Angiogenic factors and the lectin pathway of complement in women with secondary recurrent pregnancy loss

The poor remodeling of placental spiral arteries seen in preeclampsia is also discussed to contribute to recurrent pregnancy loss (RPL) preceded by abnormal angiogenesis and excessive complement activation. Low levels of Mannose-binding-lectin (MBL), a pattern recognition molecule (PRM) of the lectin pathway, have been found in women with RPL. We propose that pregnancy loss is connected to defective angiogenesis with reperfusion damage in the placenta and decreased levels of PRM in the lectin pathway in women with RPL. In this cohort study, we investigate the angiogenic factors and the lectin complement pathway in early pregnancy and their time-dependent relationship with pregnancy outcomes in 76 women with secondary RPL (sRPL) who have at least four prior pregnancy losses and a live birth. We evaluated levels of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Vascular Endothelial Growth Factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PRMs, MBL, ficolin-1, -2, -3 and an additional soluble PRM, Pentraxin-3, during the 5th, 6th, and 7th gestational weeks. Our results showed that, compared to live births, pregnancies that ended in loss were associated with elevated VEGF levels and decreased levels of the Ang-2/Ang-1 ratio. Also, increasing levels of ficolin-2 were significantly associated with pregnancy loss, with MBL showing no association. Our research suggests that women with sRPL may have inadequate placentation with impaired angiogenesis in pregnancies ending in a loss.

The association between age and long-term quality of life after curative treatment for prostate cancer: a cross-sectional study

OBJECTIVE

We aimed to investigate the associations between age at radical prostate cancer treatment and long-term global quality of life (QoL), physical function (PF), and treatment-related side effects.

MATERIAL AND METHODS

This single-center, cross-sectional study included men treated for localized prostate cancer with robotic-assisted radical prostatectomy (RARP) or external beam radiotherapy (EBRT) in 2014-2018. Global QoL and PF were assessed by the European Organisation of Research and Treatment in Cancer Quality of life Questionnaire-C30 (QLQ-C30), side effects by the Expanded Prostate Cancer Index Composite (EPIC-26). Adjusted linear regression models were estimated to assess associations between age (continuous variable) at treatment and outcomes. QLQ-C30 scores were compared to normative data after dividing the cohort in two groups, <70 years and ≥70 years at treatment.

RESULTS

Of 654 men included, 516 (79%) had undergone RARP, and 138 (21%) had undergone EBRT combined with androgen deprivation therapy for 93%. Mean time since treatment was 57 months. Median age at treatment was 68 (min-max 44-84) years. We found no statistically significant independent association between age at treatment and global QoL, PF or side effects, except for sexual function (regression coefficient [RC] -0.77; p < 0.001) and hormonal/vitality (RC 0.30; p = 0.006) function. Mean QLQ-C30 scores were slightly poorer than age-adjusted normative scores, for men <70 years (n = 411) as well as for men ≥70 years (n = 243) at treatment, but the differences were not beyond clinical significance.

CONCLUSIONS

In this cohort of prostate cancer survivors, age at treatment had little impact on long-term QoL and function. Due to the cross-sectional design, short term impact or variation over time cannot be ruled out.

Maternal carriage of H-Y restricting HLA class II alleles is a negative prognostic factor for women with recurrent pregnancy loss after birth of a boy

Immune system aberrations are suggested to be an important factor in the pathophysiology of unexplained secondary recurrent pregnancy loss (sRPL). The objective was to investigate if the sex ratio of the firstborn child in sRPL patients differs from the background population and whether the sex of the firstborn child has a negative impact on the pregnancy prognosis alone and/or in combination with carriage of male-specific minor histocompatibility (H-Y) restricting HLA class II alleles. From January 2016 to October 2022, 582 patients with unexplained RPL were admitted to the RPL Center of Western Denmark and continuously followed-up. HLA-DRB1 and -DQB1 typing was performed as part of the routine diagnostic work-up. In sRPL patients, a history of a firstborn boy was significantly more frequent than in the Danish background population and was associated with significantly lower odds of a successful reproductive outcome in the first pregnancy after admission compared to a firstborn girl (OR=0.41, 95% CI: 0.20-0.83, p = 0.014). The odds of a successful reproductive outcome were enhanced in patients carrying ≥ 1 H-Y-restricting HLA class II alleles with a first-born girl compared to a firstborn boy (OR=3.33, 95% CI: 1.40-7.88, p = 0.005), while no difference in successful reproductive outcome was seen in sRPL patients not carrying these alleles (OR=1.20, 95% CI: 0.33-4.43, p = 0.781). The sex ratio of children born after RPL was similar to the Danish background population. These findings confirm previous findings and suggests that a harmful immune response triggered by H-Y-antigen exposure during a previous pregnancy in preconditioned women may cause sRPL.

