Is thrombin activation predictive of subsequent preterm delivery?

OBJECTIVE

To determine the relation between thrombin generation (measured by thrombin-antithrombin [TAT] complexes) early in pregnancy and subsequent preterm delivery.

STUDY DESIGN

Select cohort of 731 women undergoing indicated second trimester amniocentesis prospectively followed to delivery. Primary outcome was preterm delivery. TAT levels were examined continuously and categorized by quartiles. Multivariable techniques were applied to adjust for potential confounders. Receiver operating characteristic curve analysis was used to determine a discriminatory cutoff level for TAT complexes.

RESULTS

TAT concentration was significantly higher in women who delivered preterm (median, 98.9 mcg/L) than in those who did not (median, 66.3 mcg/L; P < .001). This difference persisted when 55 spontaneous preterm deliveries (median, 87.6 mcg/L) and 34 indicated preterm deliveries (median, 117.7 mcg/L) were separately compared with controls (P = .04 and P < .001, respectively). Crude and adjusted odds ratio for preterm delivery in the upper 2 TAT quartiles relative to the uppermost quartile relative to the lowest quartile were 2.45 (95% confidence interval [CI], 1.36-4.72; P = .004) and 2.31 (95% CI, 1.18-4.65; P = .017), respectively. Despite these distinct differences, the area under the receiver operating characteristic curve was only 0.62 (95% CI, 0.56-0.69), indicating poor performance of TAT concentration as a risk discriminator.

CONCLUSION

Amniotic fluid levels of TAT complexes in the second trimester are elevated in women who subsequently deliver preterm, suggesting that thrombin generation may be involved in the various etiopathogenic mechanisms leading to preterm delivery.

Population versus customized fetal growth norms and adverse outcomes in an intrapartum cohort

OBJECTIVE

To compare population versus customized fetal growth norms in identifying neonates at risk for adverse outcomes (APO) associated with small for gestational age (SGA).

STUDY DESIGN

Secondary analysis of an intrapartum fetal pulse oximetry trial in nulliparous women at term. Birth weight percentiles were calculated using ethnicity- and gender-specific population norms and customized norms (Gardosi).

RESULTS

Of the studied neonates, 508 (9.9%) and 584 (11.3%) were SGA by population (SGApop) and customized (SGAcust) norms, respectively. SGApop infants were significantly associated with a composite adverse neonatal outcome, neonatal intensive care admission, low fetal oxygen saturation, and reduced risk of cesarean delivery; both SGApop and SGAcust infants were associated with a 5-minute Apgar score < 4. The ability of customized and population birth weight percentiles in predicting APO was poor (12 of 14 APOs had area under the curve of <0.6).

CONCLUSION

In this intrapartum cohort, neither customized nor normalized population norms adequately identified neonates at risk of APO related to SGA.

Can changes in angiogenic biomarkers between the first and second trimesters of pregnancy predict development of pre-eclampsia in a low-risk nulliparous patient population?

OBJECTIVE

To determine if change in maternal angiogenic biomarkers between the first and second trimesters predicts pre-eclampsia in low-risk nulliparous women.

DESIGN

A nested case-control study of change in maternal plasma soluble Flt-1 (sFlt-1), soluble endoglin (sEng) and placenta growth factor (PlGF). We studied 158 pregnancies complicated by pre-eclampsia and 468 normotensive nonproteinuric controls.

SETTING

A multicentre study in 16 academic medical centres in the USA.

POPULATION

Low-risk nulliparous women.

METHODS

Luminex assays for PlGF, sFlt-1 and sEng performed on maternal EDTA plasma collected at 9-12, 15-18 and 23-26 weeks of gestation. Rate of change of analyte between first and either early or late second trimester was calculated with and without adjustment for baseline clinical characteristics.

MAIN OUTCOME MEASURES

Change in PlGF, sFlt-1 and sEng.

RESULTS

Rates of change of PlGF, sEng and sFlt-1 between first and either early or late second trimesters were significantly different in women who developed pre-eclampsia, severe pre-eclampsia or early-onset pre-eclampsia compared with women who remained normotensive. Inclusion of clinical characteristics (race, body mass index and blood pressure at entry) increased sensitivity for detecting severe and particularly early-onset pre-eclampsia but not pre-eclampsia overall. Receiver operating characteristics curves for change from first to early second trimester in sEng, PlGF and sFlt-1 with clinical characteristics had areas under the curve of 0.88, 0.84 and 0.86, respectively, and for early-onset pre-eclampsia with sensitivities of 88% (95% CI 64-99), 77% (95% CI 50-93) and 77% (95% CI 50-93) for 80% specificity, respectively. Similar results were seen in the change from first to late second trimester.

CONCLUSION

Change in angiogenic biomarkers between first and early second trimester combined with clinical characteristics has strong utility for predicting early-onset pre-eclampsia.

Cost-effectiveness of trial of labor after previous cesarean in a minimally biased cohort

OBJECTIVE

To estimate the cost-effectiveness of a trial of labor after one previous cesarean delivery (TOLAC).

STUDY DESIGN

A model comparing TOLAC with elective repeat cesarean delivery (ERCD) was developed for a hypothetical cohort with no contraindication to a TOLAC. Probabilistic estimates were obtained from women matched on their baseline characteristics using propensity scores. Cost data, quality-adjusted life-years (QALYs), and data on cerebral palsy were incorporated from the literature.

RESULTS

The TOLAC strategy dominated the ERCD strategy at baseline, with $138.6 million saved and 1703 QALYs gained per 100,000 women. The model was sensitive to five variables: the probability of uterine rupture, the probability of successful TOLAC, the QALY of failed TOLAC, the cost of ERCD, and the cost of successful TOLAC without complications. When the probability of TOLAC success was at the base value, 68.5%, TOLAC was preferred if the probability of uterine rupture was 4.2% or less. When the probability of uterine rupture was at the base value, 0.8%, the TOLAC strategy was preferred as long as the probability of success was 42.6% or more.

CONCLUSION

A TOLAC is less expensive and more effective than an ERCD in a group of women with balanced baseline characteristics.

Vitamin D status and recurrent preterm birth: a nested case-control study in high-risk women

OBJECTIVE

To determine whether vitamin D status is associated with recurrent preterm birth, and any interactions between vitamin D levels and fish consumption.

DESIGN

A nested case-control study, using data from a randomised trial of omega-3 fatty acid supplementation to prevent recurrent preterm birth.

SETTING

Fourteen academic health centres in the USA.

POPULATION

Women with prior spontaneous preterm birth.

METHODS

In 131 cases (preterm delivery at <35 weeks of gestation) and 134 term controls, we measured serum 25-hydroxyvitamin D [25(OH)D] concentrations by liquid chromatography-tandem mass spectrometry (LC-MS) from samples collected at baseline (16-22 weeks of gestation). Logistic regression models controlled for study centre, maternal age, race/ethnicity, number of prior preterm deliveries, smoking status, body mass index, and treatment.

MAIN OUTCOME MEASURES

Recurrent preterm birth at <37 and <32 weeks of gestation.

RESULTS

The median mid-gestation serum 25(OH)D concentration was 67 nmol/l, and 27% had concentrations of <50 nmol/l. Serum 25(OH)D concentration was not significantly associated with preterm birth (OR 1.33; 95% CI 0.48-3.70 for lowest versus highest quartiles). Likewise, comparing women with 25(OH)D concentrations of 50 nmol/l, or higher, with those with <50 nmol/l generated an odds ratio of 0.80 (95% CI 0.38-1.69). Contrary to our expectation, a negative correlation was observed between fish consumption and serum 25(OH)D concentration (-0.18, P < 0.01).

CONCLUSIONS

In a cohort of women with a prior preterm birth, vitamin D status at mid-pregnancy was not associated with recurrent preterm birth.

Relationship between 17-hydroxyprogesterone caproate concentrations and gestational age at delivery in twin gestation

OBJECTIVE

We sought to evaluate in women with twin gestation the relationship between 17-hydroxyprogesterone caproate (17-OHPC) concentration and gestational age at delivery and select biomarkers of potential pathways of drug action.

STUDY DESIGN

Blood was obtained between 24-28 weeks (epoch 1) and 32-35 weeks (epoch 2) in 217 women with twin gestation receiving 17-OHPC or placebo. Gestational age at delivery and concentrations of 17-OHPC, 17-hydroxyprogesterone, progesterone, C-reactive protein (CRP), and corticotrophin-releasing hormone were assessed.

