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PubMed2005

SNAT4 isoform of system A amino acid transporter is expressed in human placenta.

The system A amino acid transporter is encoded by three members of the Slc38 gene family, giving rise to three subtypes: Na+-coupled neutral amino acid transporter (SNAT)1, SNAT2, and SNAT4. SNAT2 is expressed ubiquitously in mammalian tissues; SNAT1 is predominantly expressed in heart, brain, and placenta; and SNAT4 is reported to be expressed solely by the liver. In the placenta, system A has an essential role in the supply of neutral amino acids needed for fetal growth. In the present study, we examined expression and localization of SNAT1, SNAT2, and SNAT4 in human placenta during gestation. Real-time quantitative PCR was used to examine steady-state levels of system A subtype mRNA in early (6-10 wk) and late (10-13 wk) first-trimester and full-term (38-40 wk) placentas. We detected mRNA for all three isoforms from early gestation onward. There were no differences in SNAT1 and SNAT2 mRNA expression with gestation. However, SNAT4 mRNA expression was significantly higher early in the first trimester compared with the full-term placenta (P < 0.01). We next investigated SNAT4 protein expression in human placenta. In contrast to the observation for gene expression, Western blot analysis revealed that SNAT4 protein expression was significantly higher at term compared with the first trimester (P < 0.05). Immunohistochemistry and Western blot analysis showed that SNAT4 is localized to the microvillous and basal plasma membranes of the syncytiotrophoblast, suggesting a role for this isoform of system A in amino acid transport across the placenta. This study therefore provides the first evidence of SNAT4 mRNA and protein expression in the human placenta, both at the first trimester and at full term.

Amino Acid Transport System A↗
PubMed2005

P-glycoprotein and breast cancer resistance protein expression in human placentae of various gestational ages.

Placental efflux transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) protect the developing fetus from exposure to potentially toxic xenobiotics. However, little is known about the expression of these transporters in human placentae of different gestational ages. Therefore, we quantified the expression of P-gp and BCRP in human placentae of different gestational ages. We also measured the expression of various nuclear regulatory factors such as the pregnane xenobiotic factor to determine whether their expression also changes with gestational age. Syncitial microvillous plasma membranes were isolated from human placentae of various gestational ages (60-90 days, 90-120 days, and full-term C-section placentae). P-gp and BCRP expression (protein) in these preparations were measured by Western blot analysis followed by an ELISA. Expression (mRNA) of P-gp, BCRP, and nuclear regulatory factors in the placentae were quantified by quantitative real-time PCR. P-gp expression (relative to that of alkaline phosphatase) was significantly (P < 0.05) higher (44.8-fold as protein; 6.5-fold as mRNA) in early gestational age human placentae (60-90 days) vs. term placentae. In contrast, BCRP (protein and mRNA) and nuclear regulatory factors (mRNA) expression in placental tissue did not change significantly with gestational age. However, placental expression of P-gp and human chorionic gonadotropin-beta (hCG-beta) transcripts was highly correlated (r = 0.73; P < 0.0001; Spearman rank correlation). Expression of P-gp, but not BCRP, decreases dramatically with gestational age in human placentae. This decrease in P-gp expression is not caused by a change in expression of nuclear receptor transcripts but appears to be related to hCG-beta expression. The placental P-gp expression appears to be upregulated in early pregnancy to protect the fetus from xenobiotic toxicity at a time when it is most vulnerable to such toxicity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Relation between birth weight and placenta weight.

With the goal to establish a model that relates birth weight to placenta weight, adjusted for the most documented predictors of birth weight, 300 live newborns were studied, all were products of single gestation. Inclusion criteria were newborns with gestational age of 37 weeks or older according to the date of last menstruation, whose mothers did not have diabetes mellitus, high blood pressure, pre-eclampsia, or eclampsia. The weight of the newborn was identified from the anthropometry data collected by previously trained nursing personnel in each of the participating hospitals. Immediately after delivery, the placenta was weighed. Multiple linear regression was used to see the effect of placenta weight and each variable on birth weight. The mean of birth weight was 3,369 g with a standard deviation (SD) of 445 g. Placenta weight had a mean of 537 g (SD: 96 g). The relation between the weight of the placenta and the birth weight was significant, and we found that for each gram increase in placenta weight, birth weight is increased by 1.98 g (SE = 0.25, p < 0.01) and this relation is not linear, since the quadratic term is significant. Placenta weight has a nonlinear relation to the birth weight and is an important predictor of birth weight. Together with the gestational age and the maternal age and size, it explains 32% of the variability of birth weight. Placenta weight can be a 'sentinel' indicator of nutritional and/or environmental problems.

