early Hum Dev.
2005;
81
423-428
- 11
Liu Y, Harder D R, Lombard J H.
Interaction of myogenic mechanisms and hipoxic dilation in rat middle cerebral arteries.
Am J Physiol Heart Circ Physiol.
2002;
283
H2276-H2281
- 12
Greisen G, Vannucci R C.
Is periventricular leucomalacia a result of hypoxic ischemic injury? Hypocapnia and
the preterm brain.
Biol Neonate.
2001;
79
194-200
- 13 Guyton A C, Hall J E. Textbook of Medical Physiology. 11th ed. Philadelphia; Elsevier
Saunders 2006
Giancarlo MariM.D.
Department of Obstetrics and Gynecology, Wayne State University
John R (Hutzel Hospital - 7 Brush), Detroit, MI 48201