Pharmacokinetics of natural progesterone administered in the form of a vaginal tablet

Circadian serum progesterone variations on the day of frozen embryo transfer in artificially prepared cycles

RESEARCH QUESTION

What is the intra-day variation of serum progesterone related to vaginal progesterone administration on the day of frozen embryo transfer (FET) in an artificial cycle?

DESIGN

A prospective cohort study was conducted including 22 patients undergoing a single blastocyst artificial cycle (AC)-FET from August to December 2022. Endometrial preparation was achieved by administering oestradiol valerate (2 mg three times daily) and consecutively micronized vaginal progesterone (MVP; 400 mg twice daily). A blastocyst FET was performed on the 6th day of MVP administration. Serum progesterone concentrations were measured on the day of transfer at 08:00, 12:00, 16:00 and 20:00 hours. The first and last blood samples were collected just before MVP was administered.

RESULTS

The mean age and body mass index of the study population were 33.95 ± 3.98 years and 23.10 ± 1.95 kg/m2. The mean P-values at 08:00, 12:00, 16:00 and 20:00 hours were 11.72 ± 4.99, 13.59 ± 6.33, 10.23 ± 3.81 and 9.28 ± 3.09 ng/ml, respectively. A significant decline, of 2.41 ng/ml (95% confidence interval 0.81-4.00), was found between the first and last progesterone measurements.

CONCLUSION

A statistically significant intra-day variation of serum progesterone concentrations on the day of FET in artificially prepared cycles was observed. This highlights the importance of a standardized procedure for the timing of progesterone measurement on the day of AC-FET. Of note, the study results are applicable only to women using MVP for luteal phase support; therefore it is necessary to confirm its validity in comparison with the different existing administration routes of progesterone.

A model for predicting low progesterone levels on the day of embryo transfer in hormonally prepared vitrified-warmed embryo transfer cycles: A secondary analysis of a prospective cohort study

AIM

To develop a model that predicts low progesterone (P) levels on the day of embryo transfer (ET) based on patient and cycle characteristics, including serum estradiol (E2 ) concentration after vaginal administration of micronized E2 for endometrial preparation.

METHODS

A prospective cohort of 193 patients scheduled for cryopreserved blastocyst transfer during an artificial endometrial preparation cycle, using micronized E2 vaginally for first 4 days (4 mg/day), followed by oral administration (6 mg/day). Blood sampling for E2 was performed prospectively on day-5 of vaginal administration and analysis was performed retrospectively. On sixth day of P treatment (daily 300 mg of vaginal micronized P tablets), P levels were measured on ET day. Primary outcome measure was serum P levels after vaginal E2 administration.

RESULTS

Patients with low P levels on the day of ET (<7.8 ng/mL, 25th percentile) were heavier (p < 0.001) and exhibited lower day 5 serum E2 levels (p < 0.001) compared with patients with adequate P levels. Multivariate linear regression analysis revealed that weight (p = 0.003) and day 5 E2 levels (p < 0.001) were independently associated with the P levels. The sensitivity, specificity, and positive and negative predictive values (%) were 71.4, 55.6, 35.4, and 85.1 for weight ≥ 65 kg; 71.4, 61.8, 38.9, and 86.4 for day 5 E2  ≤ 1615 pg/mL; 59.2, 83.3, 54.7, and 85.7 for the combination of these two variables; and 82.9, 62.5, 54.7, and 87.0 for the sequential inclusion of these variables, respectively.

CONCLUSIONS

Low day 5 E2 levels following vaginal administration and high weight are independently associated with low P levels on the day of ET. Predictive performance is enhanced when these variables are considered sequentially or in combination.

Effectiveness of progesterone rescue in women presenting low circulating progesterone levels around the day of embryo transfer: a systematic review and meta-analysis

IMPORTANCE

Over the last decade, frozen embryo transfer (FET) has been increasingly used in contemporary fertility units. Despite the rapid increase in FET, there is still insufficient evidence to recommend an optimized protocol for endometrial preparation especially in patients with lower progesterone (P4) levels. Previous studies have concluded that P4 levels <10 ng/mL are associated with poorer pregnancy outcomes than those reported with high levels of circulating P4.

OBJECTIVE

To identify whether rescue P4 dosing in patients with low P4 can salvage adverse outcomes associated with low P4 levels, resulting in outcomes comparable to patients with adequate progesterone.

DATA SOURCES

The study was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analyses guidelines and prospectively registered under the PROSPERO database (CRD42022357125). Six databases (Embase, MEDLINE, APA PsycInfo, Global Health, HMIC Health Management Information Consortium, and Google Scholar) and 2 additional sources were searched from inception to August 29, 2022.

STUDY SELECTION AND SYNTHESIS

Prospective and retrospective cohort studies, reporting the association between rescue progesterone and one or more pregnancy outcomes, were included. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS), while the quality of evidence by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. Summative and subgroup data as well as heterogeneity were generated by the Cochrane platform RevMan (V. 5.4).

MAIN OUTCOME MEASURE(S)

To compare ongoing pregnancy rate as primary outcome and clinical pregnancy rate, miscarriage rate, and live birth rate as secondary outcomes between patients with low (<10 ng/mL) receiving rescue progesterone vs. those with adequate levels of P4 (≥10 ng/mL).

