Progesterone supplementation in natural cycles improves live birth rates after embryo transfer of frozen-thawed embryos-a randomized controlled trial

STUDY QUESTION

Does supplementation with vaginal tablets of progesterone after frozen-thawed embryo transfer in natural cycles improve the live birth rate?

SUMMARY ANSWER

Supplementation with vaginal tablets of progesterone after frozen-thawed embryo transfer in natural cycles significantly improves the number of live births.

WHAT IS KNOWN ALREADY

Progesterone supplementation during luteal phase and early pregnancy may improve the number of live births after frozen-thawed embryo transfer. However, due to the limited number of previous studies, being mainly retrospective, evidence is still limited.

STUDY DESIGN, SIZE, DURATION

This is a prospective randomized controlled trial, performed at two university clinics. In total, 500 subjects were randomized with a 1:1 allocation into two groups, during the period February 2013 to March 2018. Randomization was performed after a frozen embryo transfer in a natural cycle by use of opaque sealed envelopes. The primary outcome was live birth rate; secondary outcomes were pregnancy, biochemical pregnancy, clinical pregnancy and miscarriage rate, and if there was a possible association between the serum progesterone concentration on the day of embryo transfer and live birth rate.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women, receiving embryo transfer in natural cycles participated in the study. The embryos were frozen on Day 2, 3, 5 or 6. In total, 672 women having regular menstrual cycles were invited to participate in the study; of those, 500 agreed to participate and 488 were finally included in the study. Half of the study subjects received progesterone supplementation with progesterone vaginal tablets, 100 mg twice daily, starting from the day of embryo transfer. The other half of the subjects were not given any treatment. Blood samples for serum progesterone measurements were collected from all subjects on the day of embryo transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

There were no differences in background characteristics between the study groups. In the progesterone supplemented group, 83 of 243 patients (34.2%) had a live birth, compared to 59 of 245 patients (24.1%) in the control group (odds ratio 1.635, 95% CI 1.102–2.428, P = 0.017*). The number of pregnancies was 104 of 243 (42.8%) and 83 of 245 (33.9%), respectively (odds ratio 1.465, 95% CI 1.012–2.108, P = 0.049*) and the number of clinical pregnancies was 91 of 243 (37.4%) and 70 of 245 (28.6%), respectively (odds ratio 1.497, 95% CI 1.024–2.188, P = 0.043*). There were no significant differences in biochemical pregnancy rate or miscarriage rate. There was no correlation between outcome and serum progesterone concentration.

LIMITATIONS, REASONS FOR CAUTION

The study was not blinded because placebo tablets were not available. Supplementation started on embryo transfer day, regardless of the age of the embryos, which resulted in a shorter supplementation time for Day 5/6 embryos compared to Day 2/3 embryos.

WIDER IMPLICATIONS OF THE FINDINGS

Supplementation with progesterone in natural cycles improved the number of live births after frozen-thawed embryo transfer and should therefore be considered for introduction in clinical routine.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Uppsala University, the Uppsala-Family Planning Foundation, and Ferring Pharmaceuticals AB, Malmö, Sweden. The authors have no personal conflicting interests to declare.

TRIAL REGISTRATION NUMBER

NL4152.

TRIAL REGISTRATION DATE

5 December 2013.

DATE OF FIRST PATIENT’S ENROLMENT

18 February 2013.

No evidence for mutations in NLRP7, NLRP2 or KHDC3L in women with unexplained recurrent pregnancy loss or infertility

STUDY QUESTION

Are mutations in NLRP2/7 (NACHT, LRR and PYD domains-containing protein 2/7) or KHDC3L (KH Domain Containing 3 Like) associated with recurrent pregnancy loss (RPL) or infertility?

SUMMARY ANSWER

We found no evidence for mutations in NLRP2/7 or KHDC3L in unexplained RPL or infertility.

