Maternal Plasma RNA in First Trimester Nullipara for the Prediction of Spontaneous Preterm Birth ≤ 32 Weeks: Validation Study

The first-trimester prediction of spontaneous preterm birth (sPTB) has been elusive, and current screening is heavily dependent on obstetric history. However, nullipara lack a relevant history and are at higher risk for spontaneous (s)PTB ≤ 32 weeks compared to multipara. No available objective first-trimester screening test has proven a fair predictor of sPTB ≤ 32 weeks. We questioned whether a panel of maternal plasma cell-free (PCF) RNAs (PSME2, NAMPT, APOA1, APOA4, and Hsa-Let-7g) previously validated at 16-20 weeks for the prediction of sPTB ≤ 32 weeks might be useful in first-trimester nullipara. Sixty (60) nulliparous women (40 with sPTB ≤ 32 weeks) who were free of comorbidities were randomly selected from the King's College Fetal Medicine Research Institute biobank. Total PCF RNA was extracted and the expression of panel RNAs was quantitated by qRT-PCR. The analysis employed, primarily, multiple regression with the main outcome being the prediction of subsequent sPTB ≤ 32 weeks. The test performance was judged by the area under the curve (AUC) using a single threshold cut point with observed detection rates (DRs) at three fixed false positive rates (FPR). The mean gestation was 12.9 ± 0.5 weeks (range 12.0-14.1 weeks). Two RNAs were differentially expressed in women destined for sPTB ≤ 32 weeks: APOA1 (p < 0.001) and PSME2 (p = 0.05). APOA1 testing at 11-14 weeks predicted sPTB ≤ 32 weeks with fair to good accuracy. The best predictive model generated an AUC of 0.79 (95% CI 0.66-0.91) with observed DRs of 41%, 61%, and 79% for FPRs of 10%, 20%, and 30%, including crown-rump length, maternal weight, race, tobacco use, and age.

Early and late preterm birth rates in participants adherent to randomly assigned high dose docosahexaenoic acid (DHA) supplementation in pregnancy

BACKGROUND

Intention-to-treat analyses do not address adherence. Per protocol analyses treat nonadherence as a protocol deviation and assess if the intervention is effective if followed.

OBJECTIVE

To determine the rate of early preterm birth (EPTB, <34 weeks gestation) and preterm birth (PTB, <37 weeks gestation) in participants who adhered to a randomly assigned docosahexaenoic acid (DHA) dose of 1000 mg/day.

STUDY DESIGN

Eleven hundred women with a singleton pregnancy were enrolled before 20-weeks' gestation, provided a capsule with 200 mg/day DHA and randomly assigned to two additional capsules containing a placebo or 800 mg of DHA. In the Bayesian Adaptive Design, new randomization schedules were determined at prespecified intervals. In each randomization, the group with the most EPTB was assigned fewer participants than the other group. Adherence was defined a priori as a postpartum red blood cell phospholipid DHA (RBC-PL-DHA) ≥5.5%.and post hoc as ≥8.0% RBC-PL-DHA, the latter after examination of postpartum RBC-PL-DHA. Bayesian mixture models were fitted for gestational age and dichotomized for EPTB and PTB as a function of baseline RBC-PL-DHA and dose-adherence. Bayesian hierarchical models were also fitted for EPTB by dose adherence and quartiles of baseline RBC-PL-DHA.

RESULTS

Adherence to the high dose using both RBC-PL-DHA cut points resulted in less EPTB compared to 200 mg [Bayesian posterior probability (pp) = 0.93 and 0.92, respectively]. For participants in the two lowest quartiles of baseline DHA status, adherence to the higher dose resulted in lower EPTB (≥5.5% RBC-PL-DHA, quartiles 1 and 2, pp = 0.95 and 0.96; ≥8% RBC-PL-DHA, quartiles 1 and 2, pp = 0.94 and 0.95). Using the Bayesian model, EPTB was reduced by 65%, from 3.45% to 1.2%, using both cut points. Adherence also reduced PTB before 35, 36 and 37 weeks using both cut points (pp ≥ 0.95). In general, performance of the nonadherent subgroup mirrored that of participants assigned to 200 mg.

CONCLUSION

Adherence to high dose DHA reduced EPTB and PTB. The largest effect of adherence on reducing EPTB was observed in women with low baseline DHA levels.

CLINICALTRIALS

gov (NCT02626299).

Detection of Embryonic Trisomy 21 in the First Trimester Using Maternal Plasma Cell-Free RNA

Prenatal trisomy 21 (T21) screening commonly involves testing a maternal blood sample for fetal DNA aneuploidy. It is reliable but poses a cost barrier to universal screening. We hypothesized maternal plasma RNA screening might provide similar reliability but at a lower cost. Discovery experiments used plasma cell-free RNA from 20 women 11−13 weeks tested by RNA and miRNA microarrays followed by qRT-PCR. Thirty-six mRNAs and 18 small RNAs of the discovery cDNA were identified by qPCR as potential markers of embryonic T21. The second objective was validation of the RNA predictors in 998 independent pregnancies at 11−13 weeks including 50 T21. Initial analyses identified 9−15 differentially expressed RNA with modest predictive power (AUC < 0.70). The 54 RNAs were then subjected to machine learning. Eleven algorithms were trained on one partition and tested on an independent partition. The three best algorithms were identified by Kappa score and the effects of training/testing partition size and dataset class imbalance on prediction were evaluated. Six to ten RNAs predicted T21 with AUCs up to 1.00. The findings suggest that maternal plasma collected at 11−13 weeks, tested by qRT-PCR, and classified by machine learning, may accurately predict T21 for a lower cost than plasma DNA, thus opening the door to universal screening.

Early pregnancy prediction of spontaneous preterm birth before 32 completed weeks of pregnancy using plasma RNA: transcriptome discovery and initial validation of an RNA panel of markers

OBJECTIVE

To compare the second-trimester plasma cell-free (PCF) transcriptome of women who delivered at term with that of women with spontaneous preterm birth (sPTB) at or before 32 weeks of gestation and identify/validate PCF RNA markers present by 16 weeks of gestation.

DESIGN

Prospective case-control study.

SETTING

Academic tertiary care centre.

POPULATION

Pregnant women with known outcomes prospectively sampled.

METHODS

PCF RNAs extracted from women at 22-24 weeks of gestation (five sPTB up to 32 weeks and five at term) were hybridised to gene expression arrays. Differentially regulated RNAs for sPTB up to 32 weeks were initially selected based on P value compared with control (P < 0.01) and fold change (≥1.5×). Potential markers were then reordered by narrowness of distribution. Final marker selection was made by searching the Metacore™ database to determine whether the PCF RNAs interacted with a reported set of myometrial Preterm Initiator genes. RNAs were confirmed by quantitative reverse transcription polymerase chain reaction and tested in a second group of 40 women: 20 with sPTB up to 32 weeks (mean gestation 26.5 weeks, standard deviation ±2.6 weeks), 20 with spontaneous term delivery (40.1 ± 0.9 weeks) sampled at 16-19+5  weeks of gestation.

MAIN OUTCOME MEASURE

Identification of PCF RNAs predictive of sPTB up to 32 weeks.

