Request for Question Clarification by
hlabadie-ga
on
09 Jan 2003 09:21 PST
A chart with the fine detail that you seek might not have the
scientific basis that would make it reliable, but there has been some
research into the correlations.
Do any of these look promising?
AJR Am J Roentgenol 1995 Mar;164(3):709-17
Sonographic evaluation of intrauterine growth retardation.
Doubilet PM, Benson CB.
Department of Radiology, Harvard Medical School and Brigham and
Women's Hospital, Boston, MA 02115.
Intrauterine growth retardation (IUGR) may arise from a variety of
causes, including placental insufficiency, maternal diseases, and
fetal anomalies. Sonography plays a number of important roles in the
diagnosis and management of growth retardation. Diagnosis of IUGR is
based on fetal measurements, assessment of amniotic fluid volume, and
other sonographic findings. Once IUGR has been diagnosed, sonography
can help establish its cause. If a lethal cause is excluded, the fetus
is monitored for the remainder of the pregnancy using sonography,
including serial fetal measurements, biophysical profiles, and Doppler
waveform indexes. Used appropriately, sonography can improve the
outcome of fetuses with IUGR.
Br J Obstet Gynaecol 1997 Jun;104(6):674-81
Transvaginal Doppler ultrasound of the uteroplacental circulation in
the early prediction of pre-eclampsia and intrauterine growth
retardation.
Harrington K, Carpenter RG, Goldfrad C, Campbell S.
Department of Obstetrics and Gynaecology, Homerton Hospital, London,
UK.
OBJECTIVE: To evaluate the predictive value of transvaginal Doppler
ultrasound studies of the uterine and umbilical arteries in early
pregnancy, in identifying pregnant women at risk of subsequently
developing pre-eclampsia, or the delivery of a small for gestational
age infant. DESIGN: A multivariate logistic regression of Z scores of
Doppler indices obtained from the uterine and umbilical arteries of
652 women with singleton pregnancies at 12 to 16 weeks of gestation.
Measurements included the presence or absence of a notch, bilateral
(right and left waveform) notching, vessel diameter, the resistance
index, the pulsatility index, time averaged mean velocity (cm/s),
maximum systolic velocity (cm/s), and volume flow (mL/min). Stepwise
logistic regression and multivariate analysis of all the parameters
measured was used to construct several scoring systems. MAIN OUTCOME
MEASURES: Pre-eclampsia, birthweight, preterm delivery. RESULTS: In
women that developed complications, there was a trend towards
increased resistance and reduced velocity and volume flow. If
bilateral notches were present there was an increased risk of
pre-eclampsia (odds ratio [OR] 21.99, 95% CI 6.55-73.79), premature
delivery (OR 2.38, 95% CI 1.19-4.75), and the delivery of a small for
gestational age baby (OR 8.63, 95% CI 3.95-18.84). Using multivariate
analysis, a seven parameter model was selected (after removal of
vessel diameter, uterine and umbilical resistance index). This model
produces a scoring system with a sensitivity of 92.9% and a
specificity of 85.1% for the prediction of pre-eclampsia. A three
parameter model (bilateral notches, uterine resistance index,
umbilical pulsatility index) provides similar sensitivities, but lower
specificities, when compared with the seven parameter model.
CONCLUSION: These data indicate that there are differences in uterine
and umbilical artery Doppler blood flow indices at 12 to 16 weeks, in
pregnancies with a normal or complicated outcome. Scoring systems
derived from multivariate analysis of Doppler indices demonstrate the
potential of being able to identify, in early pregnancy, a group of
women at increased risk of the subsequent development of
pre-eclampsia, premature delivery, or the birth of a small for
gestational age baby.
Ultrasound Obstet Gynecol 1998 Jul;12(1):45-9
Imaging of placental vasculature using three-dimensional ultrasound
and color power Doppler: a preliminary study.
Pretorius DH, Nelson TR, Baergen RN, Pai E, Cantrell C.
University of California, San Diego, USA.
OBJECTIVE: To assess placental vasculature using color power Doppler
and three-dimensional ultrasound techniques. DESIGN: A prospective
study was performed in patients to correlate visualization of
placental vessels in vivo with known anatomy. SUBJECTS: Fourteen
normal patients and one patient with intrauterine growth restriction
were recruited to the study. METHODS: Vessels were assessed with
regard to, first, the number of vessels seen within the placenta,
second, the branching pattern of the vessels within the placenta,
third, the number of vessels seen along the surface of the placenta,
and, last, the number of vessels seen in the maternal circulation.
