Association Between Influenza Vaccination and SARS-CoV-2 Infection.

BACKGROUND: Recent data in nonpregnant individuals suggest a protective effect of influenza vaccination against SARS-CoV-2 infection and its severity. OBJECTIVES: Our primary objective was to evaluate whether influenza vaccination was associated with COVID-19 severity and pregnancy and neonatal outcomes among those infected with SARS-CoV-2. The secondary objective was to examine the association between influenza vaccination and SARS-CoV-2 infection. STUDY DESIGN: Secondary analysis of a multicenter retrospective cohort of pregnant people who tested positive for SARS-CoV-2 between March and August 2020, and a cohort of random deliveries during the same time period. The associations between 2019 influenza vaccination and the primary outcome of moderate-to-critical COVID-19 as well as maternal and perinatal outcomes were examined among all people who tested positive for SARS-CoV-2 between March and August 2020. The association between 2019 influenza vaccination and having a positive SARS-CoV-2 test was examined among a cohort of individuals who delivered on randomly selected dates between March and August 2020. Univariable and multivariable analyses were performed. RESULTS: Of 2325 people who tested positive for SARS-CoV-2, 1068 (45.9%) were vaccinated against influenza in 2019. Those who received the influenza vaccine were older, leaner, more likely to have private insurance, and identify as White or Hispanic. They were less likely to smoke tobacco and identify as Black. Overall, 419 (18.0%) had moderate, 193 (8.3%) severe, and 52 (2.2%) critical COVID-19. There was no association between influenza vaccination and moderate-to-critical COVID-19 (29.2% vs. 28.0%, adjusted OR 1.10, 95% CI 0.90-1.34) or adverse maternal and perinatal outcomes among those who tested positive. Of 8152 people who delivered in 2020, 4658 (57.1%) received the influenza vaccine. Prior vaccination was not associated with a difference in the odds of SARS-CoV-2 infection (3.8% vs. 4.2%, adjusted OR 0.94, 95% CI 0.74-1.19). CONCLUSION: Prior influenza vaccination was not associated with decreased severity of COVID-19 or lower odds of SARS-CoV-2 infection in pregnancy.

Cervical Pessary for Prevention of Preterm Birth in Individuals With a Short Cervix: The TOPS Randomized Clinical Trial.

Importance: A short cervix as assessed by transvaginal ultrasound is an established risk factor for preterm birth. Study findings for a cervical pessary to prevent preterm delivery in singleton pregnancies with transvaginal ultrasound evidence of a short cervix have been conflicting. Objective: To determine if cervical pessary placement decreases the risk of preterm birth or fetal death prior to 37 weeks among individuals with a short cervix. Design, Setting, and Participants: We performed a multicenter, randomized, unmasked trial comparing a cervical pessary vs usual care from February 2017 through November 5, 2021, at 12 centers in the US. Study participants were nonlaboring individuals with a singleton pregnancy and a transvaginal ultrasound cervical length of 20 mm or less at gestations of 16 weeks 0 days through 23 weeks 6 days. Individuals with a prior spontaneous preterm birth were excluded. Interventions: Participants were randomized 1:1 to receive either a cervical pessary placed by a trained clinician (n = 280) or usual care (n = 264). Use of vaginal progesterone was at the discretion of treating clinicians. Main Outcome and Measures: The primary outcome was delivery or fetal death prior to 37 weeks. Results: A total of 544 participants (64%) of a planned sample size of 850 were enrolled in the study (mean age, 29.5 years [SD, 6 years]). Following the third interim analysis, study recruitment was stopped due to concern for fetal or neonatal/infant death as well as for futility. Baseline characteristics were balanced between participants randomized to pessary and those randomized to usual care; 98.9% received vaginal progesterone. In an as-randomized analysis, the primary outcome occurred in 127 participants (45.5%) randomized to pessary and 127 (45.6%) randomized to usual care (relative risk, 1.00; 95% CI, 0.83-1.20). Fetal or neonatal/infant death occurred in 13.3% of those randomized to receive a pessary and in 6.8% of those randomized to receive usual care (relative risk, 1.94; 95% CI, 1.13-3.32). Conclusions and Relevance: Cervical pessary in nonlaboring individuals with a singleton gestation and with a cervical length of 20 mm or less did not decrease the risk of preterm birth and was associated with a higher rate of fetal or neonatal/infant mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT02901626.

