MECHANISMS OF DISEASE IN PRETERM LABOR AND COMPLICATIONS OF PREMATURITY; PRENATAL DIAGNOSIS OF CONGENITAL ANOMALIES
, Chief, Program in Perinatal Research and Obstetrics
Samuel Edwin, PhD, Senior Research Assistant
Francesca Gotsch, MD, Postdoctoral Fellow
Beth Pineles, BS, Postbaccalaureate Fellow
We conduct clinical and laboratory research in maternal and fetal diseases responsible for excessive infant mortality in the United States and focus on the mechanisms of disease responsible for preterm delivery, with particular emphasis on the role of maternal and fetal inflammation and subclinical infection. The current taxonomy of disease in obstetrics is largely based on the clinical presentation of the mother rather than on the mechanism of disease. The term “preterm labor,” for example, is not informative as to whether the condition is caused by an infection, a vascular insult, uterine overdistension, stress, or some other pathologic process. The same applies to other pregnancy complications such as pre-eclampsia, small for gestational age, and fetal death. We proposed that obstetrical disorders responsible for maternal death and perinatal morbidity and mortality are syndromes and hence designated them the Great Obstetrical Syndromes. Key features of the syndromes are (1) multiple etiology, (2) long preclinical stage, (3) frequent fetal involvement, (4) clinical manifestation that is often adaptive in nature, and (5) predisposition to a particular syndrome influenced by gene-environment interaction. The prenatal diagnosis of congenital anomalies is also a major area of interest. We have explored the value of combining sonographic and biochemical parameters to identify patients at increased risk of developing pre-eclampsia.
Clinical significance of the presence of amniotic fluid sludge in asymptomatic patients at high risk for spontaneous preterm delivery
Premature birth is the leading cause of perinatal mortality and morbidity worldwide. We defined preterm labor as a syndrome and determined that at least 25 percent of preterm neonates are born to women with subclinical intrauterine infection. Intrauterine infection has thus emerged as a frequent and important mechanism of disease in preterm birth and is the only pathologic process for which a firm causal link with prematurity has been established. The sonographic finding of dense aggregates of particulate matter in the amniotic fluid close to the uterine cervix has been previously described in women with an episode of preterm labor and referred to as amniotic fluid sludge. We conducted a retrospective case-control study of 281 asymptomatic patients at risk for spontaneous preterm delivery who underwent transvaginal ultrasound examination between 13 and 29 completed weeks of gestation. The prevalence of amniotic fluid sludge in the study population was about 24 percent. Patients with sludge had a significantly higher rate of spontaneous preterm delivery; a higher frequency of clinical chorioamnionitis, histologic chorioamnionitis, and funisitis; a higher frequency of preterm premature rupture of membranes (PPROM) and lower gestational age at PPROM; and a shorter ultrasound-to-delivery interval than those without sludge. To determine the nature of amniotic fluid sludge, we collected—under sonographic guidance—the material from patients with impending preterm delivery. Macroscopically, sludge is similar to pus and is associated with a markedly elevated white blood cell count in amniotic fluid as well as with positive Gram stain and cultures. We propose that the detection of amniotic fluid sludge represents a sign that microbial invasion of the amniotic cavity and an inflammatory process are in progress. Such an interpretation will strengthen the view that intra-amniotic infection is chronic and subclinical in nature.
Kusanovic JP, Espinoza J, Romero R, Gonçalves LF, Nien JK, Soto E, Khalek N, Camacho N, Hendler I, Mittal P, Friel LA, Gotsch F, Erez O, Than NG, Mazaki-Tovi S, Schoen ML, Hassan SS. Clinical significance of the presence of amniotic fluid sludge in asymptomatic patients at high risk for spontaneous preterm delivery. Ultrasound Obstet Gynecol 2007;30:706-14.
Romero R, Kusanovic JP, Espinoza J, Gotsch F, Nhan-Chang CL, Erez O, Kim CJ, Khalek N, Mittal P, Gonçalves LF, Schaudinn C, Hassan SS, Costerton JW. What is amniotic fluid ‘sludge’? Ultrasound Obstet Gynecol 2007;30:793-98.
Antibiotic administration to patients with PPROM does not eradicate intra-amniotic infection
Antibiotic administration has become part of the standard of care for patients with PPROM. Yet the natural history of intrauterine infection/inflammation during antibiotic therapy remains largely unknown. We conducted a study to determine if antibiotic administration to the mother eradicates intra-amniotic infection and/or reduces the frequency of intra-amniotic inflammation in patients with PPROM. The findings demonstrated that antibiotic administration (ceftriaxone, clindamycin, and erythromycin) rarely eradicates intra-amniotic infection in patients with PPROM and that intra-amniotic inflammation developed in one-third of patients without inflammation at hospital admission, despite antibiotic administration. Thus, the current standard of practice neither eradicates nor prevents infection.
