Predictors of pregnancy success in repeated miscarriage

A nomogram and risk stratification to predict subsequent pregnancy loss in patients with recurrent pregnancy loss

STUDY QUESTION

Could the risk of subsequent pregnancy loss be predicted based on the risk factors of recurrent pregnancy loss (RPL) patients?

SUMMARY ANSWER

A nomogram, constructed from independent risk factors identified through multivariate logistic regression, serves as a reliable tool for predicting the likelihood of subsequent pregnancy loss in RPL patients.

WHAT IS KNOWN ALREADY

Approximately 1-3% of fertile couples experience RPL, with over half lacking a clear etiological factor. Assessing the subsequent pregnancy loss rate in RPL patients and identifying high-risk groups for early intervention is essential for pregnancy counseling. Previous prediction models have mainly focused on unexplained RPL, incorporating baseline characteristics such as age and the number of previous pregnancy losses, with limited inclusion of laboratory and ultrasound indicators.

STUDY DESIGN, SIZE, DURATION

The retrospective study involved 3387 RPL patients who initially sought treatment at the Reproductive Immunology Clinic of Renji Hospital, Shanghai Jiao Tong University School of Medicine, between 1 January 2020 and 31 December 2022. Of these, 1153 RPL patients met the inclusion criteria and were included in the analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RPL was defined as two or more pregnancy losses (including biochemical pregnancy loss) with the same partner before 28 weeks of gestation. Data encompassing basic demographics, laboratory indicators (autoantibodies, peripheral immunity coagulation, and endocrine factors), uterine and endometrial ultrasound results, and subsequent pregnancy outcomes were collected from enrolled patients through initial questionnaires, post-pregnancy visits fortnightly, medical data retrieval, and telephone follow-up for lost patients. R software was utilized for data cleaning, dividing the data into a training cohort (n = 808) and a validation cohort (n = 345) in a 7:3 ratio according to pregnancy success and pregnancy loss. Independent predictors were identified through multivariate logistic regression. A nomogram was developed, evaluated by 10-fold cross-validation, and compared with the model incorporating solely age and the number of previous pregnancy losses. The constructed nomogram was evaluated using the AUC, calibration curve, decision curve analysis (DCA), and clinical impact curve analysis (CICA). Patients were then categorized into low- and high-risk subgroups.

MAIN RESULTS AND THE ROLE OF CHANCE

We included age, number of previous pregnancy losses, lupus anticoagulant, anticardiolipin IgM, anti-phosphatidylserine/prothrombin complex IgM, anti-double-stranded DNA antibody, arachidonic acid-induced platelet aggregation, thrombin time and the sum of bilateral uterine artery systolic/diastolic ratios in the nomogram. The AUCs of the nomogram were 0.808 (95% CI: 0.770-0.846) in the training cohort and 0.731 (95% CI: 0.660-0.802) in the validation cohort, respectively. The 10-fold cross-validated AUC ranged from 0.714 to 0.925, with a mean AUC of 0.795 (95% CI: 0.750-0.839). The AUC of the nomogram was superior compared to the model incorporating solely age and the number of previous pregnancy losses. Calibration curves, DCAs, and CICAs showed good concordance and clinical applicability. Significant differences in pregnancy loss rates were observed between the low- and high-risk groups (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

This study was retrospective and focused on patients from a single reproductive immunology clinic, lacking external validation data. The potential impact of embryonic chromosomal abnormalities on pregnancy loss could not be excluded, and the administration of medication to all cases impacted the investigation of risk factors for pregnancy loss and the model's predictive efficacy.

WIDER IMPLICATIONS OF THE FINDINGS

This study signifies a pioneering effort in developing and validating a risk prediction nomogram for subsequent pregnancy loss in RPL patients to effectively stratify their risk. We have integrated the nomogram into an online web tool for clinical applications.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (82071725). All authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

External validation of a frequently used prediction model for ongoing pregnancy in couples with unexplained recurrent pregnancy loss

STUDY QUESTION

What is the predictive performance of a currently recommended prediction model in an external Dutch cohort of couples with unexplained recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

The model shows poor predictive performance on a new population; it overestimates, predicts too extremely and has a poor discriminative ability.