Tranexamic Acid to Prevent Obstetrical Hemorrhage after Cesarean Delivery.

BACKGROUND: Prophylactic use of tranexamic acid at the time of cesarean delivery has been shown to decrease the calculated blood loss, but the effect on the need for blood transfusions is unclear. METHODS: We randomly assigned patients undergoing cesarean delivery at 31 U.S. hospitals to receive either tranexamic acid or placebo after umbilical-cord clamping. The primary outcome was a composite of maternal death or blood transfusion by hospital discharge or 7 days post partum, whichever came first. Key secondary outcomes were estimated intraoperative blood loss of more than 1 liter (prespecified as a major secondary outcome), interventions for bleeding and related complications, the preoperative-to-postoperative change in the hemoglobin level, and postpartum infectious complications. Adverse events were assessed. RESULTS: A total of 11,000 participants underwent randomization (5529 to the tranexamic acid group and 5471 to the placebo group); scheduled cesarean delivery accounted for 50.1% and 49.2% of the deliveries in the respective groups. A primary-outcome event occurred in 201 of 5525 participants (3.6%) in the tranexamic acid group and in 233 of 5470 (4.3%) in the placebo group (adjusted relative risk, 0.89; 95.26% confidence interval [CI], 0.74 to 1.07; P = 0.19). Estimated intraoperative blood loss of more than 1 liter occurred in 7.3% of the participants in the tranexamic acid group and in 8.0% of those in the placebo group (relative risk, 0.91; 95% CI, 0.79 to 1.05). Interventions for bleeding complications occurred in 16.1% of the participants in the tranexamic acid group and in 18.0% of those in the placebo group (relative risk, 0.90; 95% CI, 0.82 to 0.97); the change in the hemoglobin level was -1.8 g per deciliter and -1.9 g per deciliter, respectively (mean difference, -0.1 g per deciliter; 95% CI, -0.2 to -0.1); and postpartum infectious complications occurred in 3.2% and 2.5% of the participants, respectively (relative risk, 1.28; 95% CI, 1.02 to 1.61). The frequencies of thromboembolic events and other adverse events were similar in the two groups. CONCLUSIONS: Prophylactic use of tranexamic acid during cesarean delivery did not lead to a significantly lower risk of a composite outcome of maternal death or blood transfusion than placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT03364491.).

Maternal erythrocyte ENT1-mediated AMPK activation counteracts placental hypoxia and supports fetal growth.

Insufficient O2 supply is frequently associated with fetal growth restriction (FGR), a leading cause of perinatal mortality and morbidity. Although the erythrocyte is the most abundant and only cell type to deliver O2 in our body, its function and regulatory mechanism in FGR remain unknown. Here, we report that genetic ablation of mouse erythrocyte equilibrative nucleoside transporter 1 (eENT1) in dams, but not placentas or fetuses, results in FGR. Unbiased high-throughput metabolic profiling coupled with in vitro and in vivo flux analyses with isotopically labeled tracers led us to discover that maternal eENT1-dependent adenosine uptake is critical in activating AMPK by controlling the AMP/ATP ratio and its downstream target, bisphosphoglycerate mutase (BPGM); in turn, BPGM mediates 2,3-BPG production, which enhances O2 delivery to maintain placental oxygenation. Mechanistically and functionally, we revealed that genetic ablation of maternal eENT1 increases placental HIF-1α; preferentially reduces placental large neutral aa transporter 1 (LAT1) expression, activity, and aa supply; and induces FGR. Translationally, we revealed that elevated HIF-1α directly reduces LAT1 gene expression in cultured human trophoblasts. We demonstrate the importance and molecular insight of maternal eENT1 in fetal growth and open up potentially new diagnostic and therapeutic possibilities for FGR.