Gomez R, Romero R, Nien JK, Medina L, Carstens M, Kim YM, Espinoza J, Chaiworapongsa T, Gonzalez R, Iams JD, Rojas I. Antibiotic administration to patients with preterm premature rupture of membranes does not eradicate intra-amniotic infection. J Matern Fetal Neonatal Med 2007;20:167-73.
Dermatitis as a component of the fetal inflammatory response syndrome is associated with activation of Toll-like receptors in epidermal keratinocytes
A fetal inflammatory response is closely linked to preterm labor and delivery and has been associated with increased perinatal morbidity and long-term sequelae such as cerebral palsy and chronic lung disease. We have coined the term Fetal Inflammatory Response Syndrome (FIRS) to describe a condition characterized by fetal systemic inflammation and an elevation of fetal plasma interleukin-6. Toll-like receptors (TLRs) are essential components of the innate immune system implicated in recognizing the presence of microorganisms. The epidermis is not only a mechanical barrier but also an active immune organ that participates in the protection of the host against microbial invasion. The expression of TLR-2 and TLR-4 mRNA and proteins has been demonstrated in human keratinocytes along with accessory signaling molecules. We examined histopathological features of fetal skin exposed to microbial invasion of the amniotic cavity to assess the changes in TLR-2 and TLR-4 expression. We observed leukocytic infiltrates in the superficial dermis in cases with chorioamnionitis. TLR-2 immunoreactivity in the skin was stronger in fetuses with chorioamnionitis than in those without the condition. This study demonstrates for the first time that fetal dermatitis may be detected and is part of FIRS. We propose that this FIRS-associated fetal dermatitis is a fetal counterpart of chorioamnionitis.
Kim YM, Romero R, Chaiworapongsa T, Espinoza J, Mor G, Kim CJ. Dermatitis as a component of the fetal inflammatory response syndrome is associated with activation of Toll-like receptors in epidermal keratinocytes. Histopathology 2006;49:506-14.
Microglial activation in perinatal rabbit brain induced by intrauterine inflammation: detection with 11C-(R)-PK11195 and small-animal PET
Intrauterine infection can lead to fetal systemic inflammation, which is associated with brain injury (e.g., periventricular leukomalacia) and cerebral palsy. Activated microglia have been found in cases of brain injury and can lead to oligodendrocyte damage and white matter injury. We developed an animal model to determine if microglial activation can be detected before birth and if treatment can prevent lesions. Rabbits with timed pregnancies underwent laparotomy and were randomly allocated to receive saline or lipopolysaccharide. We scanned the pups by using small-animal Positron Emission Tomography (PET) and MRI on postnatal day 1. We observed more brain retention of (11)C-(R)-PK11195 tracer (a marker for microglia activation) in the endotoxin-treated pups than in age-matched controls, a finding that we confirmed by immunohistochemical staining. The study demonstrated, first, that intrauterine inflammation leads to activation of microglial cells that may be responsible for the development of brain injury and white matter damage in the perinatal period and, second, that molecular imaging may be used to detect the presence and progress of neuroinflammation in utero.
Kannan S, Saadani-Makki F, Muzik O, Chakraborty P, Mangner TJ, Janisse J, Romero R, Chugani DC. Microglial activation in perinatal rabbit brain induced by intrauterine inflammation: detection with 11C-(R)-PK11195 and small-animal PET. J Nucl Med 2007;48:946-54.
The calcium-binding protein S100B is elevated in the amniotic fluid of women with intra-amniotic infection/inflammation and preterm labor with intact or ruptured membranes
The calcium-binding protein S100B is produced in high concentration by astrocytes and oligodendrocytes of the nervous system and is considered a marker of neurologic injury in the perinatal period. Indeed, elevated neonatal urine S100B concentration is associated with adverse neurological outcomes, including intraventricular hemorrhage and hypoxic-ischemic encephalopathy. We designed a study to determine whether amniotic fluid S100B concentrations change with advancing gestational age in normal pregnancies and with intra-amniotic infection (IAI) in women with preterm labor and intact membranes or PPROM. S100B concentrations did not change during gestation, but two women with preterm labor or PPROM with IAI had significantly higher amniotic fluid S100B concentrations than those without IAI. Thus, amniotic fluid S100B concentration is not an independent predictor of neonatal morbidity or fetal/neonatal death.
Friel LA, Romero R, Edwin S, Nien JK, Gomez R, Chaiworapongsa T, Kusanovic JP, Tolosa JE, Hassan SS, Espinoza J. The calcium binding protein, S100B, is increased in the amniotic fluid of women with intra-amniotic infection/inflammation and preterm labor with intact or ruptured membranes. J Perinat Med 2007;35:385-93.
