Alterations in endogenous progesterone metabolism associated with spontaneous very preterm delivery

Study question: Do maternal serum levels of progesterone metabolites early in pregnancy correspond to an increased risk for very preterm delivery prior to 32 weeks? Summary answer: Maternal serum levels of 11-deoxycorticosterone (DOC) measured during the late first trimester or early second trimester correlate with an increased risk for preterm delivery prior to 32 weeks, and the correlation becomes stronger when the ratio of DOC to 16-alpha-hydroxyprogesterone was measured. What is known already: Progesterone is a pro-gestational steroid hormone that has been shown to decrease the risk of preterm birth in some pregnant women. Progesterone is metabolized by the body into various metabolites including members of the mineralocorticoid and glucocorticoid families. Our group has previously demonstrated that some progesterone metabolites enhance myometrial contractility in an ex vivo system, while others result in myometrial relaxation. The current exploratory study was designed to determine if pre-specified metabolites of progesterone measured early in pregnancy were associated with a woman's risk for delivery prior to 32 weeks, which is referred to as a very preterm delivery. Study design size duration: The Building Blocks of Pregnancy Biobank (BBPB) is a biorepository at Indiana University (IU) that follows women prospectively through their pregnancy. A variety of biospecimens are collected at various time points during a woman's pregnancy. Women participating in the IU BBPB who were enrolled after 8 weeks' gestation with pregnancy outcome data were eligible for participation. Participants/materials setting methods: Women delivering prior to 37 weeks (preterm) and at or after 37 weeks (term) who had blood samples collected during the late first trimester/early second trimester and/or during the early third trimester were identified. These samples were then processed for mass spectroscopy, and the amount of progesterone and progesterone metabolites in the samples were measured. Mean values of each measured steroid metabolite were calculated and compared among women delivering at less than 32 weeks, less than 37 weeks and greater than or equal to 37 weeks. Receiver operating characteristic (ROC) curves were constructed and threshold levels determined for each compound to identify a level above or below which best predicted a woman's risk for delivery prior to 32 and prior to 37 weeks. Mann-Whitney U nonparametric testing with Holm-Bonferroni correction for multiple comparisons was utilized to identify steroid ratios that could differentiate women delivering spontaneously at less than 32 weeks from all other pregnancies. Main results and the role of chance: Steroid hormone levels and pregnancy outcome data were available for 93 women; 28 delivering prior to 32 weeks, 40 delivering between 32 0/7 and 36 6/7 weeks and 25 delivering at or greater than 37 weeks: the mean gestational age at delivery within the three groups was 27.0, 34.4 and 38.8 weeks, respectively. Among women delivering spontaneously at less than 37 weeks, maternal 11-deoxycorticosterone (DOC) levels drawn in the late first trimester/early second trimester were significantly associated with spontaneous preterm delivery prior to 32 weeks; a threshold level of 47.5 pg/ml had 78% sensitivity, 73% specificity and an AUC of 0.77 (P = 0.044). When DOC levels were analyzed as a ratio with other measured steroid hormones, the ratio of DOC to 16-alpha-hydroxyprogesterone among women delivering spontaneously prior to 37 weeks was able to significantly discriminate women delivering prior to 32 weeks from those delivering at or greater than 32 weeks, with a threshold value of 0.2 with 89% sensitivity, 91% specificity and an AUC of 0.92 (P = 0.002). When the entire study cohort population was considered, including women delivering at term and women having an iatrogenic preterm delivery, the ratio of DOC to 16-alpha-hydroxyprogesterone was able to discriminate women delivering spontaneously prior to 32 weeks from the rest of the population at a threshold of 0.18 and 89% sensitivity, 59% specificity and an AUC of 0.81 (P = 0.003). Limitations reasons for caution: This is a discovery study, and the findings have not been validated on an independent cohort. To mitigate issues with multiple comparisons, we limited our study to pre-specified metabolites that are most representative of the major metabolic pathways for progesterone, and adjustments for multiple comparisons were made. Wider implications of the findings: Spontaneous preterm birth is increasingly being recognized to represent a common end pathway for a number of different disease phenotypes that include infection, inflammation, premature rupture of the membranes, uterine over distension, cervical insufficiency, placental dysfunction and genetic predisposition. In addition to these phenotypes, longitudinal changes in the maternal-fetal hypothalamic-pituitary-adrenal (HPA) axis also likely contribute to a significant proportion of the disease burden of spontaneous preterm birth. Here, we demonstrate that differential production of steroid metabolites is associated with very early preterm birth. The identified biomarkers may hint at a pathophysiologic mechanism and changes in the maternal-fetal dyad that result in preterm delivery. The early identification of abnormal changes in HPA axis metabolites may allow for targeted interventions that reverse the aberrant steroid metabolic profile to a more favorable one, thereby decreasing the risk for early delivery. Further research is therefore required to validate and extend the results presented here. Study funding/competing interests: Funding for this study was provided from the Office of the Vice Chancellor for Research at IUPUI, 'Funding Opportunities for Research Commercialization and Economic Success (FORCES) grant'.Both A.S.P. and C.A.G. are affiliated with Nixxi, a biotech startup. The remaining authors report no conflict of interest