The effect of combined inositol supplementation on maternal metabolic profile in pregnancies complicated by metabolic syndrome and obesity.

BACKGROUND: Myoinositol and D-chiroinositol improve insulin resistance in women with obesity and gestational diabetes and in postmenopausal women with metabolic syndrome. We previously reported that offspring born to hypertensive dams lacking endothelial nitric oxide synthase and fed a high-fat diet develop metabolic-like syndrome phenotype. OBJECTIVE: The objective of the study was to investigate the effect of a mixture of myoinositol/D-chiroinositol supplementation during pregnancy on the maternal metabolic profile in pregnancies complicated by the metabolic-like syndrome and obesity using a pregnant mouse model. STUDY DESIGN: Female heterozygous endothelial nitric oxide synthase(-/+) mice with moderate hypertension were placed on a high-fat diet for 4 weeks to induce a metabolic-like syndrome phenotype. Similarly, wild-type C57BL/6 mice were placed on a high-fat diet for 4 weeks to induce a murine obesity model. Mice were then bred with wild-type males. On gestational day 1, dams were randomly allocated to receive either a mixture of myoinositol/D-chiroinositol in water (7.2/0.18 mg/mL, respectively) or water as control (placebo). At term (gestational day 18), maternal weights, systolic blood pressure, and a glucose tolerance test were obtained. Dams were then killed; pups and placentas were weighed and maternal blood collected. Serum levels of metabolic biomarkers relevant to diabetes and obesity (ghrelin, gastric inhibitory peptide, glucagon-like peptide 1, glucagon, insulin, leptin, resistin) were measured by a multiplex enzyme-linked immunosorbent assay. Analysis was done comparing metabolic-like syndrome-myoinositol/D-chiroinositol-treated vs metabolic-like syndrome-nontreated mice and obese-myoinositol/D-chiroinositol-treated vs obese nontreated mice. RESULTS: Mean systolic blood pressure was lower in metabolic-like syndrome pregnant mice treated with myoinositol/D-chiroinositol compared with placebo (P = .04), whereas there was no difference in systolic blood pressure between treated and placebo-treated obese pregnant mice. Pregnant metabolic-like syndrome mice treated with myoinositol/D-chiroinositol showed lower glucose values during the glucose tolerance test and in the area under the curve (myoinositol/D-chiroinositol: 17512.5 ± 3984.4 vs placebo: 29687.14 ± 8258.7; P = .003), but no differences were seen in the obese pregnant mice. Leptin serum levels were lower in the metabolic-like syndrome-myoinositol/D-chiroinositol-treated mice compared with the placebo group (myoinositol/D-chiroinositol: 16985 ± 976.4 pg/dL vs placebo: 24181.9 ± 3128.2 pg/dL, P = .045). No other differences were seen in any of the remaining serum metabolic biomarkers studied in metabolic-like syndrome and in obese pregnant mice. Maternal weight gain was not different in the pregnant metabolic-like syndrome dams, whereas it was lower in the obese myoinositol/D-chiroinositol-treated dams compared with the placebo group (myoinositol/D-chiroinositol: 10.9 ± 0.5 g vs 12.6 ± 0.6 g, P = .04). Fetal and placental weights did not differ between myoinositol/D-chiroinositol-treated and nontreated pregnant dams with metabolic-like syndrome and obesity. CONCLUSION: Combined inositol treatment during pregnancy improves blood pressure, glucose levels at the glucose tolerance test, and leptin levels in pregnant dams with metabolic-like syndrome phenotype but not in obese pregnant dams. In addition, inositol treatment was associated with lower gestational weight gain in the obese but not in the metabolic-like syndrome pregnant dams.

A Rapidly Growing Abdominal Mass: Desmoid Tumor in Pregnancy.