RESULTS

Women with higher concentrations of 17-OHPC delivered at earlier gestational ages than women with lower concentrations (P < .001). Women receiving 17-OHPC demonstrated significantly higher (P = .005) concentrations of CRP in epoch 1 than women receiving placebo but CRP values were similar in epoch 2 in both groups. A highly significant (P < .0001) positive relationship was observed between 17-OHPC concentration and progesterone and 17-hydroxyprogesterone concentrations at both epochs. Corticotropin-releasing hormone concentrations did not differ by treatment group.

CONCLUSION

17-OHPC may adversely impact gestational age at delivery in women with twin gestation.

Use of complementary and alternative medications among patients in an obstetrics and gynecology clinic

OBJECTIVE

To evaluate the current use of complementary and alternative medication (CAM) products among women in obstetrics and gynecology outpatient clinics.

STUDY DESIGN

This study was performed at a major academic center among patients seen at either a faculty-led private clinical practice site (n = 250) or a resident-led clinical practice site (n = 250). Patients were requested to bring a written list and the medication bottles (prescriptions, over-the-counter medications and CAM products) to the clinic, where a survey was then administered.

RESULTS

Overall, 18.6% of participants were using CAM products. Significantly more patients reported using CAM products in the faculty private practice as compared to the resident clinic practice (28.4% vs. 8.8%, respectively, p value < 0.05). Only 29.0% of CAM products users had spoken to a healthcare provider regarding CAM products. Multivariate logistic regression model determined that older age (p < 0.0001) and Caucasian ethnicity (p = 0.0245) were associated with higher rates of CAM products use.

CONCLUSION

In this study CAM products use was not as prevalent as anticipated for this patient population, however it continues to be underreported to providers. Healthcare professionals should continue to increase their knowledge about CAM products, take a proactive role to improve documentation, and develop an open communication with patients regarding appropriate use of CAM products.

Association of polymorphisms in neuroprotection and oxidative stress genes and neurodevelopmental outcomes after preterm birth

OBJECTIVE

To estimate the associations between polymorphisms in neuronal homeostasis, neuroprotection, and oxidative stress candidate genes and neurodevelopmental disability.

METHODS

This was a nested case-control analysis of a randomized trial of magnesium sulfate administered to women at imminent risk for early (before 32 weeks) preterm birth for the prevention of death or cerebral palsy in their offspring. We evaluated 21 single-nucleotide polymorphisms (SNPs) in 17 genes associated with neuronal homeostasis, neuroprotection, or oxidative stress in umbilical cord blood. Cases included infant deaths (n=43) and children with cerebral palsy (n=24), mental delay (Bayley Mental Developmental Index less than 70; n=109), or psychomotor delay (Bayley Psychomotor Developmental Index less than 70; n=91) diagnosed. Controls were race-matched and sex-matched children with normal neurodevelopment. Associations between each SNP and each outcome were assessed in logistic regression models assuming an additive genetic pattern, conditional on maternal race and infant sex, and adjusting for study drug assignment, gestational age at birth, and maternal education.

RESULTS

The odds of cerebral palsy were increased more than 2.5 times for each copy of the minor allele of vasoactive intestinal polypeptipe (VIP, rs17083008) (adjusted odds ratio 2.67, 95% confidence interval 1.09-6.55, P=.03) and 4.5 times for each copy of the minor allele of N-methyl-D-aspartate receptor subunit 3A (GRIN3A, rs3739722) (adjusted odds ratio 4.67, 95% CI 1.36-16.01, P=.01). The association between the advanced glycosylation end product-specific receptor (AGER, rs3134945) SNP and mental delay was modulated by study drug allocation (P=.02).

CONCLUSION

Vasoactive intestinal polypeptipe and GRIN3A SNPs may be associated with cerebral palsy at age 2 in children born preterm.

Autoantibody-mediated complement C3a receptor activation contributes to the pathogenesis of preeclampsia

Preeclampsia (PE) is a prevalent life-threatening hypertensive disorder of pregnancy associated with increased complement activation. However, the causative factors and pathogenic role of increased complement activation in PE are largely unidentified. Here we report that a circulating maternal autoantibody, the angiotensin II type 1 receptor agonistic autoantibody, which emerged recently as a potential pathogenic contributor to PE, stimulates deposition of complement C3 in placentas and kidneys of pregnant mice via angiotensin II type 1 receptor activation. Next, we provide in vivo evidence that selectively interfering with C3a signaling by a complement C3a receptor-specific antagonist significantly reduces hypertension from 167±7 to 143±5 mm Hg and proteinuria from 223.5±7.5 to 78.8±14.0 μg of albumin per milligram creatinine (both P<0.05) in angiotensin II type 1 receptor agonistic autoantibody-injected pregnant mice. In addition, we demonstrated that complement C3a receptor antagonist significantly inhibited autoantibody-induced circulating soluble fms-like tyrosine kinase 1, a known antiangiogenic protein associated with PE, and reduced small placental size with impaired angiogenesis and intrauterine growth restriction. Similarly, in humans, we demonstrate that C3 deposition is significantly elevated in the placentas of preeclamptic patients compared with normotensive controls. Lastly, we show that complement C3a receptor activation is a key mechanism underlying autoantibody-induced soluble fms-like tyrosine kinase 1 secretion and decreased angiogenesis in cultured human villous explants. Overall, we provide mouse and human evidence that angiotensin II type 1 receptor agonistic autoantibody-mediated activation contributes to elevated C3 and that complement C3a receptor signaling is a key mechanism underlying the pathogenesis of the disease. These studies are the first to link angiotensin II type 1 receptor agonistic autoantibody with complement activation and to provide important new opportunities for therapeutic intervention in PE.

Fetal male gender and the benefits of treatment of mild gestational diabetes mellitus

OBJECTIVE

We evaluated whether improvements in pregnancy outcomes after treatment of mild gestational diabetes mellitus differed in magnitude on the basis of fetal gender.

STUDY DESIGN

This is a secondary analysis of a masked randomized controlled trial of treatment for mild gestational diabetes mellitus. The results included preeclampsia or gestational hypertension, birthweight, neonatal fat mass, and composite adverse outcomes for both neonate (preterm birth, small for gestational age, or neonatal intensive care unit admission) and mother (labor induction, cesarean delivery, preeclampsia, or gestational hypertension). After stratification according to fetal gender, the interaction of gender with treatment status was estimated for these outcomes.

RESULTS

Of the 469 pregnancies with male fetuses, 244 pregnancies were assigned randomly to treatment, and 225 pregnancies were assigned randomly to routine care. Of the 463 pregnancies with female fetuses, 233 pregnancies were assigned randomly to treatment, and 230 pregnancies were assigned randomly to routine care. The interaction of gender with treatment status was significant for fat mass (P = .04) and birthweight percentile (P = .02). Among women who were assigned to the treatment group, male offspring were significantly more likely to have both a lower birthweight percentile (50.7 ± 29.2 vs 62.5 ± 30.2 percentile; P < .0001) and less neonatal fat mass (487 ± 229.6 g vs 416.6 ± 172.8 g; P = .0005,) whereas these differences were not significant among female offspring. There was no interaction between fetal gender and treatment group with regard to other outcomes.

CONCLUSION

The magnitude of the reduction of a newborn's birthweight percentile and neonatal fat mass that were related to the treatment of mild gestational diabetes mellitus appears greater for male neonates.

Continuous glucose monitoring in diabetic women following antenatal corticosteroid therapy: a pilot study

To compare the timing, duration, and severity of corticosteroid-associated hyperglycemia in pregnant women with and without diabetes mellitus (DM). An observational study was conducted of pregnant women with DM and controls who received corticosteroids. Median glucose levels were calculated over 4-hour intervals after the first dose of corticosteroid with a continuous glucose monitor. A glucose level increase of at least 15% above baseline was considered significant. Nine pregnant women participated in this study (six with DM and three without DM). Elevations of glucose levels occurred at hour 20, 44, and 68 in both groups and lasted for up to 4 hours. In those with DM, glucose levels increased 33 to 48%, whereas in those without DM, glucose levels rose 16 to 33%. Several, relatively short episodes of glucose elevation occur in response to corticosteroids, and are more pronounced in diabetic women.

Association of cord blood magnesium concentration and neonatal resuscitation

OBJECTIVE

To assess the relationship between umbilical cord blood magnesium concentration and level of delivery room resuscitation received by neonates.