Adult↗
PubMed1989

Placenta previa and antepartum hemorrhage after previous cesarean section.

A prospective study was conducted to determine the risk of placenta previa and unexplained antepartum hemorrhage after a previous cesarean section (CS). Of a total of 24,644 patients, 81 (0.33%) had a placenta previa which demanded abdominal delivery. The risk of placenta previa was 0.25% with an unscarred uterus and 1.22% in patients with one or more previous CS (the difference was statistically significant p less than 0.001). The corresponding figures for unexplained antepartum hemorrhage were 0.40% and 3.81%, respectively (p less than 0.001). Patients presenting with a placenta previa and a scarred uterus had a 16% risk of undergoing cesarean hysterectomy because of placenta accreta and severe hemorrhage compared to 3.6% in patients with placenta previa and an unscarred uterus. In conclusion, cesarean deliveries predispose to placenta previa, placenta accreta and antepartum hemorrhage during subsequent pregnancies. This relationship has to be considered in the cost-benefit equation for decision of route of delivery.

Cesarean Section↗
PubMed1985

Thyrotropin-releasing hormone metabolism and extraction by the perfused guinea pig placenta.

This report describes the extraction of synthetic TRH and its metabolic conversion in the perfused guinea pig placenta. These studies were performed to obtain an estimate of fractional fetal TRH losses through the placenta and to determine if some of these losses are due to TRH metabolism. The in situ guinea pig placenta was perfused through an umbilical artery for 90 min, and placental effluent fractions were collected at timed intervals from the umbilical vein. Experiments were performed in which the perfusion buffer contained 0.01, 1, and 10 micrograms/ml or no synthetic TRH. Synthetic TRH was always perfused in the presence of 3H2O. In experiments in which TRH was perfused, the perfusion reservoir contents and placental effluent fractions were counted for 3H, and TRH and deamido-TRH were determined by RIA. Similarly, cyclo(His-Pro) was measured when 10 micrograms/ml TRH were perfused. When no TRH was perfused, the perfusion reservoir and placental effluent contents were processed to determine their content of TRH immunoreactivity. When synthetic TRH was perfused, steady state TRH concentrations were achieved in placental effluent fractions by 20-30 min. The single pass extraction of TRH by the placenta was 11.4 +/- 2.6% (mean +/- SE) compared to 56.9 +/- 7.0% for 3H2O (P less than 0.001). No significant difference was detected regardless of whether 10, 1, or 0.01 micrograms/ml TRH were perfused. A portion of the TRH that perfused the placenta was converted to deamido-TRH at all concentrations of perfused TRH. No conversion of TRH to cyclo(His-Pro) was noted when the highest concentration (10 micrograms/ml) of TRH was perfused. The conversion of TRH to TRH-OH was 4.2 +/- 0.7% in a single pass. When the perfusion buffer was devoid of synthetic TRH, a small but significant increase in the content of TRH immunoreactivity was noted in the placental effluent compared to that in the perfusion reservoir. This was not large enough to affect calculations of the placental extraction of TRH. These studies, in addition to demonstrating that the placenta contains TRH deamidase activity, suggest that losses of fetal TRH through the placenta are not large. They do not support the current impression, based on the fetal TSH response to maternal TSH administration, that the placenta is freely permeable to TRH.

Animals↗
PubMed1995

Expression of pit-1 messenger ribonucleic acid and protein in the human placenta.

It is well established that the human placenta produces a wide range of hormones similar to those secreted by the pituitary and hypothalamus. However, the physiological role and regulation of placental hormone synthesis and release are still largely unknown. GH (GH-N) is expressed in the pituitary, where it requires the tissue-specific transcription factor Pit-1. Chorionic somatomammotropin A (CS-A) and CS-B as well as the placental GH variant (GH-V), which also belong to the GH gene family and are located in the same chromosomal cluster, are expressed in the placental syncytiotrophoblast. The presence of Pit-1-binding sites in the CS-A and GH-V promoter regions predicts that Pit-1 may be expressed in the placenta. However, this has not yet been demonstrated. To examine possible similarities in the regulation of these genes in the pituitary and placenta, we studied the expression of pit-1 messenger ribonucleic acid (mRNA) in the human placenta, transformed human placental cells, and the JEG-3 choriocarcinoma cell line. Polymerase chain reaction (PCR) products of the expected size were amplified from first and third trimester placentas, transformed placental cells, and JEG-3 complementary DNA by reverse transcription-PCR. The pit-1-specific sequence was confirmed by restriction endonuclease digestion, Southern hybridization, and DNA sequencing. Human pituitary tissue was used as a positive control; no PCR product was obtained from hippocampus (negative control). In situ hybridization of placental tissue sections revealed the presence of pit-1 mRNA in first and third trimester syncytiotrophoblast. Pit-1 protein was localized by immunohistochemistry with the same tissue distribution and a nuclear localization pattern. These data demonstrate expression of pit-1 mRNA and Pit-1 protein in the human placenta, thus questioning its role as a pituitary-specific regulator of GH-N gene transcription. The expression of Pit-1 in the placenta, together with its previously demonstrated capability to bind to and activate the CS-A and the GH-V promoters, suggests that it may play a role in the regulation of hormones belonging to the GH gene family in both pituitary and placenta.