Background Desmoid tumors are benign soft tissue tumors that locally invade adjacent tissue. There is a paucity of reports describing the rapid growth of these tumors during pregnancy. Case A giant desmoid tumor arising from the left abdominal wall of a young female patient with rapid growth during pregnancy is described. Preoperative evaluation included ultrasonography and magnetic resonance imaging. Decision made by a multidisciplinary team was not to intervene before birth, and abdominal delivery at term was accomplished. Conclusion Desmoid tumors should be part of the differential diagnosis in an abdominal wall tumor of rapid growth during pregnancy. Future studies are needed for better understanding of the pathogenesis, diagnosis, and treatment of desmoid tumors in pregnant women.

Tolerability and toxicological profile of pixantrone (Pixuvri®) in juvenile mice. Comparative study with doxorubicin.

The tolerability of pixantrone dimaleate (Pixuvri(®)), an aza-anthracenedione for non-Hodgkin lymphoma, was assessed in juvenile mice after intraperitoneal injection. Twenty animals/sex/dose received pixantrone 15 or 27 mg/kg/day on Post-Natal-Days (PND) 10, 13, 17, 20, 35, 39 and 42 in comparison with doxorubicin, 3 mg/kg/day. Animals were sacrificed on PND 42, 73 and 96. All pixantrone animals survived, while doxorubicin induced 52.5% mortality and the surviving animals were sacrificed early due to severe toxicity. Recoverable bone marrow toxicity (pixantrone), and toxicity to thymus and reproductive organs (pixantrone, doxorubicin) were observed without nephro- or hepatotoxicity. Pixantrone was measurable in plasma up to 2h (occasionally 6h) post-dose. At PND 42, mean Cmax and AUC values increased proportionally with dose, without gender difference or accumulation. Pixantrone showed minimal cardiotoxicity in males and negligible in females at PND 96. Doxorubicin induced significant heart weight reduction at PND 42, however early sacrifice impeded further cardiac assessments.

The effect of prenatal pravastatin treatment on altered fetal programming of postnatal growth and metabolic function in a preeclampsia-like murine model.

OBJECTIVE: Preeclampsia alters fetal programming and results in long-term metabolic consequences in the offspring. Pravastatin has been shown to prevent preeclampsia in animal models. Our aim was to characterize the effects of preeclampsia on fetal programming of adult growth and metabolic function, and evaluate the role of preventive pravastatin therapy, using a well characterized murine model. STUDY DESIGN: CD-1 mice were injected through the tail vein with adenovirus carrying soluble fms-like tyrosine kinase 1 (sFlt-1) and randomly allocated to pravastatin (5 mg/kg/day; sFlt-1/prav, n = 7) or water (sFlt-1, n = 6) until weaning. A control group was injected with adenovirus carrying the murine immunoglobulin G2α Fc fragment (mFc, n = 8). Male and female offspring (6-8/group) were weighed every month until 6 months of age. Intraperitoneal glucose tolerance testing was performed after 16 hours of fasting at 3 and 6 months of age; glucose and insulin responses were measured. RESULTS: sFlt-1 offspring weight was lower than mFc control (P < .001) until 2 months of age for females and 5 months of age for males (P < .001). There were no differences in postnatal growth between mFc and sFlt-1/prav offspring. At 3 and 6 months, female sFlt-1 offspring had higher glucose response compared with mFc and sFlt-1/prav. Three-month-old male sFlt-1 had lower insulin response compared with mFc offspring. CONCLUSION: Preeclampsia alters postnatal growth and metabolic function in the adult offspring in this animal model. Maternal therapy with prav prevents some of these alterations in the offspring.

Effects of pravastatin on angiogenic and placental hypoxic imbalance in a mouse model of preeclampsia.