WHAT IS KNOWN ALREADY

Mutations in NLRP7 and KHDC3L are known to cause biparental hydatidiform moles (BiHMs), a rare form of pregnancy loss. NLRP2, while not associated with the BiHM pathology, is known to cause recurrent Beckwith Weidemann Syndrome (BWS).

STUDY DESIGN, SIZE, AND DURATION

Ninety-four patients with well characterized, unexplained infertility were recruited over a 9-year period from three IVF clinics in Sweden. Blood samples from 24 patients with 3 or more consecutive miscarriages of unknown etiology were provided by the Recurrent Miscarriage Clinic at St Mary's Hospital, London, UK.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients were recruited into both cohorts following extensive clinical studies. Genomic DNA was isolated from peripheral blood and subject to Sanger sequencing of NLRP2, NLRP7 and KHDC3L. Sequence electropherograms were analyzed by Sequencher v5.0 software and variants compared with those observed in the 1000 Genomes, single nucleotide polymorphism database (dbSNP) and HapMap databases. Functional effects of non-synonymous variants were predicted using Polyphen-2 and sorting intolerant from tolerant (SIFT).

MAIN RESULTS AND THE ROLE OF CHANCE

No disease-causing mutations were identified in NLRP2, NLRP7 and KHDC3L in our cohorts of unexplained infertility and RPL.

LIMITATIONS, REASONS FOR CAUTION

Due to the limited patient size, it is difficult to conclude if the low frequency single nucleotide polymorphisms observed in the present study are causative of the phenotype. The design of the present study therefore is only capable of detecting highly penetrant mutations.

WIDER IMPLICATIONS OF THE FINDINGS

The present study supports the hypothesis that mutations in NLRP7 and KHDC3L are specific for the BiHM phenotype and do not play a role in other adverse reproductive outcomes. Furthermore, to date, mutations in NLRP2 have only been associated with the imprinting disorder BWS in offspring and there is no evidence for a role in molar pregnancies, RPL or unexplained infertility.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the following sources: Estonian Ministry of Education and Research (Grant SF0180044s09), Enterprise Estonia (Grant EU30020); Mentored Resident research project (Department of Obstetrics and Gynecology, Baylor College of Medicine); Imperial NIHR Biomedical Research Centre; Grant Number C06RR029965 from the National Center for Research Resources (NCCR; NIH). No competing interests declared.

Folic acid supplementation and IVF pregnancy outcome in women with unexplained infertility

Folic acid supplements are commonly used by infertile women which leads to a positive folate status. However, the effect of folic acid supplements on pregnancy outcome in women with unexplained infertility has not been well investigated. This study evaluated folic acid supplement use and folate status in women with unexplained infertility in relation to IVF pregnancy outcome. In addition, use of folic acid supplements and folate status were compared between women with unexplained infertility and fertile, nonpregnant control women. Women with unexplained infertility used significantly more folic acid supplements and had higher median total folic acid intake from supplements compared with fertile control women (both P < 0.001). Women with unexplained infertility also had significantly higher median plasma folate and lower median plasma homocysteine concentrations than fertile women (both P < 0.001), but folic acid supplementation or folate status were not related to pregnancy outcome in women with unexplained infertility. In conclusion, folic acid supplementation or good folate status did not have a positive effect on pregnancy outcome following infertility treatment in women with unexplained infertility. Folate is one of the B vitamins which has been suggested to be related to infertility. Folic acid is an artificial form of folate which is commonly used in dietary supplements. Folic acid supplementation has been shown to increase folate concentrations and decrease concentrations of the amino acid homocysteine in the blood. Folic acid supplementation is commonly used by infertile women, but the effect on pregnancy outcome in women with a diagnosis of unexplained infertility has not been thoroughly investigated. In the present study, folic acid supplement use and folate status (concentrations of folate and homocysteine) in women with unexplained infertility were evaluated in relation to pregnancy outcome. In addition, the use of folic acid supplements and folate status were compared between women with unexplained infertility and fertile control women. Our results showed that women with unexplained infertility used considerably more folic acid supplements and had higher total folic acid intake from supplements compared with fertile control women. Women with unexplained infertility had better blood folate and homocysteine concentrations than fertile women, but folic acid supplementation or folate status were not related to pregnancy outcome following the infertility treatment. In conclusion, high folic acid intake or good folate status did not increase the possibility of a birth of a healthy baby after infertility treatment in women with unexplained infertility.