Human beta-defensin-2, a natural antimicrobial peptide present in amniotic fluid, participates in the host response to microbial invasion of the amniotic cavity
Our group previously demonstrated that microbial invasion of the amniotic cavity (MIAC), preterm labor, and PPROM are associated with increased amniotic fluid concentrations of the following antimicrobial peptides: bactericidal/permeability-increasing protein, neutrophil defensins, and calprotectin. In addition, elevated amniotic fluid concentrations of these antimicrobial peptides are associated with intra-amniotic inflammation, histological chorioamnionitis, and a shorter amniocentesis-to-delivery interval in patients with preterm labor with intact membranes. Human beta-defensin-2 (HBD-2) is a potent antimicrobial peptide that is part of the innate immune response. We aimed to determine whether HBD-2 is present in amniotic fluid and whether its concentration changes with MIAC and labor. We detected HBD-2 in all amniotic fluid samples and noted that its concentrations did not change with gestational age. MIAC was associated with a significant increase in amniotic fluid concentrations of HBD-2 in two women with preterm labor and intact membranes and in women with PPROM. We found similar results among patients with preterm labor without MIAC, but with intra-amniotic inflammation. We propose that amniotic fluid HBD-2 is part of the innate immune system within the amniotic cavity.
Soto E, Espinoza J, Nien JK, Kusanovic JP, Erez O, Richani K, Santolaya-Forgas J, Romero R. Human beta-defensin-2: a natural antimicrobial peptide present in amniotic fluid participates in the host response to microbial invasion of the amniotic cavity. J Matern Fetal Neonatal Med 2007;20:15-22.
Signature pathways identified from gene expression profiles in the human uterine cervix before and after spontaneous term parturition
The uterine cervix plays a central role in normal parturition, preterm labor, and cervical insufficiency as well as in functional disorders that are the most common cause of caesarean delivery at term (arrest of dilatation). However, our understanding of the mechanisms responsible for cervical ripening and of those associated with cervical changes during parturition remains incomplete. We have applied systems biology tools to improve our understanding of these mechanisms. We conducted a cross-sectional study—based on genes differentially expressed in the uterine cervix before and after spontaneous labor—in order to identify signature pathways that characterize biologic processes. Fifty-two pathways were significantly enriched in differentially expressed genes previously suspected for their involvement in cervical dilation and remodeling, and we identified two of the top five pathways as novel pathways involved in cervical remodeling: plasmin signaling and plasminogen activator urokinase signaling. Our investigation represents the first application of systems biology to the understanding of cervical biology before and after parturition.
Hassan SS, Romero R, Tarca AL, Draghici S, Pineles B, Bugrim A, Khalek N, Camacho N, Mittal P, Yoon BH, Espinoza J, Kim CJ, Sorokin Y, Malone J. Signature pathways identified from gene expression profiles in the human uterine cervix before and after spontaneous term parturition. Am J Obstet Gynecol 2007;197:250.e1-7.
Distinct subsets of microRNAs are expressed differentially in the human placentas of patients with pre-eclampsia
Pre-eclampsia and small-for-gestational age (SGA) neonates have partially overlapping clinicopathologic features, including morphologic changes associated with placental underperfusion and effects on the expression of several placental genes. MicroRNAs (miRNAs) are members of a class of small, non-coding RNA molecules that play a critical role in post-transcriptional regulation of protein-encoding genes. Studies of miRNA expression across several organs have revealed that miRNA expression is tissue-specific. Many miRNAs are expressed abundantly in the human placenta, but their expression patterns in placentas with distinct pathologies have not been reported. Therefore, we conducted a cross-sectional, case-control study that included (1) placentas obtained from patients with pre-eclampsia, SGA neonates, and pre-eclampsia and SGA and (2) placentas obtained from a control group with spontaneous preterm labor and delivery. In assessing the expression of 157 miRNAs by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), we found differential expression of miRNAs between pre-eclampsia and the control group (miR-210, miR-182) and between pre-eclampsia and SGA and the control group (miR-210, miR-182*, and others). Gene Ontology analysis of the target genes revealed enrichment for specific biological process categories (anti-apoptosis: miR-182; regulation of transcription: miR-210). This study demonstrates, for the first time, increased expression of specific placental miRNAs in pre-eclampsia with and without SGA, providing novel targets for further investigation of the pathophysiology of pre-eclampsia.
Pineles BL, Romero R, Montenegro D, Tarca AL, Han YM, Kim YM, Draghici S, Espinoza J, Kusanovic JP, Mittal P, Hassan SS, Kim CJ. Distinct subsets of microRNAs are expressed differentially in the human placentas of patients with preeclampsia. Am J Obstet Gynecol 2007;196:261.e1-6.