Plasma level of mannose-binding lectin is associated with the risk of recurrent pregnancy loss but not pregnancy outcome after the diagnosis

STUDY QUESTION

Are low or high plasma mannose-binding lectin (p-MBL) levels associated with recurrent pregnancy loss (RPL) and the reproductive and perinatal outcomes before and after RPL?

SUMMARY ANSWER

The prevalence of low p-MBL levels was significantly higher in RPL patients, while high levels were significantly less prevalent. No association was found between p-MBL level and reproductive and perinatal outcomes before and after RPL.

WHAT IS KNOWN ALREADY

Mannose-binding lectin (MBL) is an important component in the innate immune system. Low p-MBL levels have been associated with RPL, while the correlation with high levels has been poorly studied. Adverse perinatal outcomes are generally more frequent among RPL patients, but reports concerning the association between maternal p-MBL levels and perinatal outcomes, including birth weight (BW) and gestational age (GA), are conflicting.

STUDY DESIGN, SIZE, DURATION

This study was a combined cross-sectional and cohort study of 267 RPL patients admitted to the RPL Center of Western Denmark between January 2016 and March 2020. RPL patients were followed until birth of a liveborn child or until end of follow-up, March 2021. A sample of 185 healthy female blood donors of reproductive age was used as a MBL reference group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All RPL patients had ≥3 consecutive pregnancy losses, a regular menstrual cycle and no known significant chromosomal or uterine malformations. At the first consultation, routine blood samples including p-MBL measurement and detailed obstetrical and perinatal information were collected. p-MBL levels in RPL patients were compared to the MBL reference group. A logistic regression analysis adjusted for relevant confounders assessed the association between low p-MBL levels and an unsuccessful reproductive outcome in RPL patients in first pregnancy after admission. Perinatal outcomes before and after RPL were compared between RPL subgroups according to low (≤500 µg/l), intermediate (501–3000 µg/l) and high (>3000 µg/l) p-MBL levels.

MAIN RESULTS AND THE ROLE OF CHANCE

Significantly more RPL patients had low p-MBL levels (prevalence proportion ratio (PPR): 1.79, 95% CI: 1.34–2.38) and fewer had high p-MBL levels (PPR: 0.56, 95% CI: 0.40–0.79) compared to the reference group, while the prevalence of intermediate p-MBL level was not different between the groups (PPR: 0.86, 95% CI: 0.69–1.08). In the prospective study, low p-MBL level was not a significant risk factor for a pregnancy loss in the first pregnancy after admission after adjustment for age, BMI and smoking. Neither before nor after the RPL diagnosis were maternal p-MBL levels significantly associated with BW or GA.

LIMITATIONS, REASONS FOR CAUTION

Only 161 (60.3%) patients had given birth after RPL during the follow-up period, which limited the possibility to detect clear associations between p-MBL levels and perinatal outcomes after RPL.

WIDER IMPLICATIONS OF THE FINDINGS

In agreement with several previous studies, low p-MBL levels are strongly associated with RPL, while this study for the first time documents that high levels may play a protective role, which suggests a causal relationship. We suggest that larger prospective studies evaluate the association between p-MBL levels and RPL prognosis.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. We acknowledge the Department of Obstetrics and Gynaecology at Aalborg University Hospital for financial support. U.S.K. has reported personal fees from Merck, consulting fees from IBSA Nordic, and a grant from Gedeon Richter, Merck and IBSA Nordic outside of the submitted work.

TRIAL REGISTRATION NUMBER

ID from clinicaltrials.gov is NCT04017754.

Seminal plasma metabolomics profiles following long (4-7 days) and short (2 h) sexual abstinence periods

OBJECTIVE

Metabolomic profiling of seminal plasma has been suggested as a possible approach for a fast and non-invasive male infertility evaluation diagnosis. However, metabolomics profiles in normozoospermic men have not been thoroughly investigated, and the influence of ejaculation-abstinence has not been described. To provide interim reference values and find associations between the metabolomics profiles of human seminal plasma and length of ejaculation-abstinence period in normozoospermic men.