RESULTS: Our results show that the placental vessels seen with this
technique correlate well with known anatomy. A progressive increase in
the number of intraplacental vessels and the number of vascular
branches observed was seen with increasing gestational age. Volume
data review using three orthogonal planar images had two distinct
advantages. First, they could be obtained from orientations not
possible using two-dimensional ultrasound alone, and, second, they
could be viewed in conjunction with volume-rendered images to allow
for referencing and identification of specific vessels.
Volume-rendered images were valuable in allowing the observer to
acquire an improved overall understanding of placental anatomy. They
also assisted the observer in following the continuity of vessels as
they wrapped around and twisted through three-dimensional space.
Stereo viewing was helpful in distinguishing overlapping vessels.
CONCLUSIONS: Our study showed that sonographic volume imaging combined
with color power Doppler imaging methods allowed for individual
vessels in the placenta to be identified, both in the fetal and
maternal circulations.
Semin Roentgenol 1999 Jan;34(1):29-34
Sonographic considerations with multiple gestation.
Rode ME, Jackson M.
Department of Obstetrics and Gynecology, University of Pennsylvania
School of Medicine, Philadelphia 19104-4283, USA.
Determination of chorionicity is of paramount importance in risk
assessment and management. Best performed in the first trimester,
dichorionic placentation can be reliably assumed when the membrane is
easily seen, there is a "twin peak" sign, there are clearly separate
placentas, and there is discordant fetal gender. In a monochorionic
twin pregnancy, there is a single placental mass, the dividing
membrane is difficult to visualize until the end of the first
trimester, and the membrane inserts onto the placental surface without
a peaked appearance. Amniotic fluid volume assessment is important in
the management of twin pregnancy. Polyhydramnios-oligohydramnios may
be a manifestation of twin-twin transfusion syndrome, although
oligohydramnios with normal amniotic fluid volume in the other twin's
sac may more likely be a sign of velamentous cord insertion,
infection, or chromosomal or structural abnormality. Fetal growth
discordance is common in twin pregnancy and is associated with
increased perinatal mortality and morbidity. The most sensitive
indicator of discordant twin growth is thought to be estimated fetal
weight, and an intertwin difference of > or = 20% is considered
significant. In the clinical care of a patient with twins, it is
reasonably standard to confirm chorionicity with ultrasonography in
the first or early second trimester. At about 20 weeks, a level II
ultrasound for anatomic survey is indicated. In dichorionic
pregnancies, ultrasound examinations are then performed at 26 to 28
weeks and every 3 to 4 weeks thereafter to follow growth and amniotic
fluid volume. In monochorionic twins, we generally do an additional
ultrasound at about 23 to 24 weeks, because of the risk of twin-twin
transfusion syndrome. In the late third trimester, careful attention
should also be given to fetal position, to help with delivery
planning.
Zhonghua Fu Chan Ke Za Zhi 1998 Apr;33(4):209-12
[Color Doppler monitoring the utero-placental-fetal circulation
variety of normal pregnancy and intrauterine growth retardation]
[Article in Chinese]
Xu J, Wen L, Ma T.
Tongji Hospital, Tongji Medical University, Wuhan.
OBJECTIVE: To study the utero-placental-fetal circulation (UPFC) in
normal pregnancy and intrauterine growth retardation (IUGR) cases.
METHODS: Color doppler ultrasound was used to detect UPFC in 150
second and third trimester pregnant women, of which 89 cases were
normal pregnancy and 58 cases were IUGR. 3 cases were IUGR with
chronic renal failure. Hemodynamical value of the umbilical artery
(UmA), umbilical vein (UmV) and uterine artery (UtA) were examined
directly. The indices included time average velocity (TAV),
pulsatility index (PI), resistance index (RI), systolic/diastolic
(S/D) ratio, blood flow volume (Q). The maternal serum estriol (E3),
human placental lactogen (HPL) and plasma thromboxane B2
(TXB2)/6-keto-PGF1 alpha (6-KP) were measured simultaneously. RESULTS:
The result shows that in normal pregnancy group UPFC is abundant
gradually with increasing gestational age. In IUGR group 92.53% of
cases showed that TAV and Q of UmA, UmV markedly decreased and PI, RI
and S/D ratio of UmA elevated at 20 weeks of gestation. There were
significant difference between the two groups, maternal serum E3, HPL
level in IUGR group were significantly lower than that of the normal
pregnancy group, 6-KP level reduced, and TXB2/6-KP ratio significantly
increased. CONCLUSION: Using color doppler ultrasound examining
hemodynamical changes of UmA, UmV and UtA could observe UPFC function
directly. It is one of the best method to early diagnose and predict
the prognosis of IUGR.
