Progesterone receptor polymorphisms and clinical response to 17-alpha-hydroxyprogesterone caproate

Precision medicine activities and opportunities for shaping maternal and neonatal health in Qatar

Precision Medicine (PM) is a transformative clinical medicine strategy that aims to revolutionize healthcare by leveraging biological information and biomarkers. In the context of maternal and neonatal health, PM enables personalized care from preconception through the postnatal period. Qatar has emerged as a key player in PM research, with dedicated programs driving advancements and translating cutting-edge research into clinical applications. This article delves into neonatal and maternal health in Qatar, emphasizing PM programs and initiatives that have been implemented. It also features noteworthy clinical cases that demonstrate the effectiveness of precision interventions. Furthermore, the article highlights the role of pharmacogenomics in addressing various maternal health conditions. The review further explores potential advancements in the application of PM in maternal and neonatal healthcare in Qatar.

Placental histology for targeted risk assessment of recurrent spontaneous preterm birth

BACKGROUND

Spontaneous preterm birth significantly increases the risk for a recurrent preterm birth. Only a few identifiable clinical risk factors can be referenced in counseling for recurrent preterm birth. Furthermore, treatment using progesterone supplementation has not consistently prevented preterm birth among high-risk patients, but it may be effective in a subset of those patients. Placental pathology from a previous pregnancy may be used to predict which patients will experience a recurrent preterm birth or to identify a subset of patients more likely to respond to treatment with antenatal progesterone.

OBJECTIVE

This study aimed to determine if histologic patterns are associated with recurrent preterm birth among patients with an index spontaneous preterm birth. A secondary objective was to determine if placental histologic types and/or progesterone receptor density in the decidua are associated with the response to progesterone supplementation with intramuscular 17-hydroxyprogesterone caproate.

STUDY DESIGN

This was a retrospective cohort study at a single institution of women with singleton pregnancies with an index spontaneous preterm birth and a subsequent birth within the same hospital system between 2009 and 2019. Patients were included if placental pathology was available for the index spontaneous preterm birth. A logistic regression was used to determine if there were independent associations between 4 histologic types (acute inflammation, maternal vascular malperfusion, fetal vascular malperfusion, chronic inflammation) and recurrent preterm birth. For the secondary endpoint, 17-hydroxyprogesterone caproate response was defined as prolonging gestation by >3 weeks beyond the gestational age at delivery in the index pregnancy. Patients who delivered <3 weeks beyond the gestational age in the index pregnancy but at ≥39 weeks' gestation were excluded. A logistic regression was used to assess the independent association between placental histology and 17-hydroxyprogesterone caproate response. Sensitivity analyses were completed using only patients with an index birth <36 weeks' gestation, and then excluding those with medically indicated preterm birth in a subsequent pregnancy. A nested case-control immunohistochemical study was done among 20 patients with a subsequent term birth and 20 patients with a subsequent spontaneous preterm birth. The percentage of cells in the maternal decidua positive for progesterone receptors was correlated with the subsequent pregnancy outcome.

RESULTS

A total of 352 patients were included. Acute inflammation was the most common histologic type seen among patients with spontaneous preterm birth (44.1%), followed by chronic inflammation (40.9%) and maternal vascular malperfusion (31.3%). No histologic type was independently associated with recurrent preterm birth. A total of 155 patients received 17-hydroxyprogesterone caproate in a second pregnancy. Low-grade acute inflammation was significantly associated with a decreased likelihood of 17-hydroxyprogesterone caproate response. Low-grade maternal vascular malperfusion among those with an index pregnancy delivered at <36 weeks' gestation was significantly associated with a more than 4 times increased likelihood of 17-hydroxyprogesterone caproate response when excluding those with a subsequent iatrogenic preterm birth. Progesterone receptor staining was not associated with recurrent preterm birth.

CONCLUSION

Although acute inflammation was prevalent among spontaneous preterm births, more than half of the spontaneous preterm births were not associated with acute inflammation. Low-grade acute inflammation was associated with a significantly decreased response to 17-hydroxyprogesterone caproate supplementation. Low-grade maternal vascular malperfusion was associated with a 4-fold increased likelihood of 17-hydroxyprogesterone caproate response among those with index deliveries <36 weeks' gestation. Further work is needed to determine if placental pathologic examination can be used to target treatment in subsequent pregnancies to prevent recurrent preterm birth.

What now? A critical evaluation of over 20 years of clinical and research experience with 17-alpha hydroxyprogesterone caproate for recurrent preterm birth prevention

Spontaneous preterm birth is multifactorial, and underlying etiologies remain incompletely understood. Supplementation with progestogens, including 17-alpha hydroxyprogesterone caproate has been a mainstay of prematurity prevention strategies in the United States in the last 2 decades. Following a recent negative confirmatory trial, 17-alpha hydroxyprogesterone caproate was withdrawn from the US market and is currently available only through clinical research studies. This expert review summarized clinical and research data regarding the use of 17-alpha hydroxyprogesterone caproate in the United States from 2003 to 2023 for recurrent prematurity prevention. In 17-alpha hydroxyprogesterone caproate. The history of the use, mechanisms of action, clinical trial results, and efficacy by clinical and biologic criteria of 17-alpha hydroxyprogesterone caproate are presented. We report that disparate findings and conclusions between similarly designed rigorous studies may reflect differences in a priori risk and population incidence and extreme care should be taken in interpreting the studies and making decisions regarding efficacy of 17-alpha hydroxyprogesterone caproate for the prevention of preterm birth. The likelihood of improved obstetrical outcomes after receiving 17-alpha hydroxyprogesterone caproate may vary by clinical factors (eg, body mass index), plasma drug concentrations, and genetic factors, although the identification of individuals most likely to benefit remains imperfect. It is crucial for the medical community to recognize the importance of preserving the decades-long efforts invested in preventing recurrent preterm birth in the United States. Moreover, it is important that we thoroughly and thoughtfully evaluate 17-alpha hydroxyprogesterone caproate as a promising contender for future well-executed prematurity studies.

Mental health impact on Black, Asian and Minority Ethnic populations with preterm birth: A systematic review and meta-analysis

BACKGROUND

Preterm birth (PTB) is one of the main causes of neonatal deaths globally, with approximately 15 million infants are born preterm. Women from the Black, Asian, and Minority Ethnic (BAME) populations maybe at higher risk of PTB, therefore, the mental health impact on mothers experiencing a PTB is particularly important, within the BAME populations.

AIM

To determine the prevalence of mental health conditions among BAME women with PTB as well as the methods of mental health assessments used to characterise the mental health outcomes.

METHODS

A systematic methodology was developed and published as a protocol in PROSPERO (CRD42020210863). Multiple databases were used to extract relevant data. I² and Egger’s tests were used to detect the heterogeneity and publication bias. A trim and fill method was used to demonstrate the influence of publication bias and the credibility of conclusions.

RESULTS

Thirty-nine studies met the eligibility criteria from a possible 3526. The prevalence rates of depression among PTB-BAME mothers were significantly higher than full-term mothers with a standardized mean difference of 1.5 and a 95% confidence interval (CI) 29%-74%. The subgroup analysis indicated depressive symptoms to be time sensitive. Women within the very PTB category demonstrated a significantly higher prevalence of depression than those categorised as non-very PTB. The prevalence rates of anxiety and stress among PTB-BAME mothers were significantly higher than in full-term mothers (odds ratio of 88% and 60% with a CI of 42%-149% and 24%-106%, respectively).

CONCLUSION

BAME women with PTB suffer with mental health conditions. Many studies did not report on specific mental health outcomes for BAME populations. Therefore, the impact of PTB is not accurately represented in this population, and thus could negatively influence the quality of maternity services they receive.

A Qualitative Study Documenting Black Birthing Individuals' Perspectives on the Disproportionate Rate of Preterm Birth in the Black Community

Background:

Compared with all other racial and ethnic groups, the rate of preterm birth (PTB) is 50% higher among non-Hispanic Blacks (NHB). There are limited published data focused on the etiology of the racial disparity in PTB from the perspective of Black birthing individuals who have had a lived experience with PTB.

Methods:

To gain insights into the etiology of the race disparity in PTB from the NHB patient's perspective, we conducted a qualitative descriptive study with NHBs who have a history of PTB. We conducted both focus group discussions (FGDs), in-depth interviews (IDIs), and used applied thematic analysis to analyze the data.

Results:

Seven individuals participated in 3 FGDs and 15 individuals participated in an IDI. The majority of participants named stress as a contributor to PTB among NHBs. Participants described that stress becomes an ongoing cycle with a cumulative effect on health. Three primary sources of stress were identified: (1) individual including stress from lack of personal wellness, (2) relational stress from intimate partner and familial relationships, and (3) community-level stress from occupations and societal expectations.

Conclusion:

Uncovering NHB patient's perspectives on the etiology of PTB is a critical step to develop interventions that mitigate the disparity impacting the Black community. Our findings suggest that multilevel interventions targeting individual-, relational-, and community-level stress may be necessary to reduce rates of PTB among NHB individuals.