STUDY DESIGN

This was a secondary analysis of a controlled fetal neuroprotection trial that enrolled women at imminent risk for delivery between 24 and 31 weeks' gestation and randomly allocated them to receive either intravenous magnesium sulfate or placebo. The cohort included 1507 infants with data available on total cord blood Mg concentration and delivery room resuscitation. Multivariate logistic regression was used to estimate the association between cord blood Mg concentration and highest level of delivery room resuscitation, using the following hierarchy: none, oxygen only, bag-mask ventilation with oxygen, intubation, and chest compressions.

RESULTS

There was no relationship between cord blood Mg and delivery room resuscitation (OR, 0.92 for each 1.0-mEq/L increase in Mg; 95% CI, 0.83-1.03). Maternal general anesthesia was associated with increased neonatal resuscitation (OR, 2.51; 95% CI, 1.72-3.68). Each 1-week increase in gestational age at birth was associated with decreased neonatal resuscitation (OR, 0.63; 95% CI, 0.60-0.66).

CONCLUSION

Cord blood Mg concentration does not correlate with the level of delivery room resuscitation of infants exposed to magnesium sulfate for fetal neuroprotection.

Prospective investigation of second-trimester thrombin activation and preterm birth

OBJECTIVE

We sought to determine if second-trimester amniotic fluid thrombin-antithrombin (TAT) complexes concentration correlates with subsequent preterm birth.

STUDY DESIGN

A cohort of 550 women with singleton nonanomalous pregnancies undergoing second-trimester genetic amniocentesis was followed up to delivery and analyzed as a nested case-control study. Cases of preterm birth (n = 52) were compared with 104 term control subjects. Amniotic fluid collected at amniocentesis was tested for TAT.

RESULTS

TAT concentrations were significantly higher in women who delivered preterm (median 115.9 µg/L) than in those who did not (median 62.2 µg/L; P < .001). This difference persisted when 31 spontaneous preterm births and 21 indicated preterm births were analyzed separately. The odds ratios for preterm birth in the highest TAT quartile relative to the lowest quartile was 4.98 (95% confidence interval, 1.17-22.01; P = .007).

CONCLUSION

We found a difference in the pattern of intraamniotic thrombin generation between women destined to deliver at term and those who deliver preterm, regardless of the type of preterm birth.

Elective repeat cesarean delivery compared with spontaneous trial of labor after a prior cesarean delivery: a propensity score analysis

OBJECTIVE

The purpose of this study was to determine outcomes, after the use of propensity score techniques, to create balanced groups according to whether a woman undergoes elective repeat cesarean delivery (ERCD) or trial of labor (TOL).

STUDY DESIGN

Women who were eligible for a TOL with 1 previous low transverse incision were categorized according to whether they underwent an ERCD or TOL. A propensity score technique was used to develop ERCD and TOL groups with comparable baseline characteristics. Outcomes were assessed with conditional logistic regression.

RESULTS

The rates of endometritis, operative injury, respiratory distress syndrome, and newborn infant infection were lower and the rates of hysterectomy and wound complication were higher in the ERCD group.

CONCLUSION

Propensity score techniques can be used to generate comparable ERCD and TOL groups. Some types of maternal morbidity (such as hysterectomy) are higher; other types (such as operative injury) are lower in the ERCD group. Although the absolute risk is low, neonatal morbidity appears to be lower in the ERCD group.

Timing of delivery and pregnancy outcomes among laboring nulliparous women

OBJECTIVE

The objective of the study was to compare pregnancy outcomes by completed week of gestation after 39 weeks with outcomes at 39 weeks.

STUDY DESIGN

Secondary analysis of a multicenter trial of fetal pulse oximetry in spontaneously laboring or induced nulliparous women at a gestation of 36 weeks or longer. Maternal outcomes included a composite (treated uterine atony, blood transfusion, and peripartum infections) and cesarean delivery. Neonatal outcomes included a composite of death, neonatal respiratory and other morbidities, and neonatal intensive care unit admission.

RESULTS

Among the 4086 women studied, the risks of the composite maternal outcome (P value for trend < .001), cesarean delivery (P < .001), and composite neonatal outcome (P = .047) increased with increasing gestational age from 39 to 41 or more completed weeks. Adjusted odds ratios (95% confidence interval) for 40 and 41 or more weeks, respectively, compared with 39 weeks were 1.29 (1.03-1.64) and 2.05 (1.60-2.64) for composite maternal outcome, 1.28 (1.05-1.57) and 1.75 (1.41-2.16) for cesarean delivery, and 1.25 (0.86-1.83) and 1.37 (0.90-2.09) for composite neonatal outcome.

CONCLUSION

Risks of maternal morbidity and cesarean delivery but not neonatal morbidity increased significantly beyond 39 weeks.

Population standards of birth weight underestimate fetal growth abnormalities in diabetic pregnancies

The objective of this study was to compare the frequency of abnormal fetal growth in women with diabetes mellitus (DM) using population-based birth weight (pop BW) percentiles compared with customized birth weight (cust BW) percentiles, which include adjustments for maternal race, parity, height, weight, and fetal sex. The study design comprised a retrospective cohort of singleton DM pregnancies delivered over a 1-year period (June 2007 to May 2008) from a single tertiary care university-based medical center. Inclusion criteria were gestational age >20 weeks at delivery, live birth, and absence of major chromosomal/structural abnormalities. Small for gestational age (SGA), <10th percentile, and large for gestational age (LGA), >90th percentile pregnancies were categorized based on pop BW or cust BW standards. There were significant differences in the rates of SGA (p < 0.004) and LGA (p < 0.001) between cust BW and pop BW methods. When comparing the two methods, pop BW did not identify 13/16 (81%) of SGA and 23/39 (59%) of LGA babies defined by cust BW methods. The use of cust BW calculation in a diabetic population identified a greater percentage of neonates with pathologic fetal growth compared with pop BW standards, suggesting that the population standard may underdiagnose abnormal fetal growth in diabetic pregnancies.

The frequency of prior antenatal corticosteroid therapy in late preterm birth pregnancies

We sought to quantify how often women with late preterm birth (LPTB) receive antenatal corticosteroid (ACS) therapy prior to 34 weeks and to determine its effects on neonatal respiratory morbidity. LPTBs (34 (0)/ (7) to 36 (6)/ (7) weeks) over a 1-year period at a single tertiary care hospital were studied. A composite neonatal respiratory outcome was defined as mechanical ventilation, continuous positive airway pressure with fraction of inspired oxygen (F IO(2)) >40% for >2 hours or F IO(2) >40% for >4 hours within the first 72 hours of life. Multivariate logistic regression analysis was used to evaluate the association between ACS therapy and neonatal respiratory morbidity. Over the study period, 503 LPTBs met the study criteria and 6.8% ( N = 34) had ACS therapy <34 weeks. Most had exposure >7 days prior to delivery (64.7%). Almost one-half of those receiving prior ACS therapy delivered between 34 and 35 weeks. There was no difference in the rate of prior ACS therapy based on LPTB indication for delivery. After adjusting for confounding factors, prior ACS therapy was not associated with lower respiratory morbidity (odds ratio [OR] 2.0, 95% confidence interval [CI] 0.2 to 16.3, P = 0.53). Advancing gestational age was the only variable associated with respiratory morbidity (OR 0.50, 95% CI 0.26 to .94, P = 0.03). In our population, prior ACS therapy was infrequent and was not associated with improvements in neonatal respiratory morbidity following LPTB.

Excessive gestational weight gain in women with gestational and pregestational diabetes

We sought to determine the frequency of excessive gestational weight gain (GWG) and its impact on perinatal outcomes in women with gestational (GDM) and pregestational diabetes mellitus (DM). A retrospective cohort of diabetic women was studied. GWG was categorized by the 2009 Institute of Medicine guidelines. Perinatal outcomes were compared between those women with and without excessive GWG. There were 153 women who met study criteria. There was no difference in excessive GWG between women with GDM and pregestational DM (44.4% versus 38.5%, P = 0.51) or based on White's class ( P = 0.17). After adjusting for confounders, excessive GWG was not associated with an increased rate of adverse perinatal outcomes (odds ratio 1.49, 95% confidence interval 0.56 to 2.35) and had similar associations with both pregestational DM and GDM. Although excessive GWG was common in our diabetic population, it was not associated with an increased rate of adverse perinatal outcomes.

Repeated course antenatal steroids, inflammation gene polymorphisms, and neurodevelopmental outcomes at age 2

OBJECTIVE

We sought to evaluate the interaction between repeated-course antenatal corticosteroids and inflammation gene polymorphisms with neurodevelopmental outcomes at age 2 years.