Progesterone Metabolites Produced by Cytochrome P450 3A Modulate Uterine Contractility in a Murine Model

Objective: We seek to characterize the effect of progesterone metabolites on spontaneous and oxytocin-induced uterine contractility. Study Design: Spontaneous contractility was studied in mouse uterine horns after treatment with progesterone, 2α-hydroxyprogesterone, 6β-hydroxyprogesterone (6β-OHP), 16α-hydroxyprogesterone (16α-OHP), or 17-hydroxyprogesterone caproate (17-OHPC) at 10−9 to 10−6 mol/L. Uterine horns were exposed to progestins (10−6 mol/L), followed by increasing concentrations of oxytocin (1-100 nmol/L) to study oxytocin-induced contractility. Contraction parameters were compared for each progestin and matched vehicle control using repeated measures 2-way analysis of variance. In vitro metabolism of progesterone by recombinant cytochrome P450 3A (CYP3A) microsomes (3A5, 3A5, and 3A7) identified major metabolites. Results: Oxytocin-induced contractile frequency was decreased by 16α-OHP (P = .03) and increased by 6β-OHP (P = .05). Progesterone and 17-OHPC decreased oxytocin-induced contractile force (P = .02 and P = .04, respectively) and frequency (P = .02 and P = .03, respectively). Only progesterone decreased spontaneous contractile force (P = .02). Production of 16α-OHP and 6β-OHP metabolites were confirmed in all CYP3A isoforms tested. Conclusion: Progesterone metabolites produced by maternal or fetal CYP3A enzymes influence uterine contractility

Prediction of neonatal morbidity and very preterm delivery using maternal steroid biomarkers in early gestation

Background: Preterm delivery is a common pregnancy complication that can result in significant neonatal morbidity and mortality. Limited tools exist to predict preterm birth, and none to predict neonatal morbidity, from early in pregnancy. The objective of this study was to determine if the progesterone metabolites 11-deoxycorticosterone (DOC) and 16-alpha hydroxyprogesterone (16α-OHP), when combined with patient demographic and obstetric history known during the pregnancy, are predictive of preterm delivery-associated neonatal morbidity, neonatal length of stay, and risk for spontaneous preterm delivery prior to 32 weeks' gestation. Methods and findings: We conducted a cohort study of pregnant women with plasma samples collected as part of Building Blocks of Pregnancy Biobank at the Indiana University School of Medicine. The progesterone metabolites, DOC and 16α-OHP, were quantified by mass spectroscopy from the plasma of 58 pregnant women collected in the late first trimester/early second trimester. Steroid levels were combined with patient demographic and obstetric history data in multivariable logistic regression models. The primary outcome was composite neonatal morbidity as measured by the Hassan scale. Secondary outcomes included neonatal length of stay and spontaneous preterm delivery prior to 32 weeks' gestation. The final neonatal morbidity model, which incorporated antenatal corticosteroid exposure and fetal sex, was able to predict high morbidity (Hassan score ≥ 2) with an area under the ROC curve (AUROC) of 0.975 (95% CI 0.932, 1.00), while the model without corticosteroid and fetal sex predictors demonstrated an AUROC of 0.927 (95% CI 0.824, 1.00). The Hassan score was highly correlated with neonatal length of stay (p<0.001), allowing the neonatal morbidity model to also predict increased neonatal length of stay (53 [IQR 22, 76] days vs. 4.5 [2, 31] days, above and below the model cut point, respectively; p = 0.0017). Spontaneous preterm delivery prior to 32 weeks' gestation was also predicted with an AUROC of 0.94 (95% CI 0.869, 1.00). Conclusions: Plasma levels of DOC and 16α-OHP in early gestation can be combined with patient demographic and clinical data to predict significant neonatal morbidity, neonatal length of stay, and risk for very preterm delivery, though validation studies are needed to verify these findings. Early identification of pregnancies at risk for preterm delivery and neonatal morbidity allows for timely implementation of multidisciplinary care to improve perinatal outcomes