Base Sequence↗
PubMed2003

Mouse placenta is a major hematopoietic organ.

Placenta and yolk sac from 8- to 17-day-old (E8-E17) mouse embryos/fetuses were investigated for the presence of in vitro clonogenic progenitors. At E8-E9, the embryonic body from the umbilicus caudalwards was also analysed. Fetal liver was analysed beginning on E10. At E8, between five and nine somite pairs (sp), placenta, yolk sac and embryonic body yielded no progenitors. The first progenitors appeared at E8.5 at the stage of 15 sp in the yolk sac, 18 sp in the embryonic body, 20 sp in the placenta and only at E12 in the fetal liver (absent at E10, at E11 not determined). Progenitors with a high proliferation potential that could be replated for two months, as well as the whole range of myeloid progenitors, were found at all stages in all organs. However, the earliest of these progenitors (these yielding large, multilineage colonies) were 2-4 times more frequent in the placenta than in the yolk sac or fetal liver. In the fetal liver, late progenitors were more frequent and the cellularity increased steeply with developmental age. Thus, the fetal liver, which is a recognized site for amplification and commitment, has a very different hematopoietic developmental profile from placenta or yolk sac. Placentas were obtained from GFP transgenic embryos in which only the embryonic contribution expressed the transgene. 80% of the colonies derived from these placental cells were GFP+, and so originated from the fetal component of the placenta. These data point to the placenta as a major hematopoietic organ that is active during most of pregnancy.

Animals↗
PubMed2006

Listeria monocytogenes traffics from maternal organs to the placenta and back.

Infection with Listeria monocytogenes is a significant health problem during pregnancy. This study evaluates the role of trafficking between maternal organs and placenta in a pregnant guinea pig model of listeriosis. After intravenous inoculation of guinea pigs, the initial ratio of bacteria in maternal organs to placenta was 10(3)-10(4):1. Rapid increase of bacteria in the placenta changed the ratio to 1:1 after 24 h. Utilizing two wild-type strains, differentially marked by their susceptibility to erythromycin, we found that only a single bacterium was necessary to cause placental infection, and that L. monocytogenes trafficked from maternal organs to the placenta in small numbers. Surprisingly, bacteria trafficked in large numbers from the placenta to maternal organs. Bacterial growth, clearance, and transport between organs were simulated with a mathematical model showing that the rate of bacterial clearance relative to the rate of bacterial replication in the placenta was sufficient to explain the difference in the course of listeriosis in pregnant versus nonpregnant animals. These results provide the basis for a new model where the placenta is relatively protected from infection. Once colonized, the placenta becomes a nidus of infection resulting in massive reseeding of maternal organs, where L. monocytogenes cannot be cleared until trafficking is interrupted by expulsion of the infected placental tissues.

Animals↗
PubMed1997

Divergent deiodination of thyroid hormones in the separated parts of the fetal and maternal placenta in pigs.