RESULT(S)

Overall, 7 observational studies were included in the analysis, with a total of 5927 patients of median age 34 (interquartile range [IQR]: 31.55, 37.13). Overall, patient group comparison, namely those with low P4 that received a rescue dose and those with adequate P4 levels, did not yield significant differences for either the primary or secondary outcomes. For ongoing clinical pregnancy, patients with low P4 receiving the rescue dose vs. those with adequate P4 levels was odds ratio (OR) 0.98 (95% CI: 0.78, 1.24; P = .86, I²: 41%), whereas for miscarriage events, OR was 0.98 (95% CI: 0.81, 1.17; P = .80, I²: 0). Equally, for clinical pregnancy, OR was 0.91 (95% CI: 0.78, 1.06; P = .24; I²: 33%), and for live birth, OR was 0.92 (95% CI: 0.77, 1.09; P = .33; I²: 43%). Subgroup analysis on the basis or rescue administration route successfully explained summative heterogeneity.

CONCLUSION(S)

Rescue P4 dosing in patients with low P4 results in ongoing pregnancy rate, clinical pregnancy and live birth rates were comparable to those of patients with adequate P4 levels. However, robust randomized controlled trials assessing rescue treatment in women with low P4 are needed to confirm these findings. Rescue P4 in patients with low circulating P4 around embryo transfer day may result in reproductive outcomes comparable to those with adequate P4 levels.

STUDY REGISTRATION

CRD42022357125 (PROSPERO).

Overweight and obesity affect the efficacy of vaginal vs. intramuscular progesterone for luteal-phase support in vitrified-warmed blastocyst transfer

OBJECTIVE

To compare the difference in the live birth rates (LBRs) between vaginal progesterone and intramuscular progesterone as luteal-phase support in programmed vitrified-warmed blastocyst transfer cycles and determine whether the association was moderated by overweight/obesity.

DESIGN

Retrospective cohort study.

SETTING

Tertiary reproductive medicine center.

PATIENT(S)

Patients who underwent transfer of single vitrified-warmed blastocyst in a programmed cycle between January 2018 and June 2021.

INTERVENTION(S)

Vaginal or intramuscular progesterone as luteal-phase support. Analysis was performed using the generalized estimating equation framework and multivariate regression models. Interaction testing was used to determine whether overweight/obesity (body mass index of ≥25 kg/m²) moderated the association between progesterone replacement and LBRs.

MAIN OUTCOME MEASURE(S)

The primary outcome was live birth. The secondary outcomes were biochemical pregnancy, clinical pregnancy, miscarriage, and total pregnancy loss.

RESULT(S)

A total of 6,905 programmed cycles (4,616 with vaginal progesterone and 2,289 with intramuscular progesterone) were included in the analysis. In the general cohort who underwent cryopreserved blastocyst transfer, the LBRs were 46.23% and 48.62% in the vaginal and intramuscular progesterone groups, respectively (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.82-1.01; adjusted OR [aOR], 0.89; 95% CI, 0.81-0.98), with a significantly increased rate of pregnancy losses in the vaginal progesterone group compared with that in the intramuscular progesterone group (22.22% vs. 18.90%; OR, 1.23; 95% CI, 1.08-1.39; aOR, 1.23; 95% CI, 1.08-1.40). Among normal-weight women, the LBR in the vaginal progesterone group was lower than that in the intramuscular progesterone group (aOR, 0.84; 95% CI, 0.75-0.95). On the other hand, among women with overweight/obesity, the LBRs were similar between the 2 groups of progesterone replacement (aOR, 1.06; 95% CI, 0.86-1.33). Interaction testing of the routes of progesterone administration and overweight/obesity was significant.

CONCLUSION(S)

Luteal-phase support with vaginal progesterone was associated with reduced LBRs compared with intramuscular progesterone for vitrified-warmed blastocyst transfer, and the association was modified by maternal overweight/obesity. Further research is needed to better understand the mechanisms behind the association.

What is there to know about the effects of progestins on the human brain and cognition?

Progestins are an important component of hormonal contraceptives (HCs) and hormone replacement therapies (HRTs). Despite an increasing number of studies elucidating the effects of HCs and HRTs, little is known about the effects of different types of progestins included in these medications on the brain. Animal studies suggest that various progestins interact differently with sex steroid, mineralocorticoid and glucocorticoid receptors and have specific modulatory effects on neurotransmitter systems and on the expression of neuropeptides, suggesting differential impacts on cognition and behavior. This review focuses on the currently available knowledge from human behavioral and neuroimaging studies pooled with evidence from animal research regarding the effects of progestins on the brain. The reviewed information is highly relevant for improving women's mental health and making informed choices regarding specific types of contraception or treatment.

Vaginal Nanoformulations for the Management of Preterm Birth

Preterm birth (PTB) is a leading cause of infant morbidity and mortality in the world. In 2020, 1 in 10 infants were born prematurely in the United States. The World Health Organization estimates that a total of 15 million infants are born prematurely every year. Current therapeutic interventions for PTB have had limited replicable success. Recent advancements in the field of nanomedicine have made it possible to utilize the vaginal administration route to effectively and locally deliver drugs to the female reproductive tract. Additionally, studies using murine models have provided important insights about the cervix as a gatekeeper for pregnancy and parturition. With these recent developments, the field of reproductive biology is on the cusp of a paradigm shift in the context of treating PTB. The present review focuses on the complexities associated with treating the condition and novel therapeutics that have produced promising results in preclinical studies.

