BACKGROUND: Makena (17-hydroxyprogesterone caproate) was approved by the United States Food and Drug Administration for the prevention of recurrent spontaneous preterm birth in 2011 under the accelerated approval pathway, but fundamental pharmacokinetic or pharmacodynamic (Phase 1 and Phase 2) studies were not performed. At the time, there were no dose-response or concentration-response data. The therapeutic concentration was not known. The lack of such data brings into question the dosing regimen for 17-hydroxyprogesterone caproate and if it was optimized.
OBJECTIVE: The purpose of this study was to evaluate the dosing regimen for 17-hydroxyprogesterone by analyzing 3 data sets in which the 17-hydroxyprogesterone caproate pharmacology was evaluated, namely the Maternal-Fetal Medicine Omega 3 study, the Obstetric-Fetal Pharmacology Research Units study, and the Obstetrical-Fetal Pharmacology Research Centers study. If an inappropriate dosing regimen could be identified, such information could inform future studies of pharmacotherapy in pregnancy.
METHODS: Data from the Omega 3 study were used to determine if plasma concentration was related to spontaneous preterm birth risk and if a threshold concentration could be identified. Data from the Obstetric-Fetal Pharmacology Research Units study were used to determine the half-life of 17-hydroxyprogesterone caproate and to develop a model to simulate drug concentrations with various dosing regimens. Data from the Obstetrical-Fetal Pharmacology Research Centers study were used to determine the relationship between dose and safety outcomes.
RESULTS: Analysis of the Omega 3 data set indicated that the risk for spontaneous preterm birth decreased as the log concentration of 17-hydroxyprogesterone caproate increased (odds ratio, 0.04; 95% confidence interval, 0.00-0.90). A steady state concentration of >9 ng/mL (equivalent to >8 ng/mL at 25-28 weeks) was associated with the lowest risk for spontaneous preterm birth (hazard ratio, 0.52; 95% confidence interval, 0.27-0.98; P=.04); this concentration was not achieved in 25% of subjects who received the 250 mg weekly dose. In the Obstetrical-Fetal Pharmacology Research Units study, the adjusted half-life (median and interquartile range) of 17-hydroxyprogesterone caproate was 14.0 (11.5-17.2) days. Simulations indicated that with the 250 mg weekly dose, >5 weekly injections were required to reach the 9 ng/mL target; however, those with the shortest half-life (corresponding to higher clearance), never reached the targeted 9 ng/mL concentration. In 75% of subjects, a loading dose of 500 mg weekly for 2 weeks followed by 250 mg weekly achieved and maintained the 9 ng/mL concentration within 2 weeks but in those 25% with the shortest half-life, concentrations exceeded the 9 ng/mL target for only 3 weeks. In the Obstetrical-Fetal Pharmacology Research Centers study, all 65 subjects who received a weekly dose of 500 mg exceeded the 9 ng/mL steady state.
CONCLUSIONS: The dosing regimen for 17-hydroxyprogesterone caproate was inadequate. There is a significant inverse relationship between drug concentration and spontaneous preterm birth. The risk was lowest when the concentration exceeded 9 ng/mL, but 25% of women who received the 250 mg weekly dose never reached or maintained this concentration. The drug\'s long half-life necessitates a loading dose to achieve therapeutic concentrations rapidly. The omission of basic pharmacologic studies to determine the proper dosing may have compromised the effectiveness of 17-hydroxyprogesterone caproate. Future pharmacotherapy trials in pregnancy must first complete fundamental pharmacology studies.

BACKGROUND: Emergency cervical cerclage is a recognized method for preventing mid-trimester pregnancy loss and premature birth; however, its benefits remain controversial. This study aimed to establish preoperative models predicting preterm birth and gestational latency following emergency cervical cerclage in singleton pregnant patients with a high risk of preterm birth.
METHODS: We retrospectively reviewed data from patients who received emergency cerclage between 2015 and 2023 in three institutions. Patients were grouped into a derivation cohort (n = 141) and an independent validation cohort (n = 61). Univariate and multivariate logistic and Cox regression analyses were used to identify independent predictive variables and establish the models. Harrell\'s C-index, time-dependent receiver operating characteristic curves and areas under the curves, calibration curve, and decision curve analyses were performed to assess the models.
RESULTS: The models incorporated gestational weeks at cerclage placement, history of prior second-trimester loss and/or preterm birth, cervical dilation, and preoperative C-reactive protein level. The C-index of the model for predicting preterm birth before 28 weeks was 0.87 (95% CI: 0.82-0.93) in the derivation cohort and 0.82 (95% CI: 0.71-0.92) in the independent validation cohort; The C-index of the model for predicting gestational latency was 0.70 (95% CI: 0.66-0.75) and 0.78 (95% CI: 0.71-0.84), respectively. In the derivation set, the areas under the curves were 0.84, 0.81, and 0.84 for predicting 1-, 3- and 5-week pregnancy prolongation, respectively. The corresponding values for the external validation were 0.78, 0.78, and 0.79, respectively. Calibration curves showed a good homogeneity between the observed and predicted ongoing pregnant probabilities. Decision curve analyses revealed satisfactory clinical usefulness.
CONCLUSIONS: These novel models provide reliable and valuable prognostic predictions for patients undergoing emergency cerclage. The models can assist clinicians and patients in making personalized clinical decisions before opting for the cervical cerclage.