RESULTS

Two hundred and ninety-seven PCR RNAs were differentially expressed in sPTB up to 32 weeks of gestation. Further selection retained 99 RNAs (86 mRNAs and 13 microRNAs) and five of these interacted in silica with seven Preterm Initiator genes. Four of five RNAs were confirmed and tested on the validation group. The expression of each confirmed PCF RNA was significantly higher in sPTB up to 32 weeks of gestation. In vitro study of the four mRNAs revealed higher expression in placentas of women with sPTB up to 32 weeks and the potential to interfere with myometrial quiescence.

CONCLUSIONS

The PCF RNA markers are highly associated with sPTB up to 32 weeks by 16 weeks of gestation.

TWEETABLE ABSTRACT

Women destined for spontaneous preterm birth can be identified by 16 weeks of gestation with a panel of maternal plasma RNAs.

Higher dose docosahexaenoic acid supplementation during pregnancy and early preterm birth: A randomised, double-blind, adaptive-design superiority trial

BACKGROUND

Several meta analyses have concluded n-3 fatty acids, including docosahexaenoic acid (DHA), reduce early preterm birth (EPB, < 34 weeks), however, the amount of DHA required is unclear. We hypothesized that 1000 mg DHA per day would be superior to 200 mg, the amount in most prenatal supplements.

METHODS

This randomised, multicentre, double-blind, adaptive-design, superiority trial was conducted in three USA medical centres. Women with singleton pregnancies and 12 to 20 weeks gestation were eligible. randomization was generated in SAS® by site in blocks of 4. The planned adaptive design periodically generated allocation ratios favoring the better performing dose. Managing study personnel were blind to treatment until 30 days after the last birth. The primary outcome was EPB by dose and by enrolment DHA status (low/high). Bayesian posterior probabilities (pp) were determined for planned efficacy and safety outcomes using intention-to-treat. The study is registered with ClinicalTrials.gov (NCT02626299) and closed to enrolment.

FINDINGS

Eleven hundred participants (1000 mg, n = 576; 200 mg, n = 524) were enrolled between June 8, 2016 and March 13, 2020 with the last birth September 5, 2020. 1032 (n = 540 and n = 492) were included in the primary analyses. The higher dose had a lower EPB rate [1.7% (9/540) vs 2.4% (12/492), pp=0.81] especially if participants had low DHA status at enrolment [2.0% (5/249) vs 4.1%, (9/219), pp=0.93]. Participants with high enrolment DHA status did not realize a dose effect [1000 mg: 1.4% (4/289); 200 mg: 1.1% (3/271), pp = 0.57]. The higher dose was associated with fewer serious adverse events (maternal: chorioamnionitis, premature rupture of membranes and pyelonephritis; neonatal: feeding, genitourinary and neurologic problems, all pp>0.90).

INTERPRETATION

Clinicians could consider prescribing 1000 mg DHA daily during pregnancy to reduce EPB in women with low DHA status if they are able to screen for DHA.

FUNDING

The National Institutes of Health Child Health and Human Development (NICHD) funded the study. Life's DHA™-S oil, DSM Nutritional Products LLC, Switzerland provided all capsules.

Transplantation of Human Umbilical Cord Blood-Derived Cellular Fraction Improves Left Ventricular Function and Remodeling After Myocardial Ischemia/Reperfusion

Rationale: Human umbilical cord blood (hUCB) contains diverse populations of stem/progenitor cells. Whether hUCB-derived nonhematopoietic cells would induce cardiac repair remains unknown. Objective: To examine whether intramyocardial transplantation of hUCB-derived CD45^-Lin^- nonhematopoietic cellular fraction after a reperfused myocardial infarction in nonimmunosuppressed rats would improve cardiac function and ameliorate ventricular remodeling. Methods and Results: Nonhematopoietic CD45^-Lin^- cells were isolated from hUCB. Flow cytometry and quantitative polymerase chain reaction were used to characterize this subpopulation. Age-matched male Fischer 344 rats underwent a 30-minute coronary occlusion followed by reperfusion and 48 hours later received intramyocardial injection of vehicle or hUCB CD45^-Lin^- cells. After 35 days, compared with vehicle-treated rats, CD45^-Lin^- cell-treated rats exhibited improved left ventricular function, blunted left ventricular hypertrophy, greater preservation of viable myocardium in the infarct zone, and superior left ventricular remodeling. Mechanistically, hUCB CD45^-Lin^- cell injection favorably modulated molecular pathways regulating myocardial fibrosis, cardiomyocyte apoptosis, angiogenesis, and inflammation in postinfarct ventricular myocardium. Rare persistent transplanted human cells could be detected at both 4 and 35 days after myocardial infarction. Conclusions: Transplantation of hUCB-derived CD45^-Lin^- nonhematopoietic cellular subfraction after a reperfused myocardial infarction in nonimmunosuppressed rats ameliorates left ventricular dysfunction and improves remodeling via favorable paracrine modulation of molecular pathways. These findings with human cells in a clinically relevant model of myocardial ischemia/reperfusion in immunocompetent animals may have significant translational implications.Visual Overview: An online visual overview is available for this article.

Abstract 2235: Circulating microRNA-205 as a potential prognostic biomarker for recurrent ovarian cancer

Background:

Ovarian cancer is the most lethal gynecological malignancy and the fifth most common cancer in women in the U.S. Patients diagnosed in advanced-stage ovarian cancer have 70-95 % chance of relapse. Additional non-invasive approaches to monitor response to treatment and to predict recurrent disease are urgently needed. Aberrant expression levels of circulating microRNAs are diagnostic, prognostic, and predictive biomarkers in ovarian cancer. We recently published that microRNA-205 (miR-205) expression is elevated in ovarian cancer and correlates with advanced-stage disease. Here, we investigate circulating microRNA-205 as a potential biomarker for monitoring disease in patients diagnosed with advanced-stage ovarian cancer.

Methods:

Plasma samples from normal controls (n=12) and recurrent stage III/IV ovarian cancer patients (n=5) in our biorepository were used. Samples were collected 1 day before surgery operation and at 1 month, 2 months and 6 months after the primary surgery. All samples were from serous ovarian carcinomas. All the patients went through the standard chemotherapy and CA-125 levels were decreased to the normal range (&lt;35U/ml) at 6 months after the surgery. All recurrent disease was detected within 2 years after primary surgery. Circulating microRNAs were extracted from plasma of ovarian cancer patients and normal controls using miRNeasy Mini Kit (Qiagen). The reverse transcriptions were conducted using qScrip microRNA cDNA Synthesis Kit. (VWR). The circulating miR-205 expression was confirmed by quantitative real-time polymerase chain reaction (qPCR). Results are reported as mean ± S.E. Student’s t-test was applied.

Results:

Our results confirmed that the expression of circulating miR-205 was significantly elevated in stage III/IV ovarian cancer plasma samples compared with normal controls (5.91 fold; p&lt;0.05). Compared with levels in paired pre-operative plasma, circulating miR-205 expression was significantly lower in the post-operative plasma at 1 month (p&lt;0.01), gradually rose to pre-operative levels at 2 months, and significantly increased by 6 months post-operation (p &lt;0.05). Circulating miR-205 expression levels were significantly increased at 6 months in post-operative samples when CA-125 levels were at normal range, suggested the circulating miR-205 can potentially be used as a biomarker for ovarian cancer recurrence.

