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PubMed1985

Effects of placenta and maternal serum on prolactin secretion in vitro.

The effects of the placenta and maternal sera on the secretion of prolactin (Prl) were examined in vitro. Placentae were obtained on each of Days 8-11 of pregnancy and extracted in 2.0% butanol-saline. To determine if these extracts could inhibit Prl secretion in vitro, dispersed anterior pituitary cells were incubated with placental extracts containing 1.0 placental equivalent obtained on each of Days 8-11 of pregnancy. Prl secretion was not affected by extracts of placentae obtained on Day 8 but was significantly inhibited by placental extracts obtained on Days 9-11 of pregnancy. In fact, progressively more mature placentae induced greater degrees of Prl inhibition. Extracts of placentae that were obtained on each of Days 8-11 of pregnancy, normalized on the basis of protein and tested for a 24-h period in the dispersed pituitary bioassay, caused the same degree of inhibition over Prl release. Additionally, placental protein from any given day (Days 8-11) of pregnancy induced a highly significant dose-dependent inhibition over Prl secretion. Equivalent amounts of a nonspecific protein, bovine serum albumin, had no effect. These findings indicate that the placenta does indeed contain a Prl inhibitory factor whose specific activity remains relatively constant between Days 8 and 11 of pregnancy. To determine if the inhibitory activity is humoral, maternal sera collected on each of Days 8-11 of pregnancy were placed in culture with dispersed pituitary cells at a concentration of 15.0%. Concomitant with gestational maturity, there was a progressively greater inhibition of Prl release. These findings indicate that the placenta may secrete a substance into the blood which suppresses Prl release directly at the level of the pituitary gland.

Animals↗
PubMed2004

Conservative versus extirpative management in cases of placenta accreta.

OBJECTIVE: To compare the impact of conservative and extirpative strategies for placenta accreta on maternal morbidity and mortality. METHODS: We retrospectively reviewed the medical records of all patients diagnosed with placenta accreta admitted to our tertiary center from January 1993 through December 2002. Two consecutive periods, A and B, were compared. During period A (January 1993 to June 1997), our written protocol called for the systematic manual removal of the placenta, to leave the uterine cavity empty. In period B (July 1997 to December 2002), we changed our policy by leaving the placenta in situ. The following outcomes over the 2 periods were compared: need for blood transfusion, hysterectomy, intensive care admission, duration of stay in intensive care, and postpartum endometritis. RESULTS: Thirty-three cases of placenta accreta were observed among 31,921 deliveries (1.03/1,000). During period B, there was a reduction in the hysterectomy rate (from 11 [84.6%] to 3 [15%]; P <.001), the mean number of red blood cells transfused (3,230 +/- 2,170 mL versus 1,560 +/- 1,646 mL; P <.01), and disseminated intravascular coagulation (5 [38.5%] versus 1 [5.0%]; P =.02), compared with period A. There were 3 cases of sepsis in period B and none in period A (P =.26). At least 2 women with conservative management subsequently had successful pregnancies. CONCLUSION: Leaving the placenta accreta in situ appears to be a safe alternative to removing the placenta.

Adult↗
PubMed2004

Prenatal diagnosis of placenta accreta and percreta with ultrasonography, color Doppler, and magnetic resonance imaging.

BACKGROUND: The risk of placenta previa and accreta is increased in females with previous cesarean deliveries, and there has been an increasing number of these operations. CASES: We present 2 cases with previous cesarean and placenta previa in the following pregnancy. One patient had placenta accreta and the other, placenta percreta. In both cases, prenatal diagnosis was based on ultrasonography, where features such as loss of the hypoechoic retroplacental zone and irregular uterine serosa were found in grayscale ultrasonography. In color Doppler imaging, in both cases, increased vascularity between myometrium and placenta, as well as intraplacental lacunae, were seen. Thinning of the uterine wall, found in magnetic resonance imaging, contributed to the diagnosis of placenta percreta. CONCLUSION: Prenatal diagnosis of placenta accreta is of importance because it reduces fetal and maternal morbidity as appropriate preoperative and perioperative procedures are possible.