STUDY DESIGN

Semen samples collected after long (4-7 days) and short abstinence (2 h) from 31 normozoospermic males were assessed for routine quality parameters before the seminal plasma was separated by centrifugation. Metabolomics profiles of the seminal plasma were then determined using untargeted Nuclear Magnetic Resonance Spectroscopy.

RESULTS

In total, 30 metabolites were identified. Pyruvate showed a higher concentration, while fructose, acetate, choline, methanol, N-acetylglucosamine, O-acetylcarnitine, uridine, and sn-glycero-3-phosphocoline showed lower concentrations in samples collected after short abstinence (vs. long). All metabolites showed lower absolute amounts (volume × concentration) following shorter abstinence. However, the lower sperm concentration in samples collected after short abstinence resulted in higher absolute amounts of pyruvate and taurine per spermatozoa: pyruvate 1.92 (1.12-3.87) vs. 1.29 (0.83-2.62) (P < 0.001) and taurine 0.58 (0.36-0.92) vs. 0.43 (0.28-0.95) (P < 0.05) ng/10⁶ spermatozoa. Simultaneously, there was a higher percentage of progressively motile spermatozoa in samples collected after the short abstinence.

CONCLUSION

The generally lower concentrations of seminal metabolites after short abstinence periods may be related to the shorter time available for secretion and collection of these metabolites by the accessory glands and the epididymides. The concomitant lower number of spermatozoa in the second ejaculate resulted in increased absolute amounts of pyruvate and taurine per spermatozoa, accompanied by increased spermatozoa motility in these samples. The simultaneous increase in percentages of motile spermatozoa and absolute amounts of pyruvate and taurine per spermatozoa after shorter abstinence might indicate that these two metabolites play a more critical role in sperm motility, which should be further investigated in future studies.

HLA-DRB1 polymorphism in recurrent pregnancy loss: New evidence for an association to HLA-DRB1*07

Many cases of recurrent pregnancy loss (RPL) defined as ≥3 consecutive pregnancy losses are suggested to be caused by an aberrant maternal immune response against the fetus or trophoblast. Human leukocyte antigen (HLA)-DRB1 and -DQB1 polymorphisms are associated with most autoimmune disorders and studies of HLA-DBB1 polymorphism in RPL patients are thus relevant. In previous studies, the HLA-DRB1*03 allele was found with increased prevalence in RPL patients. We wanted to clarify whether HLA-DRB1 alleles indeed were associated with RPL among women of Caucasian descent. A total of 1078 women with unexplained RPL and 2066 bone marrow donors were HLA-DRB1-typed and subsets were also HLA-DQB1 typed. All patients were initially HLA-DRB1-typed by DNA-based low-resolution techniques and subsets of patients and all controls were typed by high-resolution techniques. Among patients, the HLA-DRB1*07 allele frequency was significantly increased compared with controls; OR 1.29 (95 % CI 1.09-1.52), p < 0.0025; after correction for multiple comparisons pc = 0.031. The HLA-DRB1*07/*07 genotype was highly increased in patients with RPL compared with controls: OR 2.27 (1.31-3.93), p = 0.0027. The frequency of the HLA-DRB1*07 phenotype in RPL patients had increased significantly (p = 0.002) in three studies from our group published 1994-2021. The allele frequency of HLA-DRB1*03 was not increased in RPL patients compared with controls; OR 0.96 (0.83-1.12). In conclusion, the previous association between HLA-DRB1*03 and RPL could not be confirmed in our study whereas an association to HLA-DRB1*07 was detected for the first time. Since the latter association is a new finding, it should be confirmed in future studies.