WHAT IS KNOWN ALREADY

In 50-75% of couples with RPL, no risk factor or cause can be determined and RPL remains unexplained. Clinical management in RPL is primarily focused on providing supportive care, in which counselling on prognosis is a main pillar. A frequently used prediction model for unexplained RPL, developed by Brigham et al. in 1999, estimates the chance of a successful pregnancy based on number of previous pregnancy losses and maternal age. This prediction model has never been externally validated.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study consisted of 739 couples with unexplained RPL who visited the RPL clinic of the Leiden University Medical Centre between 2004 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Unexplained RPL was defined as the loss of two or more pregnancies before 24 weeks, without the presence of an identifiable cause for the pregnancy losses, according to the ESHRE guideline. Obstetrical history and maternal age were noted at intake at the RPL clinic. The outcome of the first pregnancy after intake was documented. The performance of Brigham's model was evaluated through calibration and discrimination, in which the predicted pregnancy rates were compared to the observed pregnancy rates.

MAIN RESULTS AND THE ROLE OF CHANCE

The cohort included 739 women with a mean age of 33.1 years (±4.7 years) and with a median of three pregnancy losses at intake (range 2-10). The mean predicted pregnancy success rate was 9.8 percentage points higher in the Brigham model than the observed pregnancy success rate in the dataset (73.9% vs 64.0% (95% CI for the 9.8% difference 6.3-13.3%)). Calibration showed overestimation of the model and too extreme predictions, with a negative calibration intercept of -0.46 (95% CI -0.62 to -0.31) and a calibration slope of 0.42 (95% CI 0.11-0.73). The discriminative ability of the model was very low with a concordance statistic of 0.55 (95% CI 0.51-0.59). Recalibration of the Brigham model hardly improved the c-statistic (0.57; 95% CI 0.53-0.62).

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study in which only the first pregnancy after intake was registered. There was no time frame as inclusion criterium, which is of importance in the counselling of couples with unexplained RPL. Only cases with a known pregnancy outcome were included.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study externally validating the Brigham prognostic model that estimates the chance of a successful pregnancy in couples with unexplained RPL. The results show that the frequently used model overestimates the chances of a successful pregnancy, that predictions are too extreme on both the high and low ends and that they are not much more discriminative than random luck. There is a need for revising the prediction model to estimate the chance of a successful pregnancy in couples with unexplained RPL more accurately.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used and no competing interests were declared.

TRIAL REGISTRATION NUMBER

N/A.

Infertility and subsequent recurrent miscarriage: Current state of the literature and future considerations for practice and research

Background: Recurrent miscarriage (RM) and infertility are independently associated with adverse pregnancy outcomes, in addition to psychological sequelae. Experiencing pregnancy loss alongside infertility is particularly difficult. International guidance regarding RM is conflicting, and applicability to women with infertility is undetermined. The aim of this study was to: (i) establish if women/couples with a history of infertility are recognised in the literature on the investigation and management of RM, and (ii) determine if the specific needs of women/couples experiencing RM and infertility are ascertained and incorporated into clinical management strategies. Methods: We examined the wide-ranging literature to ascertain what gaps existed. Studies were retrieved through searches of PubMed and Google Scholar up to 21 January 2021 using appropriate controlled vocabulary and combinations of key words. No language or study design restrictions were applied. Results: While women/couples experiencing RM after infertility appear in studies evaluating investigations and proposed treatments, high-quality studies are lacking. Furthermore, they are largely excluded from international clinical guidance and qualitative research. Conclusions: The experiences of women/couples with RM and infertility and their specific care needs within maternity and fertility services are underexplored. It is unclear from current RM guidelines how best to manage and support this complex cohort. Women/couples with infertility and RM are underserved in the literature and in clinical guidance. Further robust studies are warranted to examine pregnancy outcomes, investigations and treatments currently used. Qualitative research is also required to identify their medical and psychological needs to better support this vulnerable group.

Genetic findings in miscarriages and their relation to the number of previous miscarriages

PURPOSE

Early pregnancy loss leads to a devastating situation for many couples. Genetic disorders found in the pregnancy tissue are a frequent cause of miscarriages. It is unclear whether maternal age or previous miscarriages are associated with a higher chromosomal anomaly rate. This study aimed to determine the cytogenetical distribution of chromosomal disorders in couples after one or more previous miscarriages as well as the influence of maternal age.

METHODS

406 fetal tissue samples obtained after spontaneous abortion between 2010 and 2014 were successfully karyotyped. This included 132 couples with at least two losses and 274 couples with sporadic miscarriage. Normal and abnormal karyotype rate was determined for age, parity, gravidity, gestational week and number of previous miscarriages by logistic regression analysis.