[Comparison of oral dydrogesterone with micronized vaginal progesterone in fresh embryo transfert in IVF/ICSI]

INTRODUCTION

Luteal insufficiency corresponds to a progesterone deficiency affecting women who receive treatment for in vitro fertilization (IVF). Different routes of progesterone administration exist and have varying degrees of acceptability to patients. The aim of this study was to compare two luteal phase support (LPS) treatments: oral dydrogesterone versus micronized vaginal progesterone on the clinical pregnancy occurrence after fresh embryo transfer.

MATERIAL AND METHODS

This study was a monocentric historical and observational cohort study carried out in the reproductive medicine department at the University Hospital, Femme Mère Enfant in Lyon. All the data were collected retrospectively. Women between 18 and 43 years old, who completed an IVF cycle with or without ICSI, followed by fresh embryo transfer on the second or third day after oocyte retrieval (D2 or D3) or at the blastocyst stage (D5 or D6) between July 2019 and July 2020 were included. The 290 patients included between July 2019 and January 2020 received 600mg per day of PMV. The 290 patients in the OD group included between January and July 2020 received 30mg OD per day.

RESULTS

In the univariate analysis, the clinical pregnancy occurrence per transfer was comparable between the MVP and OD groups (P>0.05) (OR [95% CI]): 0.904 [0.630 ; 1.296]. In the multivariate analysis, OD also appeared to be associated with a similar pregnancy occurrence compared to MVP, with a non-significant difference (OR [95% CI]): 0.940 [0.640; 1.380]. The use of OD compared to MVP did not significantly influence the clinical pregnancy occurrence in any age group. There was no significant difference between the two groups in the clinical pregnancy occurrence, whether the patients belonged to the reference population of the center or not (P>0.05) (OR [95% CI]): 2.367 [0.568; 3.568].

CONCLUSION

This important French retrospective study confirms the safety and efficacy of OD.

Progesterone and estrogen levels are associated with live birth rates following artificial cycle frozen embryo transfers

PURPOSE

Does an association exist between serum progesterone and estradiol levels and live birth rates in artificial cycle frozen embryo transfer (AC-FET)?

METHODS

Retrospective cohort study was based on prospectively collected data at a university-affiliated fertility center. Included were all cycles using an artificial endometrial preparation with estradiol hemihydrate (Estrofem, 2 mg/8 h) and vaginal progesterone (Endometrin 100 mg/8 h), autologous oocytes, and cleavage stage embryo transfers. Serum progesterone and estradiol levels were measured 14 days after FET. A total of 921 cycles in 568 patients from to December 2010 to June 2019 were investigated. Live birth was the primary outcome measure.

RESULTS

Significant association was found between live birth and progesterone as well as estradiol levels (progesterone 14.65 vs 11.62 ng/ml, p = 0.001; estradiol 355.12 vs 287.67 pg/ml, p = 0.001). A significant difference in live birth rate was found below and above the median progesterone level (10.9 ng/ml, p = 0.007). Lower estradiol level was significantly associated with lower live birth rate (< 188.2 pg/ml 8.3%, > 263.1 pg/ml 16%, p = 0.02).

CONCLUSIONS

Serum progesterone and estradiol levels impact live birth rate in AC-FET.

Impact of low serum progesterone levels on the day of embryo transfer on pregnancy outcome: a prospective cohort study in artificial cycles with vaginal progesterone

STUDY QUESTION

Is there a serum progesterone (P) threshold on the day of embryo transfer (ET) in artificial endometrium preparation cycles below which the chances of ongoing pregnancy are reduced?

SUMMARY ANSWER

Serum P levels <8.8 ng/ml on the day of ET lower ongoing pregnancy rate (OPR) in both own or donated oocyte cycles.

WHAT IS KNOWN ALREADY

We previously found that serum P levels <9.2 ng/ml on the day of ET significantly decrease OPR in a sample of 211 oocyte donation recipients. Here, we assessed whether these results are applicable to all infertile patients under an artificial endometrial preparation cycle, regardless of the oocyte origin.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study was performed between September 2017 and November 2018 and enrolled 1205 patients scheduled for ET after an artificial endometrial preparation cycle with estradiol valerate and micronized vaginal P (MVP, 400 mg twice daily).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients ≤50 years old with a triple-layer endometrium ≥6.5 mm underwent transfer of one or two blastocysts. A total of 1150 patients treated with own oocytes without preimplantation genetic testing for aneuploidies (PGT-A) (n = 184), own oocytes with PGT-A (n = 308) or donated oocytes (n = 658) were analyzed. The primary endpoint was the OPR beyond pregnancy week 12 based on serum P levels measured immediately before ET.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with serum P levels <8.8 ng/ml (30th percentile) had a significantly lower OPR (36.6% vs 54.4%) and live birth rate (35.5% vs 52.0%) than the rest of the patients. Multivariate logistic regression showed that serum P < 8.8 ng/ml was an independent factor influencing OPR in the overall population and in the three treatment groups. A significant negative correlation was observed between serum P levels and BMI, weight and time between the last P dose and blood tests and a positive correlation was found with age, height and number of days on HRT. Multivariate logistic regression showed that only body weight was an independent factor for presenting serum P levels <8.8 ng/ml. Obstetrical and perinatal outcomes did not differ in patients with ongoing pregnancy regardless of serum P levels being above/below 8.8 ng/ml.

LIMITATIONS, REASONS FOR CAUTION

Only women with MVP were included. Extrapolation to other P administration forms needs to be validated.