The effectiveness of 17-hydroxyprogesterone caproate is unclear as trials have provided conflicting results. With the absence of fundamental pharmacologic studies addressing dosing or the relationship between drug concentration and gestational age at delivery, the effectiveness of the medication cannot be evaluated.
This study aimed to evaluate the relationship between plasma concentrations of 17-hydroxyprogesterone caproate and preterm birth rates and gestational age at preterm delivery and to assess the safety of the 500-mg dose.
This study recruited 2 cohorts with previous spontaneous preterm birth; 1 cohort (n=143) was randomly assigned to either 250-mg or 500-mg 17-hydroxyprogesterone caproate, and the other cohort (n=16) was receiving the 250-mg dose for routine care. Steady-state trough plasma concentrations of 17-hydroxyprogesterone caproate obtained at 26 to 30 weeks of gestation were correlated to dose, spontaneous preterm birth rates, and measures of gestational length. Furthermore, maternal and neonatal safety outcomes were evaluated according to dose.
There was a dose proportional increase in trough plasma concentrations with the 250-mg (median, 8.6 ng/m; n=66) and 500-mg (median, 16.2 ng/mL; n=55) doses. In 116 compliant participants with blood samples, drug concentration was not related to the spontaneous preterm birth rate (odds ratio, 1.00; 95% confidence interval, 0.93-1.08). However, there was a significant relationship between drug concentration and both the interval from the first administration to delivery (interval A: coefficient, 1.11; 95% confidence interval, 0.00-2.23; P=.05) and the interval from the 26- to 30-week blood draw to delivery (interval B: coefficient, 1.56; 95% confidence interval, 0.25-2.87; P=.02). The spontaneous preterm birth rate or measures of gestational length were not related to dose. Postenrollment cerclage adversely affected all pharmacodynamic assessments because it was a powerful predictor of spontaneous preterm birth (odds ratio, 4.03; 95% confidence interval, 1.24-13.19; P=.021) and both measures of gestational length (interval A [coefficient, -14.9; 95% confidence interval, -26.3 to -3.4; P=.011] and interval B [coefficient, -15.9; 95% confidence interval, -25.8 to -5.9; P=.002]). Initial cervical length was significantly related to the risk of postenrollment cerclage (odds ratio, 0.80; 95% confidence interval, 0.70-0.92; P=.001). Maternal and neonatal safety outcomes were similar in both dosing groups.
In this pharmacodynamic study, trough plasma 17-hydroxyprogesterone caproate concentrations were significantly associated with gestational age at preterm birth but not with the preterm birth rate. Postenrollment cerclage was a powerful predictor of spontaneous preterm birth rate and gestational length. Initial cervical length predicted the risk of postenrollment cerclage. Adverse events were similar with the 500-mg and 250-mg doses of 17-hydroxyprogesterone caproate.

In early-onset preeclampsia, each additional day of pregnancy prolongation reduces offspring infant mortality about 9%. We evaluated if maternal stress at admission to hospital for early-onset preeclampsia predicted admission-to-delivery intervals in days.
This prospective, longitudinal cohort-study involved 15 singleton pregnancies with a diagnosis of preeclampsia before 34 weeks gestation with intended expectant management. Upon hospital admission, maternal psychological stress was assessed with questionnaires and physiological stress with hair cortisol. Hair samples were analyzed in three hair segments representing the preconception period, and the first and second trimester of pregnancy.
Mean pregnancy prolongation was 16.2 days. Higher maternal anxiety at hospital admission significantly correlated with shorter admission-to-delivery intervals (r = - 0.54, p = 0.04). Chronically increased hair cortisol concentrations (i.e. from preconception through the second trimester) of pregnancy tended to be related to shorter admission-to-delivery intervals (p <. 10).
Higher reported anxiety is, and chronically high hair cortisol tended to be, related with fewer days of prolongation from admission to delivery in women with early-onset preeclampsia. These findings suggest that maternal stress might be a potential determinant of disease progression. Future research into early innovative stress-reducing interventions for early-onset preeclampsia may shed more light on the etiology and treatment of this disease.