RESULTS

145 (35.71%) fetal tissue samples had a normal karyotype, and 261 (64.8%) did not. After adjusting for age, older patients have a statistically significantly higher probability of genetic disorders in the pregnancy tissue (p < 0.001, OR 1.064, 95% CI 1.03-1.11). With each additional year, the probability of finding chromosomal abnormalities in a miscarriage increased by 6.4%. Patients younger than 35 years have a lower probability of having chromosomal disorders in the aborted material after two or more miscarriages than after sporadic miscarriages (50.7 vs. 58.9%) (p = 0.014, OR 0.67, 95% CI 0.48-0.914). Nevertheless, the risk of embryonic chromosomal disorders in patients aged 35 and above increased from 75.5% in sporadic miscarriages to 82.4% after more than one pregnancy losses (p = 0.59, OR 1.14, 95% CI  - 0.72 to 1.92).

CONCLUSION

Chromosomal disorders found after one or more previous miscarriages are related to patients' age. Couples suffering two or more miscarriages should be further researched, especially in younger patients.

ESHRE guideline: recurrent pregnancy loss

STUDY QUESTION

What is the recommended management of women with recurrent pregnancy loss (RPL) based on the best available evidence in the literature?

SUMMARY ANSWER

The guideline development group formulated 77 recommendations answering 18 key questions on investigations and treatments for RPL, and on how care should be organized.

WHAT IS KNOWN ALREADY

A previous guideline for the investigation and medical treatment of recurrent miscarriage was published in 2006 and is in need of an update.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 31 March 2017 and written in English were included. Cumulative live birth rate, live birth rate and pregnancy loss rate (or miscarriage rate) were considered the critical outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the collected evidence, recommendations were formulated and discussed until consensus was reached within the guideline group. A stakeholder review was organized after finalization of the draft. The final version was approved by the guideline group and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 38 recommendations on risk factors, prevention and investigations in couples with RPL, and 39 recommendations on treatments. These include 60 evidence-based recommendations – of which 31 were formulated as strong recommendations and 29 as conditional – and 17 good practice points. The evidence supporting investigations and treatment of couples with RPL is limited and of moderate quality. Of the evidence-based recommendations, only 10 (16.3%) were supported by moderate quality evidence. The remaining recommendations were supported by low (35 recommendations: 57.4%), or very low quality evidence (16 recommendations: 26.2%). There were no recommendations based on high quality evidence. Owing to the lack of evidence-based investigations and treatments in RPL care, the guideline also clearly mentions investigations and treatments that should not be used for couples with RPL.

LIMITATIONS, REASONS FOR CAUTION

Several investigations and treatments are offered to couples with RPL, but most of them are not well studied. For most of these investigations and treatments, a recommendation against the intervention or treatment was formulated based on insufficient evidence. Future studies may require these recommendations to be revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in RPL, based on the best evidence available. In addition, a list of research recommendations is provided to stimulate further studies in RPL. One of the most important consequences of the limited evidence is the absence of evidence for a definition of RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payment. J.E. reports position funding from CARE Fertility. S.L. reports position funding from SpermComet Ltd. S.M. reports research grants, consulting and speaker’s fees from GSK, BMS/Pfizer, Sanquin, Aspen, Bayer and Daiichi Sankyo. S.Q. reports speaker’s fees from Ferring. The other authors report no conflicts of interest.

ESHRE Pages are not externally peer reviewed. This article has been approved by the Executive Committee of ESHRE.

Two-year outcome after recurrent first trimester miscarriages: prognostic value of the past obstetric history

PURPOSE

Recurrent miscarriage (RM) is a stressful condition which gives rise to extensive diagnostic evaluation and is seen as a potentially curable maternal disease. Nevertheless, epidemiological data have shown that outcome is related to fertility. In addition to maternal age and number of preceding miscarriages, further markers derived from the past history may support counselling.

METHODS

Observational trial comprising 228 couples who were referred between 1996 and 2003 for immunological evaluation at maternal ages 20-39 years after three or more spontaneously conceived primary first trimester miscarriages. They were interviewed in 2005, ongoing pregnancies were followed up until birth in 2006. Past obstetric history was correlated with 2 year cumulative pregnancy and delivery rates (CPR, CDR).

RESULTS

CPR and CDR were 206/228 (90.4 %) and 174/228 (76.4 %). Duration of infertility was associated with lower CPR (up to 3/>3 years, p < 0.01), whereas age and number of preceding losses inversely correlated with CDR (<35 years/35-39 years, p < 0.002; 3/>3 miscarriages, p < 0.002). Detection of an embryonic heart beat in 2-3 of the first three miscarriages resulted in favourable outcome (CPR: p < 0.02, CDR: p < 0.002). Prognosis was excellent in younger fertile women after three miscarriages where vital signs had been detected; under less favourable conditions not only risks for further miscarriage, but also for secondary infertility were elevated.

CONCLUSION

Secondary infertility is a feature of RM. Embryonic vital signs in preceding pregnancies are prognostic markers and should be regarded as a strong confounding factor in trials on therapeutic interventions. Prevention may be more appropriate than treatment.