Chance of live birth in the first pregnancy after referral among patients with recurrent pregnancy loss is not influenced by their relatives' reproductive history

Purpose: Recurrent pregnancy loss (RPL) is defined as three or more consecutive pregnancy losses and affects 1-3% of couples trying to conceive. Pregnancy loss is more common among RPL patients' siblings than in the general population. Our objective was to investigate whether first-degree relatives with pregnancy losses influenced the chance of live birth in the first pregnancy after referral among women with RPL.Materials and methods: This is a cohort study of 2138 women with RPL seen at the Danish RPL Unit at Copenhagen University Hospital, Rigshospitalet between January 1st 2000 and December 31st 2017 with follow-up until December 2018. Pregnancies among first-degree relatives were reported by patients at their first consultation. Chance of live birth after referral was compared by logistic regression analysis.Results: Overall, 76% of the referred women achieved a pregnancy after referral and of these, 58% delivered a live born child. Women whose mother had experienced pregnancy loss were referred at a younger age than women with no pregnancy losses among first-degree relatives (mean age 33.6 (SD 4.6) versus 34.3 (SD 4.5), p = 0.002). Pregnancy losses among first-degree relatives did not influence chance of live birth.Conclusions: Our results indicate that pregnancy losses among first-degree family members is not an important risk factor for outcome of the first pregnancy after referral among women with RPL.

Recurrent pregnancy loss: what is the impact of consecutive versus non-consecutive losses?

STUDY QUESTION

Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic impact in women with secondary RPL.

WHAT IS KNOWN ALREADY

The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy losses plays a role for the prognosis in patients with a prior birth.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study of pregnancy outcome in patients with unexplained secondary RPL included in three previously published, Danish double-blinded placebo-controlled trials of intravenous immunoglobulin (IvIg) conducted from 1991 to 2014. No other treatments were given. Patients with documented explained pregnancy losses (ectopic pregnancies and aneuploid miscarriages) were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the 168 patients included in the trials, 127 had secondary RPL and experienced a subsequent live birth or unexplained pregnancy loss in the first pregnancy after giving informed consent to participate in the trials (the index pregnancy). Data analyzed by multivariate analysis included the independent variables age, the number of early pregnancy losses before and after the last birth, respectively and a second trimester pregnancy loss before or after the last birth, respectively. The outcome variable was unexplained loss in the index pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

In patients with secondary RPL, both a late and each early loss before the last birth did not significantly influence the risk of a new pregnancy loss in the index pregnancy: incidence rate ratio (IRR) 1.31 (95% CI 0.62-2.77) and IRR 0.88 (95% CI 0.70-1.11), respectively. In contrast, the impact on risk of pregnancy loss conferred by a late and by each early pregnancy loss occurring after the birth was significant: IRR 2.15 (95% CI 1.57-2.94, P < 0.0001) and IRR 1.14 (95% CI 1.04-1.24, P = 0.002), respectively.

LIMITATIONS, REASONS FOR CAUTION

Of the patients, 48% were treated with IvIg, which could influence the results. However, allocation to IvIg was random and prognostic variables were equally distributed in IvIg and placebo-treated patients.

WIDER IMPLICATIONS OF THE FINDINGS

A birth in women with secondary RPL eradicates the negative prognostic impact of previous pregnancy losses and this finding is important for our understanding of the pathogenesis. It indicates that only consecutive pregnancy losses should count in the definition of RPL.

STUDY FUNDING/COMPETING INTERESTS

There was no particular funding for this study. The authors declare that there is no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable for two of the included randomized controlled trials. For the last trial: Clinical.Gov NCT00722475.

Placental magnetic resonance imaging T2* measurements in normal pregnancies and in those complicated by fetal growth restriction

OBJECTIVES

The magnetic resonance imaging (MRI) variable transverse relaxation time (T2*) depends on multiple factors, one important one being the presence of deoxyhemoglobin. We aimed to describe placental T2* measurements in normal pregnancies and in those with fetal growth restriction (FGR).

METHODS

We included 24 normal pregnancies at 24-40 weeks' gestation and four FGR cases with an estimated fetal weight below the 1(st) centile. Prior to MRI, an ultrasound examination, including Doppler flow measurements, was performed. The T2* value was calculated using a gradient echo MRI sequence with readout at 16 different echo times. In normal pregnancies, repeat T2* measurements were performed and interobserver reproducibility was assessed in order to estimate the reproducibility of the method. Placental histological examination was performed in the FGR cases.

RESULTS

The method was robust regarding the technical and interobserver reproducibility. However, some slice-to-slice variation existed owing to the heterogeneous nature of the normal placenta. We therefore based T2* estimations on the average of two slices from each placenta. In normal pregnancies, the placental T2* value decreased significantly with increasing gestational age, with mean ± SD values of 120 ± 17 ms at 24 weeks' gestation, 84 ± 16 ms at 32 weeks and 47 ± 17 ms at 40 weeks. Three FGR cases had abnormal Doppler flow, histological signs of maternal hypoperfusion and a reduced T2* value (Z-score < -3.5). In the fourth FGR case, Doppler flow, placental histology and T2* value (Z-score, -0.34) were normal.