Ital J Anat Embryol 1999 Oct-Dec;104(4):201-7
Placental morphometry in pregnancies complicated by intrauterine
growth retardation with absent or reversed end diastolic flow in the
umbilical artery.
Biagiotti R, Sgambati E, Brizzi E.
Department of Anatomy, Histology and Forensic Medicine, University of
Florence, Italy.
The aim of this study was to assess any possible correlation between
villous tree architecture and its vascularization, and absent or
reversed end-diastolic flow velocity (ARED) in the umbilical artery.
The study group included seven pregnancies complicated by IUGR
(estimated fetal weight < 10th percentile) and absent end-diastolic
flow velocity in the umbilical artery. A gestational-age matched group
of seven normally grown pregnancies was selected as control group. At
delivery, the placenta was weighed and immersed in 10% neutral
buffered formalin. A stratified random sampling procedure was used to
obtain 12 blocks of full-thickness tissue per organ. A single random
section was cut from each block. The following morphometric parameters
were evaluated in each section: mean vessel diameter, volume density
of the villous tissue, stem villi and terminal villi. Measurements
were performed using a computerized Video Image Analysis system. No
significant difference in mean vessel diameter was found between the
two groups (37.1 microns versus 36.1 microns; p = 0.1). There was a
significant reduction in the proportion of total villous tissue in the
ARED group (43% versus 52%): this was due to a significant reduction
in the volume of tissue occupied by the terminal villi (14.1% versus
18.4%). No significant difference was found in the proportion of
villous tissue occupied by the stem villi (42% versus 40%). Several
studies have investigated the anatomical and/or vasomotor bases of
absent end diastolic flow velocity in the umbilical artery of fetuses
with severe IUGR. Our observations of a significant reduction in the
proportion of villous tissue occupied by the peripheral villi are
consistent with the theory that failure of normal development of the
terminal villous is responsible for the increased vascular resistance
in IUGR pregnancies with ARED.
J Reprod Med 2000 Nov;45(11):923-8
Placental ratio and anemia in third-trimester pregnancy.
Lao TT, Tam KF.
Department of Obstetrics and Gynaecology, Tsan Yuk Hospital,
University of Hong Kong, Hong Kong, People's Republic of China.
OBJECTIVE: To perform a prospective, observational study in a tertiary
center to determine whether anemia (hemoglobin level < 10 g/dL)
developing in the third trimester was associated with an increased
placental weight/birth weight ratio (placental ratio) and whether the
placental ratio correlated with the hemoglobin level at different
periods and with other factors, such as gestational age and parity.
STUDY DESIGN: A total of 476 nonanemic women with low-risk singleton
pregnancies were recruited at their 28-30-week antenatal visit over a
three-month period. Excluded from the final analysis were 20 women who
delivered elsewhere and 19 found to be carriers of thalassemia traits
due to their low mean cell volume. All women received standard
obstetric care, and ferrous sulphate was prescribed for those who
developed anemia. RESULTS: Anemia developed in 45 (10.3%) of the
remaining 437 women. This group had significantly decreased red cell
indices, gestational age (38.3 +/- 2.0 vs. 39.2 +/- 1.3 weeks, P =
.004) and birth weight (3,082 +/- 416 vs. 3,220 +/- 411 g, P = .035)
but no difference in placental weight (609 +/- 102 vs. 594 +/- 108 g),
so the placental ratio was increased as compared with that in the
control group (0.196 +/- 0.026 vs. 0.185 +/- 0.026, P = .002).
Multiple regression analysis confirmed that the placental ratio
correlated only with the last hemoglobin level (P = .041). CONCLUSION:
Our results indicate that placental size increased relative to infant
size in pregnancies complicated by anemia, but whether this phenomenon
reflected actual placental hypertrophy or failure of fetal growth to
keep up with placental growth remains to be determined.