Adult↗
PubMed2005

Surgical uterine devascularization for placenta accreta: immediate and long-term follow-up.

BACKGROUND: To report immediate and long-term outcome in patients with surgical uterine devascularization for placenta accreta. METHODS: Six patients with placenta accreta were treated conservatively during a cesarean section by a bilateral uterine and ovarian surgical devascularization procedure. Menstrual flow, imaging monitoring and further pregnancy were retrospectively reported. RESULTS: Blood transfusion was necessary in five cases and a hysterectomy was performed in one patient with placenta previa accreta. All patients resumed menstruation without oral contraception but one of them reported temporary clinical symptoms of estrogen insufficiency. A chronic placental retention occurred in three patients with incomplete placenta removal. One patient with both bilateral uterine and ovarian arterial ligations had a subsequent pregnancy complicated by a recurrent placenta accreta that was subsequently treated conservatively. CONCLUSIONS: Surgical uterine devascularization for placenta accreta may be useful for uterine conservation. However, reproductive capacity may be altered by placental chronic retention and further pregnancies may be complicated by recurrent placenta accreta.

Adult↗
PubMed2005

Autologous blood transfusion in patients with placenta previa.

BACKGROUND: Several studies have shown that autologous blood storage during pregnancy is relatively safe for mother and fetus. However, the need for reappraisal of autologous blood transfusion in obstetric patients has been proposed. METHODS: We retrospectively reviewed the cases of placenta previa and low-lying placenta among pregnancies at our hospital during an 18-year period, 1985-2002. The utility of autologous blood transfusion program, which started in 1994 for those with placental positional disorders, was evaluated. RESULTS: Of the pregnancies reviewed, there were 158 cases (1.9%) of placenta previa or low-lying placenta. The number of patients transfused with homologous blood decreased from 27.6% (21/76) in the period before implementation of the autologous blood transfusion program to 8.5% (7/82) after its implementation in 1994. In the latter time period, 39.0% (32/82) of patients with placenta previa and low-lying placenta were phlebotomized and had blood stored. Of those, 71.9% (23/32) were reinfused where one patient (3.1%) needed homologous blood as well. The volume of collected blood per phlebotomy was 367 +/- 65 ml, the total volume of collected blood per patient was 803 +/- 350 ml, and the total of estimated blood loss per patient was 1326 +/- 873 ml. The volume of reinfused blood per patient was 578 +/- 326 ml. CONCLUSIONS: The program of autologous blood collection and transfusion in patients with placenta previa resulted in a decrease in homologous blood transfusion. In our program, we recommend starting blood collection and storage at 32 weeks' gestation and phlebotomize 400 ml per week to reach a volume of stored blood of 1200-1500 ml.

Adult↗
PubMed2006

Presence of IgE cells in human placenta is independent of malaria infection or chorioamnionitis.

We have shown previously that numerous IgE(+) macrophage-like cells are present in the villous stroma of full term placenta and that there was no difference in the amount of IgE(+) cells between allergic and non-allergic mothers. The presence of such an abundant number of IgE(+) cells in the placenta in allergic as well as non-allergic women suggests that the IgE is of some importance for a successful pregnancy outcome. Here we have investigated the IgE-pattern in 59 placentas from second and third trimesters from Sweden with different degrees of chorioamnionitis and 27 full term placentas from Ghana with and without malaria parasites. The immunohistochemical staining pattern for IgE looked similar to our previous study, with the IgE located on Hofbauer-like cells. We could not find any difference in the amount or distribution of IgE(+) cells between malaria-infected and non-infected placentas, nor between different degrees of chorioamnionitis. The IgE score in the placenta did not correlate with the levels of IgE in maternal serum or plasma. However, the IgE score was significantly higher in second- compared to third-trimester placentas (P = 0.03). This might reflect a maturation time-point in the fetus and in the intrauterine environment during the second trimester, or it might be associated with the increased number of intrauterine fetal deaths in the second trimester.