Differential expression of miRNAs with progression of gestation and inflammation in the human chorioamniotic membranes
As members of a class of small, non-coding RNA molecules, miRNAs play a critical role in post-transcriptional regulation of protein-encoding genes. We assessed the expression of 157 miRNAs by real-time qRT-PCR and observed the expression of more than 95 percent of the screened miRNAs as well as gestational age–dependent changes in expression for 13 miRNAs. In the presence of chorioamnionitis, the expression of miR-223 and miR-338 rose 37-fold and 24-fold, respectively. Gene Ontology database analysis of genes targeted by differentially expressed miRNAs revealed enrichment for specific biological process categories. This study reports, for the first time, the expression profiles of miRNA in human chorioamniotic membranes with advancing gestation and chorioamnionitis.
Montenegro D, Romero R, Pineles BL, Tarca AL, Kim YM, Draghici S, Kusanovic JP, Kim JS, Erez O, Mazaki-Tovi S, Hassan S, Espinoza J, Kim CJ. Differential expression of microRNAs with progression of gestation and inflammation in the human chorioamniotic membranes. Am J Obstet Gynecol 2007;197:289.e1-6.
Unexplained fetal death: another antiangiogenic state
Vasculogenesis and extensive angiogenesis are required for successful fetal and placental development. The soluble form of vascular endothelial growth factor (VEGF) receptor-1 (sVEGFR-1), an antagonist to VEGF and placental growth factor (PlGF) (two important angiogenic factors), has been implicated in the pathophysiology of pre-eclampsia and in SGA without pre-eclampsia. There is, however, a paucity of information on plasma sVEGFR-1 concentrations in other obstetrical disorders. Our research group conducted a cross-sectional study to determine the concentrations of sVEGFR-1 in plasma obtained from 499 women in the following groups: non-pregnant women, normal pregnancy, fetal death, spontaneous preterm labor with intact membranes, PPROM, and acute pyelonephritis. Women with a normal pregnancy had a significantly higher median plasma sVEGFR-1 concentration than non-pregnant women, and sVGFR-1 concentrations increased with advancing gestational age. Of interest, patients experiencing fetal death had a median delta plasma concentration of sVEGFR-1 that was significantly higher than that of normal pregnant women. However, we detected no significant differences in the median delta plasma sVEGFR-1 concentration in term and preterm parturition, rupture of fetal membranes, or acute pyelonephritis.
Espinoza J, Chaiworapongsa T, Romero R, Kim YM, Kim GJ, Nien JK, Kusanovic JP, Erez O, Bujold E, Gonçalves LF, Gomez R, Edwin S. Unexplained fetal death: another anti-angiogenic state. J Matern Fetal Neonatal Med 2007;20:495-507.
A role of the anti-angiogenic factor sVEGFR-1 in “mirror syndrome” (Ballantyne’s syndrome)
The association of fetal hydrops with placentomegaly and severe maternal edema is known as “mirror syndrome” (Ballantyne’s syndrome). Pre-eclampsia occurs in approximately 50 percent of these cases. The anti-angiogenic factor sVEGFR-1 has been implicated in the pathophysiology of pre-eclampsia. In a case-control study, we observed that the maternal plasma concentration of sVEGFR-1 was significantly higher in patients with mirror syndrome than in members of the control group and that all patients with mirror syndrome had sVEGFR-1 concentrations above the 95th percentile for gestational age. The syncytiotrophoblast showed strong staining with antibodies against sVEGFR-1 in placental samples from mirror syndrome patients but not in those from controls. We propose that sVEGFR-1 participates in the pathophysiology of mirror syndrome and that maternal plasma determination of sVEGFR-1 may help identify the hydropic fetus that places the mother at risk for pre-eclampsia.
Espinoza J, Romero R, Nien JK, Kusanovic JP, Richani K, Gomez R, Kim CJ, Mittal P, Gotsh F, Erez O, Chaiworapongsa T, Hassan S. A role of the anti-angiogenic factor sVEGFR-1 in the mirror syndrome (Ballantyne’s syndrome). J Matern Fetal Neonatal Med 2006;19:607-13.
An episode of preterm labor is a risk factor for the birth of an SGA neonate
Approximately 40 percent of patients with an episode of preterm labor subsequently deliver at term. In these patients, the episode of preterm labor may represent the uterine response to an insult not severe enough to trigger preterm parturition but may put the fetus at risk for other pregnancy complications. We compared the frequency of SGA neonates among patients with an episode of increased uterine contractility who delivered at term with those who delivered preterm. The prevalence of SGA neonates in the study population was 16 percent. Patients who delivered at term had a significantly higher frequency of SGA neonates than those who delivered preterm. Patients who delivered at term had a higher frequency of fetal or maternal vascular lesions without histologic evidence of inflammation than those who delivered preterm. Term delivery after an episode of regular preterm uterine contractions was associated with an odds ratio of 2.22 for delivery of an SGA neonate. Our study suggests that an episode of false preterm labor is not a benign condition; patients who experienced an episode of increased uterine contractility that subsided and who deliver at term are at risk for delivering an SGA neonate.