Progesterone receptor genetic variants in pregnant women and fetuses as possible predictors of spontaneous premature birth: A preliminary case-control study

AIM

To evaluate the roles of four selected genetic variations in fetal and maternal progesterone receptor gene (PGR) and to identify women who may have higher or lower odds for spontaneous premature birth compared to the general population.

METHODS

A preliminary case-control study with two groups of pregnant women (with term and premature delivery, 218 in total) and two groups of newborns (term and preterm, 218 in total) was performed. Four single nucleotide polymorphisms (SNPs) of the progesterone receptor gene (rs1042838, rs1042839, rs10895068, and rs1942836) were genotyped.

RESULTS

There was statistically significant difference between cases and controls in the distribution of newborns' allele frequency of minor C allele of the PGR SNP rs1942836 (p = 0.03, Fishers' exact test) in favor of premature birth. A statistically significant difference between the frequency of the mothers' minor T allele of rs1042838 (p = 0.005; chi-squared test) and the mothers' minor T allele of rs1042839 (p = 0.005; chi-squared test) in favor of extremely premature birth has been found. There was a statistically significant difference between the frequency of the newborns' minor C allele of rs1942836 (p = 0.03; chi-squared test) and newborns' heterozygotes CT genotype of rs1942836 (p = 0.03; Fishers' exact test) when comparing the group of term births and the group of early premature birth.

CONCLUSION

Our study suggests that patients with selected genetic variants of the progesterone receptor gene could have greater odds for premature birth compared to term birth. Replication studies with a larger population and different ethnicity are needed in order to confirm these findings.

Preventing recurrent preterm birth with 125 mg of 17-alpha-hydroxyprogesterone caproate

AIM

There is strong evidence that weekly intramuscular (IM) injections of 250 mg of 17-alpha-hydroxyprogesterone caproate (17-OHPC) reduce the risk of recurrent preterm birth (PTB); however, whether a lower dose of 17-OHPC could reduce the risk of recurrent PTB remains unclear. This study aimed to assess whether 125 mg of 17-OHPC reduces recurrent PTB among women with a prior singleton spontaneous PTB and cervical length >25 mm.

METHODS

This retrospective cohort study at a tertiary-care medical center in Japan included women with a prior singleton spontaneous PTB between 20 and 36 weeks' gestation and cervical length >25 mm, between 2008 and 2018. Primary outcomes were PTB <37 and <34 weeks' gestation. We calculated the adjusted odds ratio (aOR) and 95% confidence interval (CI) using a multiple logistic regression model. Gestational age at delivery was compared using the Kaplan-Meier survival curve and log-rank test.

RESULTS

Overall, 173 women met the inclusion criteria. Eighty-four women received weekly injections of 125 mg of 17-OHPC, and 89 did not. Treatment with 125 mg of 17-OHPC significantly reduced the risk of recurrent spontaneous PTB <37 (aOR: 0.156 [95% CI: 0.049-0.497]) and <34 weeks' gestation (aOR: 0.156 [95% CI: 0.049-0.497]). The mean delivery gestational age was also significantly longer in the 17-OHPC group (log-rank p = 0.005).

CONCLUSIONS

In this study population, weekly IM injections of 125 mg of 17-OHPC reduced the risk of recurrent PTB <37 and <34 weeks' gestation.

Understanding how biologic and social determinants affect disparities in preterm birth and outcomes of preterm infants in the NICU

To understand the disparities in spontaneous preterm birth (sPTB) and/or its outcomes, biologic and social determinants as well as healthcare practice (such as those in neonatal intensive care units) should be considered. Disparities in sPTB have been largely intractable and remain obscure in most cases, despite a myriad of identified risk factors for and causes of sPTB. We still do not know how they lead to the different outcomes at different gestational ages and if they are independent of NICU practices. Here we describe an integrated approach to study the interplay between the genome and exposome, which may drive biochemistry and physiology and lead to health disparities.

A hierarchical procedure to select intrauterine and extrauterine factors for methodological validation of preterm birth risk estimation

Background

Etiopathogenesis of preterm birth (PTB) is multifactorial, with a universe of risk factors interplaying between the mother and the environment. It is of utmost importance to identify the most informative factors in order to estimate the degree of PTB risk and trace an individualized profile. The aims of the present study were: 1) to identify all acknowledged risk factors for PTB and to select the most informative ones for defining an accurate model of risk prediction; 2) to verify predictive accuracy of the model and 3) to identify group profiles according to the degree of PTB risk based on the most informative factors.

Methods

The Maternal Frailty Inventory (MaFra) was created based on a systematic review of the literature including 174 identified intrauterine (IU) and extrauterine (EU) factors. A sample of 111 pregnant women previously categorized in low or high risk for PTB below 37 weeks, according to ACOG guidelines, underwent the MaFra Inventory. First, univariate logistic regression enabled p-value ordering and the Akaike Information Criterion (AIC) selected the model including the most informative MaFra factors. Second, random forest classifier verified the overall predictive accuracy of the model. Third, fuzzy c-means clustering assigned group membership based on the most informative MaFra factors.

Results

The most informative and parsimonious model selected through AIC included Placenta Previa, Pregnancy Induced Hypertension, Antibiotics, Cervix Length, Physical Exercise, Fetal Growth, Maternal Anxiety, Preeclampsia, Antihypertensives. The random forest classifier including only the most informative IU and EU factors achieved an overall accuracy of 81.08% and an AUC of 0.8122. The cluster analysis identified three groups of typical pregnant women, profiled on the basis of the most informative IU and EU risk factors from a lower to a higher degree of PTB risk, which paralleled time of birth delivery.

Conclusions

This study establishes a generalized methodology for building-up an evidence-based holistic risk assessment for PTB to be used in clinical practice. Relevant and essential factors were selected and were able to provide an accurate estimation of degree of PTB risk based on the most informative constellation of IU and EU factors.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12884-021-03654-3).

Pharmacokinetics of 17 alpha hydroxyprogesterone caproate in singleton pregnancy and its influence of maternal body size measures

BACKGROUND

Reducing spontaneous preterm deliveries is a worldwide public health priority. Although many interventions have been studied, 1 of the most effective treatments to decrease recurrent preterm birth is the use of weekly 17 alpha hydroxy progesterone caproate. Previous studies on the influence of excessive adipose tissue and obesity on the use of 17 alpha hydroxyprogesterone caproate for the prevention of recurrent spontaneous preterm deliveries have shown conflicting findings.

OBJECTIVE

To estimate the pharmacokinetics of weekly17 alpha hydroxyprogesterone caproate in singleton and to evaluate the effect of maternal body size on the pharmacokinetics parameters.

STUDY DESIGN

A prospective, open-label, longitudinal design was implemented for this population pharmacokinetic study. Plasma samples and clinical variables were collected in pregnant women between 16 and 36 weeks' gestational age, carrying a singleton pregnancy and receiving 17 alpha hydroxyprogesterone caproate, 250 mg intramuscularly weekly for the prevention of recurrent spontaneous preterm birth. Pharmacokinetics parameters and significant clinical covariates were estimated using mixed effect modeling. Four body size indicators were used in the model to predict pharmacokinetics parameters: lean body weight, total body weight, body mass index, and body surface area.

RESULTS

A total of 56 pregnant women, aged 18-44 years with body mass index of 14.5-54.6 kg/m², provided 114 17 alpha hydroxyprogesterone caproate plasma samples concentration for analysis. A 1-compartment model with first-order absorption satisfactorily described 17 alpha hydroxyprogesterone caproate pharmacokinetics. Compared to other body size indicators, lean body weight best explained intersubject variability. Age, race, and gestational age did not influence 17 alpha hydroxyprogesterone caproate pharmacokinetics. Lean body weight was the best descriptor for the influence of body size on 17 alpha hydroxyprogesterone caproate apparent clearance. Simulations showed that administration of a standard fixed dose of 250 mg intramuscularly produced substantially lower 17 alpha hydroxyprogesterone caproate plasma concentrations in pregnant women with body mass index >30 kg/m² compared to those with body mass index <30 kg/m². Conversely, adjustment of the standard dose for differences in total body weight among women resulted in markedly higher 17 alpha hydroxyprogesterone caproate concentrations in women with body mass index >30 kg/m² compared to women with lower body mass index. Administration of doses adjusted for lean body weight produced nearly identical 117 alpha hydroxyprogesterone caproate plasma concentrations in both the low- and high-body mass index groups.

CONCLUSION

Population pharmacokinetics analysis indicates the clearance significantly increases with increasing lean body mass. Higher 17 alpha hydroxyprogesterone caproate doses, adjusted by maternal lean body mass, may be required in patients with a body mass index >30 to achieve equivalent plasma concentrations in pregnant women with a body mass index <30. Adjustment of 17 alpha hydroxyprogesterone caproate doses for lean body weight produces equivalent systemic 17 alpha hydroxyprogesterone caproate exposure in pregnant women regardless of body size.