STUDY DESIGN

We conducted nested case-control analysis of a randomized controlled trial of single- vs repeated-course antenatal corticosteroids. Cases had mental and/or psychomotor delay at age 2 years. Controls had normal neurodevelopment. Previous analyses of 125 cases and 147 controls identified 4 inflammation gene polymorphisms associated with neurodevelopmental delay at age 2 years.

RESULTS

The interaction between repeated-course corticosteroids and the interleukin (IL)-6 -174 genotype with neurodevelopmental delay was significant (P = .046). The IL-6 -174 GG genotype was associated with neurodevelopmental delay at age 2 years in the single-course corticosteroid group (odds ratio, 6.47; 95% confidence interval, 1.86-22.50). Exposure to repeated-course antenatal corticosteroids abrogated this genotype effect (odds ratio, 1.30; 95% confidence interval, 0.48-3.54). Results were unchanged after controlling for potential confounders.

CONCLUSION

Repeated-course antenatal steroids may reduce the increased risk of neurodevelopmental delay at age 2 years associated with IL-6 -174 GG genotype.

Umbilical cord blood biomarkers of neurologic injury and the risk of cerebral palsy or infant death

To evaluate the association between cerebral palsy (CP) or infant death and putative cord blood biomarkers of neurologic injury, we performed a nested case-control secondary analysis of a multicenter randomized trial of magnesium sulfate (MgSO(4)) versus placebo to prevent CP or death among offspring of women with anticipated delivery from 24 to 31 weeks' gestation. Cases were infants who died by 1 year (n=25) or developed CP (n=16), and were matched 1:2 to a control group (n=82) that survived without developing CP. Umbilical cord sera concentrations of S100B, neuron-specific enolase (NSE) and the total soluble form of the receptor for advanced glycation end-products (sRAGE) were measured by ELISA in duplicates. Maternal characteristics were similar between the 2 groups. Cases were born at a lower gestational age (GA) and had lower birth weight compared with controls. There were no differences in concentrations of the three biomarkers and the composite outcome of CP or infant death. However, S100B was higher (median 847.3 vs. 495.7 pg/ml; P=0.03) in infants who had CP and total sRAGE was lower (median 1259.3 vs. 1813.1 pg/ml; P=0.02) in those who died compared with the control group. When corrected for delivery GA and treatment group, both differences lost statistical significance. In conclusion, cord blood S100B level may be associated with CP, but this association was not significant after controlling for GA and MgSO(4) treatment.

Size of the nanovectors determines the transplacental passage in pregnancy: study in rats

OBJECTIVE

The objective of the study was to examine whether the size of silicon nanovectors (SNVs) inhibits their entrance into the fetal circulation.

STUDY DESIGN

Pregnant rats were intravenously administered with SNVs or saline. The SNVs were spherical particles with 3 escalating diameters: 519 nm, 834 nm, and 1000 nm. The maternal and fetal distribution of SNVs was assessed.

RESULTS

In animals that received 1000 or 834 nm SNV, silicon (Si) levels were significantly higher in the maternal organs vs the saline group, whereas the silicon levels in fetal tissues were similar to controls. However, in animals receiving 519 nm SNVs, fetal silicon levels were significantly higher in the SNV group compared with the saline group (5.93 ± 0.67 μg Si per organ vs 4.80 ± 0.33, P = .01).

CONCLUSION

Larger SNVs do not cross the placenta to the fetus and, remaining within the maternal circulation, can serve as carriers for harmful medications in order to prevent fetal exposure.

Placental endothelial nitric oxide synthase in multiple and single dose betamethasone exposed pregnancies

OBJECTIVE

To compare endothelial nitric oxide synthase expression and capillary density (CDS) in placentas exposed to single or multiple courses of betamethasone.

STUDY DESIGN

Placental specimens exposed to single vs repeat courses of betamethasone were analyzed through immunohistochemistry and digital image quantification for endothelial nitric oxide synthase and CD34. Quantified endothelial nitric oxide synthase staining, calculated capillary density, ratio of endothelial nitric oxide synthase to capillary density, and clinical characteristics were compared. Linear regression was performed with these as dependent variables.

RESULTS

Mean and maximum capillary density were increased (P = .013 and .005) and the ratio of endothelial nitric oxide synthase to capillary density decreased (P = .016) in specimens exposed to 4 courses of betamethasone compared with 1 to 3 courses. Exposure to 4 courses of betamethasone was associated with increased capillary density, but not with endothelial nitric oxide synthase expression.

CONCLUSION

Exposure to 4 courses of betamethasone is associated with increased placental capillary density. The placental effects of multiple courses of betamethasone are unrelated to endothelial nitric oxide synthase expression.

Factors related to corticosteroid utilization in preterm birth

We sought to determine the rate of corticosteroid administration in preterm births in our institution and to describe factors associated with lack of corticosteroid exposure. We performed a retrospective case-control analysis. Of the 312 eligible women who delivered between 24 and 34 weeks' gestation, maternal corticosteroid administration was documented in 262 (84%) and no exposure in 50 (16%). A shorter admission to delivery interval (< 48 hours) decreased the likelihood of corticosteroid administration (odds ratio [OR] 0.11, 95% confidence interval [CI] 0.03 to 0.28, P < 0.001). Use of tocolytics was associated with a lower risk of corticosteroid nonexposure (OR 0.21, 95% CI 0.04 to 0.69, P = 0.006). Lack of prenatal care was associated with an increased risk of corticosteroid nonexposure (OR 3.18, 95% CI 1.01 to 9.15, P = 0.01). The likelihood of corticosteroid administration was also decreased by gestational ages at the upper limit of the spectrum (33 to 34 weeks; OR 0.22, 95% CI 0.09 to 0.53, P < 0.001). The latter effect persisted after exclusion of premature rupture of membranes cases. In our population, factors associated with no maternal corticosteroid administration were shorter interval between admission and delivery, gestational age at the upper limit of the currently recommended interval for corticosteroid administration, and lack of prenatal care.

Fish consumption, erythrocyte fatty acids, and preterm birth

OBJECTIVE

To estimate the association between fish consumption and erythrocyte omega-3 long-chain polyunsaturated fatty acids and preterm birth in a high-risk cohort.

METHODS

This was an ancillary study to a randomized trial of omega-3 supplementation to prevent preterm birth in women with at least one previous spontaneous preterm delivery. Dietary fish intake was assessed by questionnaire and erythrocyte fatty acids were measured at enrollment (16-21 completed weeks of gestation). The association between fish consumption and preterm delivery was modeled with linear and quadratic terms.

RESULTS

The probability of preterm birth was 48.6% among women eating fish less than once a month and 35.9% among women eating fish more often (P<.001). The adjusted odds ratio for preterm birth among women reporting moderately frequent fish consumption (three servings per week) was 0.60 (95% confidence interval 0.38-0.95), with no further reduction in preterm birth among women who consumed more than three servings of fish per week. Erythrocyte omega-3 levels correlated weakly but significantly with frequency of fish intake (Spearman r=0.22, P<.001); women in the lowest quartile of erythrocyte omega-3 levels were more likely to report consuming less than one fish meal per month (40.3%) than were women in the highest three quartiles (26.3%, P<.001).

CONCLUSION

Moderate fish intake (up to three meals per week) before 22 weeks of gestation was associated with a reduction in repeat preterm birth. More than moderate consumption did not confer additional benefit. These results support the recommendations of the U.S. Food and Drug Administration and the American Congress of Obstetricians and Gynecologists for fish consumption during pregnancy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00135902.

Autoantibody-mediated IL-6-dependent endothelin-1 elevation underlies pathogenesis in a mouse model of preeclampsia

Preeclampsia (PE) is a life-threatening hypertensive disorder of pregnancy. Elevated circulating endothelin-1 (ET-1) is associated with the disease. However the molecular basis of increased ET-1 production and its role in PE are unknown. This study aimed to investigate the causative factors, pathological role of elevated ET-1 production in PE, and the underlying mechanisms. In this study, we found that IgG from women with PE, in contrast to IgG from normotensive pregnant women, induced preproET-1 mRNA expression via angiotensin II type 1 receptor activation in kidneys and placentas in pregnant mice. The ET-A receptor-specific antagonist BQ123 significantly attenuated autoantibody-induced hypertension, proteinuria, and renal damage in pregnant mice, demonstrating that autoantibody-induced ET-1 production contributes to pathophysiology. Mechanistically, we discovered that IL-6 functioned downstream of TNF-α signaling, contributing to increased ET-1 production in pregnant mice. IL-6 blockade inhibited preeclamptic features in autoantibody-injected pregnant mice. Extending the data to human studies, we found that IL-6 was a key cytokine underlying ET-1 induction mediated by IgG from women with PE in human placental villous explants and that endothelial cells are a key source of ET-1. Overall, we provide human and mouse studies showing that angiotensin II type I receptor-agonistic autoantibody is a novel causative factor responsible for elevated ET-1 production and that increased TNF-α/IL-6 signaling is a key mechanism underlying increased ET-1 production and subsequent maternal features. Significantly, our findings revealed novel factors and signaling cascades involved in ET-1 production, subsequent disease symptom development, and possible therapeutic intervention in the management of PE.