Espinoza J, Kusanovic JP, Kim CJ, Kim YM, Kim JS, Hassan SS, Gotsch F, Gonçalves LF, Erez O, Friel L, Soto E, Romero R. An episode of preterm labor is a risk factor for the birth of a small-for-gestational-age neonate. Am J Obstet Gynecol 2007;196:574.e1-5; discussion 574.e5-6.
CXCL10/IP-10: a missing link between inflammation and antiangiogenesis in pre-eclampsia?
Pre-eclampsia and SGA share risk factors (advanced maternal age, chronic hypertension) and mechanisms of disease, such as abnormal physiologic transformation of the spiral arteries, chronic uteroplacental ischemia, and an antiangiogenic state. CXCL10/IP-10 is a member of the CXC chemokine family with proinflammatory and antiangiogenic properties. It has been proposed that this chemokine is a key link between inflammation and angiogenesis. We conducted a cross-sectional study to determine whether pre-eclampsia and SGA are associated with changes in serum concentration of CXCL10/IP-10. Patients with normal pregnancies had a significantly higher median serum concentration of CXCL10/IP-10 than non-pregnant women. Similarly, patients with pre-eclampsia had a higher median serum concentration of CXCL10/IP-10 than did normal pregnant women and those who delivered an SGA neonate. In contrast, we found no significant differences in the serum CXCL10/IP-10 concentrations between patients who delivered an SGA neonate and those with normal pregnancies. These results are likely to reflect an antiangiogenic state as well as an enhanced systemic inflammatory response in patients with pre-eclampsia. Given that pre-eclampsia and SGA share several mechanisms of disease, it is possible that a higher concentration of CXCL10/IP-10 may contribute to the clinical presentation of pre-eclampsia in patients with a similar intrauterine insult.
Gotsch F, Romero R, Friel L, Kusanovic JP, Espinoza J, Erez O, Than NG, Mittal P, Edwin S, Yoon BH, Kim CJ, Mazaki-Tovi S, Hassan S. CXCL10/IP-10: a missing link between inflammation and anti-angiogenesis in preeclampsia. J Matern Fetal Neonatal Med 2007;20:777-92.
Maternal serum concentrations of CXCL10/IP-10 are elevated in acute pyelonephritis during pregnancy
Acute pyelonephritis is one of the most frequent medical complications of pregnancy and thus a common cause of antepartum hospitalization. We designed a cross-sectional study to determine whether maternal serum concentrations of CXCL10/IP-10 change in patients with acute pyelonephritis during pregnancy. We found that the median serum concentration of CXCL10/IP-10 in pregnant patients with pyelonephritis was significantly higher than that in normal pregnant women, although the maternal median serum concentrations of CXCL10/IP-10 did not differ among patients with acute pyelonephritis with and without a positive blood culture. This first report regarding serum CXCL10/IP-10 concentrations in pregnant women with pyelonephritis is consistent with earlier reports on nonpregnant patients. It is possible that CXCL10/IP-10 participates in the host defense by orchestrating leukocyte chemotaxis. We still need to determine the mechanisms responsible for the increase in CXCL10/IP-10 during normal pregnancy and in acute infection during gestation.
Gotsch F, Romero R, Espinoza J, Kusanovic JP, Mazaki-Tovi S, Erez O, Than NG, Edwin S, Mazor M, Yoon BH, Hassan SS. Maternal serum concentrations of the chemokine CXCL10/IP-10 are elevated in acute pyelonephritis during pregnancy. J Matern Fetal Neonatal Med 2007;20:735-44.
Maternal serum soluble CD30 is increased in normal pregnancy but decreased in pre-eclampsia and SGA pregnancies
Pre-eclampsia and SGA are characterized by an exaggerated maternal inflammatory response and a predominantly T helper 1 (Th1)–biased immune response; the latter stands in contrast to the normal pregnant state (Th2-biased state). We determined the maternal blood concentrations of soluble CD30 (sCD30), which is considered a marker of a Th2 immune response. The median sCD30 serum concentration was significantly higher in women with normal pregnancies than in non-pregnant women. Patients with pre-eclampsia and those who delivered an SGA neonate had a significantly lower serum concentration of sCD30 than did normal pregnant women. These findings are consistent with the view that normal pregnancy is characterized by a Th2-biased immune response and that pre-eclampsia and SGA are associated with a polarized Th1 response, possibly attributable to a reduced Th2 response.