Conclusion:

Dynamic changes of the circulating miR-205 expression in pre- and post-operative plasma samples of recurrent stage III/IV ovarian cancer patients demonstrated that circulating miR-205 levels could be used as non-invasive biomarkers for monitoring disease in patients diagnosed with advanced stage ovarian cancer. Further investigation is warranted in larger cohorts of patients.

Citation Format: Meghan W. Kusch, Julia A. Chapman, Carl P. Weiner, Katherine F. Roby, Dineo Khabele, Helen H. Zhou. Circulating microRNA-205 as a potential prognostic biomarker for recurrent ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2235.

Expression, Regulation, and Function of the Calmodulin Accessory Protein PCP4/PEP-19 in Myometrium

OBJECTIVE

Calmodulin (CaM) plays a key role in the orchestration of Ca²⁺ signaling events, and its regulation is considered an important component of cellular homeostasis. The control of uterine smooth muscle function is largely dependent on the regulation of Ca²⁺ and CaM signaling. The objective of this study was to investigate the expression, function, and regulation of CaM regulatory proteins in myometrium during pregnancy.

STUDY DESIGN

Myometrium was obtained from nonpregnant women and 4 groups of pregnant women at the time their primary cesarean delivery: (i) preterm not in labor, (ii) preterm in labor with clinical and/or histological diagnosis of chorioamnionitis, (3) term not in labor; and (4) term in labor. The effect of perinatal inflammation on pcp4/pep-19 expression was evaluated in a mouse model of Ureaplasma parvum-induced chorioamnionitis. Human myometrial cells stably expressing wild-type and mutant forms of PCP4/PEP-19 were used in the evaluation of agonist-induced intracellular Ca²⁺ mobilization.

RESULTS

Compared to other CaM regulatory proteins, PCP4/PEP-19 transcripts were more abundant in human myometrium. The expression of PCP4/PEP-19 was lowest in myometrium of women with preterm pregnancy and chorioamnionitis. In the mouse uterus, pcp4/pep-19 expression was lower in late compared to mid-gestation and decreased in mice injected intra-amniotic with Ureaplasma parvum. In myometrial smooth muscle cells, tumor necrosis factor alpha and progesterone decreased and PCP4/PEP-19 promoter activity increased. Finally, the overexpression of PCP4/PEP-19 reduced agonist-induced intracellular Ca²⁺ levels in myometrial cells.

CONCLUSION

The decreased expression of PCP4/PEP-19 in myometrium contributes to a loss of quiescence in response to infection-induced inflammation at preterm pregnancy.

Perimortem Demonstration and Treatment of Recipient-to-Donor Transfusion in Monochorionic-Diamniotic Twin Gestation

Twin-twin transfusion syndrome is a complication of monochorionic-diamniotic placentation. Should one twin die, ≈30% of co-twins will also die, and if they survive, ≈30% experience severe morbidity rates, each believed secondary to hemorrhage of the co-twin into the deceased twin. We report apparently the first ultrasound-documented case of perimortem hemorrhage in twin-twin transfusion syndrome and its treatment by emergent ultrasound-guided percutaneous cord occlusion followed by percutaneous fetal intravascular transfusion. The case illustrates three important pathophysiologic events. First, it confirms acute twin-to-twin hemorrhage occurs and reveals it can begin before the first twin dies. Thus, delivery of the survivor after its dead co-twin is discovered is unlikely to protect the survivor. Second, the elevated fetal middle cerebral artery peak systolic velocity due to acute anemia requires hours to develop. And thirdly, intracardiac epinephrine can correct the acute fetal bradycardia associated with hemorrhage that is presumably due to fetal hypotension.

MicroRNA-205 promotes cell invasion by repressing TCF21 in human ovarian cancer

Background

Ovarian cancer is the leading lethal, gynecological malignancy in the United States. No doubt, the continued morbidity and mortality of ovarian cancer reflects a poor understanding of invasive mechanisms. Recent studies reveal that ovarian cancers express aberrant microRNAs (miRNAs or miRs), some of which have oncogenic or tumor suppressor properties. Several studies suggested that miR-205 is involved in tumorigenesis. Presently, we investigate the molecular mechanisms and target of miR-205 in ovarian cancer.

Methods

Quantitative real-time polymerase chain reaction and western blot were performed to assess miR-205 and transcription factor 21 (TCF21) expression in ovarian cancer and normal ovary samples. The effect of miR-205 on TCF21 was determined by luciferase reporter assay and western blot. The effect of miR-205 and TCF21 on cell invasion was quantitated using transwell invasion assay.

Result

miR-205 expression was increased in ovarian cancer and it promoted the invasive behavior of ovarian cancer cell lines (OVCAR-5, OVCAR-8 and SKOV-3). miR-205 directly targeted TCF21, which was significantly decreased in ovarian cancer tissue. miR-205 inhibited TCF21 expression and as a consequence blunted the inhibitory effect of TCF21 on cell invasion. Matrix Metalloproteinases (MMPs) play an important role in cancer invasion and metastasis. TCF21 inhibited MMP-2 and MMP-10 and decreased ovarian cancer cell invasion. Co-transfection of TCF21 expression plasmid with miR-205 mimic diminished the inhibitory effect of TCF21 on MMP-2 and MMP-10 in ovarian cancer cells.

Conclusion

miR-205 appears to have an important role in the spread of ovarian cancer by targeting TCF21. These findings offer a new mechanism of ovarian cancer tumorigenesis, which could be useful for the development of new therapeutic approaches to ovarian cancer treatment.

Assessment of DHA on reducing early preterm birth: the ADORE randomized controlled trial protocol

BACKGROUND

Preterm birth contributes to 0.5 million deliveries in the United States (one of eight pregnancies) and poses a huge burden on public health with costs in the billions. Of particular concern is that the rate of earliest preterm birth (<34 weeks) (ePTB), which has decreased little since 1990 and has the greatest impact on the overall infant mortality, resulting in the greatest cost to society. Docosahexaenoic acid (DHA) supplementation provides a potential high yield, low risk strategy to reduce early preterm delivery in the US by up to 75%. We propose a Phase III Clinical Trial (randomized to low or high dose DHA, double-blinded) to examine the efficacy and safety of high dose DHA supplementation to reduce ePTB. We also plan for a secondary pregnancy efficacy analysis to determine if there is a subset of pregnancies most likely to benefit from DHA supplementation.

METHODS

Between 900 and 1200 pregnant women who are ≥ 18 years old and between 12 and 20 weeks gestation will be recruited from three trial experienced academic medical institutions. Participants will be randomly assigned to two daily capsules of algal oil (totaling 800 mg DHA) or soybean and corn oil (0 mg DHA). Both groups will receive a commercially available prenatal supplement containing 200 mg DHA. Therefore, the experimental group will receive 1000 mg DHA/d and the control group 200 mg DHA/d. We will then employ a novel Bayesian response adaptive randomization design that assigns more subjects to the "winning" group and potentially allows for substantially smaller sample size while providing a stronger conclusion regarding the most effective group. The study has an overall Type I error rate of 5% and a power of 90%. Participants are followed throughout pregnancy and delivery for safety and delivery outcomes.