A systematic review and meta-analysis of randomized controlled trials comparing 17-alpha-hydroxyprogesterone caproate versus placebo for the prevention of recurrent preterm birth

BACKGROUND

Preterm birth causes an increased risk for perinatal morbidity and mortality.

OBJECTIVE

To determine whether mid-trimester 17-alpha-hydroxyprogesterone caproate (17-OHPC) reduces the risk of recurrent preterm birth and adverse perinatal outcomes.

SEARCH STRATEGY

Systematic search to identify relevant studies published in different languages, registered after 2000, using appropriate MeSH terms.

SELECTION CRITERIA

Inclusion criteria were women between 16 and 26⁺⁶  weeks of pregnancy with history of preterm delivery in any pregnancy randomized to either 17-OHPC or placebo/no treatment.

DATA COLLECTION AND ANALYSIS

The number of preterm births and adverse outcomes in the 17-OHPC and placebo arms over the total number of patients in each randomized group were used to calculate the risk ratio (RR) by random-effects models using the Mantel-Haenszel method. Between-study heterogeneity was assessed using tau² , χ² (Cochrane Q), and I² statistics.

MAIN RESULTS

Four studies were included. There was a 29% (RR 0.71; 95% CI, 0.53-0.96; P=0.001), 26% (RR 0.74; 95% CI, 0.58-0.96; P=0.021), and 40% (RR 0.60; 95% CI, 0.42-0.85; P=0.004) reduction in recurrent preterm birth at <37, <35, and <32 weeks, respectively, in the 17-OHPC group compared with placebo. The reduction in neonatal death was 68% (RR 0.32; 95% CI, 0.15-0.66; P=0.002).

CONCLUSIONS

17-OHPC could reduce the risk of recurrent preterm birth at <37, <35, and <28 weeks and neonatal death.

PROSPERO

CDR42017082190.

Principles of Pharmacokinetics in the Pregnant Woman and Fetus

Pregnancy profoundly alters a woman's physiology. These changes alter drug absorption, distribution, metabolism, and elimination and emphasize the pharmacologic complexity of pregnancy. They also emphasize the dangers of extrapolating pharmacologic expectations from nonpregnant populations to pregnant women and their fetuses. Although concerns about fetal safety have historically limited pharmacokinetic studies during pregnancy, it is important to recognize that many medications are clinically indicated for various maternal or fetal conditions, and it is particularly important that these therapies be evidence-based with appropriate study, including short-term and long-term outcomes data.

Understanding health disparities

Based upon our recent insights into the determinants of preterm birth, which is the leading cause of death in children under five years of age worldwide, we describe potential analytic frameworks that provides both a common understanding and, ultimately the basis for effective, ameliorative action. Our research on preterm birth serves as an example that the framing of any human health condition is a result of complex interactions between the genome and the exposome. New discoveries of the basic biology of pregnancy, such as the complex immunological and signaling processes that dictate the health and length of gestation, have revealed a complexity in the interactions (current and ancestral) between genetic and environmental forces. Understanding of these relationships may help reduce disparities in preterm birth and guide productive research endeavors and ultimately, effective clinical and public health interventions.

Natural Selection Has Differentiated the Progesterone Receptor among Human Populations

The progesterone receptor (PGR) plays a central role in maintaining pregnancy and is significantly associated with medical conditions such as preterm birth that affects 12.6% of all the births in U.S. PGR has been evolving rapidly since the common ancestor of human and chimpanzee, and we herein investigated evolutionary dynamics of PGR during recent human migration and population differentiation. Our study revealed substantial population differentiation at the PGR locus driven by natural selection, where very recent positive selection in East Asians has substantially decreased its genetic diversity by nearly fixing evolutionarily novel alleles. On the contrary, in European populations, the PGR locus has been promoted to a highly polymorphic state likely due to balancing selection. Integrating transcriptome data across multiple tissue types together with large-scale genome-wide association data for preterm birth, our study demonstrated the consequence of the selection event in East Asians on remodeling PGR expression specifically in the ovary and determined a significant association of early spontaneous preterm birth with the evolutionarily selected variants. To reconstruct its evolutionary trajectory on the human lineage, we observed substantial differentiation between modern and archaic humans at the PGR locus, including fixation of a deleterious missense allele in the Neanderthal genome that was later introgressed in modern human populations. Taken together, our study revealed substantial evolutionary innovation in PGR even during very recent human evolution, and its different forms among human populations likely result in differential susceptibility to progesterone-associated disease conditions including preterm birth.

Translational Systems Pharmacology Studies in Pregnant Women

Pregnancy involves rapid physiological adaptation and complex interplay between mother and fetus. New analytic technologies provide large amounts of genomic, proteomic, and metabolomics data. The integration of these data through bioinformatics, statistical, and systems pharmacology techniques can improve our understanding of the mechanisms of normal maternal physiologic changes and fetal development. New insights into the mechanisms of pregnancy‐related disorders, such as preterm birth (PTB), may lead to the development of new therapeutic interventions and novel biomarkers.

In an in-vitro model using human fetal membranes, 17-α hydroxyprogesterone caproate is not an optimal progestogen for inhibition of fetal membrane weakening

BACKGROUND

The progestogen 17-α hydroxyprogesterone caproate (17-OHPC) is 1 of only 2 agents recommended for clinical use in the prevention of spontaneous preterm delivery, and studies of its efficacy have been conflicting. We have developed an in-vitro model to study the fetal membrane weakening process that leads to rupture in preterm premature rupture of the fetal membranes (pPROM). Inflammation/infection associated with tumor necrosis factor-α (TNF-α) induction and decidual bleeding/abruption associated thrombin release are leading causes of preterm premature rupture of the fetal membranes. Both agents (TNF-α and thrombin) cause fetal membrane weakening in the model system. Furthermore, granulocyte-macrophage colony-stimulating factor (GM-CSF) is a critical intermediate for both TNF-α and thrombin-induced fetal membrane weakening. In a previous report, we demonstrated that 3 progestogens, progesterone, 17-alpha hydroxyprogesterone (17-OHP), and medroxyprogesterone acetate (MPA), each inhibit both TNF-α- and thrombin-induced fetal membrane weakening at 2 distinct points of the fetal membrane weakening pathway. Each block both the production of and the downstream action of the critical intermediate granulocyte-macrophage colony-stimulating factor.

OBJECTIVE

The objective of the study was to characterize the inhibitory effects of 17-OHPC on TNF-α- and thrombin-induced fetal membrane weakening in vitro.

STUDY DESIGN

Full-thickness human fetal membrane fragments from uncomplicated term repeat cesarean deliveries were mounted in 2.5 cm Transwell inserts and cultured with/without 17-alpha hydroxyprogesterone caproate (10^-9 to 10^-7 M). After 24 hours, medium (supernatant) was removed and replaced with/without the addition of tumor necrosis factor-alpha (20 ng/mL) or thrombin (10 U/mL) or granulocyte-macrophage colony-stimulating factor (200 ng/mL). After 48 hours of culture, medium from the maternal side compartment of the model was assayed for granulocyte-macrophage colony-stimulating factor and the fetal membrane fragments were rupture strength tested.

RESULTS

Tumor necrosis factor-alpha and thrombin both weakened fetal membranes (43% and 62%, respectively) and increased granulocyte-macrophage colony-stimulating factor levels (3.7- and 5.9-fold, respectively). Pretreatment with 17-alpha hydroxyprogesterone caproate inhibited both tumor necrosis factor-alpha- and thrombin-induced fetal membrane weakening and concomitantly inhibited the induced increase in granulocyte-macrophage colony-stimulating factor in a concentration-dependent manner. However, contrary to our prior reports regarding progesterone and other progestogens, 17-alpha hydroxyprogesterone caproate did not also inhibit granulocyte-macrophage colony-stimulating factor-induced fetal membrane weakening.

CONCLUSION

17-Alpha hydroxyprogesterone caproate blocks tumor necrosis factor-alpha- and thrombin-induced fetal membrane weakening by inhibiting the production of granulocyte-macrophage colony-stimulating factor. However, 17-alpha hydroxyprogesterone caproate did not also inhibit granulocyte-macrophage colony-stimulating factor-induced weakening. We speculate that progestogens other than 17-alpha hydroxyprogesterone caproate may be more efficacious in preventing preterm premature rupture of the fetal membranes-related spontaneous preterm birth.

The association among cytochrome P450 3A, progesterone receptor polymorphisms, plasma 17-alpha hydroxyprogesterone caproate concentrations, and spontaneous preterm birth

BACKGROUND

Infants born <37 weeks' gestation are of public health concern since complications associated with preterm birth are the leading cause of mortality in children <5 years of age and a major cause of morbidity and lifelong disability. The administration of 17-alpha hydroxyprogesterone caproate reduces preterm birth by 33% in women with history of spontaneous preterm birth. We demonstrated previously that plasma concentrations of 17-alpha hydroxyprogesterone caproate vary widely among pregnant women and that women with 17-alpha hydroxyprogesterone caproate plasma concentrations in the lowest quartile had spontaneous preterm birth rates of 40% vs rates of 25% in those women with higher concentrations. Thus, plasma concentrations are an important factor in determining drug efficacy but the reason 17-alpha hydroxyprogesterone caproate plasma concentrations vary so much is unclear. Predominantly, 17-alpha hydroxyprogesterone caproate is metabolized by CYP3A4 and CYP3A5 enzymes.

