Prenatal diagnosis of a lean umbilical cord: a simple marker for the fetus at risk of being small for gestational age at birth. (1/1267)

OBJECTIVE: The purpose of this study was to investigate whether the prenatal diagnosis of a 'lean' umbilical cord in otherwise normal fetuses identifies fetuses at risk of being small for gestational age (SGA) at birth and of having distress in labor. The umbilical cord was defined as lean when its cross-sectional area on ultrasound examination was below the 10th centile for gestational age. METHOD: Pregnant women undergoing routine sonographic examination were included in the study. Inclusion criteria were gestational age greater than 20 weeks, intact membranes, and singleton gestation. The sonographic cross-sectional area of the umbilical cord was measured in a plane adjacent to the insertion into the fetal abdomen. Umbilical artery Doppler waveforms were recorded during fetal apnea and fetal anthropometric parameters were measured. RESULTS: During the study period, 860 patients met the inclusion criteria, of whom 3.6% delivered a SGA infant. The proportion of SGA infants was higher among fetuses who had a lean umbilical cord on ultrasound examination than among those with a normal umbilical cord (11.5% vs. 2.6%, p < 0.05). Fetuses with a lean cord had a risk 4.4-fold higher of being SGA at birth than those with a normal umbilical cord. After 25 weeks of gestation, this risk was 12.4 times higher when the umbilical cord was lean than when it was of normal size. The proportion of fetuses with meconium-stained amniotic fluid at delivery was higher among fetuses with a lean cord than among those with a normal umbilical cord (14.6% vs. 3.1%, p < 0.001). The proportion of infants who had a 5-min Apgar score < 7 was higher among those who had a lean cord than among those with normal umbilical cord (5.2% vs. 1.3%, p < 0.05). Considering only patients admitted in labor with intact membranes and who delivered an appropriate-for-gestational-age infant, the proportion of fetuses who had oligohydramnios at the time of delivery was higher among those who had a lean cord than among those with a normal umbilical cord (17.6% versus 1.3%, p < 0.01). CONCLUSION: We conclude that fetuses with a lean umbilical cord have an increased risk of being small for gestational age at birth and of having signs of distress at the time of delivery.  (+info)

The 'Mickey Mouse' sign and the diagnosis of anencephaly in early pregnancy. (2/1267)

OBJECTIVES: To assess the sonographic screening for anencephaly in the first trimester in a low-risk obstetric population. METHODS: Since 1994, 5388 women attended our clinic for a first-trimester scan (11-14 weeks of gestation) and screening for structural and chromosomal abnormalities. The patients underwent transabdominal scanning, and transvaginal scanning if necessary. RESULTS: The ultrasonographic appearances of anencephaly in the first trimester are different from the familiar second-trimester signs. The cerebral hemispheres are present and exposed to the surrounding amniotic fluid. The ultrasound appearances in the coronal section of the head are best described as 'Mickey Mouse face'. There were six cases of anencephaly (incidence 1.1:1000). All cases were diagnosed in the first trimester and five demonstrated this sign. There were no false-positive diagnoses. The crown-rump length was significantly reduced in all affected fetuses. CONCLUSION: First-trimester ultrasonographic diagnosis of anencephaly is accurate, but sonographers should be familiar with the ultrasound appearances that are different from those in the second trimester.  (+info)

Adrenomedullin production is increased in normal human pregnancy. (3/1267)