Previous work from this laboratory has shown that the thyroid gland of the fetal pig begins to function at about day 46-47 (0.40-0.415 fraction of gestational age). Sera from fetuses contain lower thyroxine (T4), 3,3',5-triiodothyronine (T3) and 3,3',5'-triiodothyronine (rT3) concentrations than maternal sera, except for about 2 weeks before term. The fetal T4 metabolism is dominated by the 5'-monodeiodinating activity (5'-MD). In the present study we measured the iodothyronines content, and the outer (5'-MD) and inner (5-MD) monodeiodinases activity, in homogenates of the placenta. The pig placenta, which is of the epitheliochorial type, was separated into the fetal and the maternal part. The concentrations of T4, T3 and rT3 were lower, and the deiodinating activity of 5'-MD and 5-MD higher, in the fetal than in the maternal placenta. The fetal placenta not only deiodinated more actively T4 to T3 and T4 to rT3, but degraded T3 to 3,3'-diiodothyronine (3,3'-T2) more actively than rT3 to 3,3'-T2. Such divergent deiodinating activity of T4 to T3, T3 to 3,3'-T2 and rT3 to 3,3'-T2 might favor establishing a relatively high and constant rT3 concentrations in fetal and maternal placentas, and a lower T3 in the fetal placenta. The inner ring deiodinating activity (excluding a day before parturition) was always more active in the fetal placenta, while the outer ring deiodinations varied in this respect, depending on the gestation stage. These results support the hypothesis that in the fetal pig, enzymatic deiodination of thyroid hormones forms a barrier which reduces transplacental passage of the hormones and that the fetal part of the placenta is the primary factor in the mechanism regulating the hormonal transfer. In spite of the presence of the barrier, there is an adequate maternal supply of thyroid hormones to the fetus in early gestation, which suggests that the enzymatic mechanism is influenced in some way by the thyroid status of the fetus.

Animals↗
PubMed2006

Stereological analysis of mature human placenta of pregnant women of different age.

The normal placentas, regular pregnancies and deliveries were structurally examined. The aim of this research was to compare the results and to confirm if there were some difference in the structure of placenta related to the age of pregnant women. We examined 30 human placentas. The examined group of women were divided into two groups: 1) pregnant women 20-35 years old; 2) pregnant women over 35 years old. The stereological method was used. The volume density, absolute volume, the surface density and absolute surface of terminal villi of placentas in younger and older pregnant women were not significantly different. The volume density, absolute volume, the surface density and absolute surface of the other placentas villi in younger pregnant women compared to older ones, were significantly increased (p<0.001). The volume density of fibrinoid of placentas in older pregnant women compared to younger ones was significantly increased (p<0.02). The surface density, absolute volume and absolute surface of fibrinoid in these two examined groups of pregnant women were not significantly different. The volume density of intervillous space of placentas in older pregnant women compared to younger ones was significantly increased (p<0.05). Absolute volumes of intervillous space of placentas in these two examined groups of pregnant women are not significantly different.

Adult↗
PubMed1991

Fatty acid metabolism by the porcine placenta.

Two experiments were performed to determine whether esterification is a major pathway of fatty acid utilization within porcine placenta and to determine what metabolic parameters may limit fatty acid transfer to the fetal pig. Maternal (endometrium) and fetal (chorioallantois) placenta were obtained by Caesarean section at d 110 of gestation in both experiments. Eight gilts were used in the first experiment. Tissue sections were incubated with palmitate at concentrations ranging from .25 to 2.0 mM. Maternal placenta metabolized palmitate at a higher rate than fetal placenta, although fetal placenta was more efficient in esterifying palmitate. Esterification composed the majority of palmitate utilization within fetal and maternal placenta. The second experiment evaluated the effect of dietary lipid on placental fatty acid metabolism and evaluated the ability of placenta to mobilize lipids. Fourteen gilts were divided into two groups of seven and fed a diet containing 15% tallow diet or a diet not supplemented with tallow (control) from d 90 to 110 of gestation. Dietary lipid had no detectable effects on lipoprotein lipase activity, [14C]palmitate metabolism, or lipolysis by the maternal or fetal placenta. Lipolytic activity of placental tissues was minimally affected by incubation with various proposed lipolytic activity of placental tissues was minimally affected by incubation with various proposed lipolytic agents. The data indicate that supply of fatty acids to the fetal pig may be limited by transfer of plasma fatty acids into the cytoplasm of placental cells or by regulatory enzymes for intermediate esterification; both types of limitations have been proposed to be influenced by fatty-acid binding proteins.

Animals↗
PubMed1995

Placenta previa, maternal smoking and recurrence risk.

In order to assess the risk of placenta previa among women who smoked during pregnancy and to study the recurrence risk of placenta previa, we analyzed data from the Swedish Medical Birth Registry. Among 1,825,998 infants of women delivered in 1973-1990, 5,683 had placenta previa registered. The overall incidence of placenta previa was 0.3%, the incidence in twin deliveries was also 0.3%. The recurrence rate of placenta previa was 2.4%, which is an eightfold increase compared with the rate of a placenta previa among all births. Maternal smoking was studied for births in 1983-1990 and appeared as an independent risk factor for placenta previa. A dose-response between the number of cigarettes smoked during pregnancy and the risk of having a placenta previa was indicated.