OBJECTIVE

We sought to: (1) determine the relation between 17-alpha hydroxyprogesterone caproate plasma concentrations and single nucleotide polymorphisms in CYP3A4 and CYP3A5; (2) test the association between progesterone receptor single nucleotide polymorphisms and spontaneous preterm birth; and (3) test whether the association between plasma concentrations of 17-alpha hydroxyprogesterone caproate and spontaneous preterm birth varied by progesterone receptor single nucleotide polymorphisms.

STUDY DESIGN

In this secondary analysis, we evaluated genetic polymorphism in 268 pregnant women treated with 17-alpha hydroxyprogesterone caproate, who participated in a placebo-controlled trial to evaluate the benefit of omega-3 supplementation in women with history of spontaneous preterm birth. Trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were measured between 25-28 weeks of gestation after a minimum of 5 injections of 17-alpha hydroxyprogesterone caproate. We extracted DNA from maternal blood samples and genotyped the samples using TaqMan (Applied Biosystems, Foster City, CA) single nucleotide polymorphism genotyping assays for the following single nucleotide polymorphisms: CYP3A4*1B, CYP3A4*1G, CYP3A4*22, and CYP3A5*3; and rs578029, rs471767, rs666553, rs503362, and rs500760 for progesteronereceptor. We adjusted for prepregnancy body mass index, race, and treatment group in a multivariable analysis. Differences in the plasma concentrations of 17-alpha hydroxyprogesterone caproate by genotype were evaluated for each CYP single nucleotide polymorphism using general linear models. The association between progesterone receptor single nucleotide polymorphisms and frequency of spontaneous preterm birth was tested using logistic regression. A logistic model also tested interaction between 17-alpha hydroxyprogesterone caproate concentrations with each progesterone receptor single nucleotide polymorphism for the outcome of spontaneous preterm birth.

RESULTS

The association between CYP single nucleotide polymorphisms *22, *1G, *1B, and *3 and trough plasma concentrations of 17-alpha hydroxyprogesterone caproate was not statistically significant (P = .68, .44, .08, and .44, respectively). In an adjusted logistic regression model, progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 were not associated with the frequency of spontaneous preterm birth (P = .29, .10, .76, .09, and .43, respectively). Low trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were statistically associated with a higher frequency of spontaneous preterm birth (odds ratio, 0.78; 95% confidence ratio, 0.61-0.99; P = .04 for trend across quartiles), however no significant interaction with the progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 was observed (P = .13, .08, .10, .08, and .13, respectively).

CONCLUSION

The frequency of recurrent spontaneous preterm birth appears to be associated with trough 17-alpha hydroxyprogesterone caproate plasma concentrations. However, the wide variation in trough 17-alpha hydroxyprogesterone caproate plasma concentrations is not attributable to polymorphisms in CYP3A4 and CYP3A5 genes. Progesterone receptor polymorphisms do not predict efficacy of 17-alpha hydroxyprogesterone caproate. The limitations of this secondary analysis include that we had a relative small sample size (n = 268) and race was self-reported by the patients.

Bitter taste receptors as targets for tocolytics in preterm labor therapy

Preterm birth (PTB) is the leading cause of neonatal mortality and morbidity, with few prevention and treatment options. Uterine contraction is a central feature of PTB, so gaining new insights into the mechanisms of this contraction and consequently identifying novel targets for tocolytics are essential for more successful management of PTB. Here we report that myometrial cells from human and mouse express bitter taste receptors (TAS2Rs) and their canonical signaling components (i.e., G-protein gustducin and phospholipase C β2). Bitter tastants can completely relax myometrium precontracted by different uterotonics. In isolated single mouse myometrial cells, a phenotypical bitter tastant (chloroquine, ChQ) reverses the rise in intracellular Ca2+ concentration ([Ca2+]i) and cell shortening induced by uterotonics, and this reversal effect is inhibited by pertussis toxin and by genetic deletion of α-gustducin. In human myometrial cells, knockdown of TAS2R14 but not TAS2R10 inhibits ChQ's reversal effect on an oxytocin-induced rise in [Ca2+]i Finally, ChQ prevents mouse PTBs induced by bacterial endotoxin LPS or progesterone receptor antagonist mifepristone more often than current commonly used tocolytics, and this prevention is largely lost in α-gustducin-knockout mice. Collectively, our results reveal that activation of the canonical TAS2R signaling system in myometrial cells produces profound relaxation of myometrium precontracted by a broad spectrum of contractile agonists, and that targeting TAS2Rs is an attractive approach to developing effective tocolytics for PTB management.-Zheng, K., Lu, P., Delpapa, E., Bellve, K., Deng, R., Condon, J. C., Fogarty, K., Lifshitz, L. M., Simas, T. A. M., Shi, F., ZhuGe, R. Bitter taste receptors as targets for tocolytics in preterm labor therapy.

17-alpha Hydroxyprogesterone caproate did not reduce the rate of recurrent preterm birth in a prospective cohort study

BACKGROUND

17-alpha Hydroxyprogesterone caproate for prevention of recurrent preterm birth is recommended for use in the United States.

OBJECTIVE

We sought to assess the clinical effectiveness of 17-alpha hydroxyprogesterone caproate to prevent recurrent preterm birth ≤35 weeks compared to similar births in our obstetric population prior to the implementation of 17-alpha hydroxyprogesterone caproate.

STUDY DESIGN

This was a prospective cohort study of 17-alpha hydroxyprogesterone caproate in our obstetric population. The primary outcome was the recurrence of birth ≤35 weeks for the entire study cohort compared to a historical referent rate of 16.8% of recurrent preterm birth in our population. There were 3 secondary outcomes. First, did 17-alpha hydroxyprogesterone caproate modify a woman's history of preterm birth when taking into account her prior number and sequence of preterm and term births? Second, was recurrence of preterm birth related to 17-alpha hydroxyprogesterone caproate plasma concentration? Third, was duration of pregnancy modified by 17-alpha hydroxyprogesterone caproate treatment compared to a prior preterm birth?

RESULTS

From January 2012 through March 2016, 430 consecutive women with prior births ≤35 weeks were treated with 17-alpha hydroxyprogesterone caproate. Nearly two thirds of the women (N = 267) began injections ≤18 weeks and 394 (92%) received a scheduled weekly injection within 10 days of reaching 35 weeks or delivery. The overall rate of recurrent preterm birth was 25% (N = 106) for the entire cohort compared to the 16.8% expected rate (P = 1.0). The 3 secondary outcomes were also negative. First, 17-alpha hydroxyprogesterone caproate did not significantly reduce the rates of recurrence regardless of prior preterm birth number or sequence. Second, plasma concentrations of 17-alpha hydroxyprogesterone caproate were not different (P = .17 at 24 weeks; P = .38 at 32 weeks) between women delivered ≤35 weeks and those delivered later in pregnancy. Third, the mean (±SD) interval in weeks of recurrent preterm birth before 17-alpha hydroxyprogesterone caproate use was 0.4 ± 5.3 weeks and the interval of recurrent preterm birth after 17-alpha hydroxyprogesterone caproate treatment was 0.1 ± 4.7 weeks (P = .63). A side effect of weekly 17-alpha hydroxyprogesterone caproate injections was an increase in gestational diabetes. Specifically, the rate of gestational diabetes was 13.4% in 17-alpha hydroxyprogesterone caproate-treated women compared to 8% in case-matched controls (P = .001).

CONCLUSION

17-alpha Hydroxyprogesterone caproate was ineffective for prevention of recurrent preterm birth and was associated with an increased rate of gestational diabetes.

Fundamentals of Clinical Pharmacology With Application for Pregnant Women

Medication use is common in pregnancy, yet for most medications the optimal formulation and dosage have not been described specifically for pregnant women. Often, adverse effects are only discovered anecdotally or after extensive off-label use occurs. Since pharmacologic research that includes pregnant women is sparse and animal studies are often not applicable to the human fetus, providers must use knowledge of drug behavior and normal physiologic changes of pregnancy to personalize treatment for pregnant women. In this review, we present an overview of the basic concepts of clinical pharmacology: pharmacokinetics, pharmacodynamics, and pharmacogenomics. The normal physiologic changes of pregnancy are presented as a framework to understand alterations in drug behavior. A clinical vignette that addresses 4 pregnancy scenarios involving medications-preterm birth, vaccination, herpes simplex virus infection, and codeine toxicity-is provided to illustrate application of core clinical pharmacologic concepts. Discussion of relevant literature illustrates the challenges of offering individualized pharmacologic therapy in pregnancy.