In order to determine the effects of pravastatin (Pra) on angiogenic and placental hypoxic imbalance in a model of preeclampsia induced by overexpression of soluble fms-like tyrosine kinase 1 (sFlt-1), we randomly allocated pregnant CD1 mice to injection with adenovirus-carrying sFlt-1 or mFc (control). The sFlt-1 group received either Pra (sFlt-1 + Pra) or water (sFlt-1). Mice were sacrificed at day 18, and serum levels of sFlt-1 and soluble endoglin (sEng) were measured. Placental expression of placental (PLGF) and vascular endothelial (VEGF) growth factors and other markers of angiogenesis and hypoxia were assayed. We observed that Pra treatment in sFlt-1 mice reduced sFlt-1 and sEng concentrations at day 18 to levels similar to control group. Placental PLGF and VEGF expression were upregulated, and markers of hypoxia downregulated to levels similar to control group. Hence, Pra prevents the rise in circulating antiangiogenic factors in a mouse model of preeclampsia. Statins may represent a novel approach to prevention of preeclampsia.

Single-nucleotide polymorphisms in genes involved in placental function and unexplained stillbirth.

OBJECTIVE: The purpose of this study was to evaluate the association between unexplained stillbirth (SB) and single-nucleotide polymorphisms (SNPs) in genes involved in placental function using a well-characterized cohort. STUDY DESIGN: Placentas were obtained from 50 unexplained SB and 46 live birth controls. Classification of stillbirth was by Wigglesworth criteria. SBs were stratified by weight: appropriate (AGA-SB) and small for gestational age (SGA-SB, less than the 10th percentile) and gestational age: before 32 and after 32 weeks. Placental DNA was extracted and various SNPs in the endothelial nitric oxide synthase (eNOS), Klotho, hypoxic inducible factor-1α, and and tumor necrosis factor-α genes were evaluated. RESULTS: None of the SNPs were associated with SB overall. Significantly different genotype distribution emerged for eNOS-SNP rs1800783 when comparing AGA-SB with SGA-SB and control (P = .004). Its allele-A was more frequent in AGA-SB compared with both controls (P = .03) and SGA-SB (P = .001). No differences were seen accordingly to gestational age. CONCLUSION: Unexplained stillbirth in the setting of adequate growth is associated with carrier of allele A of rs1800783 eNOS gene in the placenta.

Can statins reduce the inflammatory response associated with preterm birth in an animal model?

OBJECTIVE: The objective of the study was to determine the effect of statins on lipopolysaccharide (LPS)-induced inflammatory response in a mouse model of preterm birth (PTB). STUDY DESIGN: Day 15 CD1 mice were randomly allocated to intraperitoneal LPS injection (100 µg) or control. Mice in the LPS group were pretreated, 16 and 2 hours prior, with pravastatin (10 µg/g), simvastatin (10 µg/g), or vehicle control. Animals were sacrificed 6 hours after LPS. Cytokine messenger ribonucleic acid (mRNA) expression in the uterus and cervix, and concentrations in the maternal serum and amniotic fluid (AF) were determined. RESULTS: Pravastatin reduced interleukin (IL)-1ß and IL-6 mRNA expression in the uterus and cervix, respectively, and serum IL-1ß and granulocyte-macrophage colony-stimulating factor (GM-CSF) concentrations. Simvastatin reduced IL-1ß and IL-6 mRNA expressions in the uterus, IL-6 and tumor necrosis factor alpha (TNF-α) in the cervix, and IL-1ß, IL-2, IL-12p70, IL-13, TNF-α, GM-CSF, and interferon-γ concentrations in the serum and IL-6 in AF. CONCLUSION: Statins reduce the LPS-induced inflammatory responses in a mouse model of PTB.

Sex-specific effects of nicotine exposure on developmental programming of blood pressure and vascular reactivity in the C57Bl/6J mouse.

OBJECTIVE: The objective of the study was to determine whether perinatal nicotine exposure adversely affects cardiovascular health in adulthood. STUDY DESIGN: C57Bl/6J female mice were randomized to 200 µg/mL nicotine in 2% saccharin or 2% saccharin alone from 2 weeks before breeding until weaning. Offspring weight, vital signs, and carotid artery vascular reactivity were studied. A second cohort was subjected to shaker stress on day 4 of 7 days. Selected mediators of vascular tone were evaluated by molecular studies. Student t or Mann-Whitney U test was performed for statistical analysis (significance: P < .05). RESULTS: Nicotine-exposed compared with control female offspring had significantly elevated mean blood pressure under normal and stress conditions. Nicotine females lacked heart rate elevation after stress. Nicotine males had higher mean heart rate and a blunted contractile response to phenylephrine compared with controls, without an increase in blood pressure. CONCLUSION: Perinatal nicotine exposure has an impact on the developmental programming of future cardiovascular health, with adverse effects more evident in female offspring.