Endometrial gene expression analysis at the time of embryo implantation in women with unexplained infertility

Successful embryo implantation depends on the quality of the embryo, as well as on the receptivity of the endometrium. The aim of this study was to investigate the endometrial gene expression profile in women with unexplained infertility in comparison with fertile controls at the time of embryo implantation in order to find potential predictive markers of uterine receptivity and to identify the molecular mechanisms of infertility. High-density oligonucleotide gene arrays, comprising 44 000 gene targets, were used to define the endometrial gene expression profile in infertile (n = 4) and fertile (n = 5) women during the mid-secretory phase (day LH + 7). Microarray results were validated using real-time PCR. Analyses of expression data were carried out using non-parametric methods. Hierarchical clustering and principal component analysis showed a clear distinction in endometrial gene expression between infertile and fertile women. In total we identified 145 significantly (>3-fold change) up-regulated and 115 down-regulated genes in infertile women versus controls. Via Database for Annotation, Visualization and Integrated Discovery functional analysis we detected a substantial number of dysregulated genes in the endometria of infertile women, involved in cellular localization (21.1%) and transport (18.8%) and transporter activity (13.1%) and with major localization in extracellular regions (19.2%). Ingenuity Pathways Analysis of the gene list showed dysregulation of gene pathways involved in leukocyte extravasation signalling, lipid metabolism and detoxification in the endometria of infertile women. In conclusion, endometrial gene expression in women with unexplained infertility at the time of embryo implantation is markedly different from that in fertile women. These results provide new information on genes and pathways that may have functional significance as regards to endometrial receptivity and subsequent embryo implantation.

Vitrification with DMSO protects embryo membrane integrity better than solutions without DMSO

Vitrification has become common for cryopreservation of embryos. However, the most optimal protocol for vitrification is still to be found. Two vitrification protocols with similar osmolarities were compared: Protocol A, containing dimethyl sulphoxide (DMSO), propane-2-diol, and ethylene glycol, and Protocol B, containing propane-2-diol and ethylene glycol. Viability and the importance of specific incubation times for early embryo recovery, survival, and cleavage were studied. For assessment of cryodamage, embryos were labelled with Alexa Fluor 488-conjugated annexin V and propidium iodide. Vitrification studies on early mouse embryos were followed up with studies on human embryos. The two vitrification protocols did not differ in embryo survival rates and were equally efficient in both mouse and human embryo models. Morphological assessment of embryos directly after vitrification was not a useful tool for assessing survival in this study. Extended exposure of embryos with both vitrification protocols showed that the DMSO-containing vitrification solutions did not lead to cell membrane damage and death as quickly as the DMSO-free vitrification solutions. To assess embryo viability, the authors recommend that vitrification of early embryos should be combined with extended culture and assessment of normal blastocyst development before transferring to patients.

Regulation of muscular contractions in the human Fallopian tube through prostaglandins and progestagens

BACKGROUND

Transport of gametes and embryos is an important function of the Fallopian tube. Both muscular contractions and cilia activity are involved in the transportation. Prostaglandins (PGs) are known mediators of muscular contractility. PG receptors have previously been demonstrated in the human Fallopian tube. The aim was to study the effect of PGs and progestagens, antiprogestin, hCG and oxytocin on muscular contractions in the human Fallopian tube, and the hormonal regulation of PG receptors.