Acute Disease↗
PubMed2006

Carboxypeptidase E in the mouse placenta.

Carboxypeptidase E (CPE) has important functions in processing of endocrine pro-peptides, such as pro-insulin, pro-opiomelanocortin, or pro-gonadotropin-releasing hormone, as evidenced by the hyper-pro-insulinemia, obesity, and sterility of Cpe mutant mice. Down-regulation of Cpe in enlarged placentas of interspecific hybrid (interspecies hybrid placental dysplasia (IHPD)) and cloned mice suggested that reduced CPE enzyme and receptor activity could underlie abnormal placental phenotypes. In this study, we have explored the role of Cpe in murine placentation by determining its expression at various stages of gestation, and by phenotypic analysis of Cpe mutant placentas. Our results show that Cpe and Carboxypeptidase D (Cpd), another carboxypeptidase with a very similar function, are strictly co-localized in the mouse placenta from late mid-gestation to term. We also show that absence of CPE causes a sporadic but striking placental phenotype characterized by an increase in giant and glycogen cell numbers and giant cell hypertrophy. Microarray-based transcriptional profiling of Cpe mutant placentas identified only a very small number of genes with altered expression, including Dtprp, which belongs to the prolactin gene family. Concordant deregulation of Cpe and Cpd in abnormal placentas of interspecies hybrids before the onset of IHPD phenotype and recapitulation of some phenotypes of IHPD hyperplastic placentas in Cpe mutant placentas suggests that these two genes are causally involved in IHPD and may function as speciation genes in the genus Mus.

Animals↗
PubMed1998

Abruptio placentae: risk factors and perinatal outcome.

OBJECTIVE: It is a case control study, conducted in order to determine the risk factors, and to find out the perinatal outcome of abruptio placentae in women delivered at the Princess Badeea Teaching Hospital in North Jordan. METHODS: We reviewed all cases of placental abruption delivered between 15th April 1994 till 26 November 1995 and to compare that with pregnancies and deliveries not complicated by abruptio placentae. RESULTS: During the study period there were 108 cases of abruptio placentae and 108 cases of the control group. The total number of women delivered were 18,256, so the incidence of abruptio placentae was 5.9 per 1000 births. When compared to the control group, abruptio placentae occurred more in parous women (para > or = 5) (p < 0.0005), more preterm deliveries (p < 0.0001) with more birth weight < 2,500 g (p < 0.0001). Preeclampsia and pregnancy induced hypertension, intrauterine growth retardation, caesarean delivery, and intrauterine fetal death occurred more in patients with abruptio placentae. CONCLUSION: High parity, preeclampsia and hypertension are significant etiological determinants of abruptio placentae.

Abruptio Placentae↗
PubMed1982

The fetal arterial vasculature in placentas of insulin-dependent diabetic mothers.

Seventeen placentas from insulin-dependent diabetic women and ten placentas from non-diabetics were studied with angiography. The fresh placentas were injected in both umbilical arteries with barium sulphate suspension. After fixation in formaldehyde, the placentas were X-rayed, intact and after being sliced in 0.8 cm slices. There were two clearly distinguishable types of intracotyledonary arteries. Type A is long, narrow and usually runs in the periphery of the cotyledon; type B is wider and usually runs towards the centre of a cotyledon. The cotyledons were classified according to the distribution of these two types of arteries. Type I contained only A-arteries and Type II, both A- and B-arteries or only B-arteries. Twelve per cent of the cotyledons in the control group belonged to Type I, but in the diabetes group 29 per cent. One block of tissue from every placenta was examined histologically to check that the contrast medium filled the stem villus vessels but not the capillaries in the peripheral villi. The histological sections in both groups were compared. Endarteritis appeared to be a feature of the diabetes placenta. The angiographic findings were compared with results of previous direct light microscopical studies. A high percentage of hypovascular villi was found in placentas with a high number of Type I cotyledons.

Arteries↗
PubMed2006

Use of amnion and placenta in neonatal screening for canine GM1-gangliosidosis and the risk of diagnostic misclassifications.