Adult↗
PubMed2000

Clinical significance of placenta previa detected at early routine transvaginal scan.

Transvaginal ultrasonography in early pregnancy was used to determine the prevalence of placenta previa and the rate of persistence until delivery. The location of the placenta was registered systematically in 2342 pregnant women who underwent transvaginal ultrasonography at 10 to 16 weeks' gestation as a primary examination. The outcome of pregnancy as well as the presence or absence of placenta previa at delivery was noted in a total of 2158 cases. A receiver operating characteristic curve was generated for the different measurements from the edge of the placenta to the internal cervical os versus placenta previa at delivery. In 105 of the 2158 women screened in the early stages of pregnancy (4.9%) the placenta extended to or over the internal cervical os, and in 34 of 2158 patients (1.6%) the distance to the placental edge beyond the internal cervical os was equal to or greater than 14 mm. Of the eight cases of placenta previa at delivery, six (75%) were identified in our study, and two cases were missed. When a cutoff value of greater than 14 mm is used for the receiver operating characteristic curve the likelihood is 17.6% (95% confidence interval = 6.8 to 34.5) for placenta previa at delivery. Although a high percentage of false-positive results occur owing to the low prevalence at delivery, this screening procedure can identify high-risk patients who should be rescanned later in pregnancy.

Adolescent↗
PubMed1998

[Lipid and protein peroxidation process and catalase activity in pre-eclamptic placenta].

There are some suggestions that free radicals are involved in some dysfunctions observed in preeclampsia. In this study we have examined the antioxidant status of preeclamptic placentas. We have used placentas obtained from normal pregnant women and women with preeclampsia. Lipoperoxidative process was measured by means of Okhawa method. Sedlak method was used to measured the total thiol groups. The catalase activity was measured by means of Pffeifer method. The results show that the catalase activity decreases, the amount of MDA increases and the total amount of thiol groups is smaller in preeclamptic placentas. The level of lipid peroxides in preeclamptic placentas is about 1.8 times higher in comparison with normal placentas. The decreased level of total thiol groups in preeclamptic placentas can be caused by a more intensive process of protein peroxidation. Catalase is less active in preeclamptic placentas. It can be due to lower activity of antioxidant systems or the destruction of antioxidant systems by reactive oxygen species. The results of our experiments confirm lower antioxidant status in preeclamptic placentas and suggest that peroxidative reaction may cause many dysfunctions associated with preeclampsia.

Catalase↗
PubMed2000

Abruptio placentae after auto accidents. A case-control study.

OBJECTIVE: To compare accident and injury characteristics in pregnant women with and without abruptio placentae involved in auto accidents (AAs). STUDY DESIGN: A retrospective, case-control study involving 12 pregnant women (16-39 weeks) with a diagnosis of abruptio placentae after AAs and 12 control subjects matched for gestational age (+/- 2 weeks) involved in AAs without abruptio placentae from 1988 through 1997. Numerous variables were compared, including restraint system use, estimated speed of the collision, injury severity score (ISS), clinical findings and patient position in the vehicle. Patient complaints and physical examination on admission were also recorded, and obstetric and neonatal outcomes were compared. Statistical analysis was performed using the independent sample t, Mann-Whitney and Fisher's exact tests, when appropriate. RESULTS: There was no significant difference in the frequency of unrestrained subjects or position in the vehicle between cases and controls. Estimated speed of the vehicle at the time of collision was significantly higher in the abruptio placentae group (> 30 mph, 92% vs. 50%, P = .03), as was the mean ISS code (20 [SD 12.71] vs. 4 [SD 5.13], P < .001). Abdominal pain and vaginal bleeding were seen more frequently in women with abruptio placentae as compared to controls (58% vs. 25% and 33% vs. 0, respectively). Patients with abruptio placentae had a higher incidence of preterm delivery (mean gestational age at delivery = 29 weeks [SD 7.99] vs. 36 weeks [SD 7.21], P = .008) and stillbirth (57% vs. 0%, P = .002) and lower mean birth weight (1,924 g [SD 931] vs. 3,069 g [SD 450], P = .003). There was no significant difference in cesarean section rates between the groups (58% vs. 30%, P = .23). There was no difference in the two groups in placental location on ultrasonography. CONCLUSION: Pregnant women who were involved in severe accidents (i.e., higher speed or ISS) were more likely to suffer abruptio placentae. In severe accidents, proper restraints were frequently not used. Because of the severity of these accidents, current restraint systems may not be sufficient to prevent abruptio placentae even with proper restraint use. Efforts toward designing new restraint systems for pregnant women should be encouraged.