CONCLUSIONS

The established reference values for placental T2* may be clinically useful, as T2* values were significantly lower in FGR cases with histological signs of maternal hypoperfusion. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Depression and emotional stress is highly prevalent among women with recurrent pregnancy loss

STUDY QUESTION

Is the prevalence of psychological stress and moderate/severe depression higher for women with recurrent pregnancy loss (RPL) than pregnancy planners trying to conceive naturally?

SUMMARY ANSWER

Both psychological stress and major depression are significantly more common among women with RPL than in those trying to conceive naturally.

WHAT IS KNOWN ALREADY

RPL has a significant emotional impact on couples, especially the woman. Previous studies have shown inconclusive results.

STUDY DESIGN, SIZE, DURATION

In this cross-sectional study, we compared the prevalence of stress and depression among 301 women with RPL and 1813 women attempting to conceive naturally. We defined RPL as three or more pregnancy losses before 12 weeks' gestation. RPL patients were enrolled from 2010 to 2013 and the comparison group from 2011 to 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RPL patients completed an online questionnaire before their first consultation at the Danish RPL Unit. In addition, we included data from a comparison group of 1813 women who participated in the Soon Parents Study (www.SnartForældre.dk). The Major Depression Index (MDI) was used to assess symptoms of depression, and Cohen's Perceived Stress Scale (PSS) was used to measure stress. Relevant demographic data were also retrieved.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the RPL patients, 26 (8.6%) had a score on the MDI corresponding to moderate/severe depression, as did 40 (2.2%) of the women in Soon Parents Study (adjusted odds ratio (OR) 5.53 (95% confidence interval (CI): 2.09; 14.61)). A high stress level, defined as ≥19 on the PSS scale, was reported by 124 (41.2%) of the patients and 420 (23.2%) in the comparison group (adjusted OR 1.59 (95% CI 1.03; 2.44)).

LIMITATIONS, REASONS FOR CAUTION

We used online questionnaires, and have no interview data. We were unaware if any of the women in the comparison group suffer from RPL.

WIDER IMPLICATIONS OF THE FINDINGS

This study should entail a heightened awareness of mental distress among care providers for women with RPL.

STUDY FUNDING/COMPETING INTERESTS

No specific funding was sought for this study. The Soon Parents Study is funded by National Institute of Child Health and Human Development (R01 HD060680-01A4). No authors have competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Intravenous immunoglobulin treatment for secondary recurrent miscarriage: a randomised, double-blind, placebo-controlled trial

OBJECTIVE

To determine whether infusions with intravenous immunoglobulin (IVIg) during early pregnancy increase live birth rate in women with secondary recurrent miscarriage compared with placebo.

DESIGN

A single-centre, randomised, double-blind, placebo-controlled trial.

SETTING

A tertiary centre for recurrent miscarriage in Copenhagen, Denmark.

POPULATION

A group of 82 women with unexplained secondary recurrent miscarriage and at least four miscarriages.

METHODS

Women were randomly assigned to repeated infusions with IVIg or placebo (albumin) from the time of positive pregnancy test to gestational week 15 or pregnancy loss.

MAIN OUTCOME MEASURE

Primary outcome was birth with neonatal survival in all randomised women.

RESULTS

In the intention-to-treat analyses, live birth rates were 23/42 (54.8%) in the IVIg and 20/40 (50.0%) in the placebo group, relative risk 1.11 (95% CI 0.70-1.74). In a per protocol analysis, almost identical results were found. The median gestational length at delivery was higher in the IVIg than the placebo group (282 versus 272 days, P = 0.02) but the mean birthweight was not significantly increased.

CONCLUSIONS

In this trial, which is the largest so far, IVIg did not increase the live birth rate in patients with secondary recurrent miscarriage and the treatment cannot be recommended in clinical practice.

Terminology for pregnancy loss prior to viability: a consensus statement from the ESHRE early pregnancy special interest group

Pregnancy loss prior to viability is common and research in the field is extensive. Unfortunately, terminology in the literature is inconsistent. The lack of consensus regarding nomenclature and classification of pregnancy loss prior to viability makes it difficult to compare study results from different centres. In our opinion, terminology and definitions should be based on clinical findings, and when possible, transvaginal ultrasound. With this Early Pregnancy Consensus Statement, it is our goal to provide clear and consistent terminology for pregnancy loss prior to viability.