DISCUSSION

We hypothesize that DHA will decrease the frequency of ePTB <34 weeks. Reducing ePTB is clinically important as these earliest preterm deliveries carry the highest risk of neonatal morbidity, as well as contribute significant stress for families and post a large societal burden.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov (identifier: NCT02626299 ) on December 8, 2015. Additional summary details may be found in Table 1.

In Vivo Neurochemical Characterization of Developing Guinea Pigs and the Effect of Chronic Fetal Hypoxia

The guinea pig is a frequently used animal model for human pregnancy complications, such as oxygen deprivation or hypoxia, which result in altered brain development. To investigate the impact of in utero chronic hypoxia on brain development, pregnant guinea pigs underwent either normoxic or hypoxic conditions at about 70 % of 65-day term gestation. After delivery, neurochemical profiles consisting of 19 metabolites and macromolecules were obtained from the neonatal cortex, hippocampus, and striatum from birth to 12 weeks postpartum using in vivo (1)H MR spectroscopy at 9.4 T. The effects of chronic fetal hypoxia on the neurochemical profiles were particularly significant at birth. However, the overall developmental trends of neurochemical concentration changes were similar between normoxic and hypoxic animals. Alterations of neurochemicals including N-acetylaspartate (NAA), phosphorylethanolamine, creatine, phosphocreatine, and myo-inositol indicate neuronal loss, delayed myelination, and altered brain energetics due to chronic fetal hypoxia. These observed neurochemical alterations in the developing brain may provide insights into hypoxia-induced brain pathology, neurodevelopmental compromise, and potential neuroprotective measures.

Myths and realities of training in obstetric emergencies

Training for intrapartum emergencies is a promising strategy to reduce preventable harm during birth; however, not all training is clinically effective. Many myths have developed around such training. These principally derive from misinformed beliefs that all training must be effective, cheap, independent of context and sustainable. The current evidence base for effective training supports local, unit-based and multi-professional training, with appropriate mannequins, and practice-based tools to support the best care. Training programmes based on these principles are associated with improved clinical outcomes, but we need to understand how and why that is, and also why some training is associated with no improvements, or even deterioration in outcomes. Effective training is not cheap, but it can be cost-effective. Insurers have the fiscal power to incentivise training, but they should demand the evidence of clinical effect; aspiration and proxies alone should no longer be sufficient for funding, in any resource setting.

Chronic fetal hypoxia affects axonal maturation in guinea pigs during development: A longitudinal diffusion tensor imaging and T2 mapping study

PURPOSE

To investigate the impact of chronic hypoxia on neonatal brains, and follow developmental alterations and adaptations noninvasively in a guinea pig model. Chronic hypoxemia is the prime cause of fetal brain injury and long-term sequelae such as neurodevelopmental compromise, seizures, and cerebral palsy.

MATERIALS AND METHODS

Thirty guinea pigs underwent either normoxic and hypoxemic conditions during the critical stage of brain development (0.7 gestation) and studied prenatally (n = 16) or perinatally (n = 14). Fourteen newborns (7 hypoxia and 7 normoxia group) were scanned longitudinally to characterize physiological and morphological alterations, and axonal myelination and injury using in vivo diffusion tensor imaging (DTI), T2 mapping, and T2 -weighted magnetic resonance imaging (MRI). Sixteen fetuses (8 hypoxia and 8 normoxia) were studied ex vivo to assess hypoxia-induced neuronal injury/loss using Nissl staining and quantitative reverse transcriptase polymerase chain reaction methods.

RESULTS

Developmental brains in the hypoxia group showed lower fractional anisotropy in the corpus callosum (-12%, P = 0.02) and lower T2 values in the hippocampus (-16%, P = 0.003) compared with the normoxia group with no differences in the cortex (P > 0.07), indicating vulnerability of the hippocampus and cerebral white matter during early development. Fetal guinea pig brains with chronic hypoxia demonstrated an over 10-fold increase in expression levels of hypoxia index genes such as erythropoietin and HIF-1α, and an over 40% reduction in neuronal density, confirming prenatal brain damage.

CONCLUSION

In vivo MRI measurement, such as DTI and T2 mapping, provides quantitative parameters to characterize neurodevelopmental abnormalities and to monitor the impact of prenatal insult on the postnatal brain maturation of guinea pigs.

Effect of prostaglandin E2 on multidrug resistance transporters in human placental cells

Prostaglandin (PG) E2, a major product of cyclooxygenase (COX)-2, acts as an immunomodulator at the maternal-fetal interface during pregnancy. It exerts biologic function through interaction with E-prostanoid (EP) receptors localized to the placenta. The activation of the COX-2/PGE2/EP signal pathway can alter the expression of the ATP-binding cassette (ABC) transporters, multidrug resistance protein 1 [P-glycoprotein (Pgp); gene: ABCB1], and breast cancer resistance protein (BCRP; gene: ABCG2), which function to extrude drugs and xenobiotics from cells. In the placenta, PGE2-mediated changes in ABC transporter expression could impact fetal drug exposure. Furthermore, understanding the signaling cascades involved could lead to strategies for the control of Pgp and BCRP expression levels. We sought to determine the impact of PGE2 signaling mechanisms on Pgp and BCRP in human placental cells. The treatment of placental cells with PGE2 up-regulated BCRP expression and resulted in decreased cellular accumulation of the fluorescent substrate Hoechst 33342. Inhibiting the EP1 and EP3 receptors with specific antagonists attenuated the increase in BCRP. EP receptor signaling results in activation of transcription factors, which can affect BCRP expression. Although PGE2 decreased nuclear factor κ-light chain-enhancer of activated B activation and increased activator protein 1, chemical inhibition of these inflammatory transcription factors did not blunt BCRP up-regulation by PGE2. Though PGE2 decreased Pgp mRNA, Pgp expression and function were not significantly altered. Overall, these findings suggest a possible role for PGE2 in the up-regulation of placental BCRP expression via EP1 and EP3 receptor signaling cascades.

ATP-binding cassette transporter expression in human placenta as a function of pregnancy condition

Fetal drug exposure is determined by the type and concentration of placental transporters, and their regulation is central to the development of new treatments and delivery strategies for pregnant women and their fetuses. We tested the expression of several clinically important transporters in the human placenta associated with various pregnancy conditions (i.e., labor, preeclampsia, and preterm labor-inflammation). Placentas were obtained from five groups of women at the time of primary cesarean section: 1) term no labor; 2) term labor; 3) preterm no labor (delivered for severe preeclampsia); 4) preterm labor without inflammation (PTLNI); and 5) preterm labor with inflammation (PTLI). Samples were analyzed by Western blot and immunohistochemistry to identify changes in protein expression. Relative mRNA expression was determined by quantitative real-time polymerase chain reaction. A functional genomic approach was used to identify placental gene expression and elucidate molecular events that underlie the given condition. Placental expression of ATP-binding cassette transporters from women in labor and women with preeclampsia was unaltered. Multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP) and mRNA expression increased in placentas of women with preterm labor with inflammation. Molecular pathways of genes up-regulated in PTLI samples included cytokine-cytokine receptor interactions and inflammatory response compared with those in the PTLNI group. The mRNA expression of MDR1 and BCRP was correlated with that of interleukin-8, which also increased significantly in PTLI samples. These data suggest that the transfer of drugs across the placenta may be altered in preterm pregnancy conditions associated with inflammation through changes in MDR1 and BCRP.