WIDER IMPLICATIONS OF THE FINDINGS

This study identified the threshold of serum P as 8.8 ng/ml on the day of ET for artificial endometrial preparation cycles necessary to optimize outcomes, in cycles with own or donated oocytes. One-third of patients receiving MVP show inadequate levels of serum P that, in turn, impact the success of the ART cycle. Monitoring P levels in the mid-luteal phase is recommended when using MVP to adjust the doses according to the needs of the patient.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

NCT03272412.

Individualised luteal phase support in artificially prepared frozen embryo transfer cycles based on serum progesterone levels: a prospective cohort study

STUDY QUESTION

Does an individualised luteal phase support (iLPS), according to serum progesterone (P4) level the day prior to euploid frozen embryo transfer (FET), improve pregnancy outcomes when started on the day previous to embryo transfer?

SUMMARY ANSWER

Patients with low serum P4 the day prior to euploid FET can benefit from the addition of daily subcutaneous P4 injections (Psc), when started the day prior to FET, and achieve similar reproductive outcomes compared to those with initial adequate P4 levels.

WHAT IS KNOWN ALREADY

The ratio between FET/IVF has spectacularly increased in the last years mainly thanks to the pursuit of an ovarian hyperstimulation syndrome free clinic and the development of preimplantation genetic testing (PGT). There is currently a big concern regarding the endometrial preparation for FET, especially in relation to serum P4 levels around the time of embryo transfer. Several studies have described impaired pregnancy outcomes in those patients with low P4 levels around the time of FET, considering 10 ng/ml as one of the most accepted reference values. To date, no prospective study has been designed to compare the reproductive outcomes between patients with adequate P4 the day previous to euploid FET and those with low, but restored P4 levels on the transfer day after iLPS through daily Psc started on the day previous to FET.

STUDY DESIGN, SIZE, DURATION

A prospective observational study was conducted at a university-affiliated fertility centre between November 2018 and January 2020 in patients undergoing PGT for aneuploidies (PGT-A) IVF cycles and a subsequent FET under hormone replacement treatment (HRT). A total of 574 cycles (453 patients) were analysed: 348 cycles (leading to 342 euploid FET) with adequate P4 on the day previous to FET, and 226 cycles (leading to 220 euploid FET) under iLPS after low P4 on the previous day to FET, but restored P4 levels on the transfer day.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall we included 574 HRT FET cycles (453 patients). Standard HRT was used for endometrial preparation. P4 levels were measured the day previous to euploid FET. P4 > 10.6 ng/ml was considered as adequate and euploid FET was performed on the following day (FET Group 1). P4 < 10.6 ng/ml was considered as low, iLPS was added in the form of daily Psc injections, and a new P4 analysis was performed on the following day. FET was only performed on the same day when a restored P4 > 10.6 ng/ml was achieved (98.2% of cases) (FET Group 2).

MAIN RESULTS AND THE ROLE OF CHANCE

Patient's demographics and cycle parameters were comparable between both euploid FET groups (FET Group 1 and FET Group 2) in terms of age, weight, oestradiol and P4 levels and number of embryos transferred. No statistically significant differences were found in terms of clinical pregnancy rate (56.4% vs 59.1%: rate difference (RD) -2.7%, 95% CI [-11.4; 6.0]), ongoing pregnancy rate (49.4% vs 53.6%: RD -4.2%, 95% CI [-13.1; 4.7]) or live birth rate (49.1% vs 52.3%: RD -3.2%, 95% CI [-12; 5.7]). No significant differences were also found according to miscarriage rate (12.4% vs 9.2%: RD 3.2%, 95% CI [-4.3; 10.7]).

LIMITATIONS, REASONS FOR CAUTION

Only iLPS through daily Psc was evaluated. The time for Psc injection was not stated and no serum P4 determinations were performed once the pregnancy was achieved.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides information regarding an 'opportunity window' for improved ongoing pregnancy rates and miscarriage rates through a daily Psc injection in cases of inadequate P4 levels the day previous to FET (P4 < 10.6 ng/ml) and restored values the day of FET (P4 > 10.6 ng/ml). Only euploid FET under HRT were considered, avoiding one of the main reasons of miscarriage and implantation failure and overcoming confounding factors such as female age, embryo quality or ovarian stimulation protocols.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. B.C. reports personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, IBSA and Gedeon Richter outside the submitted work. N.P. reports grants and personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, Theramex and Besins International and personal fees from IBSA and Gedeon Richter outside the submitted work. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NCT03740568.

Factors associated with serum progesterone concentrations the day before cryopreserved embryo transfer in artificial cycles

RESEARCH QUESTION

What factors determine serum progesterone concentrations the day before cryopreserved embryo transfer in artificially prepared cycles?

DESIGN

Retrospective cohort study at a university-affiliated fertility centre including infertile women under 45 years old using own oocytes who underwent a total of 685 single cryopreserved blastocyst transfers under hormonal therapy. Determinants that affected live birth rate (LBR) were analysed using a multivariate logistic regression. Univariate analysis and multivariate linear regression were used to evaluate independent factors that affect serum progesterone concentrations.