OBJECTIVE: Adrenomedullin, a recently discovered vasoactive peptide originally identified in pheochromocytoma, has been found to be increased in the plasma of pregnant women at term. This study was designed to elucidate whether adrenomedullin secretion is dependent on gestational age and the possible source and function of this peptide in human pregnancy. STUDY DESIGN: Adrenomedullin concentrations were determined by RIA in amniotic fluid and maternal plasma obtained from 110 pregnant women between 8 and 40 weeks of gestation. Subjects were stratified into five groups according to gestational age. In term patients (n = 15), adrenomedullin was also measured in the umbilical artery and vein separately. RESULTS: High concentrations of adrenomedullin were present in plasma and amniotic fluid samples from patients in the first, second and third trimester. There was no significant difference in mean maternal plasma concentration of adrenomedullin between the five patient groupings. Amniotic fluid adrenomedullin concentrations decreased from 81.2 +/- 11.7 pg/ml at 8-12 weeks of gestation to 63.7 +/- 6.0 pg/ml at 13-20 weeks of gestation and then increased at 21-28 weeks of gestation to 99.1 +/- 10.4 pg/ml. A further increase was found in samples collected after 37 weeks of gestation (132.6 +/- 10.1 pg/ml). In the umbilical vein, adrenomedullin concentration was higher (P < 0.05) than in the artery (65.7 +/- 6.1 pg/ml and 48.5 +/- 5.2 pg/ml respectively), suggesting that adrenomedullin in the fetal circulation derives from the placenta. CONCLUSIONS: Our results demonstrate the presence of adrenomedullin in maternal plasma and amniotic fluid throughout gestation, and show that its production starts very early in gestation, suggesting that this hormone may have an important role in human reproduction, from implantation to delivery.  (+info)

Amniotic fluid concentrations of dimeric inhibins, activin A and follistatin in pregnancy. (4/1267)

OBJECTIVE: The feto-placental unit is the major source of circulating concentrations of inhibin A and activin A in human pregnancy. The aim of this study was to measure the amniotic fluid concentrations of inhibin A, inhibin B, activin A and follistatin in pregnancies bearing male and female fetuses. DESIGN AND METHOD: Amniotic fluid samples collected by amniocentesis were stored at -20 degrees C. Dimeric inhibins, 'total' activin A and 'total' follistatin were measured using specific two-site enzyme immunoassays. Samples were assayed blindly and the information on fetal sex was obtained from the cytogenetics laboratory. RESULTS: Data show that amniotic fluid concentrations of inhibin A, inhibin B and activin A gradually increase with gestation whilst concentrations of follistatin are similar between weeks 15 and 20 of pregnancy. Mean amniotic fluid levels of inhibin A and inhibin B at 16 and 17 weeks gestation and mean activin A levels at 15 and 16 weeks gestation are considerably lower in pregnancies with male (n=24) compared with female (n=28) fetuses. Levels of follistatin are not different in the male and female fetal pregnancies at any studied gestation. CONCLUSIONS: The results indicate that amniotic fluid contains high concentrations of inhibins (A and B), activin A and follistatin in early pregnancy suggesting that these hormones are produced by the fetal membranes and may be involved in the development of the fetus.  (+info)

SMN protein analysis in fibroblast, amniocyte and CVS cultures from spinal muscular atrophy patients and its relevance for diagnosis. (5/1267)

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by the homozygous absence of the telomeric copy of the survival motor neuron (SMNt) gene, due to deletion, gene conversion or point mutation. SMNt and its homologous centromeric copy (SMNc) encode the SMN protein, which is diffusely present in the cytoplasm and in dot-like structures, called gems, in the nucleus. We have studied the SMN protein in different cell cultures, including fibroblasts, amniocytes and CVS cells from SMA individuals and controls. By immunofluorescence analysis we found a marked reduction in the number of gems in fibroblasts, amniocytes and chorionic villus cells of all SMA patients and foetuses, independent of the type of the genetic defect. We also show that immunolocalisation of the SMN protein may be a useful tool for the characterisation of particular patients of uncertain molecular diagnosis.  (+info)

Secretory leukocyte protease inhibitor concentration increases in amniotic fluid with the onset of labour in women: characterization of sites of release within the uterus. (6/1267)