Kusanovic JP, Romero R, Hassan SS, Gotsch F, Edwin S, Chaiworapongsa T, Erez O, Mittal P, Mazaki-Tovi S, Soto E, Than NG, Friel LA, Yoon BH, Espinoza J. Maternal serum soluble CD30 is increased in normal pregnancy, but decreased in preeclampsia and small for gestational age pregnancies. J Matern Fetal Neonatal Med 2007;20:867-78.
Maternal serum soluble CD30 is increased in pregnancies complicated with acute pyelonephritis
Normal pregnancy is characterized by activation of innate immunity and suppression of the adaptive limb of the immune response. However, pregnant women are more susceptible to the effects of infection and microbial products than non-pregnant women. CD30 is preferentially expressed by activated T cells producing Th2-type cytokines, and sCD30 is proposed to be an index of Th2 immune response. Given conflicting evidence about serum sCD30 concentration in patients with bacterial infections, we conducted a cross-sectional study to determine whether changes occur in the serum concentration of sCD30 in pregnant women with pyelonephritis. Such women had a significantly higher median serum concentration of sCD30 than women with a normal pregnancy. Our novel finding suggests that pregnant women with pyelonephritis may have a complex immune state with activation of some components of what is considered a Th2 immune response.
Kusanovic JP, Romero R, Hassan SS, Gotsch F, Edwin S, Chaiworapongsa T, Erez O, Mittal P, Mazaki-Tovi S, Soto E, Than NG, Friel LA, Yoon BH, Espinoza J, Mazor M. Maternal serum soluble CD30 is increased in pregnancies complicated with acute pyelonephritis. J Matern Fetal Neonatal Med 2007;20:867-78.
Pre-eclampsia is associated with low concentrations of protein Z
Pregnancy is considered a hypercoagulable state. Thrombosis has been proposed as a mechanism of disease in pre-eclampsia, intrauterine growth restriction, stillbirth, recurrent pregnancy losses, and preterm delivery. Protein Z is a vitamin K–dependent plasma protein that plays an important role in the regulation of the coagulation cascade; its deficiency has been associated with unexplained pregnancy loss and adverse pregnancy outcome in patients with thrombophilia. We conducted a study to determine if pre-eclampsia, SGA, and fetal demise are associated with changes in maternal plasma concentrations of protein Z. Patients with an SGA neonate and those with fetal demise did not have plasma protein Z concentrations that differed significantly from those of normal pregnant women, although the rate of protein Z deficiency was significantly higher in patients with pre-eclampsia and fetal demise than in women with normal pregnancies. Of interest, only patients with pre-eclampsia had significantly lower median plasma concentrations of protein Z than normal pregnant women; such concentrations may be secondary to a higher activation of the coagulation system in patients with this pregnancy complication.
Erez O, Hoppensteadt D, Romero R, Espinoza J, Gonçalves L, Nien JK, Kusanovic JP, Fareed J, Gotsch F, Pineles B, Chaiworapongsa T. Preeclampsia is associated with low concentrations of protein Z. J Matern Fetal Neonatal Med 2007;20:661-7.
Plasma protein Z concentrations in pregnant women with idiopathic intrauterine bleeding and in women with spontaneous preterm labor
Preterm parturition has been associated with decidual vascular disorders and excessive thrombin generation. Protein Z, a glycoprotein, binds to the protein Z–dependent protease inhibitor (ZPI) and is thought to regulate thrombin generation. We designed a cross-sectional study to examine the maternal plasma concentration of protein Z in women with a normal pregnancy and in women presenting with spontaneous preterm labor or intrauterine bleeding during pregnancy. At term, the mean maternal plasma concentration of protein Z was significantly lower in women during spontaneous labor than in those not in labor. Women with spontaneous preterm labor without intra-amniotic infection/inflammation who delivered preterm had a significantly lower mean protein Z concentration than did normal pregnant women. Of interest, we found no association between spontaneous preterm labor with intra-amniotic infection/inflammation and lower plasma concentrations of protein Z and no association in patients who experienced spontaneous preterm labor but delivered at term. Patients with idiopathic intrauterine bleeding who had spontaneous preterm labor and delivery had a significantly lower mean plasma protein Z concentration than those who delivered at term. Collectively, our observations suggest that a subgroup of patients with spontaneous preterm labor have a hemostatic disorder that involves bleeding/thrombosis as a mechanism of disease.
Kusanovic JP, Espinoza J, Romero R, Hoppensteadt D, Nien JK, Kim CJ, Erez O, Soto E, Fareed J, Edwin S, Chaiworapongsa T, Than NG, Yoon BH, Gomez R, Papp Z, Hassan SS. Plasma protein Z concentrations in pregnant women with idiopathic intrauterine bleeding and in women with spontaneous preterm labor. J Matern Fetal Neonatal Med 2007;20:453-63.