RESULTS

Age (odds ratio [OR] 0.93; 95% confidence interval [CI] 0.89-0.96), duration of oestradiol (OR 0.96; 95% CI 0.92-0.99), serum progesterone concentrations (OR 1.04; 95% CI 1.01-1.08) and patients who underwent preimplantation genetic testing for aneuploidies (PGT-A) (OR 2.17; 95% CI 1.55-3.03) were independently associated with LBR. After univariate analysis, determinants of progesterone concentrations were: age, weight, history of a previous cryopreserved embryo transfer with serum progesterone concentrations <10 ng/ml, and time of blood extraction. The multivariate linear regression showed that increasing age presented a positive correlation with progesterone concentrations (β = 0.11; 95% CI 0.01-0.20). On the contrary, significant negative correlations with progesterone concentrations were shown for a previous history of serum progesterone value <10 ng/ml (β = -3.13; 95% CI -4.45 to -1.81]), higher weight (β = -0.05; 95% CI -0.08 to -0.01) and the time of blood sampling during the day (β = -0.13; 95% CI -0.25 to -0.01).

CONCLUSIONS

This study adds more evidence regarding the importance of serum progesterone concentrations before frozen embryo transfer (FET). It also showed that body weight, age, time of blood sampling and a history of low progesterone are determinants associated with progesterone concentrations before blastocyst FET.

Challenges and innovations of drug delivery in older age

Both drug delivery performance and various age-related physical, mental and physiological changes can affect drug effectiveness and safety in elderly patients. The many drug delivery systems developed over the years include recent novel transdermal, nasal, pulmonary and orally disintegrating tablets that provide consistent, precise, timely and more targeted drug delivery. Certain drug delivery systems may be associated with suboptimal outcomes in the elderly because of the nature of drug present, a lack of appreciation of the impact of age-related changes in drug absorption, distribution and clearance, the limited availability of pharmacokinetic, safety and clinical data. Polypharmacy, patient morbidity and poor adherence can also contribute to sub-optimal drug delivery systems outcomes in the elderly. The development of drug delivery systems for the elderly is a poorly realised opportunity, with each system having specific advantages and limitations. A key challenge is to provide the innovation that best meets the specific physiological, psychological and multiple drug requirements of individual elderly patients.

Progesterone Modulation of Pregnancy-Related Immune Responses

Progesterone (P4) is an important steroid hormone for the establishment and maintenance of pregnancy and its functional withdrawal in reproductive tissue is linked with the onset of parturition. However, the effects of P4 on adaptive immune responses are poorly understood. In this study, we took a novel approach by comparing the effects of P4 supplementation longitudinally, with treatment using a P4 antagonist mifepristone (RU486) in mid-trimester pregnancies. Thus, we were able to demonstrate the immune-modulatory functions of P4. We show that, in pregnancy, the immune system is increasingly activated (CD38, CCR6) with greater antigen-specific cytotoxic T cell responses (granzyme B). Simultaneously, pregnancy promotes a tolerant immune environment (IL-10 and regulatory-T cells) that gradually reverses prior to the onset of labor. P4 suppresses and RU486 enhances antigen-specific CD4 and CD8 T cell inflammatory cytokine (IFN-γ) and cytotoxic molecule release (granzyme B). P4 and RU486 effectively modulate immune cell-mediated interactions, by regulating differentiated memory T cell subset sensitivity to antigen stimulation. Our results indicate that P4 and RU486, as immune modulators, share a reciprocal relationship. These data unveil key contributions of P4 to the modulation of the maternal immune system and suggests targets for future modulation of maternal immune function during pregnancy.

A randomised trial to compare 200 mg micronised progesterone effervescent vaginal tablet daily with 250 mg intramuscular 17 alpha hydroxy progesterone caproate weekly for prevention of recurrent preterm birth

For prevention of a recurrent preterm birth (PTB), intramuscular 17-α-hydroxy progesterone caproate (IM 17 OHPC) weekly is recommended. Vaginal progesterone is preferred for women at risk for PTB due to a short cervical length, but may be useful in women with a prior PTB. However, there is no consensus about the optimal vaginal formulation or its efficacy as compared to 17 OHPC to prevent recurrent PTB. We randomised 100 women with a singleton pregnancy between 16 and 24 weeks of gestation and ≥ one prior spontaneous PTB, of a singleton (>16 to <37 weeks of gestation) to receive the 200 mg vaginal progesterone effervescent tablet daily (Group A) or IM 17-OHPC, 250 mg weekly (Group B) till 37 weeks of gestation or delivery. The spontaneous PTB rate of <37 weeks was similar (20% in Group A and 20.8% in Group B, p =  .918). The PTB rate of <34 weeks or <28 weeks were also comparable. The mean birth weight and other neonatal outcomes were similar in the two groups. Two neonates in Group A and four neonates in Group B required NICU admission, one of whom (Group B) died due to prematurity. Twenty percent of women in Group A and 29.2% in Group B reported adverse effects from their respective study medications (p =  .408, NS). Thus, there did not appear to be a difference between vaginal progesterone and 17-OHPC when used for the prevention of a recurrent PTB. Impact statement What is already known on this subject? Progesterone administration is useful for prevention of a recurrent preterm birth (PTB) and these women are prescribed the intramuscular 17-α-hydroxy progesterone caproate (IM 17 OHPC), 250 mg, weekly. Some studies found that vaginal progesterone (once daily) is also beneficial in these women, but there is no consensus regarding its efficacy when compared to 17 OHPC, or its optimal formulation and dose. What do the results of this study add? In the present study, 100 women with a singleton pregnancy between 16 and 24 weeks of gestation and ≥ one prior spontaneous singleton PTB or mid-trimester abortion were randomised to receive 200 mg of vaginal progesterone effervescent tablet daily (Group A) or 250 mg IM 17-OHPC weekly (Group B) till 37 weeks of gestation or delivery. The spontaneous PTB rate <37 weeks was similar in the two groups (20% in Group A and 20.8% in Group B, p = .918). The PTB rate <34 weeks or <28 weeks were also comparable. The mean birth weight and other neonatal outcomes were similar. Twenty percent of women in Group A and 29.2% of women in Group B reported adverse effects from their respective study medications (p = .408, NS). Thus, there did not appear to be a difference between the vaginal progesterone effervescent tablet and 17-OHPC when used for the prevention of a recurrent PTB. What are the implications of these findings for clinical practice and/or further research? The vaginal progesterone effervescent tablet may be a suitable alternative to IM 17 OHPC to prevent recurrent PTB. Future studies should identify the most appropriate route (IM or vaginal) and vaginal progesterone formulation for PTB prevention in women at risk for a recurrent PTB and in women with a short cervical length.