Computerized physician order entry reduces medication turnaround time of labor induction agents

We sought to determine whether computerized physician order entry (CPOE) improves the induction agent turnaround time on the labor and delivery unit (L&D) compared with paper-based order entry (PBOE). We conducted a retrospective study of singleton, term pregnancies admitted to L&D for induction of labor. Outcomes of women who delivered 3 months before or 3 months after universal CPOE implementation were compared including induction agent turnaround time. The induction agent turnaround time was significantly shorter in the CPOE group ( N = 83) compared with PBOE group ( N = 71) [71 (range 8 to 411) versus 100 (2 to 442) minutes, P = 0.004]. There were no differences in cesarean section rate or length of hospital stay. After controlling for time of day of induction, induction agent, and type of order entry, CPOE continued to significantly decrease the induction agent turnaround time by 25 minutes ( P = 0.042). CPOE improved the process of induction of labor and efficiency of care of pregnant women.

Maternal insulin resistance and preeclampsia

OBJECTIVE

The purpose of this study was to determine whether mid-trimester insulin resistance is associated with subsequent preeclampsia.

STUDY DESIGN

This was a secondary analysis of 10,154 nulliparous women who received vitamin C and E or placebo daily from 9-16 weeks gestation until delivery. Of these, 1187 women had fasting plasma glucose and insulin tested between 22 and 26 weeks gestation. Insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index.

RESULTS

Obese women were twice as likely to have a HOMA-IR result of ≥75th percentile. Hispanic and African American women had a higher percentage at ≥75th percentile for HOMA-IR than white women (42.2%, 27.2%, and 16.9%, respectively; P < .001). A HOMA-IR result of ≥75th percentile was higher among the 85 nulliparous women who subsequently had preeclampsia, compared with women who remained normotensive (40.5% vs 24.8%; adjusted odds ratio, 1.9; 95% confidence interval, 1.1-3.2). Quantitative insulin sensitivity check index results were similar to the HOMA-IR results.

CONCLUSION

Midtrimester maternal insulin resistance is associated with subsequent preeclampsia.

Approximately one-third of medically indicated late preterm births are complicated by fetal growth restriction

OBJECTIVE

The purpose of this study was to report the frequency of fetal growth restriction (FGR) based on indication for late preterm birth (LPTB).

STUDY DESIGN

Singleton live born pregnancies that were delivered from 34-36 weeks 6 days of gestation over a 1-year period at a tertiary care medical center were studied. Indications for delivery were categorized as spontaneous (spontaneous preterm birth or premature rupture of membranes), medically indicated, or elective. A customized birthweight percentile was calculated for each pregnancy; the rate of FGR was compared based on indication for LPTB.

RESULTS

There were 482 LPTBs that met all criteria. Customized birthweight percentiles (median; interquartile range) were different among groups (spontaneous, 45.5%; 20.8-73.5%; medically indicated, 26.9%; 4.1-63.6%; elective, 45.9%; 22.2-78.3%; P = .001). The rate of FGR was also different among groups (spontaneous, 13%; medically indicated, 32%; elective, 21%; P = .001).

CONCLUSION

With the use of customized birthweight standards, we found that FGR complicated approximately one-third of all cases of medically indicated LPTB.

Maternal serum interleukin-6, C-reactive protein, and matrix metalloproteinase-9 concentrations as risk factors for preterm birth <32 weeks and adverse neonatal outcomes

Elevated concentrations of interleukin-6 (IL-6), C-reactive protein (CRP), and matrix metalloproteinase-9 (MMP-9) in fetal and neonatal compartments have been associated with an increased risk for preterm birth (PTB) and/or neonatal morbidity. The purpose of this study was to determine if the maternal serum concentration of IL-6, CRP, and MMP-9 in women at risk for PTB, who are not in labor and have intact membranes, are associated with an increased risk for PTB <32 weeks and/or neonatal morbidity. Maternal serum samples collected from 475 patients enrolled in a multicenter randomized controlled trial of single versus weekly corticosteroids for women at increased risk for preterm delivery were assayed. Serum was collected at randomization (24 to 32 weeks' gestation). Maternal serum concentrations of IL-6, CRP, and MMP-9 were subsequently determined using enzyme-linked immunoassays. Multivariate logistic regression analysis was performed to explore the relationship between maternal serum concentrations of IL-6, CRP, and MMP-9 and PTB <32 weeks, respiratory distress syndrome (RDS), chronic lung disease (CLD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), and any sepsis. Maternal serum concentrations of IL-6 and CRP, but not MMP-9, above the 90th percentile at the time of randomization were associated with PTB <32 weeks. In contrast, there was no significant relationship between RDS and NEC and the maternal serum concentration of IL-6, CRP, or MMP-9 (univariate analysis). The development of CLD was associated with a high (above 90th percentile) IL-6 and CRP in maternal serum, even after adjustment for gestational age (GA) at randomization and treatment group. However, when GA at delivery was added to the model, this finding was nonsignificant. Neonatal sepsis was more frequent in neonates born to mothers with a high maternal serum concentration of CRP (>90th percentile). However, there was no significant association after adjustment for GA at randomization and treatment group. Logistic regression analysis for each analyte indicated that high maternal serum concentrations of IL-6 and CRP, but not MMP-9, were associated with an increased risk of IVH (odds ratio [OR] 4.60, 95% confidence interval [CI] 1.86 to 10.68; OR 4.07, 95% CI 1.63 to 9.50) after adjusting for GA at randomization and treatment group. Most babies (25/30) had grade I IVH. When GA at delivery was included, elevated IL-6 remained significantly associated with IVH (OR 2.77, 95% CI 1.02 to 7.09). An elevated maternal serum concentration of IL-6 and CRP are risk factors for PTB <32 weeks and subsequent development of neonatal IVH. An elevated maternal serum IL-6 appears to confer additional risk for IVH even after adjusting for GA at delivery.

The effect of plurality and obesity on betamethasone concentrations in women at risk for preterm delivery

OBJECTIVE

Antenatal corticosteroids (ACS) decrease respiratory distress syndrome in singleton gestations. Twin data are less clear. Obesity and body mass index (BMI) also affect medication distribution volume. We evaluated whether maternal or neonatal cord betamethasone concentrations differed in twin gestations or obese patients.

STUDY DESIGN

Participants receiving betamethasone in a randomized controlled trial of weekly ACS were identified. We analyzed maternal delivery and cord serum betamethasone concentrations comparing singletons with twins and obese (BMI > or =30 kg/m(2)) with nonobese women.

RESULTS

Fifty-five maternal and 45 cord blood samples were available. Unadjusted median maternal serum concentrations appeared paradoxically higher in both twin gestations and the obese. However, after controlling for confounders, there were no differences in betamethasone concentrations in maternal serum or cord blood between singletons and twins (P = .61 vs P = .14) or nonobese and obese women (P = .67 vs .12).

CONCLUSION

Maternal and umbilical cord blood serum betamethasone concentrations are not different in twin gestations or obese women.

Absence of mitochondrial progesterone receptor polymorphisms in women with spontaneous preterm birth

OBJECTIVE

The truncated mitochondrial progesterone receptor (PR-M) is homologous to nuclear PRs with the exception of an amino terminus hydrophobic membrane localization sequence, which localizes PR-M to mitochondria. Given the matrilineal inheritance of both spontaneous preterm birth (SPTB) and the mitochondrial genome, we hypothesized that (a) PR-M is polymorphic and (b) PR-M localization sequence polymorphisms could result in variable progesterone-mitochondrial effects and variable responsiveness to progesterone prophylaxis.

METHODS

Secondary analysis of DNA from women enrolled in a multicenter, prospective, study of 17 alpha-hydroxyprogesterone caproate (17OHPC) versus placebo for the prevention of recurrent SPTB. DNA was extracted from stored saliva.