Nonresponse to 17-alpha hydroxyprogesterone caproate for recurrent spontaneous preterm birth prevention: clinical prediction and generation of a risk scoring system

BACKGROUND

Spontaneous preterm birth remains a leading cause of neonatal morbidity and mortality among nonanomalous neonates in the United States. Spontaneous preterm birth tends to recur at similar gestational ages. Intramuscular 17-alpha hydroxyprogesterone caproate reduces the risk of recurrent spontaneous preterm birth. Unfortunately, one-third of high-risk women will have a recurrent spontaneous preterm birth despite 17-alpha hydroxyprogesterone caproate therapy; the reasons for this variability in response are unknown.

OBJECTIVE

We hypothesized that clinical factors among women treated with 17-alpha hydroxyprogesterone caproate who suffer recurrent spontaneous preterm birth at a similar gestational age differ from women who deliver later, and that these associations could be used to generate a clinical scoring system to predict 17-alpha hydroxyprogesterone caproate response.

STUDY DESIGN

Secondary analysis of a prospective, multicenter, randomized controlled trial enrolling women with ≥1 previous singleton spontaneous preterm birth <37 weeks' gestation. Participants received daily omega-3 supplementation or placebo for the prevention of recurrent preterm birth; all were provided 17-alpha hydroxyprogesterone caproate. Women were classified as a 17-alpha hydroxyprogesterone caproate responder or nonresponder by calculating the difference in delivery gestational age between the 17-alpha hydroxyprogesterone caproate-treated pregnancy and her earliest previous spontaneous preterm birth. Responders were women with pregnancy extending ≥3 weeks later compared with the delivery gestational age of their earliest previous preterm birth; nonresponders delivered earlier or within 3 weeks of the gestational age of their earliest previous preterm birth. A risk score for nonresponse to 17-alpha hydroxyprogesterone caproate was generated from regression models via the use of clinical predictors and was validated in an independent population. Data were analyzed with multivariable logistic regression.

RESULTS

A total of 754 women met inclusion criteria; 159 (21%) were nonresponders. Responders delivered later on average (37.7±2.5 weeks) than nonresponders (31.5±5.3 weeks), P<.001. Among responders, 27% had a recurrent spontaneous preterm birth (vs 100% of nonresponders). Demographic characteristics were similar between responders and nonresponders. In a multivariable logistic regression model, independent risk factors for nonresponse to 17-alpha hydroxyprogesterone caproate were each additional week of gestation of the earliest previous preterm birth (odds ratio, 1.23; 95% confidence interval, 1.17-1.30, P<.001), placental abruption or significant vaginal bleeding (odds ratio, 5.60; 95% confidence interval, 2.46-12.71, P<.001), gonorrhea and/or chlamydia in the current pregnancy (odds ratio, 3.59; 95% confidence interval, 1.36-9.48, P=.010), carriage of a male fetus (odds ratio, 1.51; 95% confidence interval, 1.02-2.24, P=.040), and a penultimate preterm birth (odds ratio, 2.10; 95% confidence interval, 1.03-4.25, P=.041). These clinical factors were used to generate a risk score for nonresponse to 17-alpha hydroxyprogesterone caproate as follows: black +1, male fetus +1, penultimate preterm birth +2, gonorrhea/chlamydia +4, placental abruption +5, earliest previous preterm birth was 32-36 weeks +5. A total risk score >6 was 78% sensitive and 60% specific for predicting nonresponse to 17-alpha hydroxyprogesterone caproate (area under the curve=0.69). This scoring system was validated in an independent population of 287 women; in the validation set, a total risk score >6 performed similarly with a 65% sensitivity, 67% specificity and area under the curve of 0.66.

CONCLUSIONS

Several clinical characteristics define women at risk for recurrent preterm birth at a similar gestational age despite 17-alpha hydroxyprogesterone caproate therapy and can be used to generate a clinical risk predictor score. These data should be refined and confirmed in other cohorts, and women at high risk for nonresponse should be targets for novel therapeutic intervention studies.

Spontaneous preterm birth and single nucleotide gene polymorphisms: a recent update

Background

Preterm birth (PTB), birth at <37 weeks of gestation, is a significant global public health problem. World-wide, about 15 million babies are born preterm each year resulting in more than a million deaths of children. Preterm neonates are more prone to problems and need intensive care hospitalization. Health issues may persist through early adulthood and even be carried on to the next generation. Majority (70 %) of PTBs are spontaneous with about a half without any apparent cause and the other half associated with a number of risk factors. Genetic factors are one of the significant risks for PTB. The focus of this review is on single nucleotide gene polymorphisms (SNPs) that are reported to be associated with PTB.

Results

A comprehensive evaluation of studies on SNPs known to confer potential risk of PTB was done by performing a targeted PubMed search for the years 2007–2015 and systematically reviewing all relevant studies. Evaluation of 92 studies identified 119 candidate genes with SNPs that had potential association with PTB. The genes were associated with functions of a wide spectrum of tissue and cell types such as endocrine, tissue remodeling, vascular, metabolic, and immune and inflammatory systems.

Conclusions

A number of potential functional candidate gene variants have been reported that predispose women for PTB. Understanding the complex genomic landscape of PTB needs high-throughput genome sequencing methods such as whole-exome sequencing and whole-genome sequencing approaches that will significantly enhance the understanding of PTB. Identification of high risk women, avoidance of possible risk factors, and provision of personalized health care are important to manage PTB.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3089-0) contains supplementary material, which is available to authorized users.

What we have learned about the role of 17-alpha-hydroxyprogesterone caproate in the prevention of preterm birth

Despite major advances in neonatal care, the burden of preterm birth remains high. This is not unexpected since strategies to identify and treat risk factors in early pregnancy have not been very effective in reducing the preterm birth rate. Initial studies suggested a potential benefit for 17-alpha-hydroxyprogesterone caproate (17-OHPC) in decreasing the risk of recurrent preterm birth women with a singleton gestation. However, the use of 17-OHPC has not conferred benefit for other categories of women at high risk for preterm delivery (twins, triplets, and short cervical length). The increasing body of evidence suggests that preterm birth is a complex condition with variable mechanisms of disease and significant individual heterogeneity. This review will examine the plausibility of 17-OHPC in preventing preterm birth and the investigation of its clinical efficacy. We will also highlight factors to explain variations in clinical trial outcomes and outline the trajectory needed for future investigations.

Population pharmacokinetics of 17α-hydroxyprogesterone caproate in singleton gestation

AIMS

17α-hydroxyprogesterone caproate (17-OHPC) reduces the rate of preterm birth in women with a prior preterm birth. Limited data exist on the pharmacokinetics (PK) of 17-OHPC or the plasma concentrations achieved during therapy. In this study, we evaluated the population PK of 17-OHPC in pregnant subjects with singleton gestation and also evaluated intrinsic and extrinsic factors that may potentially affect 17-OHPC PK in this patient population.

METHODS

Sixty-one women with singleton pregnancies participated in this trial. Subjects received weekly intramuscular injections of 250 mg 17-OHPC in 1 ml castor oil from the time of enrolment (16 0/7 weeks - 20 6/7 weeks) up to 35 weeks gestation or until delivery. Blood samples were obtained between 24 and 28 weeks, between 32 and 35 weeks and over a 28-day period beyond the last injection. Maternal and/or cord blood were obtained at delivery. Data analysis was performed by nonlinear mixed effects modelling (NONMEM(®) ).

RESULTS

The 17-OHPC PK were best described by a model with one maternal compartment and one fetal compartment, with first-order absorption and elimination from the maternal compartment. Maternal body weight was a significant covariate for both clearance (CL/F) and volume of distribution (Vmaternal /F). The final population mean estimates were: CL/F 1797 l/d, Vmaternal /F 32 610 l and mother to cord rate constant 0.005 day(-1) . This report describes for the first time the population PK of 17-OHPC in singleton pregnancy.

CONCLUSIONS

The population PK study reported here represents the initial steps in understanding and optimizing 17-OHPC therapy for preventing preterm birth.

Patient characteristics associated with 17-alpha hydroxyprogesterone caproate use among a high-risk cohort

BACKGROUND

Preterm birth (PTB) remains a significant cause of neonatal morbidity and mortality. Women with a prior PTB are at risk for recurrent PTB. Treatment with 17-alpha hydroxyprogesterone caproate (17OHP-C) has become standard of care for women with prior PTB to help reduce this risk. Factors that affect a woman's decision to use this medication are largely unknown.

OBJECTIVE

The objective of our study was to investigate patient-level barriers to 17OHP-C. We studied a cohort of women eligible for 17OHP-C with the hypothesis that 17OHP-C is underutilized and certain patient characteristics, such as obstetrical history, influence its use.

STUDY DESIGN

A cross-sectional study of all women seen at a specialty prematurity clinic from 2009 through 2013 was performed. Women with a singleton pregnancy were included if they had a prior spontaneous PTB (sPTB). The χ(2) tests were performed for univariate analyses. Multivariable logistic regression was used to control for confounders.