BACKGROUND: A closed breeding colony of Shiba dogs with GM1-gangliosidosis is maintained at Hokkaido University (Sapporo, Japan). Neonatal genotyping is essential to control the breeding colony genetically as an animal model for the human disease. OBJECTIVES: The purpose of the present study was to determine the utility of amnion and placenta in the neonatal screening or diagnosis for canine GM1-gangliosidosis. METHODS: Twenty neonatal Shiba dogs of a pedigree with GM1- gangliosidosis were differentiated into 3 genotypes--normal, heterozygous, and affected dogs--by using a previously reported DNA mutation assay. Acid beta-galactosidase activity was measured in amnion and placenta and compared among the 3 genotypes. RESULTS: The level of beta-galactosidase activity in the amnion of affected dogs was negligible and <2% of the mean activity in normal dogs; there was no significant difference among the 3 genotypes. In placenta, beta-galactosidase activity was significantly different among all the genotypes; however, there was wide overlap in enzyme activity between normal and heterozygous dogs. The level of activity in affected dogs was relatively high and >10% of the mean activity in normal dogs. The DNA mutation assay gave correct information about genotype with genomic DNA extracted from amnion but ambiguous information with DNA from placenta. CONCLUSIONS: Amnion and placenta were not useful as enzyme sources in neonatal screening in canine GM1-gangliosidosis because of the risk of misdiagnosis. DNA from amnion is applicable as a template for genotyping, whereas placenta should not be used because canine placenta contains maternal cells.

Amnion↗
PubMed1986

Transport of calcium by the placenta of the rat.

Transport of 45Ca and of radioactively labelled inert saccharides across the intact or perfused placenta was measured in the rat on day 21 of pregnancy, the day after mating being day 1. The values of permeability--surface area product (PS) of the intact placenta to radioactive mannitol, sucrose, raffinose, and methoxyinulin were approximately proportional to their diffusion coefficients in water. This suggests that diffusion of inert hydrophilic molecules across the rat placenta takes place through wide aqueous channels. Net flux of Ca from mother to fetus, estimated from the increase of the fetal Ca content between day 20 and day 21 is 100 +/- 4 nmol min-1 (the limits here and below are S.E. of means). The unidirectional maternal-fetal flux of Ca (Jmf) in non-anaesthetized animals, estimated from the flux of 45Ca, is 100 +/- 7 nmol min-1. The similarity of the two values suggests that the fetal-maternal flux (Jfm) is small The umbilical vascular bed of the rat placenta was perfused in situ with Krebs-dextran fluid. Jmf estimated from the transfer of 45Ca from maternal plasma to perfusate was 81 +/- 4 nmol min-1. PS of the perfused placenta to radioactive sucrose was 2.6 +/- 0.3 microliter min-1. Jmf decreased reversibly when the placenta was perfused with 0.5 mM-dinitrophenol or 1 mM-CN-, which is consistent with the presumed active nature of the maternal-fetal transport of Ca. Jmf did not decrease when the placenta was perfused with Na-free fluids (substitution with Tris, Li or sucrose), indicating that Na-Ca exchange across the fetal border of the placental trophoblast is not involved in maternal-fetal transport of Ca. Transport of 45Ca to the perfusate was reduced to about 60% when maternal plasma concentration of Ca was doubled. This suggests that the affinity of the maternal-fetal transport system to Ca is high. Jmf did not change when the umbilical concentration of Ca was varied between 0.1 and 3 mM. There thus seems to be no rapid feed-back between umbilical concentration of Ca and transport of Ca from mother to fetus. Fetal-maternal transfer of Ca, estimated from the steady-state extraction of 45Ca from the umbilical perfusate, is only about 20% of the maternal-fetal transfer. Umbilical extraction of 45Ca changed only little when umbilical concentration of Ca was varied between 0.1 and 3 mM. This suggests that either most of the fetal-maternal transport of Ca is diffusional or the fetal-maternal transport system has a very low affinity to Ca.(ABSTRACT TRUNCATED AT 400 WORDS)

Anesthesia↗
PubMed1988

Economic and reproductive consequences of retained placenta in dairy cattle.