RESULTS

The PR-M localization sequence was sequenced on 344 patients. Sequences were compared with the previously published 48 base-pair sequence, and all were identical.

CONCLUSIONS

We did not detect genetic variation in the mitochondrial localization sequence of the truncated PR-M in a group of women at high risk for SPTB.

Association of fetal inflammation and coagulation pathway gene polymorphisms with neurodevelopmental delay at age 2 years

OBJECTIVE

The purpose of this study was to evaluate the association between fetal inflammation and coagulation gene single-nucleotide polymorphisms (SNPs) and neurodevelopmental delay at age 2 years.

STUDY DESIGN

We conducted a case-controlled secondary analysis of a randomized trial of single- vs multiple-course corticosteroids. Multiplex assay assessed 46 SNPs. Cases had mental developmental and/or psychomotor delay at age 2 years. Control subjects had normal neurodevelopment.

RESULTS

One hundred twenty-five cases and 147 control subjects were analyzed. Allele frequencies were different between cases and control subjects for interleukin (IL)1beta-511 (P = .009), IL4R-148 (P = .03), IL6-174 (P = .02), and IL6-176 (P = .007). Genotype frequencies were different for IL1beta-511 (P = .03) and IL6-174 (P = .04). Results for IL1beta-511, IL4R-148, and IL6-176 remained significant after logistic regression analysis. IL1beta-511 and IL6-176 minor alleles were associated with increased risk of neurodevelopmental delay (odds ratio, 3.1; 95% confidence interval [CI], 1.2-8.2 and 2.2; 95% CI, 1.2-3.9, respectively). IL4R-148 minor allele was protective (odds ratio, 0.6; 95% CI, 0.4-0.9).

CONCLUSION

Fetal SNPs in IL1beta, IL-4R, and IL-6 may be associated with neurodevelopmental delay at age 2 years.

Neonatal outcomes and operative vaginal delivery versus cesarean delivery

We compared outcomes for neonates with forceps-assisted, vacuum-assisted, or cesarean delivery in the second stage of labor. This is a secondary analysis of a randomized trial in laboring, low-risk, nulliparous women at >or=36 weeks' gestation. Neonatal outcomes after use of forceps, vacuum, and cesarean were compared among women in the second stage of labor at station +1 or below (thirds scale) for failure of descent or nonreassuring fetal status. Nine hundred ninety women were included in this analysis: 549 (55%) with an indication for delivery of failure of descent and 441 (45%) for a nonreassuring fetal status. Umbilical cord gases were available for 87% of neonates. We found no differences in the base excess (P = 0.35 and 0.78 for failure of descent and nonreassuring fetal status) or frequencies of pH below 7.0 (P = 0.73 and 0.34 for failure of descent and nonreassuring fetal status) among the three delivery methods. Birth outcomes and umbilical cord blood gas values were similar for those neonates with a forceps-assisted, vacuum-assisted, or cesarean delivery in the second stage of labor. The occurrence of significant fetal acidemia was not different among the three delivery methods regardless of the indication.

Second trimester cervical length and risk of preterm birth in women with twin gestations treated with 17-α hydroxyprogesterone caproate

OBJECTIVE

To compare rates of preterm birth before 35 weeks based on cervical length measurement at 16-20 weeks in women with twin gestations who received 17-α hydroxyprogesterone caproate (17OHPC) or placebo.

METHODS

This is a secondary analysis of a randomised, double-blind, placebo-controlled trial of twin gestations exposed to 17OHPC or placebo. Baseline transvaginal ultrasound evaluation of cervical length was performed prior to treatment assignment at 16-20 weeks. Cervical length measurements were categorised according to the 10th, 25th, 50th and 75th percentiles in the women studied. The effect of 17OHPC administration in women with a short (25th percentile) and long (75th percentile) cervix was evaluated.

RESULTS

Of 661 twin gestations studied, 221 (33.4%) women enrolled at 11 centers underwent cervical length measurement. The 10th, 25th, 50th, 75th percentiles for cervical length at 16-20 weeks were 32, 36, 40 and 44 mm, respectively. The risk of preterm birth <35 weeks was increased in women with a cervical length <25th percentile (55.8 vs. 36.9%, p=0.02). However, a cervical length >75th percentile at this gestational age interval was not protective for preterm birth (36.5 vs. 42.9%, p=0.42). Administration of 17OHPC did not reduce preterm birth before 35 weeks among those with either a short or a long cervix (64.3 vs. 45.8%, p=0.18 and 38.1 vs. 35.5%, p=0.85, respectively).

CONCLUSION

Women with twin gestations and a cervical length below the 25th percentile at 16-20 weeks had higher rates of preterm birth. In this subgroup of women, 17 OHPC did not prevent preterm birth before 35 weeks gestation. A cervical length above the 75th percentile at 16-20 weeks did not significantly reduce the risk of preterm birth in this high risk population.

Vitamins C and E to prevent complications of pregnancy-associated hypertension

BACKGROUND

Oxidative stress has been proposed as a mechanism linking the poor placental perfusion characteristic of preeclampsia with the clinical manifestations of the disorder. We assessed the effects of antioxidant supplementation with vitamins C and E, initiated early in pregnancy, on the risk of serious adverse maternal, fetal, and neonatal outcomes related to pregnancy-associated hypertension.

METHODS

We conducted a multicenter, randomized, double-blind trial involving nulliparous women who were at low risk for preeclampsia. Women were randomly assigned to begin daily supplementation with 1000 mg of vitamin C and 400 IU of vitamin E or matching placebo between the 9th and 16th weeks of pregnancy. The primary outcome was severe pregnancy-associated hypertension alone or severe or mild hypertension with elevated liver-enzyme levels, thrombocytopenia, elevated serum creatinine levels, eclamptic seizure, medically indicated preterm birth, fetal-growth restriction, or perinatal death.

RESULTS

A total of 10,154 women underwent randomization. The two groups were similar with respect to baseline characteristics and adherence to the study drug. Outcome data were available for 9969 women. There was no significant difference between the vitamin and placebo groups in the rates of the primary outcome (6.1% and 5.7%, respectively; relative risk in the vitamin group, 1.07; 95% confidence interval [CI], 0.91 to 1.25) or in the rates of preeclampsia (7.2% and 6.7%, respectively; relative risk, 1.07; 95% CI, 0.93 to 1.24). Rates of adverse perinatal outcomes did not differ significantly between the groups.

CONCLUSIONS

Vitamin C and E supplementation initiated in the 9th to 16th week of pregnancy in an unselected cohort of low-risk, nulliparous women did not reduce the rate of adverse maternal or perinatal outcomes related to pregnancy-associated hypertension (ClinicalTrials.gov number, NCT00135707).

Autoantibody-mediated angiotensin receptor activation contributes to preeclampsia through tumor necrosis factor-alpha signaling

Preeclampsia is a prevalent life-threatening hypertensive disorder of pregnancy for which the pathophysiology remains largely undefined. Recently, a circulating maternal autoantibody, the angiotensin II type I (AT(1)) receptor agonistic autoantibody (AA), has emerged as a contributor to disease features. Increased circulating maternal tumor necrosis factor alpha (TNF-alpha) is also associated with the disease; however, it is unknown whether this factor directly contributes to preeclamptic symptoms. Here we report that this autoantibody increases the proinflammatory cytokine TNF-alpha in the circulation of AT(1)-AA-injected pregnant mice but not in nonpregnant mice. Coinjection of AT(1)-AA with a TNF-alpha neutralizing antibody reduced cytokine availability in AT(1)-AA-injected pregnant mice. Moreover, TNF-alpha blockade in AT(1)-AA-injected pregnant mice significantly attenuated the key features of preeclampsia. Autoantibody-induced hypertension was reduced from 131+/-4 to 110+/-4 mm Hg, and proteinuria was reduced from 212+/-25 to 155+/-23 microg of albumin per milligram of creatinine (both P<0.05). Injection of AT(1)-AA increased the serum levels of circulating soluble fms-like tyrosine kinase 1 and soluble endoglin (34.1+/-5.1, 2.4+/-0.3 ng/mL, respectively) and coinjection with the TNF-alpha blocker significantly reduced their levels (21.7+/-3.4 and 1.2+/-0.4 ng/mL, respectively). Renal damage and placental abnormalities were also decreased by TNF-alpha blockade. Lastly, the elevated circulating TNF-alpha in preeclamptic patients is significantly correlated with the AT(1)-AA bioactivity in our patient cohort. Similarly, the autoantibody, through AT(1) receptor-mediated TNF-alpha induction, contributed to increased soluble fms-like tyrosine kinase 1, soluble endoglin secretion, and increased apoptosis in cultured human villous explants. Overall, AT(1)-AA is a novel candidate that induces TNF-alpha, a cytokine that may play an important pathogenic role in preeclampsia.