Prolactin family of the guinea pig, Cavia porcellus

Prolactin (PRL) is a multifunctional hormone with prominent roles in regulating growth and reproduction. The guinea pig (Cavia porcellus) has been extensively used in endocrine and reproduction research. Thus far, the PRL cDNA and protein have not been isolated from the guinea pig. In the present study, we used information derived from the public guinea pig genome database as a tool for identifying guinea pig PRL and PRL-related proteins. Guinea pig PRL exhibits prominent nucleotide and amino acid sequence differences when compared with PRLs of other eutherian mammals. In contrast, guinea pig GH is highly conserved. Expression of PRL and GH in the guinea pig is prominent in the anterior pituitary, similar to known expression patterns of PRL and GH for other species. Two additional guinea pig cDNAs were identified and termed PRL-related proteins (PRLRP1, PRLRP2). They exhibited a more distant relationship to PRL and their expression was restricted to the placenta. Recombinant guinea pig PRL protein was generated and shown to be biologically active in the PRL-responsive Nb2 lymphoma cell bioassay. In contrast, recombinant guinea pig PRLRP1 protein did not exhibit PRL-like bioactivity. In summary, we have developed a new set of research tools for investigating the biology of the PRL family in an important animal model, the guinea pig.

Human effector/initiator gene sets that regulate myometrial contractility during term and preterm labor

OBJECTIVE

Distinct processes govern transition from quiescence to activation during term (TL) and preterm labor (PTL). We sought gene sets that are responsible for TL and PTL, along with the effector genes that are necessary for labor independent of gestation and underlying trigger.

STUDY DESIGN

Expression was analyzed in term and preterm with or without labor (n=6 subjects/group). Gene sets were generated with logic operations.

RESULTS

Thirty-four genes were expressed similarly in PTL/TL but were absent from nonlabor samples (effector set); 49 genes were specific to PTL (preterm initiator set), and 174 genes were specific to TL (term initiator set). The gene ontogeny processes that comprise term initiator and effector sets were diverse, although inflammation was represented in 4 of the top 10; inflammation dominated the preterm initiator set.

CONCLUSION

TL and PTL differ dramatically in initiator profiles. Although inflammation is part of the term initiator and the effector sets, it is an overwhelming part of PTL that is associated with intraamniotic inflammation.

Brain injury caused by chronic fetal hypoxemia is mediated by inflammatory cascade activation

The prevalence of cerebral palsy (CP) shows little temporal or geographic variation and is associated with preterm birth, maternal/fetal infection/inflammation, and fetal growth restriction (IUGR), a potential surrogate for chronic fetal hypoxemia (CHX). We previously demonstrated CHX causes a fetal inflammatory response syndrome (FIRS). Herein, we test the hypothesis that CHX may cause fetal brain injury by upregulating inflammatory cytokine cascades, culminating in apoptosis pathway activation. Time-mated guinea pigs were housed in 12% or 10.5% O(2) for the last 21% of gestation. Chronic fetal hypoxemia increased the lactate/pyruvate and decreased the glutathione (GSH)/oxidized glutathione (GSSH) ratios, confirming a shift to a prooxidant state. The end result was a >30% decrease in hippocampal neuron density. Based on a microarray spotted with 113 cytokines and receptors, 22 genes were upregulated by CHX in proportion to the degree of hypoxia; the findings were confirmed by quantitative polymerase chain reaction (PCR). Thus, CHX triggers fetal brain inflammation inversely proportional to its severity characterized by increased apoptosis and neuronal loss. We suggest CHX fetal brain injury is not directly caused by oxygen deprivation but rather is an adaptive response that becomes maladaptive.

Uterine and fetal blood flow indexes and fetal growth assessment after chronic estrogen suppression in the second half of baboon pregnancy

Although estrogen regulates important aspects of maternal cardiovascular physiology, the role of estrogen on uteroplacental and fetal blood flow is incompletely understood. This study tested the hypothesis that chronically suppressing endogenous estrogen production during the second half of baboon pregnancy alters uterine and fetal blood flow dynamics assessed by ultrasonography. Pregnant baboons were untreated or treated daily with the aromatase inhibitor letrozole or letrozole plus estradiol on days 100-160 of gestation (term = 184 days). Blood flow dynamics were determined by Doppler ultrasonography on day 60 and longitudinally between days 110 and 160 of gestation. Letrozole decreased maternal serum estradiol and estrone concentrations by 95% (P < 0.001). Fetal growth biometrical parameters increased (P < 0.001) between days 110 and 160 of gestation and were similar in untreated and letrozole-treated animals. Uterine, umbilical, and fetal middle cerebral artery pulsatility index and resistance index declined (P < 0.01) by 30-50% and uterine artery volume flow increased sixfold (P < 0.001) between days 60 and 160, but values were similar in untreated, letrozole-treated, and letrozole plus estradiol-treated baboons. Thus uterine and fetal artery blood flow indexes, uterine artery volume flow, and fetal growth were maintained at normal levels despite chronic estrogen suppression in the second half of baboon pregnancy. This suggests that elevated levels of endogenous estrogen are not required to maintain low impedance blood flow within the uteroplacental vascular bed during the second half of nonhuman primate pregnancy.

Accuracy of C-reactive protein determination in predicting chorioamnionitis and neonatal infection in pregnant women with premature rupture of membranes: a systematic review

Preterm premature rupture of the fetal membranes (PPROM) is associated with intra-uterine infection. Early detection of intra-uterine infection may help prevent neonatal sepsis. C-reactive protein (CRP) is an acute phase protein often elevated when inflammation is present. The aim of this review was to assess whether CRP accurately predicts chorioamnionitis and/or neonatal sepsis in women with PPROM. We searched Medline and Embase databases for articles reporting on CRP and chorioamnionitis and/or neonatal sepsis. Two reviewers extracted clinical and methodological study characteristics and test accuracy data. Accurate data were used to form 2 x 2 data tables comparing CRP and the occurrence of infection. For the selected studies, sensitivity and specificity of CRP in the prediction of histological chorioamnionitis, clinical chorioamnionitis and neonatal sepsis were calculated separately. A bivariate meta-regression model was used to calculate pooled estimates of sensitivity and specificity. The search revealed 200 articles, of which only five met the inclusion criteria. These five articles reported on 381 patients, of which four articles (227 patients) reported on CRP as a predictor for histological chorioamnionitis and four studies (330 patients) reported on CRP as a predictor for clinical chorioamnionitis. None of the selected articles fulfilled our criteria for the use of CRP as a predictor of neonatal sepsis. CRP was moderately predictive of histological chorioamnionitis. Unfortunately, the studies of clinical chorioamnionitis were too heterogeneous to pool data. Current literature does not support the use of CRP in women with PPROM.