Changes in fetal cardiac geometry with gestation; implications for three- and four-dimensional fetal echocardiography
Congenital anomalies continue to be a leading cause of perinatal mortality in the United States. Advances in imaging techniques have allowed the prenatal detection of many anatomical defects with ultrasound. Our goal is to improve the diagnosis and treatment of fetal disease and congenital anomalies. We use three- and four-dimensional (3D/4D) ultrasound and develop novel approaches and algorithms to improve the prenatal diagnosis of congenital anomalies, particularly congenital heart disease, which is the leading cause of infant death among newborns with congenital anomalies.
Examination of the fetal heart with two-dimensional ultrasound requires the use of conventional sonographic planes. The planes may be obtained with 3D and 4D ultrasound by using novel algorithms. However, the algorithms assume that the spatial relationships among cardiac chambers and great vessels remain constant throughout gestation. This year, we performed a cross-sectional study by reviewing 3D/4D volume data sets from 85 healthy fetuses obtained between 12 and 41 weeks’ gestation. We measured the following parameters: (1) the angle between the ductal arch and fetal thoracic aorta, (2) the angle between the ductal arch and aortic arch, and (3) the mean angle between the left outflow tract and main pulmonary artery, as seen in the short axis of the heart. Our analyses demonstrated that the angle between the ductal arch and fetal thoracic aorta decreased with gestational age. In contrast, the angle between the ductal and aortic arches and the mean angle between the left outflow tract and the short axis of the heart increased with gestational age. The findings suggest significant changes in fetal cardiac geometry with advancing gestational age. Accordingly, we propose that algorithms for 3D/4D fetal echocardiography may need to be modified to address such changes.
Espinoza J, Gotsch F, Kusanovic JP, Gonçalves LF, Lee W, Hassan S, Mittal P, Schoen ML, Romero R. Changes in fetal cardiac geometry with gestation: implications for 3- and 4-dimensional fetal echocardiography. J Ultrasound Med 2007;26:437-43; quiz 444.
The role of the sagittal view of the ductal arch in the prenatal diagnosis of conotruncal anomalies using 4D ultrasonography
Conotruncal anomalies represent one-fifth of all congenital heart defects diagnosed prenatally. However, in about 20 percent of cases, the spatial relationship of the great vessels is incorrectly defined. In fetal echocardiography, the sagittal view of the ductal arch is considered a standard ultrasonographic view that may be easily visualized with 4D ultrasonography by using an algorithm that we developed. The current study used volume data sets, acquired with the spatiotemporal image correlation (STIC) technique, from fetuses with and without confirmed conotruncal anomalies. The visualization rate of the sagittal view of the ductal arch was significantly lower in fetuses with conotruncal anomalies than in fetuses without abnormalities and in fetuses with other congenital heart diseases. Moreover, absence of visualization of the sagittal view of the ductal arch was associated with a likelihood ratio of 9.44 for a conotruncal anomaly. Visualization of the sagittal view of the ductal arch may play an important role in the screening and prenatal diagnosis of conotruncal anomalies with the use of 4D ultrasonography.
Espinoza J, Romero R, Kusanovic JP, Gotsch F, Erez O, Lee W, Gonçalves LF, Schoen ML, Hassan SS. The role of the sagittal view of the ductal arch in identification of fetuses with conotruncal anomalies using 4-dimensional ultrasonography. J Ultrasound Med 2007;26:1181-8.
Differential prenatal diagnosis of congenital diaphragmatic eventration and congenital diaphragmatic hernia
The prognosis and postnatal management of congenital diaphragmatic eventration and congenital diaphragmatic hernia differ. Thus, the accurate prenatal diagnosis of these two congenital anomalies is important for patient management. We recently reported that a higher proportion of fetuses with diaphragmatic eventration had associated pleural and pericardial effusions compared with fetuses with diaphragmatic hernia. Thus, the presence of pleural and/or pericardial effusion in patients with diaphragmatic defects should raise the index of suspicion for the diagnosis of congenital diaphragmatic eventration, potentially helping with the differential diagnosis of the two conditions.
Jeanty C, Nien JK, Espinoza J, Kusanovic JP, Gonçalves LF, Qureshi F, Jacques S, Lee W, Romero R. Pleural and pericardial effusion: a potential ultrasonographic marker for the prenatal differential diagnosis between congenital diaphragmatic eventration and congenital diaphragmatic hernia. Ultrasound Obstet Gynecol 2007;29:378-87.
Evaluation of fetal brain sulcation with 3D ultrasound; evaluation of fetal cerebral cortex sulcation is important for the prenatal diagnosis of neuronal migration disorders
The diagnosis of an abnormal sylvian fissure relies on subjective interpretation of ultrasonographic images. We conducted a cross-sectional study in order to develop an objective ultrasonographic parameter for sylvian fissure evaluation. Using 3D ultrasound with multiplanar display, we measured the distance of the sylvian fissure to parietal bone (SPB) from the midpoint to the inner surface of the parietal bone, perpendicular to the falx cerebri. Our results demonstrated that the SPB can be reproducibly measured from 12 weeks’ gestation to term and showed a strong positive correlation with gestational age. This parameter may be useful in the prenatal diagnosis of abnormal cerebral sulcation.