The effect of maternal body mass index on neonatal outcome in women receiving a single course of antenatal corticosteroids

OBJECTIVE

The aim of this study was to determine the effect of maternal body mass index on the incidence of neonatal prematurity morbidities in those who receive corticosteroids.

STUDY DESIGN

This was a secondary analysis of a trial of corticosteroids in women at risk for preterm birth. Women receiving a single course of corticosteroids were classified by their prepregnancy body mass index (<25 and > or = 25) and compared on a composite outcome comprised of several neonatal morbidities and on each individual outcome.

RESULTS

Of 183 eligible women, 96 (52.5%) had a body mass index of <25 and 87 (47.5%) had a body mass index of > or = 25. The composite outcome occurred more frequently in the body mass index of > or = 2 5 group (28.7%), compared with those with a body mass index of <25 (18.8%), although this was not statistically significant (odds ratio, 1.75; 95% confidence interval, 0.83-3.72). Body mass index was not associated with outcomes after adjusting for confounding.

CONCLUSION

Maternal body mass index did not affect neonatal prematurity morbidities in those receiving corticosteroids.

Angiotensin receptor agonistic autoantibody-mediated tumor necrosis factor-alpha induction contributes to increased soluble endoglin production in preeclampsia

BACKGROUND

Preeclampsia is a prevalent life-threatening hypertensive disorder of pregnancy. The circulating antiangiogenic factor, soluble endoglin (sEng), is elevated in the blood circulation of women with preeclampsia and contributes to disease pathology; however, the underlying mechanisms responsible for its induction in preeclampsia are unknown.

METHODS AND RESULTS

Here, we discovered that a circulating autoantibody, the angiotensin receptor agonistic autoantibody (AT(1)-AA), stimulates sEng production via AT(1) angiotensin receptor activation in pregnant mice but not in nonpregnant mice. We subsequently demonstrated that the placenta is a major source contributing to sEng induction in vivo and that AT(1)-AA-injected pregnant mice display impaired placental angiogenesis. Using drug screening, we identified tumor necrosis factor-alpha as a circulating factor increased in the serum of autoantibody-injected pregnant mice contributing to AT(1)-AA-mediated sEng induction in human umbilical vascular endothelial cells. Subsequently, among all the drugs screened, we found that hemin, an inducer of heme oxygenase, functions as a break to control AT(1)-AA-mediated sEng induction by suppressing tumor necrosis factor-alpha signaling in human umbilical vascular endothelial cells. Finally, we demonstrated that the AT(1)-AA-mediated decreased angiogenesis seen in human placenta villous explants was attenuated by tumor necrosis factor-alpha-neutralizing antibodies, soluble tumor necrosis factor-alpha receptors, and hemin by abolishing both sEng and soluble fms-like tyrosine kinase-1 induction.

CONCLUSIONS

Our findings demonstrate that AT(1)-AA-mediated tumor necrosis factor-alpha induction, by overcoming its negative regulator, heme oxygenase-1, is a key underlying mechanism responsible for impaired placental angiogenesis by inducing both sEng and soluble fms-like tyrosine kinase-1 secretion from human villous explants. Our results provide important new targets for diagnosis and therapeutic intervention in the management of preeclampsia.

Angiotensin receptor agonistic autoantibody is highly prevalent in preeclampsia: correlation with disease severity

Preeclampsia (PE), a syndrome affecting 5% of pregnancies, characterized by hypertension and proteinuria, is a leading cause of maternal and fetal morbidity and mortality. The condition is often accompanied by the presence of a circulating maternal autoantibody, the angiotensin II type I receptor agonistic autoantibody (AT(1)-AA). However, the prevalence of AT(1)-AA in PE remains unknown, and the correlation of AT(1)-AA titers with the severity of the disease remains undetermined. We used a sensitive and high-throughput luciferase bioassay to detect AT(1)-AA levels in the serum of 30 normal, 37 preeclamptic (10 mild and 27 severe), and 23 gestational hypertensive individuals. Here we report that AT(1)-AA is highly prevalent in PE ( approximately 95%). Next, by comparing the levels of AT(1)-AA among women with mild and severe PE, we found that the titer of AT(1)-AA is proportional to the severity of the disease. Intriguingly, among severe preeclamptic patients, we discovered that the titer of AT(1)-AA is significantly correlated with the clinical features of PE: systolic blood pressure (r=0.56), proteinuria (r=0.70), and soluble fms-like tyrosine kinase-1 level (r=0.71), respectively. Notably, only AT(1)-AA, and not soluble fms-like tyrosine kinase-1, levels are elevated in gestational hypertensive patients. These data serve as compelling clinical evidence that AT(1)-AA is highly prevalent in PE, and its titer is strongly correlated to the severity of the disease.

The detrimental role of angiotensin receptor agonistic autoantibodies in intrauterine growth restriction seen in preeclampsia

Growth-restricted fetuses are at risk for a variety of lifelong medical conditions. Preeclampsia, a life-threatening hypertensive disorder of pregnancy, is associated with fetuses who suffer from intrauterine growth restriction (IUGR). Recently, emerging evidence indicates that preeclamptic women harbor AT₁ receptor agonistic autoantibodies (AT₁-AAs) that contribute to the disease features. However, the exact role of AT₁-AAs in IUGR and the underlying mechanisms have not been identified. We report that these autoantibodies are present in the cord blood of women with preeclampsia and retain the ability to activate AT₁ receptors. Using an autoantibody-induced animal model of preeclampsia, we show that AT₁-AAs cross the mouse placenta, enter fetal circulation, and lead to small fetuses with organ growth retardation. AT₁-AAs also induce apoptosis in the placentas of pregnant mice, human villous explants, and human trophoblast cells. Finally, autoantibody-induced IUGR and placental apoptosis are diminished by either losartan or an autoantibody-neutralizing peptide. Thus, these studies identify AT₁-AA as a novel causative factor of preeclampsia-associated IUGR and offer two possible underlying mechanisms: a direct detrimental effect on fetal development by crossing the placenta and entering fetal circulation, and indirectly through AT₁-AA–induced placental damage. Our findings highlight AT₁-AAs as important therapeutic targets.

Does information available at admission for delivery improve prediction of vaginal birth after cesarean?

We sought to construct a predictive model for vaginal birth after cesarean (VBAC) that combines factors that can be ascertained only as the pregnancy progresses with those known at initiation of prenatal care. Using multivariable modeling, we constructed a predictive model for VBAC that included patient factors known at the initial prenatal visit as well as those that only become evident as the pregnancy progresses to the admission for delivery. We analyzed 9616 women. The regression equation for VBAC success included multiple factors that could not be known at the first prenatal visit. The area under the curve for this model was significantly greater ( P < 0.001) than that of a model that included only factors available at the first prenatal visit. A prediction model for VBAC success, which incorporates factors that can be ascertained only as the pregnancy progresses, adds to the predictive accuracy of a model that uses only factors available at a first prenatal visit.

Late preterm birth: how often is it avoidable?

OBJECTIVE

Our objective was to describe indications for late preterm birth (LPTB) and estimate the frequency of potentially avoidable LPTB deliveries.

STUDY DESIGN

Singleton pregnancies delivered between 34(0/7)-36(6/7) weeks over a 1-year period at a tertiary care medical center were studied. Indications for delivery were categorized as spontaneous (spontaneous preterm birth or premature rupture of membranes) or iatrogenic (elective or medically indicated). Potentially avoidable deliveries were defined as those with elective or medical stable, but high-risk indications.

RESULTS

During the study period there were 514 LPTB (spontaneous preterm birth 36.2%, preterm premature rupture of membranes 17.7%, medically indicated 37.9%, and elective 8.2%). Potentially avoidable LPTB accounted for 17% of LPTB and were associated with later gestational age (odds ratio [OR], 4.7; 95% confidence interval [CI], 2.5-8.6), nonfaculty physician status (OR, 2.8; 95% CI, 1.5-5.1), and prior cesarean delivery (OR, 1.5; 95% CI, 1.0-2.1).

CONCLUSION

At our institution, <10% of LPTB are purely elective and >80% are clearly unavoidable.

A multicenter, randomized trial of treatment for mild gestational diabetes

BACKGROUND

It is uncertain whether treatment of mild gestational diabetes mellitus improves pregnancy outcomes.