Characterization of RAGE, HMGB1, and S100beta in inflammation-induced preterm birth and fetal tissue injury

Immune activation represents an adaptive reaction triggered by both noxious exogenous (microbes) and endogenous [high mobility group box-1 protein (HMGB1), S100 calcium binding proteins] inducers of inflammation. Cell stress or necrosis lead the release of HMGB1 and S100 proteins in the extracellular compartment where they act as damage-associated molecular pattern molecules (or alarmins) by engaging the receptor for advanced glycation end-products (RAGE). Although the biology of RAGE is dictated by the accumulation of damage-associated molecular pattern molecules at sites of tissue injury, the role of RAGE in mediating antenatal fetal injury remains unknown. First, we studied the relationships at birth between the intensity of human fetal inflammation and sRAGE (an endogenous RAGE antagonist), HMGB1, and S100beta protein. We found significantly lower sRAGE in human fetuses that mounted robust inflammatory responses. HMGB1 levels correlated significantly with levels of interleukin-6 and S100beta in fetal circulation. We then evaluated the levels and areas of tissue expression of RAGE, HMGB1, and S100beta in specific organs of mouse fetuses on E16. Using an animal model of endotoxin-induced fetal damage and preterm birth, we determined that inflammation induces a significant change in expression of RAGE and HMGB1, but not S100beta, at sites of tissue damage. Our findings indicate that RAGE and HMGB1 may be important mediators of cellular injury in fetuses delivered in the setting of inflammation-induced preterm birth.

The active components of effective training in obstetric emergencies

Confidential enquiries into poor perinatal outcomes have identified deficiencies in team working as a common factor and have recommended team training in the management of obstetric emergencies. Isolated aviation-based team training programmes have not been associated with improved perinatal outcomes when applied to labour ward settings, whereas obstetric-specific training interventions with integrated teamwork have been associated with clinical improvements. This commentary reviews obstetric emergency training programmes from hospitals that have demonstrated improved outcomes to determine the active components of effective training. The common features identified were: institution-level incentives to train; multi-professional training of all staff in their units; teamwork training integrated with clinical teaching and use of high fidelity simulation models. Local training also appeared to facilitate self-directed infrastructural change.

Chronic hypoxemia absent bacterial infection is one cause of the fetal inflammatory response syndrome (FIRS)

The object of the investigation was to determine whether chronic fetal hypoxemia triggers a systemic fetal inflammatory response absent bacterial infection. Chronically hypoxemic (10.5% O(2)) and lipopolysaccharide (LPS; 400 microg/kg of maternal body weight) injected intrauterine (but extra-amniotic) treated pregnant guinea pigs were used with appropriate controls. The presence of bacteria in the amniotic cavity was sought using polymerase chain reaction (PCR). Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) protein levels were measured in fetal sera and amniotic fluid (AF) by a commercially available, sensitive enzyme-linked immunosorbent assay (ELISA; IL-6 and TNF-alpha messenger RNA (mRNA) were also quantified in multiple fetal organs using real-time PCR. Prokaryotic DNA was not amplified from any sample, confirming the animals were not infected. Chronic hypoxemia dramatically increased IL-6 and TNF-alpha proteins in fetal sera and mRNA in lung, heart, and brain. There were no significant changes in either cytokine observed in the AF, fetal membranes, or fetal liver. Intrauterine but extra amniotic LPS also increased IL-6 and TNF-alpha protein in fetal sera and mRNA in lung, heart, and brain, plus increased the levels of both cytokines (protein/mRNA) in AF, fetal membranes, and fetal liver. Thus, an elevation in fetal blood IL-6 is not a specific marker of infection-induced fetal inflammatory response syndrome (FIRS). And in contrast to the fetal blood, an elevation in AF IL-6 seems associated only with LPS-induced FIRS.

Determinants of the middle cerebral artery peak systolic velocity in the human fetus

OBJECTIVE

The purpose of this study was to identify physiologic determinants of the peak systolic blood flow velocity (PSV) of the middle cerebral artery (MCA) in the human fetus.

STUDY DESIGN

MCA PSV was measured with pulsed wave Doppler ultrasound in human fetuses who underwent cordocentesis. Hemoglobin, hematocrit, and blood gas values were analyzed from umbilical venous blood, and the data were normalized for gestational age. Total oxygen content of fetal venous blood was calculated from oxygen saturation, hemoglobin value, and pO2. Correlation and logistic regression analyses were performed to identify primary physiologic determinants of MCA PSV.

RESULTS

In 136 fetuses who underwent cordocentesis (predominantly for alloimmune disease), hematocrit, hemoglobin, and blood oxygen content correlated significantly with the MCA PSV (P < .01). Logistic regression modeling demonstrated that fetal hemoglobin content (odds ratio, 7.1; 95% CI, 3.71-13.7) and pCO2, but not pO2 or fetal blood oxygen content, accounted for increases in MCA PSV.

CONCLUSION

Under physiologic circumstances, fetal hemoglobin, and not fetal oxygenation, primarily determines the middle cerebral artery peak systolic velocity.

Biomechanical Properties of the Lower Uterine Segment Above and Below the Reflection of the Urinary Bladder Flap

OBJECTIVE

To test the hypothesis that differences in the matrix arrangement of the lower uterine segment (above and below the reflection of the bladder flap) translate to differences in biomechanical or structural properties of the uterine wall.

METHODS

We enrolled prospectively 40 women at term randomized to a bladder flap (n=21) versus no bladder flap (n=19) at the time of a cesarean delivery for dystocia. Tensile properties of tissue biopsies from the upper and lower edges of the hysterotomy incision were quantitated using a stretching regimen designed to mimic labor. Parameters such as slope, yield point, and break point were analyzed in relationship to biochemical (total collagen, sulfated glycosaminoglycans, pyridinoline-deoxypyridinoline) and histological (collagen birefringence) properties of the tissue.

RESULTS

The lower edge of the hysterotomy had a higher collagen content than the upper, independently of whether the hysterotomy site was above or below the reflection of the bladder (P<.001 for edge level, P=.8 for bladder flap). The pyridinoline-to-collagen ratio (a reflection of collagen cross-linking) was significantly decreased in the lower edge of the hysterotomy, independently of a bladder flap (P<.001). Neither collagen birefringence nor the amount of sulfated glycosaminoglycans differed among sites. There were no significant differences in biomechanical properties between the upper and lower edges of the hysterotomy, whether or not a bladder flap was created.

CONCLUSION

The lower uterine segment of women with dystocia maintains its overall biomechanical properties despite significant quantitative and qualitative differences in fibrillar collagen between the upper and lower edge of the hysterotomy incision.

LEVEL OF EVIDENCE

II.

Proteomic profiling of the amniotic fluid to detect inflammation, infection, and neonatal sepsis

BACKGROUND

Proteomic analysis of amniotic fluid shows the presence of biomarkers characteristic of intrauterine inflammation. We sought to validate prospectively the clinical utility of one such proteomic profile, the Mass Restricted (MR) score.