METHODS

Twenty-two healthy women operated for benign causes were included in the study. The ampullary-isthmic junction of the Fallopian tubes was excised and used for in vitro contractility studies. The effect of PGE(1), PGE(2), PGF(2alpha), progesterone, mifepristone, levonorgestrel, oxytocin and hCG on contractility was studied. Explants of Fallopian tubes were cultured for 24 h to study the effect of progestagens and hCG on the expression of PG receptors using immunohistochemistry and real-time PCR.

RESULTS

Muscular contractions increased after treatment with PGF(2alpha) and PGE(2) (P < 0.05). The contractions decreased after PGE(1), progesterone, levonorgestrel, mifepristone, oxytocin and hCG (P < 0.05). In tubal explant studies, relative mRNA expression of EP1, EP2, EP3 and FP increased after levonorgestrel treatment (P < 0.05). Mifepristone and levonorgestrel treatment increased immunostaining intensity of EP1 and EP2 protein, in lumen, muscle and vessels. Progesterone and mifepristone increased immunostaining of FP in vessels.

CONCLUSIONS

These data suggest that the transport of gametes and embryos involves the action of PGs, progesterone, oxytocin and hCG on muscular contractility.

Mifepristone, but not levonorgestrel, inhibits human blastocyst attachment to an in vitro endometrial three-dimensional cell culture model

BACKGROUND

The use of fertility regulating drugs is limited among various socio-ethnic groups due to limited knowledge about their mechanism of action. This study investigates the effect of levonorgestrel and mifepristone on attachment of human embryos to an in vitro endometrial construct.

METHOD

Three-dimensional endometrial constructs were established by co-culturing early luteal phase human endometrial stromal and epithelial cells. Expression of endometrial receptivity markers in this construct were examined by immunohistochemistry. Effects of mifepristone and levonorgestrel on viability and attachment of human blastocysts were investigated.

RESULTS

Endometrial constructs expressed the factors involved in endometrial receptivity: estrogen receptor, progesterone receptor, vascular endothelial growth factor, leukemia inhibitory factor, interleukin-1, COX-2, MUC-1 and integrin-alpha(V)beta(3). None of the 15 embryos cultured with mifepristone attached to the endometrial construct (P < 0.01), whereas 10/17 in control, and 6/14 in levonorgestrel, groups attached. The attachment was confirmed by the positive expression of cytokeratin 7 at the attachment site.

CONCLUSION

Mifepristone inhibits blastocyst attachment. Levonorgestrel did not impair the attachment of human embryos to the in vitro endometrial construct. This model could be used to understand endometrial receptivity and embryo-endometrial dialog and to develop new fertility regulating substances.

Leukaemia inhibitory factor receptor and gp130 in the human Fallopian tube and endometrium before and after mifepristone treatment and in the human preimplantation embryo

Leukaemia inhibitory factor (LIF) is a cytokine, which is associated with reproductive processes such as embryo development and implantation. The objectives of this study were to detect the presence of LIF receptor (LIFR) and glycoprotein 130 (gp 130) in the human Fallopian tube, endometrium and preimplantation embryo and to study the effect of mifepristone on the expression of LIFR and gp130 in the Fallopian tube. Twenty-two healthy fertile women received a single dose of 200 mg mifepristone or placebo immediately after ovulation (LH + 2). Biopsies were obtained from the Fallopian tubes during laparoscopic sterilization once between days LH + 4 and LH + 6 and from endometrium once between days LH + 6 and LH + 8. Preimplantation embryos were received from couples undergoing in vitro fertilization treatment. Immunohistochemistry was used to detect the presence of LIFR and gp130 in the Fallopian tube, endometrium and preimplantation embryo. Real-time PCR was used to study LIFR and gp130 expression in the Fallopian tube and endometrium. LIFR and gp130 were localized in the Fallopian tube, preimplantation embryo and endometrium. LIFR was more abundant in the Fallopian tube than in the endometrium. In the blastocyst, the staining of gp130 was mainly localized in the inner cell mass, whereas LIFR was expressed in all cells. The presence of LIFR and gp130 in the Fallopian tube and preimplantation embryo indicates a role for LIF in communication between the embryo and the Fallopian tube. Mifepristone did not affect the expression of LIFR and gp130 in the Fallopian tube, nor in the endometrium suggesting that progesterone might not be directly involved in the regulation of LIFR or gp130.