Ultrasound Obstet Gynecol 2002 Oct;20(4):351-5
The influence of maternal hematocrit on placental development from the
first to the second trimesters of pregnancy.
Michailidis GD, Morris RW, Mamopoulos A, Papageorgiou P, Economides
DL.
Fetal Medicine Unit, Department of Obstetrics and Gynaecology, Royal
Free Hospital, Pond Street, London, UK.
OBJECTIVES: To study the influence of maternal hematocrit (Ht) and
hemoglobin (Hb) levels on placental size and growth in the first and
mid-second trimesters of pregnancy. SUBJECTS/METHODS: This was a
prospective study performed at the fetal medicine unit of a university
hospital. One hundred and eighty-one women with a singleton pregnancy
were recruited at 11-14 weeks' gestation. For each case three scans of
the placenta were performed, the first at recruitment and the
following two at 3-week intervals. The volume of the placenta was
measured at each visit using a three-dimensional ultrasound scanner.
The maternal Hb and Ht were measured within 2 weeks of the first scan.
RESULTS: The placental growth during the second trimester was
inversely related to the Ht levels (r = -0.29, P = 0.001). It was also
related to the Hb level (r = -0.20, P = 0.021). An increase of 0.1
units of Ht was associated with 38% less growth of the placenta (95%
confidence interval: 18-54% less growth). DISCUSSION: This study
demonstrates the effects of maternal environment on placental growth.
Our data suggest that the levels of Ht appear to affect the placental
growth during the second trimester. Further studies on the factors
that regulate placental growth are needed to elucidate the
pathophysiology of these interactions and their effect on pregnancy
outcome.
Ultrasound Obstet Gynecol 2001 Aug;18(2):116-20
Three-dimensional sonographic volumetry of the placenta and the fetus
between weeks 15 and 17 of gestation.
Hafner E, Schuchter K, van Leeuwen M, Metzenbauer M, Dillinger-Paller
B, Philipp K.
Ludwig Boltzmann Institute for Clinical Obstetrics and Gynaecology,
Department of Gynecology/Observation, Donauspital am SMZ-Ost,
Langobardenstrasse 122, A-1220 Vienna, Austria.
erich.hafner@smz.magwien.gv.at
OBJECTIVES: Three-dimensional sonographic volume measurement enables
for the first time direct comparison of the increase in size of
different but closely interacting structures like the placenta and
fetus. Our aim was to calculate the fetal and placental volumes
between weeks 15 and 17 of gestation, to monitor the difference in the
increase of the fetal and placental sizes and to determine their
mutual relationship. METHODS: Fetal and placental sonographic volume
measurements were made in 356 singleton pregnancies. To measure the
relationship between fetal and placental volumes, a quotient was
calculated. Regression analyses were performed to analyze the
dependence of the fetal and placental volumes and placental quotient
on the week of gestation and other influencing variables. RESULTS: The
mean of the fetal volume increased markedly from 67.8 to 76.6 mL (by
13%) within the 3 weeks of observation, whereas placental volume
increased only slightly (111.1 to 114 mL (by 2.6%)). The random
variation of placental volumes around the mean in all three
gestational weeks was considerably higher than that of fetal volumes,
indicating that in this early period of gestation there is little
correlation between fetal and placental sizes. Fetal volume correlated
better to gestational week than did placental volume. CONCLUSION: The
quotient of fetal and placental volume might assist in the diagnosis
of high-risk pregnancies and the assessment of a normal or large fetus
with a small placenta.
Obstet Gynecol 2001 Aug;98(2):279-83
Second-trimester placental volume and infant size at birth.
Thame M, Osmond C, Wilks R, Bennett FI, Forrester TE.
Tropical Metabolism Research Unit, Tropical Medicine Research
Institute, The University of the West Indies, Mona, Kingston, Jamaica.
OBJECTIVE: To investigate the ability of second-trimester placental
volume measured sonographically to predict birth size. METHODS: A
total of 712 women were recruited from the antenatal clinic of the
University Hospital of the West Indies; 561 fulfilled the study
criteria and progressed to delivery. Placental volume and fetal
anthropometry (biparietal diameter, head and abdominal circumferences,
and femoral length) were measured sonographically at 14, 17, and 20
weeks. The main outcome measures were infant birth and placental
weights, length, head, chest, and abdominal circumferences at birth.