The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗
PubMed1982

Low-lying placenta.

Routine ultrasonographic examinations were performed in 255 pregnant women. Most of the patients (95%) had the examination prior to 32 weeks of gestation. In 16 patients (6%) the placenta was identified as low-lying placenta or placenta previa. Of those 16 patients, the placenta was located on the anterior wall in 6, on the posterior wall in 7, and on both the anterior and posterior walls in 3. Ultrasonographic follow-up examination showed conversion to normal position in 10 of those 16 patients (63%). Three of the 7 patients with posterior placentas and all 3 of the patients with placentas located on both posterior and anterior walls failed to demonstrate conversion of the placenta to a normal position. Bleeding complications were also more common in those 2 groups.

Adult↗
PubMed2002

Expression of nitric oxide synthase isoforms and detection of nitric oxide in rat placenta.

Nitric oxide (NO) production in the rat placenta was monitored and quantified by electron paramagnetic resonance (EPR) spectroscopy with hemoglobin and an Fe-N-(dithiocarboxy)sarcosine (DTCS) complex as NO-trapping reagents. Expression of nitric oxide synthase (NOS) isoforms was also examined by quantitative RT-PCR analysis. The EPR spectrum of the placenta with hemoglobin trapping showed a three-line hyperfine structure (g = 2.008 and a = 1.66-mT). The EPR signal was diminished after the placenta was homogenized or the NOS inhibitor L-NAME was administered to pregnant rats. Therefore, the specific signal was definitely identified as being derived from endogenous NO spin-trapped by hemoglobin, and the EPR spectrum showed that the NO adduct existed as a pentacoordinate alpha-NO heme species. The EPR spectrum of the placenta with Fe-DTCS trapping showed a triplet signal (g = 2.038) derived from an NO-Fe-DTCS complex. The height of the triplet signal did not vary significantly with gestational stage during the last few days of gestation. At the gestational stages examined, the level of NOS II mRNA expression was significantly higher than that of NOS III mRNA. NOS II expression in term (day 21.5) placenta was significantly increased compared with that in preterm (day 19.5) placenta (P < 0.01, n = 4 or 5). These results suggest that NOS II is the predominant producer of NO in the placenta and that NOS II-generated NO plays significant roles in the maintenance of placental functions immediately before birth.

Animals↗
PubMed2004

System beta and system A amino acid transporters in the feline endotheliochorial placenta.

There is no knowledge of the transport mechanisms by which solutes cross the cat placenta or any other endotheliochorial placenta. Here, we investigated whether the amino acid transport systems beta and A are present in the cat placenta using a placental fragment uptake technique. Data were compared with studies in the human placenta, in which the presence of these two transport systems has been well established. A time course of [(3)H]taurine (substrate for system beta) and [(14)C]MeAIB (nonmetabolizable substrate for system A) uptake was determined in the term cat and human placental fragments in the presence and absence (choline substituted) of Na(+), and further studies were carried out over 15 min. Taurine uptake into both cat and human placenta fragments was found to be Na(+) and Cl(-) dependent, and Na(+)-dependent taurine uptake was blocked by excess beta-alanine. MeAIB uptake was found to be Na(+) dependent, and Na(+)-dependent MeAIB uptake was blocked by excess MeAIB or glycine. Western blotting and immunohistochemistry performed on cat and human placenta showed expression of TAUT and ATA2 (SNAT2), proteins associated with system beta and system A activity, respectively. This study therefore provides the first evidence of the presence of amino acid transport systems beta and A in the cat placenta.

Amino Acid Transport Systems↗
PubMed2002

Anticipation of uterine bleeding in placenta previa based on vaginal sonographic evaluation.