Prostaglandin E2 and F2alpha receptors in the human Fallopian tube before and after mifepristone treatment

Prostaglandins are associated with several reproductive processes in addition to their effects on the vascular system and muscular contractility. The aim of this study was to gain information about the localization of the receptors for PGE(2) (EP1-EP4) and PGF(2alpha) (FP) in the human Fallopian tube and their regulation following treatment with mifepristone. Sixteen healthy fertile women received a single dose of 200 mg mifepristone or placebo immediately after ovulation (LH+2). Laparoscopic sterilization was performed on days LH+4 to LH+6. Biopsies were taken from the Fallopian tubes bilaterally. The expression of EP1, EP2, EP3, EP4 and FP was analysed using immunohistochemistry and RT-PCR. The co-localization of prostaglandin receptors and c-kit or e-nos was analysed using confocal microscopy. The effect of progesterone, mifepristone and prostaglandin on tubal contractility was studied. The presence of EP1-EP4 and FP in the Fallopian tube was detected using immunostaining. The receptors were expressed in serosal cells, luminal epithelial cells, and the muscular wall and vessels of the Fallopian tube. Co-localization studies showed that the endothelial cells stained positive for EP1-EP4 and FP and that co-localization was seen for EP4 and c-kit. Decreased contractility was seen after progesterone treatment, whereas increased contractility was seen after PGF(2alpha) and PGE(2) treatment. These data suggest that both the transport of the embryo and the communication between the embryo and the Fallopian tube involve the action of prostaglandins through EP and FP receptors in addition to the effect of prostaglandins on the vascular system and muscular contractility.

Implantation of the human embryo: research lines and models. From the implantation research network 'Fruitful'

Infertility is an increasing problem all over the world, and it has been estimated that 10-15% of couples in fertile age have fertility problems. Likewise induced unsafe abortion is a serious threat to women's health. Despite advances made in assisted reproduction techniques, little progress has been made in increasing the success rate during fertility treatment. This document describes a wide range of projects carried out to increase the understanding in the field of embryo implantation research. The 'Fruitful' research network was created to encourage collaborations within the consortium and to describe our different research potentials to granting agencies or private sponsors.

Effect of mifepristone on the expression of cytokines in the human Fallopian tube

Cytokines are believed to play a critical role as mediators between the oviduct and the developing embryo. A synchronous development of embryo and endometrium is essential to successful implantation. It seems to be beneficial for embryo development to rest for some time in the Fallopian tube. Expression of cytokines in the human Fallopian tube and the effect of mifepristone were investigated. Fourteen women with regular menstrual cycles and proven fertility, admitted to the hospital for tubal ligation, were randomly allocated to control or treatment groups. Mifepristone 200 mg was given on day LH+2. Surgery was performed on day LH+3 to LH+5. Biopsies were obtained from the ampullar and isthmic regions of the tubes. Expression of interleukin 8 (IL-8), tumour necrosis factor alpha (TNFalpha), transforming growth factor beta (TGFbeta) and leukaemia inhibitory factor (LIF) was analysed using immunohistochemistry. All cytokines except IL-8 showed the same staining intensity both in the ampullar and isthmic region, while IL-8 was more pronounced in the ampullar region in both epithelial and stromal cells. Exposure to mifepristone made the spatial difference in IL-8 disappear and increased the expression of TNFalpha in the epithelium of the isthmus, but had no effect on the expression of TGFbeta1 or LIF. Changes in cytokine expression in the Fallopian tube are likely to influence embryo development, which could contribute to the contraceptive effect of mifepristone.

Formation of pinopodes in human endometrium is associated with the concentrations of progesterone and progesterone receptors

OBJECTIVE

To investigate the relation between the development of endometrial pinopodes and the serum concentration of hormones and the distribution of estrogen receptor-alpha, estrogen receptor-beta, progesterone receptor A, and progesterone receptor B.