Secretory leukocyte protease inhibitor is a potent inhibitor of neutrophil function, a mediator of mucosal immunity and an inhibitor of NF|gkB regulated inflammatory responses. However, its source, function and regulation within the uterus during pregnancy and at parturition are not well defined. In amniotic fluid, the concentration of secretory leukocyte protease inhibitor increased significantly from 2nd trimester (24+/-3 ng/ml; mean+/-s.e.m.; n=20) to term (751+/-53 ng/ml; P<0.05; n=15) with a further profound increase (P<0.005) with the onset of labour (3929+/-1076 ng/ml; n=15). To establish the intra-uterine sites of secretion, explants (n=6 different patients per tissue) were collected at term after elective caesarean section. High levels of secretory leukocyte protease inhibitor were released by decidua (135.2+/-12.4 pg/mg; mean+/-s.e.m.) and chorio-decidua (325.1+/-26.4 pg/mg) with less by amnion (55.6+/-6.0 pg/mg) and placenta (9.2+/-1.9 pg/mg). Intense immunoreactivity for secretory leukocyte protease inhibitor was detected predominantly in decidua parietalis cells adherent to the chorion laeve and myometrium, and also in decidua basalis. We propose that, within the pregnant uterus, secretory leukocyte protease inhibitor is released by decidua, fetal membranes and potentially the fetal lung. The increase in secretory leukocyte protease inhibitor may act to modulate pro-inflammatory paracrine interactions for the maintenance of pregnancy and limit those occurring at parturition within the uterus.  (+info)

Secretion of matrix metalloproteinase-2, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinases into the intrauterine compartments during early pregnancy. (7/1267)

Matrix metalloproteinases (MMPs) are important enzymes in tissue remodelling, a key event for the development of the fetal membranes and placenta and establishing the feto-maternal interface during early pregnancy. This study has examined the secretion of the gelatinases, MMP-2 (72 kDa) and MMP-9 (92 kDa), and the endogenous tissue inhibitors of metalloproteinases (TIMPs) into extra-embryonic coelomic and amniotic fluids, the two principal intra-uterine compartments of the first trimester, and compared them to amniotic fluid collected later in gestation. In extra-embryonic coelomic fluid, gelatin zymography demonstrated that MMP-2 (72 kDa) was the predominant gelatinase, with some MMP-9 present. A broad range of TIMPs corresponding to TIMP-1 and TIMP-2, glycosylated and unglycosylated TIMP-3 and TIMP-4 was detected in this compartment by reverse zymography and immunoblot analyses. There was little gelatinase or TIMP activity in amniotic fluid in the first trimester. In amniotic fluid from the second trimester after fusion of the membranes obliterating the extra-embryonic coelom, and at term elective caesarean section, MMP-2 is the predominant gelatinase present, with a broad spectrum of TIMPs. These findings demonstrate that predominantly MMP-2 and also MMP-9, regulated by a range of TIMPs, are involved in intra-uterine tissue remodelling during the establishment of pregnancy.  (+info)

Vascular endothelial growth factor is bound in amniotic fluid and maternal serum. (8/1267)

To study vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF) concentrations and their possible binders, serum from 22 non-pregnant and 55 pregnant women (15 at weeks 10-13; 40 at term), umbilical vein (n = 24) and artery (n = 13) and amniotic fluid (a pool of 50 at weeks 15-17; 11 at term) were assessed for VEGF and PlGF by an enzyme-linked immunosorbent assay. In amniotic fluid and maternal serum VEGF concentrations were <16 ng/ml and added VEGF was not recovered. VEGF was detected in serum from mothers post-partum (137 +/- 142 ng/l, mean +/- SD), umbilical artery (421 +/- 288 ng/l) and vein (502 +/- 339 ng/l) and non-pregnant controls (182 +/- 147 ng/l), and added VEGF was fully recovered. PlGF was detected in pregnancy serum (52 +/- 23 ng/l early pregnancy; 439 +/- 217 ng/l term pregnancy) and in amniotic fluid (early pregnancy 56 ng/l; term pregnancy 30 +/- 18 ng/l). PlGF was fully recovered in all samples. Gel filtration and isoelectric focusing revealed that in maternal serum and amniotic fluid [125I]VEGF was bound to a protein with an Mr of 400-700 kDa and an isoelectric point of approximately 8. This protein was not identical with alpha-2-macroglobulin (by an immunofluorometric assay), pregnancy zone protein or pregnancy associated plasma protein-A (by immunodiffusion). In conclusion, VEGF-binding activity is present in amniotic fluid and maternal blood. It disappears after delivery and is not detectable in fetal or non-pregnant serum.  (+info)