RESULTS: Placental volume in the second trimester was positively
associated with all birth measurements. Of the fetal measurements at
14 and at 17 weeks, head circumference was the strongest predictor of
birth weight (B [slope of the regression line] =.095, P =.014 at 14
weeks; B =.118, P =.012 at 17 weeks), but at 20 weeks, abdominal
circumference was the strongest. However, at each age, placental
volume was the strongest determinant of birth weight, and improved the
prediction based only on fetal measurements. The odds ratio for low
birth weight (under 2500 g) increased by 1.68 (95% confidence interval
1.05, 2.69, P = 0.03) for every standard deviation decrease in
placental volume at 14 weeks' gestation. CONCLUSION: The present study
suggests that low birth weight was often preceded by small placental
volume in the second trimester. Placental volume may be a more
reliable predictor of size at birth than fetal measurements, and may
be useful in early identification of the fetus at risk in the
perinatal period.
Am J Obstet Gynecol 2000 Feb;182(2):443-8
Low midpregnancy placental volume in rural Indian women: A cause for
low birth weight?
Kinare AS, Natekar AS, Chinchwadkar MC, Yajnik CS, Coyaji KJ, Fall CH,
Howe DT.
King Edward Memorial Hospital and Research Centre, Rasta Peth, Pune,
Maharashtra, India.
OBJECTIVE: We sought to study midpregnancy placental volume in rural
Indian women, its maternal determinants, and its relationship to
neonatal size. STUDY DESIGN: We performed a prospective
community-based study of maternal nutrition and fetal growth in 6
villages near the city of Pune. Measurements included midpregnancy
placental volume determined by means of ultrasonography at 15 to 18
weeks' gestation, maternal anthropometric measurements before and
during pregnancy, and maternal blood pressure and biochemical
parameters during pregnancy. Neonatal size and placental weight were
measured at birth. RESULTS: The mothers were short and underweight
(mean height, 1.52 m; weight, 42 kg; body mass index, 18 kg/m(2)) and
produced small babies (mean birth weight, 2648 g). Midpregnancy
placental volume (median, 144 mL) was related to the mother's
prepregnancy weight (r = 0.15; P <.001) but not to weight gain during
pregnancy, blood pressure, or circulating hemoglobin, ferritin, red
blood cell folate, or glucose concentrations. Midpregnancy placental
volume was related to placental weight at birth (r = 0.29; P <.001)
and birth weight (r = 0.25; P <.001) independent of maternal size.
CONCLUSION: In Indian mothers midpregnancy placental volume is
significantly associated with prepregnant maternal weight and is an
independent predictor of birth weight. Our findings may provide clues
to the high prevalence of low-birth-weight infants in India.
Int J Gynaecol Obstet 2001 Jun;73(3):229-35
Apoptosis in the placenta of pregnancies complicated with IUGR.
Erel CT, Dane B, Calay Z, Kaleli S, Aydinli K.
Department of Obstetrics and Gynecology, Cerrahpasa School of
Medicine, Istanbul University, Istanbul, Turkey.
tamererel@superonline.com
OBJECTIVE: In this study we have investigated the presence of
apoptosis in the placental tissue of pregnancies complicated with
intra-uterine growth restriction (IUGR). METHOD: Placental samples
were obtained from 22 normal third trimester pregnancies and 20
pregnancies complicated with IUGR. The criteria for fetal growth
impairment were clinical evidence of sub-optimal growth,
ultrasonographic demonstration of deviation from normal percentiles of
growth and birth weight under 10th percentile. Terminal
deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick
end labelling (TUNEL) staining was used to demonstrate the apoptotic
cells in all samples. Student-t, Mann-Withney U-test, Fisher exact
test and Spearman correlation were used for statistical analysis.
RESULTS: We detected apoptosis in 10 placentas in the study group vs.
none in the control group. Placentas from pregnancies complicated with
IUGR demonstrated 0.12% (0.1%-0.4%) apoptotic cells. The rate of
apoptotic cells in the placenta was significantly higher in
pregnancies complicated with IUGR than normal uncomplicated pregnancy
(P=0.0019). Apoptosis were more abundant in the trophoblasts,
especially cytotrophoblasts, in the placenta. We could not find a
correlation between the apoptosis in the placenta of pregnancies
complicated with IUGR and birth weight, multi-parity, gestational age,
birth weight percentile and mode of delivery (C/S vs. vaginal
delivery). CONCLUSION: We believe that the increased number of
apoptosis in the placenta of pregnancies complicated with IUGR may
have an important compensatory role to transmit nutrition and gas
exchange easily to the fetus.