DESIGN

Prospective clinical study.

SETTING

Hospital-based unit of reproductive health and university-affiliated reproductive research laboratories.

PATIENT(S)

Twenty-seven healthy fertile women with normal menstrual cycles.

INTERVENTION(S)

Urine and blood sampling for hormone measurement, vaginal ultrasonography, and endometrial biopsy.

MAIN OUTCOME MEASURE(S)

Appearance of the endometrium on light microscopy, pinopode formation, serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), and expression of progesterone receptors A and B and estrogen receptors alpha and beta.

RESULT(S)

Pinopode formation and regression were closely associated with increases and decreases, respectively, in serum progesterone concentration. At pinopode development, levels progesterone receptors A and B in the glandular and luminal epithelial cells decreased; this effect was mainly dependent on the absence of progesterone receptor B. Serum estrogen levels and levels of estrogen receptor alpha and beta did not correlate with pinopode formation.

CONCLUSION(S)

The increase in serum progesterone level and down-regulation of progesterone receptor B are important in development of pinopodes.

A new method to study the process of implantation of a human blastocyst in vitro

OBJECTIVES

To develop a "miniorgan" culture of human endometrium dated according to the LH peak in order to study the process of implantation of a human blastocyst in vitro.

DESIGN

Preliminary results of a more extensive study with the same objectives.

SETTING

Hospital-based unit of reproductive health and university-related reproductive research laboratories.

PATIENTS

Six apparently healthy women with normal regular menstrual cycles providing endometrial material 4, 5 and 6 days after the LH peak.

INTERVENTION

One part of the biopsy was used for histologic dating. The other part was incubated in culture medium RPMI-1640 and exposed to the contact with one to three embryos fertilized in vitro.

MAIN OUTCOME MEASURE

Biopsy material before and after incubation was studied by morphometric methods in a light microscope. The histologic changes were recorded by photomicrographs.

RESULTS

Implantation of an embryo obtained 4 days after IVF penetrated the lining endometrial epithelium of a biopsy obtained 4 days after the LH peak and kept in vitro for 24 hours. The embryo was placed on the lining epithelium of the endometrium within 3 hours after the biopsy was taken.

CONCLUSION

A new method to study the process of implantation of a human embryo in vitro has been described, allowing the embryo to penetrate the lining endometrial epithelium in a biopsy obtained at LH +4/+5.

Induction of the estrogen receptor by growth hormone and glucocorticoid substitution in primary cultures of rat hepatocytes

Hepatic estrogen receptors (ER) mediate estrogenic effects on mammalian liver metabolism and are thereby involved in the regulation of important physiological/pathological processes, such as coagulation, atherosclerosis, and hypertension. The regulation of the formation of the ER in primary cultures of rat hepatocytes was studied by assaying ER and ER mRNA under different endocrine conditions. The ER concentration was measured using two different methods, a ligand-binding technique and an ER enzyme immunoassay. The results obtained by the two methods showed good correlation, and linear regression analysis gave a correlation coefficient of 0.95. ER concentrations fell to low steady state levels within 16 h after establishing the cell culture and remained low in the absence of hormonal substitution. Upon medium supplementation with pituitary GH and the glucocorticoid dexamethasone (DEX) in combination, the ER concentration increased 6-fold from 4.2 +/- 1.0 to 25.8 +/- 7.0 fmol/mg cytosolic protein. ER mRNA was measured by solution hybridization. Substitution with GH and DEX in combination increased ER mRNA to 210 +/- 14% of control levels. No effect on ER mRNA stability was seen after hormone treatment. It is concluded that the regulatory effects of GH and DEX on the hepatic ER in this in vitro system are very similar to the effects of these hormones under in vivo conditions. The inducible expression of the ER has never before, to our knowledge, been demonstrated in any mammalian liver cell culture system.