In vitro myometrial contractility profiles of different pharmacological agents used for induction of labor.

OBJECTIVE: To investigate the effects of different pharmacological induction agents on myometrial contractility. STUDY DESIGN: Myometrial biopsies were obtained from 13 term nonlaboring women undergoing scheduled cesarean delivery. Tissue strips were suspended in organ chambers for isometric tension recording. The effects of cumulative doses (10-10 mol/L to 10-5 mol/L) of prostaglandin E1 (PGE1), E2 (PGE2), and oxytocin on spontaneous uterine contractility were determined. Areas under the contraction curve were compared using one-way analysis of variance on ranks with Dunn post hoc test. RESULTS: Oxytocin-induced myometrial contractility was superior to PGE1, PGE2, and time controls (CTR) at all the concentrations tested. When only prostaglandins were compared with CTR, PGE1 10-5 mol/L increased myometrial contractility, and PGE2 had no effects. CONCLUSION: Oxytocin and prostaglandins have different effects on myometrial contractility accounting for different mechanisms of action and side effects. The increased uterine contractility observed with PGE1 as compared with PGE2 can contribute to explain the higher success of vaginal delivery.

Effects of pravastatin on mediators of vascular function in a mouse model of soluble Fms-like tyrosine kinase-1-induced preeclampsia.

OBJECTIVE: We sought to investigate the mechanisms of action by which pravastatin improves vascular reactivity in a mouse model of preeclampsia induced by overexpression of soluble Fms-like tyrosine kinase-1 (sFlt)-1. STUDY DESIGN: Pregnant CD-1 mice were randomly allocated to tail vein injection with adenovirus carrying sFlt-1 or murine immunoglobulin G2 Fc (control), and thereafter to receive pravastatin (5 mg/kg/d) or water. Mice were sacrificed at gestational day 18. Protein expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor receptor-1, and hemeoxygenase-1 were assayed by Western blot in aorta, liver, and kidneys. Serum total cholesterol concentrations were measured. RESULTS: Pravastatin up-regulated eNOS expression in the aorta of sFlt-1 mice by nearly 2-fold (P = .005) to levels similar to control mice. Total cholesterol levels, vascular endothelial growth factor receptor-1, and hemeoxygenase-1 protein expression were similar across groups. CONCLUSION: Pravastatin prevents vascular dysfunction in part by up-regulation of eNOS in the vasculature. Our data support a role for statins in preeclampsia prevention.

Endothelial growth factor therapy improves preeclampsia-like manifestations in a murine model induced by overexpression of sVEGFR-1.

This study examines the effects of VEGF-121 therapy in an animal model of preeclampsia induced by overexpression of soluble VEGF receptor 1 (sVEGFR-1). At day 8 of gestation, CD-1 mice were implanted with subcutaneous osmotic pumps containing either VEGF-121 or vehicle and fitted with telemetric blood pressure (BP) catheters for continuous BP monitoring (days 8-18 of gestation). On day 9, the animals in the VEGF-121 group were randomly allocated for injection with adenovirus carrying sVEGFR-1 or the murine immunoglobulin G2α Fc fragment (mFc) as virus control (Adv-sVEGFR-1; Adv-mFc). Animals in the vehicle group were injected with Adv-sVEGFR-1. On day 18, mice were euthanized, placentas and pups weighted, carotid arteries isolated, and their responses studied in vitro using a wire myograph for isometric tension recording. In mice overexpressing sVEGFR-1, treatment with VEGF-121 significantly reduced BP from days 10 to 18 of gestation compared with that of vehicle. VEGF-sVEGFR-1 animals had significantly higher vasorelaxant response to sodium nitroprusside and significantly lower contractile response to the thromboxane agonist (U-46619) compared with that of the vehicle-sVEGFR-1 mice. Phenylephrine and acetylcholine responses did not significantly vary between the VEGF-sVEGFR-1 and the vehicle-sVEGFR-1 mice. Average pup weight was significantly lower in the vehicle-sVEGFR-1 group compared with the VEGF-sVEGFR-1 and VEGF-mFc groups. In conclusion, VEGF-121 therapy attenuates vascular dysfunction and diminishes intrauterine growth abnormality in an animal model of preeclampsia induced by overexpression of sVEGFR-1. Modulation of VEGF pathway turns into a promising therapeutic approach of preeclampsia.