RESULTS

In all, 243 women had 17OHP-C recommended to them based on obstetrical history. There were 218 women with a pregnancy during our study period that were included in our analysis. A total of 163 (74.7%) had documented 17OHP-C use. Women were more likely to accept 17OHP-C if they had a history of a second-trimester loss only (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.17-4.58) or received recommendation for cerclage due to a short cervical length (OR, 4.12; 95% CI, 1.55-10.99). Women with a prior full-term birth were less likely to accept 17OHP-C (OR, 0.48; 95% CI, 0.26-0.89), especially when the prior full-term birth was subsequent rather than prior to the PTB (OR, 0.19; 95% CI, 0.08-0.47). Race, obesity, and insurance status did not impact 17OHP-C use. There was no difference in the rate of sPTB between those who used and did not use 17OHP-C (37.2 vs 34.0%, P = .7).

CONCLUSION

Obstetric history impacted 17OHP-C use. This study identifies biases regarding 17OHP-C at the patient level and can be used to develop strategies to increase its use. However, the similarity in the sPTB rate between users and nonusers highlights the importance of identifying specific populations where 17OHP-C is and is not effective in preventing PTB.

Predictors of response to 17-alpha hydroxyprogesterone caproate for prevention of recurrent spontaneous preterm birth

BACKGROUND

Prematurity is the leading cause of neonatal morbidity and death among nonanomalous neonates in the United States. Intramuscular 17-alpha hydroxyprogesterone caproate injections reduce the risk of recurrent prematurity by approximately one third. Unfortunately, prophylactic 17-alpha hydroxyprogesterone caproate is not always effective, and one-third of high-risk women will have a recurrent preterm birth, despite 17-alpha hydroxyprogesterone caproate therapy. The reasons for this variability in response are unknown. Previous investigators have examined the influence of a variety of factors on 17-alpha hydroxyprogesterone caproate response but have analyzed data that used a fixed outcome of term delivery to define progesterone response.

OBJECTIVE

We hypothesized that the demographics, history, and pregnancy course among women who deliver at a similar gestational age with 17-alpha hydroxyprogesterone caproate for recurrent spontaneous preterm birth prevention differs when compared with those women who deliver later with 17-alpha hydroxyprogesterone caproate and that these associations could be refined by the use of a contemporary definition of 17-alpha hydroxyprogesterone caproate "responder."

STUDY DESIGN

This was a planned secondary analysis of a prospective, multicenter, longitudinal study of women with ≥1 previous documented singleton spontaneous preterm birth at <37 weeks gestation. Data were collected at 3 prespecified gestational age epochs during pregnancy. All women who were included in this analysis received 17-alpha hydroxyprogesterone caproate during the studied pregnancy. We classified women as a 17-alpha hydroxyprogesterone caproate responder or nonresponder by calculating the difference in delivery gestational age between the 17-alpha hydroxyprogesterone caproate-treated pregnancy and her earliest spontaneous preterm birth. Responders were defined as those with pregnancy that extended ≥3 weeks later with 17-alpha hydroxyprogesterone caproate, compared with the delivery gestational age of their earliest previous spontaneous preterm birth. Data were analyzed with the use of chi-square test, t-test, and logistic regression.

RESULTS

One hundred fifty-five women met the inclusion criteria. The 118 responders delivered later on average (37.7 weeks gestation) than the 37 nonresponders (33.5 weeks gestation; P < .001). Among responders, 32% (38/118 women) had a recurrent spontaneous preterm birth. Demographics (age, race/ethnicity, education, and parity) were similar between groups. In the regression model, the gestational age of the previous spontaneous preterm birth (odds ratio, 0.68; 95% confidence interval, 0.56-0.82; P < .001), vaginal bleeding/abruption in the current pregnancy (odds ratio, 0.24; 95% confidence interval, 0.06-0.88; P = .031), and first-degree family history of spontaneous preterm birth (odds ratio, 0.37; 95% confidence interval, 0.15-0.88; P = .024) were associated with response to 17-alpha hydroxyprogesterone caproate. Because women with a penultimate preterm pregnancy were more likely to be 17-alpha hydroxyprogesterone caproate nonresponders, we performed an additional limited analysis examining only the 130 women whose penultimate pregnancy was preterm. In regression models, the results were similar to those in the main cohort.

CONCLUSION

Several historic and current pregnancy characteristics define women who are at risk for recurrent preterm birth at a similar gestational age, despite 17-alpha hydroxyprogesterone caproate therapy. These data should be studied prospectively in larger cohorts and combined with genetic and environmental data to identify women who are most likely to benefit from this intervention.

Progesterone, Inflammatory Cytokine (TNF-α), and Oxidative Stress (H2O2) Regulate Progesterone Receptor Membrane Component 1 Expression in Fetal Membrane Cells

Progesterone receptor membrane component 1 (PGRMC1) is an important novel mediator of progesterone (P4) function in fetal membrane cells. We demonstrated previously that PGRMC1 is differentially expressed in fetal membranes among pregnancy subjects and diminished in preterm premature rupture of membrane subjects. In the current study, we aim to elucidate whether PGRMC1 expression is regulated by P4, tumor necrosis factor α (TNF-α), and H2O2 in fetal membrane cells. Primary cultured membrane cells were serum starved for 24 hours followed by treatments of P4, 17 hydroxyprogesterone caproate, and medroxyprogesterone 17 acetate (MPA) at 10(-7) mol/L with ethanol as vehicle control; TNF-α at 10, 20, and 50 ng/mL with phosphate-buffered saline (PBS) as control; and H2O2 at 10 and 100 μmol/L with culture media as control for 24, 48, and 72 hours. The messenger RNA (mRNA) and protein expression of PGRMC1 was quantified using polymerase chain reaction and Western blotting, respectively. We found that PGRMC1 protein expression was regulated by MPA, TNF-α, and H2O2 in a dose-dependent manner. This regulation is also specific to the type of cell (amnion, chorion, or decidua). The upregulation of PGRMC1 by MPA might be mediated through glucocorticoid receptor (GR) demonstrated using amnion and chorion cells model with GR knockdown by specific small interfering RNA transfection. The mRNA expression of PGRMC1 was decreased by H2O2 (100 μmol/L) treatment in amnion cells, which might ultimately result in downregulation of PGRMC1 protein as our data demonstrated. None of other treatments changed PGRMC1 mRNA level in these cells. We conclude that these stimuli act as regulatory factors of PGRMC1 in a cell-specific manner.

Prevention of preterm birth with vaginal progesterone or 17-alpha-hydroxyprogesterone caproate: a critical examination of efficacy and safety

Progestogens are the first drugs to demonstrate reproducibly a reduction in the rate of early preterm birth. The efficacy and safety of progestogens are related to individual pharmacologic properties of each drug within this class of medication and characteristics of the population that is treated. The synthetic 17-hydroxyprogesterone caproate and natural progesterone have been studied with the use of a prophylactic strategy in women with a history of preterm birth and in women with a multiple gestation. Evidence from a single large comparative efficacy trial suggests that vaginal natural progesterone is superior to 17-hydroxyprogesterone caproate as a prophylactic treatment in women with a history of mid-trimester preterm birth. Progestogen therapy is indicated for women with this highest risk profile based on evidence from 2 trials. A therapeutic approach based on the identification of a sonographic short cervix has been studied in several phase III trials. Independent phase III trials and an individual patient metaanalysis suggest that vaginal progesterone is efficacious and safe in women with a singleton and a short cervix. Two trials that tested 17-hydroxyprogesterone caproate in women with a short cervix showed no benefit. No consistent benefit for the prophylactic or therapeutic use of progestogens has been demonstrated in larger trials of women whose pregnancies were complicated by a multiple gestation (twins or triplets), preterm labor, or preterm rupture of membranes. Unfortunately, several large randomized trials in multiple gestations have identified harm related to 17-hydroxyprogesterone caproate exposure, and the synthetic drug is contraindicated in this population. The current body of evidence is evaluated by the Grading of Recommendations Assessment, Development, and Evaluation guidelines to derive the strength of recommendation in each of these populations. A large confirmatory trial that is testing 17-hydroxyprogesterone caproate exposure in women with a singleton pregnancy and a history of preterm birth is near completion. Additional study of the efficacy and safety of progestogens is suggested in well-selected populations based on the presence of biomarkers.

PROGESTERONE RECEPTOR GENE POLYMORPHISMS AS GENETIC RISK FACTOR OF THREATENED ABORTION

Determination of the progesterone receptor gene polymor- phisms rs590688 C/G and rs500760 A/G was provided using PCR method. To investigate the genetical precursors of threatened abortion the next groups were included: 67 patients with threatened abortion and 93 healthy persons. These allelic variants have the significantly different at rs590688 study: C/C - 23,9%, C/G - 44,8%, GIG - 31,3%, and C/C - 27,2%, C/G - 58,7%, GIG - 14,1% in the control group (P<0,05 by x2-test). The allelic variants of the rs500760 polymorphism did not differ statistically in the study group A/A 53,7%, A/G - 40,3%, GIG - 6% in the control group A/A- 52,2%, A/G - 44,6%, GIG - 3,3% (P>0,05 by x2-test). Distribution of minor homozygote GIG polymorphism rs590688 progesterone receptor gene in patients with threatened abortion in our study almost in 10 times higher in comparing with women of Taiwanese Han population, who had idiopathic recurrent pregnancy loss. The obtained data indicate significant ethnic differences in PGR and show polymorphism rs590688 clinical significance.