METHODS AND FINDINGS

We enrolled 169 consecutive women with singleton pregnancies admitted with preterm labor or preterm premature rupture of membranes. All women had a clinically indicated amniocentesis to rule out intra-amniotic infection. A proteomic fingerprint (MR score) was generated from fresh samples of amniotic fluid using surface-enhanced laser desorption ionization (SELDI) mass spectrometry. Presence or absence of the biomarkers of the MR score was interpreted in relationship to the amniocentesis-to-delivery interval, placental inflammation, and early-onset neonatal sepsis for all neonates admitted to the Newborn Special Care Unit (n = 104). Women with "severe" amniotic fluid inflammation (MR score of 3 or 4) had shorter amniocentesis-to-delivery intervals than women with "no" (MR score of 0) inflammation or even "minimal" (MR score of 1 or 2) inflammation (median [range] MR 3-4: 0.4 d [0.0-49.6 d] versus MR 1-2: 3.8 d [0.0-151.2 d] versus MR 0: 17.0 d [0.1-94.3 d], p < 0.001). Nonetheless, a "minimal" degree of inflammation was also associated with preterm birth regardless of membrane status. There was a significant association between the MR score and severity of histological chorioamnionitis (r = 0.599, p < 0.001). Furthermore, neonatal hematological indices and early-onset sepsis significantly correlated with the MR score even after adjusting for gestational age at birth (OR for MR 3-4: 3.3 [95% CI, 1.1 to 9.2], p = 0.03). When compared with other laboratory tests routinely used to diagnose amniotic fluid inflammation and infection, the MR score had the highest accuracy to detect inflammation (white blood cell count > 100 cells/mm3), whereas the combination of Gram stain and MR score was best for rapid prediction of intra-amniotic infection (positive amniotic fluid culture).

CONCLUSIONS

High MR scores are associated with preterm delivery, histological chorioamnionitis, and early-onset neonatal sepsis. In this study, proteomic analysis of amniotic fluid was shown to be the most accurate test for diagnosis of intra-amniotic inflammation, whereas addition of the MR score to the Gram stain provides the best combination of tests to rapidly predict infection.

Mechanisms of paracrine regulation by fetal membranes of human uterine quiescence

OBJECTIVE

To test the hypothesis that fetal membranes (chorion or amnion) release one or more factors responsible for myometrial quiescence.

METHODS

Myometrial samples were excised from women at elective term cesarean delivery prior to the onset of labor. Fetal membranes were obtained after cesarean delivery either before or during labor, and either term (greater than 37 weeks) or preterm (less than or equal to 36 weeks). Myometrial strips were placed in organ baths and contractions stimulated by oxytocin (10(-8) M). Contractility was measured under isometric conditions before and after exposure to fetal membranes or conditioned medium. The impact of either membrane or conditioned media on contractility was determined before and after myometrial K+ channel blockade.

RESULTS

Both chorion and amnion and their respective conditioned mediums decrease oxytocin-stimulated myometrial contraction. The inhibitory effect was greatest with membranes from preterm pregnancies (mean gestation 32 weeks, P <.05). The inhibitory effect was detectable in the presence of term labor, but was absent when the fetal membranes were obtained after preterm labor. Iberiotoxin, an inhibitor of large conductance Ca2+-activated K+ channels (BK(Ca)) reduced the effect of fetal membranes by 50% (P <.05).

CONCLUSION

We conclude that human fetal membranes release one or more factors that inhibit oxytocin-induced myometrial contractility. We suggest this factor (or factors) acts mainly by opening myometrial BK(Ca). The findings further support our hypothesis that the fetal membranes release a factor (or factors) that is central to myometrial quiescence and its premature loss leads to preterm delivery.

Proteomics, Part II: The Emerging Role of Proteomics Over Genomics in Spontaneous Preterm Labor/Birth

Conventional wisdom holds that complications of immature organ systems such as respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia are the primary causes of the high neonatal morbidity and mortality attendant preterm delivery. However, recent evidence suggests that a major cause of prematurity-associated neonatal pathology is the fetal and neonatal response to inflammation/infection. Although functional genomics offered the promise of providing answers to many of these questions, the identification of the genes intrinsic to human parturition proved to be a difficult task. Proteomic profiling of the amniotic fluid (AF) provides a precise means for detection of inflammation by revealing the presence of 4 biomarkers (defensins-2 and -1, calgranulin-C, and calgranulin-A) that are highly predictive of intrauterine inflammation (MR score). The MR score is especially useful as it presents a gradient of disease activity progressing from "absent" to "mild" to "severe" inflammation. Thus, it provides the ability to identify patients who may benefit from interventions in utero in a modern diagnostic-therapeutic framework.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to explain that the cause or causes of preterm delivery are still unknown, recall that functional genomics has not given the answer to these causes, and state that proteomic profiling of amniotic fluid, through mass-restricted (MR) scoring, may be predictive of intrauterine inflammation and allow for potential diagnosis and potential therapy.

Clinical Proteomics: A Novel Diagnostic Tool for the New Biology of Preterm Labor, Part I: Proteomics Tools

The molecular mechanisms regulating myometrial contractility and preterm premature rupture of the membranes leading to preterm birth are poorly understood. The completion of the human genome sequence led to the development of functional genomics and gene array technology to simultaneously identify candidate genes potentially involved in regulation of human parturition. However, the study of living systems can now be expanded past genomics based on the rationale that it is the protein products of the genes, not simply gene expression, that have effects and cause disturbances at the cellular level. Therefore, identification of disease biomarkers, followed by a description of their functional networks, has the potential to significantly aid the development of new strategies for the prediction, diagnosis, and prevention of preterm birth. Interest in mass spectrometry and its use as a new clinical diagnostic tool has grown rapidly and is poised to become an important medical field for the next century.

Pregnancy and estradiol modulate myometrial G-protein pathways in the guinea pig

OBJECTIVE

Coupled to hundreds of receptors, G-proteins modulate signal transduction pathways and are important hormonal targets. The first objective was to determine the effect of pregnancy and estradiol on myometrial guanosine triphosphatase activity. The second objective was to begin dissecting the molecular mechanism(s) underlying alterations in guanosine triphosphatase activity.

STUDY DESIGN

Myometrial tissue was obtained from pregnant, nonpregnant, and ovariectomized untreated and estradiol-treated guinea pigs. Myometrial membranes were prepared by homogenization and differential centrifugation. Basal high-affinity specific guanosine triphosphatase activity was quantitated by enzymatic assay and expressed in rhomol 32Pi per milligram protein per minute. Guanosine triphosphatase activity was stimulated using oxytocin, isoproterenol, and prostaglandin F2alpha. Specific G-protein subunits were quantitated using Western blots. G-protein associated gene expression was semiquantitated using HGU133A gene array chips from Affymetrix.