A questionnaire-based audit to assess overall experience and convenience among patients using vaginal progesterone tablets (Lutigest®) for luteal phase support during IVF treatment

Purpose

The aim of this audit was to assess the overall experience and patient convenience of vaginal progesterone tablets (Lutigest^®, marketed as Endometrin^® in the USA) used for luteal phase support (LPS) during in vitro fertilization (IVF) treatment.

Patients and methods

This questionnaire-based audit included responses from 100 patients undergoing IVF treatment at six IVF clinics in the UK from September 2015 to November 2016. Fourteen days after starting progesterone supplementation for LPS during their IVF treatment, patients rated overall experience and perceived convenience of the prescribed progesterone by completing a questionnaire.

Results

Of the 100 patients included, 96 received vaginal progesterone tablets for LPS. Overall, 53.1% (51/96) indicated that the progesterone tablets were “very easy” to use; 42.7% (41/96) and 44.8% (43/96) found it “very convenient” or “neither convenient or inconvenient” to administer the tablet, respectively. Overall experience with using progesterone tablets was rated as “very comfortable” by 34.4% (33/96) and “neither comfortable or uncomfortable” by 56.3% (54/96) of patients. The applicator was used by 93.8% (90/96) of patients to administer the tablet, and 86.5% (83/96) indicated that the applicator was easy to clean for repeated use. A total of 33 patients had a previous IVF cycle during which they were prescribed vaginal progesterone pessaries for LPS. Compared with progesterone pessaries, the majority found treatment with progesterone tablets to be more comfortable (60.6%; 20/33) and more convenient (57.6%; 19/33) and indicated that the progesterone tablet was their preferred progesterone formulation for LPS (60.6%; 20/33).

Conclusion

These findings offer insights into real-world patient experiences with the progesterone vaginal tablet formulation. The results suggest overall patient convenience, ease, and comfort with using progesterone vaginal tablets for LPS. The majority of patients found progesterone vaginal tablets more convenient and comfortable to use compared with progesterone pessaries.

Strategies to prevent preterm birth

After several decades of research, we now have evidence that at least six interventions are suitable for immediate use in contemporary clinical practice within high-resource settings and can be expected to safely reduce the rate of preterm birth. These interventions involve strategies to prevent non-medically indicated late preterm birth; use of maternal progesterone supplementation; surgical closure of the cervix with cerclage; prevention of exposure of pregnant women to cigarette smoke; judicious use of fertility treatments; and dedicated preterm birth prevention clinics. Quantification of the extent of success is difficult to predict and will be dependent on other clinical, cultural, societal, and economic factors operating in each environment. Further success can be anticipated in the coming years as other research discoveries are translated into clinical practice, including new approaches to treating intra-uterine infection, improvements in maternal nutrition, and lifestyle modifications to ameliorate maternal stress. The widespread use of human papillomavirus vaccination in girls and young women will decrease the need for surgical interventions on the cervix and can be expected to further reduce the risk of early birth. Together, this array of clinical interventions, each based on a substantial body of evidence, is likely to reduce rates of preterm birth and prevent death and disability in large numbers of children. The process begins with an acceptance that early birth is not an inevitable and natural feature of human reproduction. Preventative strategies are now available and need to be applied. The best outcomes may come from developing integrated strategies designed specifically for each health-care environment.

Testosterone and progesterone, but not estradiol, stimulate muscle protein synthesis in postmenopausal women

CONTEXT

The effect of the female sex steroids, estradiol and progesterone, on muscle protein turnover is unclear. Therefore, it is unknown whether the changes in the hormonal milieu throughout the life span in women contribute to the changes in muscle protein turnover and muscle mass (eg, age associated muscle loss).

OBJECTIVE

The objective of this study was to provide a comprehensive evaluation of the effect of sex hormones on muscle protein synthesis and gene expression of growth-regulatory factors [ie, myogenic differentiation 1 (MYOD1), myostatin (MSTN), follistatin (FST), and forkhead box O3 (FOXO3)].

SUBJECTS AND DESIGN

We measured the basal rate of muscle protein synthesis and the expression of muscle growth-regulatory genes in 12 premenopausal women and four groups of postmenopausal women (n=24 total) who were studied before and after treatment with T, estradiol, or progesterone or no intervention (control group). All women were healthy, and pre- and postmenopausal women were carefully matched on body mass, body composition, and insulin sensitivity.