Pharmacogenomics of preterm birth prevention and treatment

Pharmacogenomics and personalised medicine incorporate genetic factors, historical data, and environmental exposures to predict individual variation in response to medications. The study of pharmacology and pharmacogenomics is challenging in obstetrics, and our knowledge in this area lags behind other disciplines of medicine. Some preliminary data, however, suggest that some of the interindividual variation seen in response to medications given for the prevention (progesterone) and the treatment (nifedipine, terbutaline, and others) of preterm labour may be caused by pharmacogenomic effects. A comprehensive approach, integrating clinical data, environmental factors, including concomitant medications and genotype, to optimise the prevention and treatment strategies for preterm birth, is urgently needed.

TWEETABLE ABSTRACT

Some of the variation to meds for prematurity prevention/treatment may arise from pharmacogenomic effects.

Altered IgG autoantibody levels and CD4(+) T cell subsets in lupus-prone Nba2 mice lacking the nuclear progesterone receptor

Important interactions between female reproduction and autoimmunity are suggested by the female-predominance of systemic lupus erythematosus (SLE) and other autoimmune diseases and the amelioration of certain autoimmune diseases during pregnancy. Sexually dimorphic risk of developing SLE involves modulation of genetic risk by environmental factors, sex hormones and non-hormonal factors encoded on the sex chromosomes. In some lupus models, estrogen, via estrogen receptor alpha (ER-α), enhances production of highly pathogenic IgG2a/c autoantibodies (autoAbs). Some studies indicate that treatment with progesterone, a chief female reproductive steroid, can suppress IgG2a/2c autoAb production. Little is known about how endogenous progesterone impacts lupus autoimmunity. To investigate this, we introduced a disruptive progesterone receptor (PR) gene mutation into lupus-prone mice and tracked the development of spontaneous IgG autoAbs. Here, we present evidence that PR can suppress the emergence of class-switched IgG2c autoAbs, suggesting that PR and ER-α counter-regulate a critical step in lupus autoimmunity. PR's control of IgG2c autoAb production correlates with alterations in the relative abundance of splenic T follicular helper (TFH) cells and non-TFH CD4(+) T cells, especially regulatory T cells (TREGS). Surprisingly, PR also appears to help to maintain sexually dimorphic abundance of splenic leukocytes, a feature common to many mouse models of SLE. Together our results identify a novel molecular link between female reproduction and lupus autoimmunity. Further investigation into the immunomodulatory functions of PR promises to inform reproductive health care in women and offers mechanistic insight into important immunologic phenomena of pregnancy.

Genomics of preterm birth

The molecular mechanisms controlling human birth timing at term, or resulting in preterm birth, have been the focus of considerable investigation, but limited insights have been gained over the past 50 years. In part, these processes have remained elusive because of divergence in reproductive strategies and physiology shown by model organisms, making extrapolation to humans uncertain. Here, we summarize the evolution of progesterone signaling and variation in pregnancy maintenance and termination. We use this comparative physiology to support the hypothesis that selective pressure on genomic loci involved in the timing of parturition have shaped human birth timing, and that these loci can be identified with comparative genomic strategies. Previous limitations imposed by divergence of mechanisms provide an important new opportunity to elucidate fundamental pathways of parturition control through increasing availability of sequenced genomes and associated reproductive physiology characteristics across diverse organisms.

Is personalized medicine achievable in obstetrics?

Personalized medicine seeks to identify the right dose of the right drug for the right patient at the right time. Typically, individualization of therapy is based on the pharmacogenomic makeup of the individual and environmental factors that alter drug disposition and response. In addition to these factors, during pregnancy, a woman's body undergoes many changes that can impact the therapeutic efficacy of medications. Yet, there is minimal research regarding personalized medicine in obstetrics. Adoption of pharmacogenetic testing into the obstetrical care is dependent on evidence of analytical validity, clinical validity, and clinical utility. Here, we briefly present information regarding the potential utility of personalized medicine for treating the obstetric patient for pain with narcotics, hypertension, and preterm labor, and discuss the impediments of bringing personalized medicine to the obstetrical clinic.

Prevention of preterm delivery with 17-hydroxyprogesterone caproate: pharmacologic considerations

Despite advances in neonatal care, the burden of preterm birth remains high. Preterm birth is a multifactorial problem, and strategies to identify and treat medical risk factors in early pregnancy have not been effective in reducing preterm birth rates. In a sentinel clinical trial, prophylactic therapy with 17-hydoxyprogesterone caproate (17-OHPC) reduced the risk of recurrent, spontaneous preterm birth in 34% of women. As a result, clinical practice changed and extensive research on 17-OHPC followed. The increasing body of evidence demonstrated a variable efficacy of the drug. This review will examine the plausibility, pharmacology, clinical efficacy, and safety of 17-OHPC when used in the setting of preterm birth prevention. We will also discuss pharmacokinetic and pharmacodynamics data to highlight drug metabolism and mechanism of action, which will help clarify the variability in clinical outcomes and efficacy.

A randomised controlled double-blind clinical trial of 17-hydroxyprogesterone caproate for the prevention of preterm birth in twin gestation (PROGESTWIN): evidence for reduced neonatal morbidity

OBJECTIVE

To determine whether 17 alpha-hydroxyprogesterone caproate (17OHPC) prolongs gestation beyond 37 weeks of gestation (primary outcome) and reduces neonatal morbidity (secondary outcome) in twin pregnancy.

DESIGN

Randomised controlled double-blind clinical trial.

SETTING

Tertiary-care university medical centre.

POPULATION

Unselected women with twin pregnancies.

METHODS

Participants received weekly injections of 250 mg 17OHPC (n = 194) or placebo (n = 94), from 16-20 to 36 weeks of gestation. Randomisation was performed using the permuted-block randomisation method. Data were analysed on an intention-to-treat basis.

MAIN OUTCOME MEASURE

Preterm birth (PTB) rate before 37 weeks of gestation.

RESULTS

There were no significant differences in the average gestational age at delivery, or in the rates of PTB before 37, 32, and 28 weeks of gestation, between the two groups. The proportion of very-low-birthweight neonates (<1500 g) was significantly lower in the 17OHPC group (7.6%) compared with placebo (14.3%) (relative risk, RR 0.5; 95% confidence interval, 95% CI 0.3-0.9; P = 0.01). Progestogen-treated neonates had a significantly lower composite neonatal morbidity (19.1%) compared with placebo (30.9%) (odds ratio, OR 0.53; 95% CI 0.31-0.90; P = 0.02), with significantly lower odds for respiratory distress syndrome (14.4 versus 23.4%; OR 0.55; 95% CI 0.31-0.98; P = 0.04), retinopathy of prematurity (1.1 versus 4.6%; OR 0.21; 95% CI 0.05-0.96; P = 0.04), and culture-confirmed sepsis (3.4 versus 12.8%; OR 0.24; 95% CI 0.10-0.57; P = 0.00).

CONCLUSIONS

Intramuscular 17OHPC therapy did not reduce PTB before 37 weeks of gestation in unselected twin pregnancies. Nonetheless, 17OHPC significantly reduced neonatal morbidity parameters and increased birthweight.

Pharmacogenomics of 17-alpha hydroxyprogesterone caproate for recurrent preterm birth prevention

OBJECTIVE

We hypothesized that genetic variation affects responsiveness to 17-alpha hydroxyprogesterone caproate (17P) for recurrent preterm birth prevention.

STUDY DESIGN

Women of European ancestry with ≥1 spontaneous singleton preterm birth at <34 weeks' gestation who received 17P were recruited prospectively and classified as a 17P responder or nonresponder by the difference in delivery gestational age between 17P-treated and -untreated pregnancies. Samples underwent whole exome sequencing. Coding variants were compared between responders and nonresponders with the use of the Variant Annotation, Analysis, and Search Tool (VAAST), which is a probabilistic search tool for the identification of disease-causing variants, and were compared with a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway candidate gene list. Genes with the highest VAAST scores were then classified by the online Protein ANalysis THrough Evolutionary Relationships (PANTHER) system into known gene ontology molecular functions and biologic processes. Gene distributions within these classifications were compared with an online reference population to identify over- and under- represented gene sets.

RESULTS

Fifty women (9 nonresponders) were included. Responders delivered 9.2 weeks longer with 17P vs 1.3 weeks' gestation for nonresponders (P < .001). A genome-wide search for genetic differences implicated the NOS1 gene to be the most likely associated gene from among genes on the KEGG candidate gene list (P < .00095). PANTHER analysis revealed several over-represented gene ontology categories that included cell adhesion, cell communication, signal transduction, nitric oxide signal transduction, and receptor activity (all with significant Bonferroni-corrected probability values).