Cent Afr J Med 1992 Oct;38(10):414-20
Correlations between weights of newborn babies, placental parameters
and gestational age.
Mapfurira MJ, Msamati BC, Banadda BM.
Department of Anatomy, UZ School of Medicine, Mount Pleasant, Harare,
Zimbabwe.
The relationships between foetal weights, placental parameters and
gestational ages were studied in 200 placentae. In addition to
confirming that foetal weight, placental weight and gestational age
correlated, the results showed that baby weight, placental weight,
placental surface area correlate to the length of cord and that the
length of cord correlates to gestational age (p < 0.05). These
correlations are reported for the first time and are difficult to
explain. It is recommended to establish birthweight standards in order
to assess intra-uterine growth retardation, and to re-examine the
correlations reported here through prospective studies as they might
be relevant clinically and provide important clues on morbidity
prospects of an individual during postnatal life.
Eur J Obstet Gynecol Reprod Biol 1991 Jul 25;40(3):179-90
Placental morphology in relation to umbilical artery blood velocity
waveforms.
Nordenvall M, Ullberg U, Laurin J, Lingman G, Sandstedt B, Ulmsten U.
Department of Obstetrics & Gynecology, Karolinska Institute, Danderyd
Hospital, Sweden.
The association between umbilical artery flow velocity waveforms,
placental morphology and arterial vascular pattern was investigated in
30 pregnant women at risk for intra-uterine growth retardation. The
blood velocity waveform was assessed in the umbilical arteries with
pulsed Doppler ultrasound. Placentas from fetuses with an
end-diastolic zero flow were small and thick with an extrachorial
configuration, marginal cord insertion, magistral or mixed
allantochorial vessel pattern and few cotyledons. The incidence and
the extension of gross lesions were slightly increased in these
placentas compared to placentas from fetuses with a normal S/D ratio
(peak systolic velocity/minimum diastolic velocity). Placentas from
fetuses with an increased S/D ratio (greater than +2SD) were large and
thin with a high maximum diameter/maximum thickness ratio. Heavily
smoking mothers were overrepresented in the group, with an increased
S/D ratio and corresponding SGA infants. End-diastolic zero flow in
the umbilical artery was strongly correlated with placental
developmental abnormalities.
Eur J Obstet Gynecol Reprod Biol 1989 Jun;31(3):213-9
Feto-placental haemodynamics in growth retardation: a pulsed Doppler
study.
Bogatti P, Veglio PC, Rustia D, Mandruzzato GP.
Department of Obstetrics and Gynaecology, Istituto per l'Infanzia,
Trieste, Italy.
69 singleton pregnancies, with a diagnosis of intra-uterine growth
retardation (IUGR) at ultrasound, were followed until delivery by
pulsed Doppler evaluations in fetal thoracic descending aorta (DA) and
umbilical artery (UA). Three haemodynamic groups were described
according to flow characteristics expressed as the pulsatility index
(PI) of the vessel under study. In each group the relative incidence
of fetal distress, diagnosed according to CTG monitoring, was
evaluated. Fetal distress occurred in 75% of the cases with a raised
PI both in DA and UA, in 40% of the cases with a raised PI only in DA
and in 21% of the cases with 'normal' PI values in both vessels. It
can be said that Doppler flow measurements can be useful in defining
the actual haemodynamic situation of the fetus with possible
clarifications concerning its 'stressed' or 'distressed' condition and
residual capacities to substain hypoxia.
Am J Obstet Gynecol 1994 Jan;170(1 Pt 1):130-7
Ultrasonographic investigation of placental morphologic
characteristics and size during the second trimester of pregnancy.
Jauniaux E, Ramsay B, Campbell S.
Department of Obstetrics and Gynecology, King's College School of
Medicine and Dentistry, University of London, United Kingdom.
OBJECTIVE: The aim of the study was to establish the incidence of
abnormal placental ultrasonographic findings in an unselected
obstetric population and determine the usefulness of simple
measurements of placental size. In addition, the relationship between
these findings, uterine artery Doppler measurements, maternal serum
alpha-fetoprotein levels, and subsequent pregnancy outcome was
explored. STUDY DESIGN: A prospective, cross-sectional study of 210
women recruited at the time of routine ultrasonographic scan between
16 and 28 weeks' gestation was performed. Placental ultrasonographic
investigations included measurements of thickness, circumference, and
volume and morphologic studies. Uterine Doppler and maternal serum
alpha-fetoprotein measurements were performed at the same time.