OBJECTIVES: The aim of this study was to predict massive uterine bleeding during pregnancy and cesarean section in women with placenta previa using transvaginal ultrasonography. METHODS: Transvaginal ultrasonography was performed prospectively at and after 28 gestational weeks with follow-up scans at 5- to 7-day intervals until cesarean section in 35 women with placenta previa. The patients were classified into 3 groups based on the following sonographic features of the placental edge in relation to the internal cervical os: type A = two thirds of the placenta from the placental center overlapping the internal os (13 cases); type B = one third of the placenta from the periphery to outside overlapping the internal os (10 cases), and type C = echo-free space (EFS) in the placental edge overlapping the internal os (12 cases). In some cases of type-A placentas, lacunae with blood flow in the placenta from the basal plate to the chorionic plate were also observed. All types were further subdivided based on the presence or absence of associated sponge-like echo (S-echo) in the wall of the uterus adjacent to the placental location. In each type, the relation with the amount of bleeding during hospitalization and preterm delivery was examined. RESULTS: Incidences of sudden massive bleeding during hospitalization were 7.7% (1/13), 10.0% (1/10), and 83.3% (10/12), in types A, B and C, respectively, being significantly higher in type C (p < 0.01). The risk of antepartum massive bleeding was also significantly higher in type C (p < 0.01). The incidence of preterm delivery due to sudden massive bleeding and the amount of bleeding during cesarean section were significantly higher in type A + S and type A + S with lacunae, respectively. CONCLUSIONS: Sonographic EFS in the lower edge of the placenta overlying the cervix indicates the risk of sudden massive antepartum bleeding. Furthermore, lacunae with sponge-like echo may also reflect the risk of massive bleeding at cesarean section. These findings warrant further observational studies to verify their clinical implications.

Cesarean Section↗
PubMed1975

Vascular anastomoses in twin placentae and their recognition.

166 placentae from multiple pregnancies (including three triplets and 17 monochorral) have been studied by injection corrosion technique, using cellulose acetate buterite in acetone, under continuous pressure within physiological limits. It has been shown that vascular anastomoses in twin placentae are usually multiple. The direct type is frequently found in monochorial twin placentae and is mostly arterial or venous in nature. The indirect type is observed more commonly in dichorial twin placentae and is mostly arteriovenous in nature. Both types are almost universally found in monochorial monoamniotic placentae. The presence of direct anastomotic channels has a highly significant association with the incidence of marginal vessels and an exaggeration of parameters of stress to an abnormal quantum--both singly and in combinations of three or more-, and is independent of the pattern of branching. In the ontogenetic time-sequence perspective, direct anastomoses, marginal vessels and parameters of stress in a twin placenta can be regarded as different phases of the sequelae of an altered vascular relationship caused by disturbances in the vicinity of the 12th week of gestation. It has been further shown that direct vascular anastomoses are a greater risk to the twins than indirect ones. The importance of early and timely recognition of such channels, by an examination of twin placentae for the presence of marginal vessels, is stressed.

Arteriovenous Anastomosis↗
PubMed1978

Fine structure of the human placenta in prolonged pregnancy. Preliminary report.

Placentas from 15 prolonged (is greater than 42 weeks), but otherwise normal pregnancies, and 8 normal-term placentas were studied. Placental villi from term placentas revealed intact syncytial and cytotrophoblast elements. All term placentas presented a minimal to mild degree of villous necrosis and deposition of fibrinoid material. Placental villi from cases of prolonged pregnancy presented a moderate to severe degree of necrosis in 11 of 15 placentas and a minimal to mild degree in 4 of 15 placentas. A moderate to severe degree of fibrinoid deposition was noted in 7 of 15 placentas, whilst 8 of 15 revealed a minimal to mild degree of deposition. The presence or absence of meconium was noted in the prolonged-pregnancy group and correlated with the above morphological features. Statistically, a correlation was found between prolonged pregnancy and necrosis (p is less than 0.001), prolonged pregnancy and fibrinoid deposition (p is less than 0.03) and between necrosis and deposition of fibrinoid (p is less than 0.05). There was no correlation between the incidence of meconium staining and the above parameters.

Chorionic Villi↗