RESULTS

The muscle protein fractional synthesis rate was approximately 20% faster, and MYOD1, FST, and FOXO3 mRNA expressions were approximately 40%-90% greater (all P<.05) in postmenopausal than premenopausal women. In postmenopausal women, both T and progesterone treatment increased the muscle protein fractional synthesis rate by approximately 50% (both P<.01), whereas it was not affected by estradiol treatment and was unchanged in the control group. Progesterone treatment increased MYOD1 mRNA expression (P<.05) but had no effect on MSTN, FST, and FOXO3 mRNA expression. T and estradiol treatment had no effect on skeletal muscle MYOD1, MSTN, FST, and FOXO3 mRNA expression.

CONCLUSION

Muscle protein turnover is faster in older, postmenopausal women compared with younger, premenopausal women, but these age-related differences do not appear to be explained by the age- and menopause-related changes in the plasma sex hormone milieu.

The role of progesterone in prevention of preterm birth

Preterm birth continues to provide an enormous challenge in the delivery of perinatal health care, and is associated with considerable short and long-term health consequences for surviving infants. Progesterone has a role in maintaining pregnancy, by suppression of the calcium-calmodulin-myosin light chain kinase system. Additionally, progesterone has recognized anti-inflammatory properties, raising a possible link between inflammatory processes, alterations in progesterone receptor expression and the onset of preterm labor. Systematic reviews of randomized controlled trials evaluating the use of intramuscular and vaginal progesterone in women considered to be at increased risk of preterm birth have been published, with primary outcomes of perinatal death, preterm birth <34 weeks, and neurodevelopmental handicap in childhood. Eleven randomized controlled trials were included in the systematic review, involving 2714 women and 3452 infants, with results presented according to the reason women were considered to be at increased risk of preterm birth. While there is a potential beneficial effect in the use of progesterone for some women considered to be at increased risk of preterm birth, primarily in the reduction in the risk of preterm birth before 34 weeks gestation, it remains unclear if the observed prolongation of pregnancy translates into improved health outcomes for the infant.

Drug delivery for in vitro fertilization: rationale, current strategies and challenges

In vitro fertilization has experienced phenomenal progress in the last thirty years and awaits the additional refinement and enhancement of medication delivery systems. Opportunity exists for the novel delivery of gonadotropins, progesterone and other adjuvants. This review highlights the rationale for various medications, present delivery methods and introduces the status of novel ideas and possibilities.

Luteal Phase Support in assisted reproductive technology treatment: focus on Endometrin(R) (progesterone) vaginal insert

Supplementation of progesterone in the luteal phase and continuance of progesterone therapy during the first trimester has been found in several studies to have benefits in promoting fertility, preventing miscarriages and even preventing pre-term labor. Though it can be administered orally, intramuscularly or even sublingually, a very effective route with fewer side effects can be achieved by an intravaginal route. The first vaginal preparations were not made commercially but were compounded by pharmacies. This had the disadvantage of lack of control by the Food and Drug Administration (FDA) ensuring efficacy of the preparations. Furthermore there was a lack of precise dosing leading to batch to batch variation. The first commercially approved vaginal progesterone preparation in the United States was a vaginal gel which has proven very effective. The main side effect was accumulation of a buildup of the vaginal gel sometimes leading to irritation. Natural micronized progesterone for vaginal administration with the brand name of Utrogestan A^® had been approved even before the gel in certain European countries. Endometrin^® vaginal tablets are the newest natural progesterone approved by the FDA. Comparisons to the vaginal gel and to intramuscular progesterone have shown similar efficacy especially in studies following controlled ovarian hyperstimulation and oocyte egg retrieval and embryo transfer. Larger studies are needed to compare side effects.

A randomized comparison of side effects and patient convenience between Cyclogest suppositories and Endometrin tablets used for luteal phase support in IVF treatment

OBJECTIVE

This study compared side effects and patient convenience of vaginal progesterone suppositories (Cyclogest) and vaginal progesterone tablets (Endometrin) used for luteal phase support in in vitro fertilization/embryo transfer (IVF/ET) cycles using pituitary downregulation.

STUDY DESIGN

One hundred and thirty-two infertile patients were randomized on the day of ET by a computer-generated randomization list in sealed envelopes to receive either Cyclogest 400mg or Endometrin 100mg twice daily for 14 days. On days 6 and 16 after ET, they rated side effects and patient convenience into four grades: none, mild, moderate and severe by completing a questionnaire.

RESULTS

No significant differences in perineal irritation were found on days 6 and 16 after ET between the two groups, although there was a trend of fewer patients with perineal irritation in the Endometrin group. Significantly more patients in the Endometrin group had difficulty of administration on day 6 after ET. There were no differences in the hormonal profile on day 6 after ET and IVF outcomes between the two groups.

CONCLUSION

There was no difference in perineal irritation after the use of Cyclogest suppositories or Endometrin tablets for luteal phase support although more patients found administration of Endometrin tablets difficult.

Progesterone supplementation for preventing preterm birth: a systematic review and meta-analysis

AIM

The aim of this study is to assess the role of progesterone in preterm birth prevention.

METHODS

A MEDLINE search (from 1966 to the present; date of last search January 2005) was performed - using the key words progesterone, pregnancy, preterm birth, preterm labor, and randomized, controlled trial - in order to identify randomized, controlled trials in which progesterone (either intramuscular or vaginal administration) was compared with placebo or no treatment. Data were extracted and a meta-analysis was performed.