METHODS

Women who were in the 24th to 31st week of gestation and who met the criteria for mild gestational diabetes mellitus (i.e., an abnormal result on an oral glucose-tolerance test but a fasting glucose level below 95 mg per deciliter [5.3 mmol per liter]) were randomly assigned to usual prenatal care (control group) or dietary intervention, self-monitoring of blood glucose, and insulin therapy, if necessary (treatment group). The primary outcome was a composite of stillbirth or perinatal death and neonatal complications, including hyperbilirubinemia, hypoglycemia, hyperinsulinemia, and birth trauma.

RESULTS

A total of 958 women were randomly assigned to a study group--485 to the treatment group and 473 to the control group. We observed no significant difference between groups in the frequency of the composite outcome (32.4% and 37.0% in the treatment and control groups, respectively; P=0.14). There were no perinatal deaths. However, there were significant reductions with treatment as compared with usual care in several prespecified secondary outcomes, including mean birth weight (3302 vs. 3408 g), neonatal fat mass (427 vs. 464 g), the frequency of large-for-gestational-age infants (7.1% vs. 14.5%), birth weight greater than 4000 g (5.9% vs. 14.3%), shoulder dystocia (1.5% vs. 4.0%), and cesarean delivery (26.9% vs. 33.8%). Treatment of gestational diabetes mellitus, as compared with usual care, was also associated with reduced rates of preeclampsia and gestational hypertension (combined rates for the two conditions, 8.6% vs. 13.6%; P=0.01).

CONCLUSIONS

Although treatment of mild gestational diabetes mellitus did not significantly reduce the frequency of a composite outcome that included stillbirth or perinatal death and several neonatal complications, it did reduce the risks of fetal overgrowth, shoulder dystocia, cesarean delivery, and hypertensive disorders. (ClinicalTrials.gov number, NCT00069576.)

The effect of 17-alpha hydroxyprogesterone caproate on the risk of gestational diabetes in singleton or twin pregnancies

OBJECTIVE

To compare the rates of gestational diabetes among women who received serial doses of 17-alpha hydroxyprogesterone caproate vs placebo.

STUDY DESIGN

Secondary analysis of 2 double-blind randomized placebo-controlled trials of 17-alpha hydroxyprogesterone caproate given to women at risk for preterm delivery. The incidence of gestational diabetes was compared between women who received 17-alpha hydroxyprogesterone caproate or placebo.

RESULTS

We included 1094 women; 441 had singleton and 653 had twin gestations. Combining the 2 studies, 616 received 17-alpha hydroxyprogesterone caproate and 478 received placebo. Among singleton and twin pregnancies, rates of gestational diabetes were similar in women receiving 17-alpha hydroxyprogesterone caproate vs placebo (5.8% vs 4.7%; P = .64 and 7.4% vs 7.6%; P = .94, respectively). In the multivariable model, progesterone was not associated with gestational diabetes (adjusted odds ratio, 1.04; 95% confidence interval, 0.62-1.73).

CONCLUSION

Weekly administration of 17-alpha hydroxyprogesterone caproate is not associated with higher rates of gestational diabetes in either singleton or twin pregnancies.

Multicenter randomized trial of cerclage for preterm birth prevention in high-risk women with shortened midtrimester cervical length

OBJECTIVE

The objective of the study was to assess cerclage to prevent recurrent preterm birth in women with short cervix.

STUDY DESIGN

Women with prior spontaneous preterm birth less than 34 weeks were screened for short cervix and randomly assigned to cerclage if cervical length was less than 25 mm.

RESULTS

Of 1014 women screened, 302 were randomized; 42% of women not assigned and 32% of those assigned to cerclage delivered less than 35 weeks (P = .09). In planned analyses, birth less than 24 weeks (P = .03) and perinatal mortality (P = .046) were less frequent in the cerclage group. There was a significant interaction between cervical length and cerclage. Birth less than 35 weeks (P = .006) was reduced in the less than 15 mm stratum with a null effect in the 15-24 mm stratum.

CONCLUSION

In women with a prior spontaneous preterm birth less than 34 weeks and cervical length less than 25 mm, cerclage reduced previable birth and perinatal mortality but did not prevent birth less than 35 weeks, unless cervical length was less than 15 mm.

In vitroquantification of dexamethasone-induced surfactant protein B expression in human lung cells

OBJECTIVE

To determine whether the effect of a single 48-h exposure to dexamethasone in human lung cells is limited to 7-8 days.

STUDY DESIGN

We used the NCI-H441 cell line, in which stability can be maintained beyond 7 days. The outcome was the stimulatory effect of dexamethasone on surfactant protein B (SP-B) gene transcription as expressed by SP-B mRNA accumulation. The experiment was conducted five times, in parallel with control. SP-B mRNA was determined at baseline, 48 h after dexamethasone exposure, and at 48-h intervals thereafter, up to 14 days, by quantitative reverse transcription polymerase chain reaction. Comparisons were made by the Mann-Whitney test.

RESULTS

In conditions of our experiment, the inductive profile of SP-B mRNA after exposure to dexamethasone demonstrated maximal stimulation at 48 h (13-fold over control). Subsequently, there was a decline in mRNA, with return to near control levels by day 8, suggesting reversibility of dexamethasone action.

CONCLUSION

Our data support the view that the surfactant-inducing properties of corticosteroids are limited to 7-8 days.

Timing of elective repeat cesarean delivery at term and neonatal outcomes

BACKGROUND

Because of increased rates of respiratory complications, elective cesarean delivery is discouraged before 39 weeks of gestation unless there is evidence of fetal lung maturity. We assessed associations between elective cesarean delivery at term (37 weeks of gestation or longer) but before 39 weeks of gestation and neonatal outcomes.

METHODS

We studied a cohort of consecutive patients undergoing repeat cesarean sections performed at 19 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network from 1999 through 2002. Women with viable singleton pregnancies delivered electively (i.e., before the onset of labor and without any recognized indications for delivery before 39 weeks of gestation) were included. The primary outcome was the composite of neonatal death and any of several adverse events, including respiratory complications, treated hypoglycemia, newborn sepsis, and admission to the neonatal intensive care unit (ICU).

RESULTS

Of 24,077 repeat cesarean deliveries at term, 13,258 were performed electively; of these, 35.8% were performed before 39 completed weeks of gestation (6.3% at 37 weeks and 29.5% at 38 weeks) and 49.1% at 39 weeks of gestation. One neonatal death occurred. As compared with births at 39 weeks, births at 37 weeks and at 38 weeks were associated with an increased risk of the primary outcome (adjusted odds ratio for births at 37 weeks, 2.1; 95% confidence interval [CI], 1.7 to 2.5; adjusted odds ratio for births at 38 weeks, 1.5; 95% CI, 1.3 to 1.7; P for trend <0.001). The rates of adverse respiratory outcomes, mechanical ventilation, newborn sepsis, hypoglycemia, admission to the neonatal ICU, and hospitalization for 5 days or more were increased by a factor of 1.8 to 4.2 for births at 37 weeks and 1.3 to 2.1 for births at 38 weeks.

CONCLUSIONS

Elective repeat cesarean delivery before 39 weeks of gestation is common and is associated with respiratory and other adverse neonatal outcomes.

Can a prediction model for vaginal birth after cesarean also predict the probability of morbidity related to a trial of labor?

OBJECTIVE

The objective of the study was to determine whether a model for predicting vaginal birth after cesarean (VBAC) can also predict the probabilty of morbidity associated with a trial of labor (TOL).

STUDY DESIGN

Using a previously published prediction model, we categorized women with 1 prior cesarean by chance of VBAC. Prevalence of maternal and neonatal morbidity was stratfied by probability of VBAC success and delivery approach.

RESULTS

Morbidity became less frequent as the predicted chance of VBAC increased among women who underwent TOL (P < .001) but not elective repeat cesarean section (ERCS) (P > .05). When the predicted chance of VBAC was less than 70%, women undergoing a TOL were more likely to have maternal morbidity (relative risk [RR], 2.2; 95% confidence interval [CI], 1.5-3.1) than those who underwent an ERCS; when the predicted chance of VBAC was at least 70%, total maternal morbidity was not different between the 2 groups (RR, 0.8; 95% CI, 0.5-1.2). The results were similar for neonatal morbidity.

CONCLUSION

A prediction model for VBAC provides information regarding the chance of TOL-related morbidity and suggests that maternal morbidity is not greater for those women who undergo TOL than those who undergo ERCS if the chance of VBAC is at least 70%.