RESULTS

Basal myometrial guanosine triphosphatase activity was increased in pregnant compared with nonpregnant animals. Estradiol increased basal myometrial guanosine triphosphatase activity, compared with untreated controls. The effect of estradiol on stimulated activity was agonist dependent. Both Galphas and Galphai isoform 1 protein levels were increased in myometrium from late pregnant compared with nonpregnant animals. By late gestation, the messenger ribonucleic acid levels of those genes were unaltered, compared with the nonpregnant animal. In general, the impact of pregnancy on G-protein family member gene messenger ribonucleic acid expression was modest. Only the small guanosine triphosphatase Rap1b demonstrated altered expression more than 2-fold during either myometrial quiescence (midpregnancy) or activation (term pregnancy) (up 3-fold during quiescence). Genomic network analyses revealed that the expression of another small guanosine triphosphatase, Rab7, was exclusively up-regulated (80%) during quiescence. During late pregnancy, network analysis showed that only G-protein beta was exclusively altered (up-regulated). Estradiol mimicked the pregnancy effect on both transcription and translation of G-protein family members for some but not all potentially relevant genes.

CONCLUSION

The increase in functional myometrial guanosine triphosphatase activity during pregnancy may reflect increased synthesis of 1 or more small guanosine triphosphatase.

Long-term neurodevelopmental outcome and brain volume after treatment for hydrops fetalis by in utero intravascular transfusion

OBJECTIVE

We tested the hypothesis that long-term neurodevelopmental outcomes of successfully treated fetuses with immune hydrops are similar to their unaffected siblings according to a protocol that addresses the underlying pathophysiologic condition.

STUDY DESIGN

Sixteen of 18 consecutive hydropic fetuses (89%) who were treated in a dedicated fetal medicine unit between July 1985 and October 1995 survived. The transfusion protocol used a 2-step correction over a 2 to 4 day interval, combined with umbilical venous pressure measurements to avoid over transfusion and bicarbonate administration to assure a posttransfusion UV pH of >7.30. Survivors were evaluated at a mean age of 10 years. Statistical analyses included t-test, Wilcoxon rank-sum test, Fisher's exact test, and Pearson coefficients.

RESULTS

Overall, death or major neurologic morbidity occurred in 4 of 18 of the fetuses (22%) who were treated (2/16 of survivors [12.5%]). Among the survivors, the children with immune hydrops had physical, neurologic, and cognitive outcomes statistically similar to their siblings, except for a measure of visual attention. Two of the children (12%) had major neurologic sequelae. Brain volumes were statistically smaller than unrelated control subjects by 8.8%, but these control subjects were not matched for height at testing or gestational age at birth. Both groups had brain volumes within the normal range.

CONCLUSION

Intravascular transfusion of fetuses with profoundly anemic immune hydrops results in high survival rates and favorable long-term neuropsychological outcomes.

Screening in women's health, with emphasis on fetal Down's syndrome, breast cancer and osteoporosis

Screening tests have become increasingly popular in women's health care over the last two decades. The initiative for screening is typically generated by either an agency or the health care professional being consulted for some reason. In many instances, however, the demand for screening tests is patient driven with the health care provider being poorly prepared to determine the usefulness of screening. This review illustrates the complexity of screening using three disorders where early detection and treatment have the potential to improve the quality and longevity of life. Prenatal diagnosis of Down's syndrome does not offer the parents the opportunity for cure but does offer the opportunity for education and rational choice as the impact of the diagnosis on the family is weighed. The evidence for breast cancer screening is more persuasive for older than younger women, but even in older women, there is a balance of risks and benefits. Treatment options for osteoporosis have improved in terms of reductions in fracture risk as well as beneficial effects on bone density, but evidence of the effectiveness of a screening programme for this condition in an unselected population is lacking. Ultimately, it is crucial that women be provided with clear and comprehensive information about the screening programme, in terms of possible gains but also costs of various kinds: physical, economic and psychological.

Identification of interactive gene networks: a novel approach in gene array profiling of myometrial events during guinea pig pregnancy

OBJECTIVE

The transition from myometrial quiescence to activation is poorly understood, and the analysis of array data is limited by the available data mining tools. We applied functional analysis and logical operations along regulatory gene networks to identify molecular processes and pathways underlying quiescence and activation.

STUDY DESIGN

We analyzed some 18,400 transcripts and variants in guinea pig myometrium at stages corresponding to quiescence and activation, and compared them to the nonpregnant (control) counterpart using a functional mapping tool, MetaCore (GeneGo, St Joseph, MI) to identify novel gene networks composed of biological pathways during mid (MP) and late (LP) pregnancy.

RESULTS

Genes altered during quiescence and or activation were identified following gene specific comparisons with myometrium from nonpregnant animals, and then linked to curated pathways and formulated networks. The MP and LP networks were subtracted from each other to identify unique genomic events during those periods. For example, changes 2-fold or greater in genes mediating protein biosynthesis, programmed cell death, microtubule polymerization, and microtubule based movement were noted during the transition to LP.

CONCLUSION

We describe a novel approach combining microarrays and genetic data to identify networks associated with normal myometrial events. The resulting insights help identify potential biomarkers and permit future targeted investigations of these pathways or networks to confirm or refute their importance.

The effect of dystocia and previous cesarean uterine scar on the tensile properties of the lower uterine segment

OBJECTIVE

The remodeling of uterine connective tissue during labor can lead to the reorganization of the extracellular matrix that, in turn, may influence the biomechanical properties of the myometrial wall. We hypothesized that the stretching of the lower uterine segment in laboring women with dystocia changes the viscoelastic properties of the uterine wall.

STUDY DESIGN

We tested the tensile strength of lower uterine segment myometrium in 68 pregnant women at term. The biomechanical, structural, and biochemical properties were compared among 3 groups: (1) 39 laboring women who underwent primary low-transverse cesarean delivery for labor dystocia, (2) 12 nonlaboring women who underwent primary elective low-transverse cesarean delivery and (3) 17 women who underwent an elective repeat low-transverse cesarean delivery at term. The tensile properties were quantitated with a stretching regimen that was designed to mimic the conditions of labor. Parameters such as slope, yield point, and break point were recorded, analyzed, and interpreted. Biochemical properties were determined by the measurement of the sulfated glycosaminoglycans, hydroxyproline, and pyridinoline-deoxypyridinoline. Histologic properties of the connective tissue were assessed by collagen birefringence. Lastly, the association between these properties and biomechanical responses were compared among groups.

RESULTS

Lower uterine segment myometrium specimens obtained from laboring women were stiffer compared with specimens from women who were not in labor (P = .013) or had scarred myometrium (P < .001). The force that was required to reach the yield point was similar between labor and nonlabor groups (P = .216). Likewise, a previous lower uterine segment scar did not alter the yield point. The break point was similar among all groups (P = .317). Sulfated glycosaminoglycan levels were unaffected by labor or scarring (P = .354). Scarred lower uterine segment myometrium had a higher collagen content compared with unscarred myometrium specimens that were obtained during labor (P = .025). Although there were similar degrees of collagen cross-linking among groups (P = .212), there was lower collagen birefringence in myometrium from laboring women compared with nonlaboring women (P < .001).

CONCLUSION

Labor alters the viscoelastic properties of myometrium. Lower uterine segment myometrium is stiffest in women with dysfunctional labor compared with nonlabor control subjects. Labor and scarring also alter the pattern of collagen birefringence. Similar collagen cross-linking among the study groups may explain the reason that the breaking strength of the tissue is not altered by the state of labor and the reason that the rupture of the uterine scar is a rare event.