First-Trimester Maternal Serum C-reactive Protein as a Predictor of Third-Trimester Impaired Glucose Tolerance

We evaluated whether first-trimester high-sensitivity C-reactive protein (hsCRP), a suggested marker of pregnancy-associated hyperglycemia, predicts third-trimester impaired glucose tolerance (IGT) in a secondary analysis of a prospective cohort of nondiabetic singletons enrolled at <26 weeks gestation

Association of Autism With Induced or Augmented Childbirth in North Carolina Birth Record (1990-1998) and Education Research

IMPORTANCE One in 88 children in the United States is diagnosed as having autism spectrum disorder. Significant interest centers on understanding the environmental factors that may contribute to autism risk. OBJECTIVE To examine whether induced (stimulating uterine contractions prior to the onset of spontaneous labor) and/or augmented (increasing the strength, duration, or frequency of uterine contractions with spontaneous onset of labor) births are associated with increased odds of autism. DESIGN, SETTING, AND PARTICIPANTS We performed an epidemiological analysis using multivariable logistic regression modeling involving the North Carolina Detailed Birth Record and Education Research databases. The study featured 625 042 live births linked with school records, including more than 5500 children with a documented exceptionality designation for autism. EXPOSURES Induced or augmented births. MAIN OUTCOMES AND MEASURES Autism as assessed by exceptionality designations in child educational records. RESULTS Compared with children born to mothers who received neither labor induction nor augmentation, children born to mothers who were induced and augmented, induced only, or augmented only experienced increased odds of autism after controlling for potential confounders related to socioeconomic status, maternal health, pregnancy-related events and conditions, and birth year. The observed associations between labor induction/augmentation were particularly pronounced in male children. CONCLUSIONS AND RELEVANCE Our work suggests that induction/augmentation during childbirth is associated with increased odds of autism diagnosis in childhood. While these results are interesting, further investigation is needed to differentiate among potential explanations of the association including underlying pregnancy conditions requiring the eventual need to induce/augment, the events of labor and delivery associated with induction/augmentation, and the specific treatments and dosing used to induce/augment labor (eg, exogenous oxytocin and prostaglandins)

Cigarette Smoke-Induced Placental Adrenomedullin Expression and Trophoblast Cell Invasion

Smoking in pregnancy reduces preeclampsia risk, but the mechanism of this effect is unknown. Prior studies have demonstrated that women with preeclampsia have lower placental adrenomedullin (AM) expression, and cigarette smoke extract (CSE) treatment of placental trophoblast cells in culture increases AM cellular production. We hypothesized that CSE alters trophoblast invasion through an AM-mediated mechanism, and that placental AM expression is greater among smokers. HTR-8/SVneo trophoblast cells were incubated for 24 hours in Matrigel-invasion chambers with 6 treatment groups: nonstimulated (NS), AM, AM inhibitor (AM22-52), 1% CSE, AM + AM22-52, and 1% CSE + AM22-52. Cells that penetrated the lower surface of the chambers were quantified, invasion indices were calculated, and compared using a 1-way analysis of variance with Bonferroni corrections for multiple comparisons. Trophoblast cells treated with both AM and 1% CSE demonstrated increased cellular invasion compared to NS controls (1.5-fold [P < .01] and 1.45-fold [P < .01], respectively). Cotreatment with the AM inhibitor significantly attenuated the increased invasion seen with both AM and CSE alone. Next, the placental tissue was obtained from 11 smokers and 11 nonsmokers at term and processed for immunohistochemistry (IHC) and real-time quantitative polymerase chain reaction (PCR) for AM. Placentas from smokers demonstrated more intense AM staining and increased AM gene (ADM) expression compared to placentas from nonsmokers (P = .004 for IHC, P = .022 for PCR). The CSE increases trophoblast cell invasion through an AM-mediated process, and placental AM expression is increased among term smokers compared to nonsmokers. These findings provide evidence that the AM pathway may play a role in the protection from preeclampsia seen in smokers