Non-visualized pregnancy losses are prognostically important for unexplained recurrent miscarriage

STUDY QUESTION

Are non-visualized pregnancy losses (biochemical pregnancy loss and failed pregnancy of unknown location combined) in the reproductive history of women with unexplained recurrent miscarriage (RM) negatively associated with the chance of live birth in a subsequent pregnancy?

SUMMARY ANSWER

Non-visualized pregnancy losses contribute negatively to the chance for live birth: each non-visualized pregnancy loss confers a relative risk (RR) for live birth of 0.90 (95% CI 0.83; 0.97), equivalent to the RR conferred by each additional clinical miscarriage.

WHAT IS KNOWN ALREADY

The number of clinical miscarriages prior to referral is an important determinant for live birth in women with RM, whereas the significance of non-visualized pregnancy losses is unknown.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study comprising 587 women with RM seen in a tertiary RM unit 2000-2010. Data on the outcome of the first pregnancy after referral were analysed for 499 women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted in the RM Unit at Rigshospitalet, Copenhagen, Denmark. We included all women with unexplained RM, defined as ≥3 consecutive clinical miscarriages or non-visualized pregnancy losses following spontaneous conception or homologous insemination. The category 'non-visualized pregnancy losses' combines biochemical pregnancy loss (positive hCG, no ultrasound performed) and failed PUL (pregnancy of unknown location, positive hCG, but on ultrasound, no pregnancy location established). Demographics were collected, including BMI, age at first pregnancy after referral and outcome of pregnancies prior to referral. Using our own records and records from other Danish hospitals, we verified the outcome of the first pregnancy after referral. For each non-visualized pregnancy loss and miscarriage in the women's reproductive history, the RR for live birth in the first pregnancy after referral was determined by robust Poisson regression analysis, adjusting for risk factors for negative pregnancy outcome.

MAIN RESULTS AND THE ROLE OF CHANCE

Non-visualized pregnancy losses constituted 37% of reported pregnancies prior to referral among women with RM. Each additional non-visualized pregnancy loss conferred an RR for live birth of 0.90 (95% CI 0.83; 0.97), which was not statistically significantly different from the corresponding RR of 0.87 (95% CI 0.80; 0.94) conferred by each clinical miscarriage. Among women with ≥2 clinical miscarriages, a reduced RR for live birth was also shown: 0.82 (95% CI 0.74; 0.92) for each clinical miscarriage and 0.89 (95% CI 0.80; 0.98) for each non-visualized pregnancy loss, respectively. Surgically treated ectopic pregnancies (EPs) were significantly more common for women with primary RM and no confirmed clinical miscarriages, compared with women with primary RM and ≥1 clinical miscarriage (22 versus 6%, difference 16% (95% CI 9.1%; 28.7%); RR for ectopic pregnancy was 4.0 (95% CI 1.92; 8.20).

LIMITATIONS, REASONS FOR CAUTION

RM was defined as ≥3 consecutive pregnancy losses before 12 weeks' gestation, and we included only women with unexplained RM after thorough evaluation. It is uncertain whether the findings apply to other definitions of RM and among women with known causes for their miscarriages.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first comprehensive investigation of prior non-visualized pregnancy losses and their prognostic significance for live birth in a subsequent pregnancy in women with unexplained RM. We show that a prior non-visualized pregnancy loss has a negative prognostic impact on subsequent live birth and is thus clinically significant.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

A genome-wide scan in affected sibling pairs with idiopathic recurrent miscarriage suggests genetic linkage