RESULTS

Seven randomized, controlled trials were identified. Women who received progesterone were statistically significantly less likely to give birth before 37 weeks (seven studies, 1020 women, RR = 0.58, 95% CI = 0.48-0.70), to have an infant with birth weight of < or =2.5 kg (six studies, 872 infants, RR = 0.62, 95% CI = 0.49-0.78), or to have an infant diagnosed with intraventricular hemorrhage (one study, 458 infants, RR = 0.25, 95% CI = 0.08-0.82).

CONCLUSIONS

For progesterone supplementation to be advocated for women at the risk of preterm birth, the prolongation of gestation demonstrated in this meta-analysis must translate into improved infant outcomes, including a reduction in mortality. There is currently insufficient information to allow recommendations regarding the optimal dose, route, and timing of administration of progesterone supplementation.

The transport of chemicals in semen

Three mechanisms have been proposed for exposure of the conceptus to chemicals in semen: access of chemicals to the maternal circulation after absorption from the vagina, direct chemical exposure of the conceptus following transport from the vagina to the uterine cavity, and delivery to the egg and subsequent conceptus of chemical bound to the sperm cell. We review published data for each of these three mechanisms. Human seminal fluid chemical concentrations are typically similar to or lower than blood concentrations, although some antimicrobial agents achieve higher concentrations in semen than in blood. Vaginal absorption of medications has been shown to occur, although the vehicles in which these medications are delivered to the vagina may maintain contact with the vaginal epithelium to a greater extent than does semen. Assuming total absorption of a seminal dose of a chemical with a high semen:blood concentration ratio, distribution within the recipient woman would result in a blood concentration at least three orders of magnitude lower than that in the man. Direct delivery of seminal chemicals into the uterine cavity of humans has not been shown to occur, although it may occur in species such as the rat in which seminal fluid has access to the uterine cavity. Chemicals in or on human sperm cells have been demonstrated with respect to tetracycline and cocaine in vitro and aluminum, lead, and cadmium in vivo. The in vitro cocaine study offers sufficiently quantitative data with which to predict that oocyte concentrations would be five orders of magnitude lower than blood concentrations associated with cocaine abuse, assuming a maximally cocaine-bound sperm were capable of fertilizing. Thus, even using liberal assumptions about transmission of chemicals in semen or sperm, predicted exposure levels of a pregnant woman or of the conceptus are three or more orders of magnitude lower than blood concentrations in the man whose semen is the putative vehicle for chemical transport.

Predictive Models of CYP3A4 Heteroactivation: In Vitro-in Vivo Scaling and Pharmacophore Modeling

Although activation of CYP3A4 is frequently observed in vitro, predictive computational-based models and methods for in vitro-in vivo scaling are scarce. It has been previously shown that in vitro CYP3A4 heteroactivation of carbamazepine (CBZ)-epoxide (ep) formation can be associated with the clinical drug interaction between felbatame and CBZ. The previously reported prediction methodology is applied here to an additional set of in vitro CYP3A4 heteroactivators, some exerting this effect at concentrations relevant in vivo. The antimalarial artemisinin potently increases CBZ-ep formation by a maximum of 500% at 300 microM. Testosterone and progesterone activates by a maximum of 1680 and 920%, respectively, at 150 microM, and quinidine causes a 130% increase at 300 microM. The predicted maximum in vivo decrease in steady-state concentration of carbamazepine (Css(CBZ)) at saturating effector concentrations is 85 to 90% for testosterone and progesterone, 75% for artemisinin, and 45% for quinidine. The corresponding predicted in vivo increase in Css(CBZ-ep) is 50, 60, 55, and 30% for artemisinin, testosterone, progesterone, and quinidine, respectively. At effector concentrations relevant in vivo, the Css(CBZ) change is predicted to </=20% for testosterone, artemisinin, and quinidine and </=10% for progesterone, with a concomitant Css(CBZ-ep) increase of 12% for testosterone and </=10% for progesterone, artemisinin, and quinidine. Structure-heteroactivation relationships were evaluated by generating a pharmacophore. The model includes two hydrogen bond acceptor features separated by hydrophobic features. Internal predictivity is high, and heteroactivation of an external test set correlate to observed in vitro heteroactivation.

A randomised comparison of side effects and patient inconvenience of two vaginal progesterone formulations used for luteal support in in vitro fertilisation cycles

OBJECTIVE

To compare side effects and patient inconvenience of two vaginal progesterone (P) formulations for luteal support in in vitro fertilisation cycles.

STUDY DESIGN

Sixty infertile patients at risk of developing ovarian hyperstimulation syndrome were randomised to receive either Cyclogest vaginal suppositories 400mg twice daily or Crinone 8% vaginal gel once daily for 14 days as the luteal support. On Day 6 and Day 16 after embryo transfer, they rated side effects and patient inconvenience into four grades: none, mild, moderate and severe by completing a questionnaire.

RESULTS

Perineal irritation was reported by about 20% of patients in each group. Significantly more patients using Cyclogest suppositories graded inconvenience of administration, leaking out and interference with coitus as moderate or severe.

CONCLUSION

There was no difference in perineal irritation after Cyclogest suppositories or Crinone 8% gel although significantly more patients found inconvenience of administration, leaking out and interference with coitus after Cyclogest.