[Recurrent early pregnancy loss: What the life-birth chances are? A 10-years retrospective study]

OBJECTIVES

Recurrent miscarriages are a current consultation pattern. Etiologic evaluation is classically proposed and preventive therapy should be discussed. We wanted to study our University Hospital pregnancies outcomes, following 3 repetitive early miscarriages, and how those patients are managed.

MATERIALS AND METHODS

A 10-years retrospective study has been performed in our center, with 296 patients found having a three-repetitive miscarriage experience. Information about diagnostic evaluation following miscarriages, preventive therapy initiation, and next pregnancy outcome has been provided.

RESULTS

Around 62.5% of the patients experienced a life-birth. When investigations were done (n=148), a 64.9% part of the patients had abnormal results. Life-birth rate was more important when there were normal karyotypes or no thrombophilia found (respectively p equal 0.30 and 0.45). We noticed a better prognostic in the group of patients with normal investigations results who had a preventive therapy (n=20, 85% of life-birth, P=0.19).

CONCLUSION

When done, investigations for recurrent miscarriages, allow the finding of an abnormality in two thirds of cases. Wonderingly, outcomes are very encouraging since that almost two thirds of the patients experienced life-birth. Investigations indications, results interpretations, and consecutive therapy should be well thought but preventive therapy seems to be efficient in the normal results patient group.

Secondary recurrent miscarriage is associated with previous male birth

Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13/32 vs. 6/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

Is previous aberrant reproductive outcome predictive of subsequently reduced fecundity?

BACKGROUND

Effect of past reproductive performance on subsequent fecundity is uncertain.

METHODS

A total of 2983 consecutive pregnant women self-completed questionnaires about time to pregnancy (TTP), pregnancy planning, previous pregnancies, contraceptive use, age, and individual/lifestyle variables. Outcome measures were: TTP, conception rates (CR) and, subfecundity odds ratio (OR; with 95% confidence intervals) before and after each outcome of last pregnancy.

RESULTS

After miscarriage, TTP was longer than before miscarriage [2.1 (1.4-3.0), P < 0.001] and than TTP after livebirth [OR = 2.1 (1.6-2.6), P < 0.001]. Also subfecundity OR after miscarriage increased [1.7 (1.2-2.4), 1.8 (1.2-2.5), P = 0.001, 0.002 respectively]. This effect was more evident in older and obese women. Compared with livebirth, time to ectopic pregnancy (EP) was longer [OR = 13.8 (1.8-108.5), P = 0.001] but TTP after EP was not significantly different. Subfecundity OR relative to livebirth were 12.8 (3.6-45.0) (P<0.001) before, and 3.9 (1.4-11.0) (P=0.01) after, EP. The CR after EP increased 3-fold (1.1-8.3) over those prior to EP. Time to the terminated pregnancies even without contraceptive failures was shorter than that to livebirth [OR = 0.5 (0.3-0.7), P = 0.001] and than TTP after termination [0.35 (0.1-0.8), P = 0.001]. Also subfecundity OR increased after termination [7.2 (1.8-29.7), P = 0.02].

CONCLUSIONS

Miscarriers should be counselled about short-term reduction in subsequent fecundity, and earlier investigations should be considered in those who have other potential risk factors for reduced fertility. Further studies are required to clarify the relatively favourable effect on fecundity following EP and the relative reduction in fecundity after termination of pregnancy.

Predictive factors in recurrent spontaneous aborters--a multicenter study

PROBLEM

Compare data from several centers relating to success rates in recurrent spontaneous miscarriage and assess the significance of indicators of subsequent pregnancy loss.

METHOD

Data from 777 couples with unexplained recurrent spontaneous abortion from independent studies at seven centers were analyzed using logistic regression analysis. The following covariates were considered: age of patient, number of previous spontaneous abortions, length of previous abortions history, sub-fertility index (defined as the product of the number of spontaneous abortions and the abortion history), whether a patient was a primary or secondary aborter, and whether a patient had received leukocyte immunotherapy.

RESULTS

There was a highly significant difference between the seven centers in success rates in the subsequent pregnancy and a highly significant association between success rate and each of the following covariates: the number of previous abortions, the length of the previous abortion history and the sub-fertility index. In particular, for each increase of 10 units in the value of the sub-fertility index, up to a value of 30, the odds in favor of a successful pregnancy decreased by a factor of 0.6, i.e., 40%. There was, however, little evidence of an association between the success rate in the subsequent pregnancy and age, parity, or immunization with cells from the husband.

CONCLUSIONS

The sub-fertility index may be a useful measure of likelihood of success in a subsequent pregnancy.