OBJECTIVE: To investigate the effect of chronic hypertension on expectant management for preeclampsia (PE).
METHODS: Pregnant women who were diagnosed with severe PE before 34 weeks of gestation between 2005 and 2016 and managed at a tertiary center were the subjects of the study. Mothers were classified into two groups: a severe superimposed PE (SSP) group and a severe PE (SP) group. We compared the groups in terms of perinatal outcomes.
METHODS: Pregnancy prolongation from the diagnosis of severe PE to delivery.
RESULTS: The SSP group included 30 women whereas the SP group included 79 women. Expectant management could be performed in 24 subjects (80.0%) in the SSP group and 49 (62.0%) in the SP group (P = 0.110). Gestational age at diagnosis of PE (P = 0.016) and gestational age at delivery (P = 0.031) were significantly lower in the SSP group than in the SP group. There were no significant differences between the groups in terms of pregnancy prolongation (SSP, 8.5 days versus SP, 6.0 days; P = 0.25) or maternal and neonatal complications.
CONCLUSIONS: Compared to severe PE, severe PE superimposed on chronic hypertension does not increase the prevalence of maternal complications, and an equivalent pregnancy prolongation was obtained. Expectant management was possible in severe superimposed PE on chronic hypertension, as it was in severe PE.

OBJECTIVE: To determine the cutoff of antithrombin activity for predicting the interval from diagnosis of early-onset pre-eclampsia to delivery.
METHODS: At Hokkaido University Hospital, Japan, data were retrospectively assessed on antithrombin activity measured at both diagnosis of pre-eclampsia and delivery among women with singleton pregnancy and pre-eclampsia (defined by combined gestational hypertension and proteinuria) between 2009 and 2017. The timing of delivery was determined by maternal and fetal well-being.
RESULTS: Among 2904 singleton deliveries, antithrombin activity was measured for 94 (3.2%) women diagnosed with pre-eclampsia. The median (range) interval was significantly longer for 38 (40%) women with early-onset than for 56 (60%) women with late-onset pre-eclampsia (6.5 [0-27] vs 1 [0-29] days, respectively; P<0.001). In the early-onset group, median antithrombin activity at diagnosis was significantly lower for 19 women with an interval of less than 7 days (72% [60%-92%]) than for 19 women with a longer interval (≥7 days) (84% [59%-110%]; P=0.012). Antithrombin activity of 78% at diagnosis of early-onset pre-eclampsia was optimal for predicting a delivery interval of less than 7 days.
CONCLUSIONS: A cutoff of 78% antithrombin activity at diagnosis of early-onset pre-eclampsia might be used as a predictor of delivery within 7 days.

OBJECTIVE: We investigated whether women with severe fetal growth restriction (FGR <5th percentile) associated with severe preeclampsia (PE) occurring in the second trimester are candidates for expectant management.
METHODS: This is a retrospective study involving 33 women who developed severe PE or superimposed PE in the second trimester and were expectantly managed at a tertiary center. They were divided into groups with and without severe FGR on admission (severe FGR (+) group: 17 women; severe FGR (-) group: 16 women) for comparison of the duration of pregnancy prolongation, major maternal complications, and perinatal outcomes. The data are presented as medians (range) or frequencies (percentage).
RESULTS: The duration of pregnancy prolongation was 10days in both groups. Major maternal complications occurred in 5 of 17 women (29.4%) in the severe FGR (+) and 5 of 16 (31.3%) in the severe FGR (-) group, showing very similar incidence rates in the 2 groups. The perinatal survival rates were favorable at 82.4% (14/17) in the severe FGR (+) and 100% (16/16) in the severe FGR (-) group.
CONCLUSIONS: Regarding expectant management of severe preeclampsia occurring in the second trimester, there was no difference in the duration of pregnancy prolongation between the groups with and without severe FGR on admission. Because favorable perinatal outcomes can be expected without compromising maternal safety by prolonging pregnancy as expectant management for severe FGR, it was suggested that women with severe FGR are suitable candidates for expectant management.