Effect of maternal body mass index on in vitro response to tocolytics in term myometrium.

OBJECTIVE: We sought to investigate the effect of body mass index (BMI) on in vitro response to tocolytics. STUDY DESIGN: Myometrial biopsies were obtained at the time of scheduled cesarean deliveries from term nonlaboring women with BMI < or =29.9 (26.3 +/- 1.3; n = 7), 30-34.9 (31.8 +/- 1.2; n = 16), and > or = 35 (39.5 +/- 4.9; n = 9). Tissue strips were suspended in organ chambers for isometric tension recording. The effects of cumulative doses (10(-10) to 10(-5) mol/L) of nifedipine or indomethacin on spontaneous uterine contractility were determined. Areas under the contraction curve were compared using 1-way analysis of variance with Tukey post hoc test. RESULTS: Myometrial response to tocolytics did not differ between the BMI groups. Nifedipine, but not indomethacin, significantly inhibited myometrial contractility independent of BMI. CONCLUSION: BMI does not affect uterine response to tocolytics in isolated uterine tissue from term nonlaboring women.

Does sildenafil citrate affect myometrial contractile response to nifedipine in vitro?

OBJECTIVE: We sought to test the hypothesis that sildenafil citrate (SC) at low concentrations potentiates the tocolytic effects of nifedipine in vitro. STUDY DESIGN: Myometrial biopsies were obtained from 22 term nonlaboring women undergoing scheduled cesarean delivery. Tissue strips were suspended in organ chambers for isometric tension recording, and incubated for 30 minutes with either SC at 231 ng/mL or solvent. The effects of cumulative doses (10(-10) to 10(-5) mol/L) of nifedipine on spontaneous and oxytocin-induced uterine contractility were then determined. Areas under the contraction curve were compared using 1-way analysis of variance with Tukey post hoc test (significance: P < .05). RESULTS: Nifedipine significantly inhibited spontaneous and oxytocin-induced myometrial contractility. Preincubation with SC increased response to nifedipine and significantly potentiated its inhibitory effect at 10(-8) mol/L, without affecting oxytocin-induced contractile response. CONCLUSION: At concentrations within a therapeutic window, SC increases myometrial sensitivity to nifedipine.

Using pravastatin to improve the vascular reactivity in a mouse model of soluble fms-like tyrosine kinase-1-induced preeclampsia.