RESULTS: At delivery 25 fetuses were small for gestational age, in
association with hypertension in 11; 14 were delivered prematurely but
were appropriately grown, and three were macrosomic. Significant
correlations were found in uncomplicated pregnancies (n = 168) between
gestational age and placental thickness, circumference, and volume and
also between fetal abdominal and placental circumferences. Large
sonolucent lakes were found with a similar incidence in both
complicated and uncomplicated pregnancies. Jelly-like placental
appearance was seen in 12 of the 17 cases complicated by hypertension,
11 of which also had abnormal uterine Doppler features and elevated
maternal serum alpha-fetoprotein levels. CONCLUSIONS: This study shows
an association between abnormal placental development,
ultrasonographic appearances, and subsequent abnormal fetal growth or
hypertensive disorders of pregnancy. The interrelationships
demonstrated between the different techniques suggest that a
combination of placental thickness and morphologic characteristics,
uterine Doppler analysis, and evaluation of maternal serum
alpha-fetoprotein level may allow more efficient screening for these
complications than is currently possible using any single method.
J Perinat Med 1994;22 Suppl 1:9-17
The effect of early maternal maladaptation on fetal growth.
Peeters LL.
Department of Obstetrics and Gynecology, University of Limburg,
Medical Faculty, Maastricht, The Netherlands.
IUGR can develop, either in response to a reduced IGP or in response
to a deficient transplacental supply of O2 and nutrients.
Particularly, insight in the pathogenesis of extrinsic IUGR is
important for the clinician to offer him tools for a more causal
treatment. Extrinsic IUGR is usually preceded by a gradually
developing uteroplacental insufficiency. Uteroplacental hypoperfusion
may represent the common starting point for extrinsic IUGR and
maternal systemic symptomatology (PIH, (pre)eclampsia). In addition,
it may be the common endpoint of two different (subclinical) pathways:
defective trophoblast differentiation ("primary") and decompensation
of early-pregnancy circulatory maladaptation ("secondary"). From a
theoretical point of view, the primary pathway may develop at a slower
rate. Therefore, the primary pathway is more likely to result in
extrinsic IUGR. In contrast, the secondary pathway assumes
decompensation of an initially maladapted maternal circulation. This
implies a highly variable rate of development and with it, severity of
clinical symptomatology. It also indicates that the the pathogenesis,
eventually leading to manifest vascular disease, is superimposed on a
pre-existent inadequacy in maternal hemodynamics, renal function
and/or volume homeostasis. It is understood that intertwining of these
two pathways is common. Unfortunately, our current knowledge, about
placentation and the concomitant early-pregnancy adjustments is poor.
Current research of trophoblast differentiation and of the concomitant
maternal end-organ effects in normal and pathologic pregnancy, is
likely to increase our understanding of the first-trimester phenomena
preceding IUGR soon.
Clin Exp Pharmacol Physiol Suppl 1995 Dec;22(1):S286-7
Studies on pregnancy hypertension and IUGR-SFD: effects of drugs on
the blood vessels in the placenta of pregnant SHRSP.
Fuchi I, Noda K, Matsubara Y.
Department of Obstetrics and Gynecology, Kinki University School of
Medicine, Osaka-Sayama, Japan.
1. Based upon our previous work, we came to the conclusion that a
decrease in placental blood volume was a possible factor behind
intrauterine growth retardation (IUGR) in pregnancy-induced
hypertension. 2. In a second study, we used an image analysis system
to measure cross-sectional areas and wall thicknesses of central blood
vessels of the spiral artery, the so-called 'central artery'. 3. It
was thought that one of the more basic factors behind IUGR in
pregnancy-induced hypertension might possibly be narrowings and spasms
of the maternal placental blood vessels. 4. In this study, we found
that the three drugs we used (MgSO4 center dot 7H2O, Solcoseryl and
KCl) all resulted in an enlargement of the cross-sectional areas of
the maternal blood vessels, and that MgSO4 center dot 7H2O, in
particular, also relaxed maternal blood vessel spasms in SHRSP
placenta.
Some of these articles can be obtained online through subscription,
while all could be had at the public library through interlibrary
loan.
hlabadie-ga