Abruptio Placentae↗
PubMed2000

[Changes of selenium concentration in blood and placenta in intrahepatic cholestasis of pregnancy].

OBJECTIVE: To explore the effect of deficiency of blood selenium and placental selenium on the damage of histomorphology of the placentas in ICP. METHODS: We measured the selenium concentration by a catalytic polorographic method in blood and placenta and glutathione peroxidase (GSH-Px) activity by a 5,5'-dithionbis (2-nitrobenzoic acid) direct method in blood in 30 women with ICP (ICP group) and 30 normal pregnant women (control group). Furthermore, the features of the placentas (10 from control group and 10 from ICP group) pathologic changes were observed microscopically. RESULTS: (1) The selenium concentrations in blood (0.0389 +/- 0.0090) mg/L and placenta (0.3770 +/- 0.0964) mg/kg and the activity of GSH-Px (59.31 +/- 11.42) U in ICP group were found to be significantly lower than those in blood (0.0477 +/- 0.0094) mg/L and placenta (0.4554 +/- 0.0626) mg/kg and the activity of GSH-Px (68.48 +/- 10.47) U in control group, respectively (P < 0.002). (2) The activity of GSH-Px had a significant positive correlation with selenium concentration in blood in ICP group (r = 0.05498, P < 0.001) and in control group (r = 0.06234, P < 0.001). There was a positive correlation between blood and placental selenium concentrations in ICP group (r = 0.6473, P < 0.001). On the other hand, there was not correlation in women with normal pregnancies. (3) Placentas obtained from women with ICP had swelling and fibrinoid necrosis of villi, increasing number of syncytial sprouts, thickening of vasculo-syncytial membrane (VSM) and decreasing size of the intervillous space under light microscopy. Placentas from control group did not show the pathologic changes as mentioned above. CONCLUSIONS: As selenium constitutes the active part of GSH-Px, these results suggest that the placental selenium deficiency may lead to reduced placental GSH-Px activity and the antioxidative defence may have been defective which may be associated with the damage of histomorphology of the placentas in ICP.

Adult↗
PubMed2002

Spiral artery of placenta: development and pathology-immunohistochemical, microscopical, and electron-microscopic study.

The spiral artery (=SA) is an important muscular artery, which controls the blood volume to the placenta. Preeclampsia is thought to be induced by the failure of the placenta by dysfunction of SA. To clarify the function of SA, we examined forty-eight placentae and its morphological and biological characteristics: 36 normal placentae and 12 placentae with preeclampsia. Gestational age of normal placentas was between 19 and 40 weeks and placentae with preeclampsia was between 31-36 weeks. The wall of the placental segment of SA by both light and electron microscope, and the wall width of SA and gestation age were compared each other. The wall of SA, with the invasion of trophoblast, was thin, but SA without trophoblasts was thick in width. At normal placenta, the diameter of SA was dilative constantly, but the width of the wall showed a tendency of getting thinning as advances. Ultrastructually, we found the trophoblast of thin wall of SA with dilated lumen. These ultrastructual alternations were consistence with the light microscopical findings. In preeclampsia, the lumen of SA between normal pregnancy and one with preeclampsia was almost same, but the wall width was thick, compared with normal pregnancy (P<0.05). We concluded that trophoblastic invasion control the functions of SA.

Arteries↗
PubMed2003

Risk factors of placenta accreta in Ile-Ife, Nigeria.

Our objective was to identify the independent risk factors of placenta accreta. The hospital records of 44 pregnancies complicated by placenta accreta, and 1371 controls over a 10-year period were reviewed. Univariate analysis was followed by multivariate logistic regression analyses with adjustment for potentially confounding variables to determine the statistically significant independent predictors of placenta accreta (p <.05). The following factors were associated with placenta accreta: maternal age of at least 35 years (P =.004), gravidity = 5 (P =.004), placenta praevia (P <.001), previous uterine curettage (P =.006) and previous caesarean delivery (P =.014). However, when examined with a multivariate model, only placenta praevia (Odds Ratio [OR] 49.3; 95% confidence interval [95% CI] 13.1, 119.0) and maternal age = 35 (OR 2.7; 95% CI 1.3, 7.9) reached a significant association. Independent risk factors of placenta accreta include placenta praevia and maternal age 35 and over.

Female↗