OBJECTIVE: To estimate the effects of pravastatin on the altered vascular function in a mouse model of preeclampsia induced by overexpression of soluble fms-like tyrosine kinase-1 (sFlt-1). METHODS: Pregnant CD1 mice, at day 8 of gestation, were randomly allocated to injection using the tail vein of the adenovirus carrying sFlt-1 (10 plaque-forming units in 100 microliters; sFlt-1 group) or mFc (10 plaque-forming units) as virus control, and then to receive pravastatin (Pra; 5 mg/kg/d) dissolved in drinking water or control. The mice in four groups (sFlt-1, sFlt-1-pravastatin, mFc, and mFc-pravastatin; n=4-6 per group) were killed at day 18 of gestation and 2-mm segments of carotid artery were used for vascular reactivity studies. Serum sFlt-1 levels were also measured by enzyme-linked immunosorbent assay. RESULTS: Mice in the sFlt-1 group had the highest responses to phenylephrine. Treatment with pravastatin decreased the contractile responses to phenylephrine (maximal effect [mean+/-standard error of the mean] 137.35+/- 27.70 compared with 42.24+/-8.76; P=.006) for sFlt-1 compared with sFlt-1-pravastatin, respectively. There were no differences in the contractile responses to thromboxane A2. The vasorelaxant responses to acetylcholine were significantly highest in the mFc-pravastatin group, with a maximal effect of 108.37+/-5.25 compared with 89.77+/-3.96 in the mFc group (P=.008), and those with sodium nitroprusside were not different across the four groups. Serum sFlt-1 levels were not different at baseline (day 8) but were significantly lower in sFlt-1-pravastatin compared with sFlt-1 at day 18 (59.42+/-5.31 compared with 102.59+/-15.15 ng/mL; P=.01). CONCLUSION: Pravastatin improved the vascular reactivity in this murine model of preeclampsia by decreasing sFlt-1 levels. Statins should be evaluated for the prevention of the vascular abnormalities of preeclampsia.

Long-term maternal cardiovascular function in a mouse model of sFlt-1-induced preeclampsia.

Our aim was to evaluate the long-term effects of preeclampsia on vascular function in a mouse model induced by sFlt-1 overexpression. CD-1 mice at day 8 of gestation were injected via the tail vein with adenovirus carrying sFlt1 (AdsFlt1), adenovirus carrying the murine IgG2alpha Fc fragment as the adenovirus control (AdmFc), or saline. Vascular function in the mothers was investigated 6-8 mo after delivery by recording blood pressure (BP) by telemetry (AdsFlt1 n = 8, AdmFc n = 6, saline n = 4) and exploring carotid artery reactivity in a wire myograph (AdsFlt1 n = 6, AdmFc n = 8, saline n = 4). sFlt-1 blood levels at 6-8 mo postpartum had returned to low levels and were comparable between the three groups (P = 0.808). There was no statistically significant difference in BP (P = 0.067) or vascular reactivity between the three groups of postpartum mice (phenylephrine P = 0.079, thromboxane P = 0.979, serotonin P = 0.659, acetylcholine P = 0.795, sodium nitroprusside P = 0.728, isoproterenol P = 0.370). Our results indicate that in a mouse model overexpression of sFlt-1 does not lead to increased in BP and altered vascular function in the absence of the pregnancy and has no long-term effect on BP and vascular function in the postpartum mothers. Our findings favor the hypothesis that increased cardiovascular diseases in women with history of preeclampsia are likely the result of preexisting risk factors common to preeclampsia and cardiovascular diseases.

The effect of prepregnancy obesity and sFlt-1-induced preeclampsia-like syndrome on fetal programming of adult vascular function in a mouse model.

OBJECTIVE: The purpose of this study was to test the hypothesis that prepregnancy obesity and soluble fms-like tyrosine kinase-1 (sFlt-1)-induced preeclampsia lead to altered vascular function in the offspring later in life. STUDY DESIGN: CD-1 female mice were placed on a low-fat (LF) or high-fat (HF) diet before mating. On day 8 of pregnancy, the HF mice were injected with adenovirus that carried either sFlt-1 (HF sFlt-1) or murine immunoglobulin G2alpha Fc fragment (HF mFc). LF dams received saline solution. After being weaned, all offspring were placed on a standard diet. At 3 months of age, the carotid artery was isolated for in vitro vascular reactivity studies. RESULTS: Among male offspring, the response to phenylephrine was significantly lower in the HF sFlt-1 group. The response to serotonin in males and to thromboxane in females was lower in the HF sFlt-1 and HF mFc groups. In females, the HF sFlt-1 and LF groups displayed less relaxation to acetylcholine. The response to phenylephrine was significantly lower in females than males in the HF mFc and LF groups. The response to thromboxane was significantly lower in the HF sFlt-1 females, compared with males. CONCLUSION: Prepregnancy obesity and preeclampsia alter fetal programming of adult vascular function. The mechanism is complex and gender specific.