Mittal P, Gonçalves LF, Kusanovic JP, Espinoza J, Lee W, Nien JK, Soto E, Romero R. Objective evaluation of sylvian fissure development by multiplanar 3-dimensional ultrasonography. J Ultrasound Med 2007;26:347-53.
Quantitative assessment of gestational sac shape
The use of 3D ultrasound in obstetrics permits capture of the entire volume of small objects, such as the gestational sac and small placentas. Morphological and quantitative analysis of the gestational sac may provide baseline parameters for studying patients at risk for early pregnancy failure. However, volume information requires location of the object’s surface so that the object’s volume may be defined. This year, we developed a quantitative method for characterizing the gestational sac shape with a single number, called the gestational sac shape score. We obtained the 3D coordinates of surface-point sets in 20 first-trimester gestational sacs in normal pregnancies. We used cubic spline interpolation to determine the coordinates of a standard surface-point sample (3,660) for each sac in each slice sample, giving each sac a standard configuration by moving its center of gravity to the origin and aligning its inertial axes along the coordinate axes. Cubic spline interpolations were accurate in most cases, with means close to 0 percent and approximately 95 percent of the errors at less than 10 percent. This approach provides quantitative shape information about a variety of biological shapes and how they change over time.
Deter RL, Li J, Lee W, Liu S, Romero R. Quantitative assessment of gestational sac shape: the gestational sac shape score. Ultrasound Obstet Gynecol 2007;29:574-82.
The combination of ultrasound and biochemical markers for the identification of patients at risk for development of pre-eclampsia
We conducted a prospective cohort study to examine—between 22 and 26 week’s gestation—the relationship between abnormal uterine artery Doppler velocimetry (UADV) and plasma concentrations of Placental Growth Factor (PlGF) in 3,348 pregnant women. An abnormal UADV and maternal plasma PlGF of less than 280 pg/mL were independent risk factors for the occurrence of pre-eclampsia, severe pre-eclampsia, early-onset pre-eclampsia, and SGA without pre-eclampsia. Of note, the combination of abnormal UADV and maternal plasma PlGF of less than 280 pg/mL was associated with an odds ratio (OR) of 43.8 for development of early-onset pre-eclampsia (at less than 34 weeks), an OR of 37.4 for development of severe pre-eclampsia, and an OR of 8.6 for development of pre-eclampsia. Thus, a combination of abnormal UADV in the second trimester of pregnancy and a low concentration of PlGF in maternal blood can identify a subgroup of patients at a very high risk of developing early-onset and/or severe pre-eclampsia. These patients may be candidates for future randomized clinical trials.
Espinoza J, Romero R, Nien JK, Gomez R, Kusanovic JP, Gonçalves LF, Medina L, Edwin S, Hassan S, Carstens M, Gonzalez R. Identification of patients at risk for early onset and/or severe preeclampsia with the use of uterine artery Doppler velocimetry and placental growth factor. Am J Obstet Gynecol 2007;196:326.e1-13.
COLLABORATORS
Russell Deter, MD, Baylor College of Medicine, Houston, TX
Offer Erez, MD, Wayne State University School of Medicine, Detroit, MI
Jimmy Espinoza, MD, Wayne State University School of Medicine, Detroit, MI
Ricardo Gomez, MD, Sotero del Rio Hospital, Puente Alto, Chile
Luis F. Gonçalves, MD, Wayne State University School of Medicine, Detroit, MI
Sonia Hassan, MD, Wayne State University School of Medicine, Detroit, MI
Sujatha Kannan, MD, Wayne State University School of Medicine, Detroit, MI
Chong-Jai Kim,MD, PhD, Wayne State University School of Medicine, Detroit, MI
Jung Sun Kim, MD, PhD, Wayne State University School of Medicine, Detroit, MI
Yeon Mee Kim, MD, Wayne State University School of Medicine, Detroit, MI
Juan Pedro Kusanovic, MD, Wayne State University School of Medicine, Detroit, MI
Wesley Lee, MD, William Beaumont Hospital, Royal Oak, MI
Pooja Mittal, MD, Wayne State University School of Medicine, Detroit, MI
Daniel Montenegro, BS, Wayne State University School of Medicine, Detroit, MI
Karina Richani, MD, Wayne State University School of Medicine, Detroit, MI
Eleazar Soto, MD, Wayne State University School of Medicine, Detroit, MI
For further information, contact powersJ@mail.nih.gov.