CONCLUSION

We identified sets of over-represented genes in key processes among responders to 17P, which is the first step in the application of pharmacogenomics to preterm birth prevention.

Regulation of progesterone signaling during pregnancy: implications for the use of progestins for the prevention of preterm birth

Preterm birth is a major cause of neonatal morbidity and mortality. Progesterone plays a critical role in suppressing the inflammatory signals that would induce parturition prior to term. Progesterone signaling is regulated in a variety of ways during pregnancy. Endocrine production of high levels of progesterone by the placenta ensures the availability of high levels of progesterone throughout pregnancy. Paracrine regulation of progesterone metabolism in target tissues, particularly the myometrium and cervix, also determines the amount of progesterone ligand available. Progesterone metabolism can also lead to the formation of metabolites that contribute to its effects. In particular, 5β-dihydroprogesterone formation by aldo-keto reductase 1D1 appears to play an important role in maintaining uterine quiescence. Progesterone signaling can also be regulated at the receptor level through changes in the relative expression of the nuclear progesterone receptor isoforms, reduced expression of membrane receptors, and changes in the expression levels of coactivators and/or corepressors, including nuclear factor κB. Progesterone and 17α-hydroxyprogesterone caproate (17OH-PC) have recently been shown to reduce preterm births in women with previous preterm birth or shortened cervix. It is important to realize that these two progestins are likely to act in significantly different ways, which will likely influence their efficacy. The structural differences and resistance to metabolism exhibited by 17OH-PC means that it will be unable to activate some of the pathways that progesterone activates, but that it also will not be subject to paracrine inactivation. The fact that progesterone therapy works for maintaining pregnancy in some women, indicates that for those women insufficient levels of progesterone ligand in target tissues is a determining factor in early parturition, despite high levels of circulating progesterone. This article is part of a Special Issue entitled 'Pregnancy and Steroids'.

Prenatal administration of progesterone for preventing preterm birth in women considered to be at risk of preterm birth

BACKGROUND

Preterm birth is a major complication of pregnancy associated with perinatal mortality and morbidity. Progesterone for the prevention of preterm labour has been advocated.

OBJECTIVES

To assess the benefits and harms of progesterone for the prevention of preterm birth for women considered to be at increased risk of preterm birth and their infants.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 January 2013) and reviewed the reference list of all articles.

SELECTION CRITERIA

Randomised controlled trials, in which progesterone was given for preventing preterm birth.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated trials for methodological quality and extracted data.

MAIN RESULTS

Thirty-six randomised controlled trials (8523 women and 12,515 infants) were included. Progesterone versus placebo for women with a past history of spontaneous preterm birth Progesterone was associated with a statistically significant reduction in the risk of perinatal mortality (six studies; 1453 women; risk ratio (RR) 0.50, 95% confidence interval (CI) 0.33 to 0.75), preterm birth less than 34 weeks (five studies; 602 women; average RR 0.31, 95% CI 0.14 to 0.69), infant birthweight less than 2500 g (four studies; 692 infants; RR 0.58, 95% CI 0.42 to 0.79), use of assisted ventilation (three studies; 633 women; RR 0.40, 95% CI 0.18 to 0.90), necrotising enterocolitis (three studies; 1170 women; RR 0.30, 95% CI 0.10 to 0.89), neonatal death (six studies; 1453 women; RR 0.45, 95% CI 0.27 to 0.76), admission to neonatal intensive care unit (three studies; 389 women; RR 0.24, 95% CI 0.14 to 0.40), preterm birth less than 37 weeks (10 studies; 1750 women; average RR 0.55, 95% CI 0.42 to 0.74) and a statistically significant increase in pregnancy prolongation in weeks (one study; 148 women; mean difference (MD) 4.47, 95% CI 2.15 to 6.79). No differential effects in terms of route of administration, time of commencing therapy and dose of progesterone were observed for the majority of outcomes examined. Progesterone versus placebo for women with a short cervix identified on ultrasound Progesterone was associated with a statistically significant reduction in the risk of preterm birth less than 34 weeks (two studies; 438 women; RR 0.64, 95% CI 0.45 to 0.90), preterm birth at less than 28 weeks' gestation (two studies; 1115 women; RR 0.59, 95% CI 0.37 to 0.93) and increased risk of urticaria in women when compared with placebo (one study; 654 women; RR 5.03, 95% CI 1.11 to 22.78). It was not possible to assess the effect of route of progesterone administration, gestational age at commencing therapy, or total cumulative dose of medication. Progesterone versus placebo for women with a multiple pregnancy Progesterone was associated with no statistically significant differences for the reported outcomes. Progesterone versus no treatment/placebo for women following presentation with threatened preterm labour Progesterone, was associated with a statistically significant reduction in the risk of infant birthweight less than 2500 g (one study; 70 infants; RR 0.52, 95% CI 0.28 to 0.98). Progesterone versus placebo for women with 'other' risk factors for preterm birth Progesterone, was associated with a statistically significant reduction in the risk of infant birthweight less than 2500 g (three studies; 482 infants; RR 0.48, 95% CI 0.25 to 0.91).

AUTHORS' CONCLUSIONS

The use of progesterone is associated with benefits in infant health following administration in women considered to be at increased risk of preterm birth due either to a prior preterm birth or where a short cervix has been identified on ultrasound examination. However, there is limited information available relating to longer-term infant and childhood outcomes, the assessment of which remains a priority.Further trials are required to assess the optimal timing, mode of administration and dose of administration of progesterone therapy when given to women considered to be at increased risk of early birth.

Progesterone receptor membrane component 1 as the mediator of the inhibitory effect of progestins on cytokine-induced matrix metalloproteinase 9 activity in vitro

Progesterone (P4) and the progestin, 17α-hydroxyprogesterone caproate, are clinically used to prevent preterm births (PTBs); however, their mechanism of action remains unclear. Cytokine-induced matrix metalloproteinase 9 (MMP-9) activity plays a key role in preterm premature rupture of the membranes and PTB. We demonstrated that the primary chorion cells and the HTR8/SVneo cells (cytotrophoblast cell line) do not express the classical progesterone receptor (PGR) but instead a novel progesterone receptor, progesterone receptor membrane component 1 (PGRMC1), whose role remains unclear. Using HTR8/SVneo cells in culture, we further demonstrated that 6 hours pretreatment with medroxyprogesterone acetate (MPA) and dexamethasone (Dex) but not P4 or 17α-hydroxyprogesterone hexanoate significantly attenuated tumor necrosis factor α-induced MMP-9 activity after a 24-hour incubation period. The inhibitory effect of MPA, but not Dex, was attenuated when PGRMC1 expression was successfully reduced by PGRMC1 small interfering RNA. Our findings highlight a possible novel role of PGRMC1 in mediating the effects of MPA and in modulating cytokine-induced MMP-9 activity in cytotrophoblast cells in vitro.

Demystifying animal models of adverse pregnancy outcomes: touching bench and bedside

This represents an overview of the use of animal models to study the adverse pregnancy outcomes seen in humans. The purpose is to entice clinicians to utilize some of this information to seek out the literature and have more meaningful and profitable discussions with their academic colleagues and enhance transdisciplinary research in reproductive health.

Critical appraisal of the efficacy, safety, and patient acceptability of hydroxyprogesterone caproate injection to reduce the risk of preterm birth

Prevention of preterm delivery is a major desiderate in contemporary obstetrics and a societal necessity. The means to achieve this goal remain elusive. Progesterone has been used in an attempt to prevent preterm delivery since the 1970s, but the evidence initially accumulated was fraught by mixed results and was based on mostly underpowered studies with variable eligibility criteria, including history of spontaneous abortion as an indication for treatment. More recent randomized controlled clinical trials restimulated the interest in progesterone supplementation, suggesting that progesterone may favorably influence the rate of preterm delivery. Preterm delivery is a complex disorder and consequently it is unlikely that one generalized prevention strategy will be effective in all patients. Further, an additional impediment in accepting progesterone as the "magic bullet" in the prevention of preterm delivery is that its mechanism of action is not fully understood and the optimal formulations, route of administration, and dose have yet to be established. We have concerned ourselves in this review with the most recent status of 17 alpha-hydroxyprogesterone caproate (17OH-PC) supplementation for prevention of preterm delivery. Our intention is to emphasize the efficacy, safety, and patient acceptability of this intervention, based on a comprehensive and unbiased review of the available literature. Currently there are insufficient data to suggest that 17OH-PC is superior or inferior to natural progesterone. Based on available evidence, we suggest a differential approach giving preferential consideration to either 17OH-PC or other progestins based on obstetric history and cervical surveillance. Progestin therapy for risk factors other than a history of preterm birth and/or a short cervix in the current pregnancy is not currently supported by the published evidence. The experience to date with 17OH-PC indicates that there are population subgroups that may be harmed by administration of 17OH-PC. Therefore, extending the use of 17OH-PC to unstudied populations or for indications that are not evidence-based is inadvisable outside of a research protocol.

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.