Previously, siblings of patients with idiopathic recurrent miscarriage (IRM) have been shown to have a higher risk of miscarriage. This study comprises two parts: (i) an epidemiological part, in which we introduce data on the frequency of miscarriage among 268 siblings of 244 patients with IRM and (ii) a genetic part presenting data from a genome-wide linkage study of 38 affected sibling pairs with IRM. All IRM patients (probands) had experienced three or more miscarriages and affected siblings two or more miscarriages. The sibling pairs were genotyped by the Affymetrix GeneChip 50K XbaI platform and non-parametric linkage analysis was performed via the software package Merlin. We find that siblings of IRM patients exhibit a higher frequency of miscarriage than population controls regardless of age at the time of pregnancy. We identify chromosomal regions with LOD scores between 2.5 and 3.0 in subgroups of affected sibling pairs. Maximum LOD scores were identified in four occurrences: for rs10514716 (3p14.2) when analyzing sister-pairs only; for rs10511668 (9p22.1) and rs341048 (11q13.4) when only analyzing families where the probands have had four or more miscarriages; and for rs10485275 (6q16.3) when analyzing one sibling pair from each family only. We identify no founder mutations. Concluding, our results imply that IRM patients and their siblings share factors which increase the risk of miscarriage. In this first genome-wide linkage study of affected sibling pairs with IRM, we identify regions on chromosomes 3, 6, 9 and 11 which warrant further investigation in order to elucidate their putative roles in the genesis of IRM.

Hereditary thrombophilia and recurrent pregnancy loss: a retrospective cohort study of pregnancy outcome and obstetric complications

BACKGROUND

The association among hereditary thrombophilia, recurrent pregnancy loss (RPL) and obstetric complications is yet uncertain. The objective of the study was to assess the prognostic value of the factor V Leiden (FVL) and prothrombin (PT) mutations for the subsequent chance of live birth for women with RPL.

METHODS

Pregnancy outcome was recorded in a retrospective cohort of 363 women with a minimum of three consecutive pregnancy losses (early miscarriage, late miscarriage or stillbirth/neonatal death) who were not treated with anticoagulation therapy.

RESULTS

Of the 363 women, 29 were FVL-mutation carriers and 6 were PT-mutation carriers. The unadjusted live birth rate was 45.7% in FVL/PT carriers versus 63.4% in FVL/PT non-carriers, P = 0.04. The adjusted odds ratio for live birth in FVL/PT carriers was 0.48 (95% CI = 0.23-1.01), P = 0.05. Among the obstetric complications, only excessive bleeding was found to be associated with FVL/PT mutations.

CONCLUSIONS

In the unadjusted analysis, FVL and PT mutations have a negative prognostic impact on the live birth rate in women with RPL; however, when adjusting for significant covariates, the results no longer reach statistical significance. Strong conclusions on the association between obstetric complications and hereditary thrombophilia cannot be drawn from this study. Whether anticoagulation therapy would improve the prognosis in women with RPL and FVL/PT mutations remains to be documented in large randomized controlled trials.

H-Y antibody titers are increased in unexplained secondary recurrent miscarriage patients and associated with low male : female ratio in subsequent live births

BACKGROUND

The birth of a boy is significantly more common than a girl prior to secondary recurrent miscarriage (SRM) and is associated with a poorer chance of a subsequent live birth. Children born after SRM are more likely to be girls. High-titer antisera specific for male antigens (H-Y) have been shown to arrest development of male bovine embryos efficiently. We consequently questioned the role of H-Y antibodies in women with SRM.

METHODS

Serum samples from patients with unexplained SRM (n = 84), unexplained primary recurrent miscarriage (PRM) (n = 12) and healthy women (n = 37) were obtained. The samples were taken during pregnancy (gestational weeks 4-5) for 77 (80%) of the patients. Enzyme-linked immunosorbent assay was used to detect immunoglobulin G antibodies that specifically recognized any of the five recombinant H-Y proteins (EIF1AY, RPS4Y1, ZFY, DDX3Y and UTY) and their H-X homologs.

RESULTS

H-Y-specific antibodies were more frequent in SRM patients (46%) compared with female controls (19%, P = 0.004) and PRM patients (8%, P = 0.01). The presence of H-Y antibodies in early pregnancy was associated with a low male: female birth ratio among the subsequent live births, as only 12% of children born to H-Y antibody-positive patients were boys compared with 44% boys born to H-Y antibody negative patients (P = 0.03).

CONCLUSIONS

The high frequency of H-Y antibody-positive SRM patients and the association between the presence of these antibodies in early pregnancy and the low number of male offspring, suggest that maternal immune responses against H-Y antigens can cause pregnancy losses. Further exploring these mechanisms may increase our understanding of unexplained SRM.

Association between human leukocyte antigen-G genotype and success of in vitro fertilization and pregnancy outcome

To determine if a 14-bp deletion/insertion polymorphism in the 3'-untranslated region of exon 8 of the gene encoding human leukocyte antigen (HLA)-G in a homozygous form is associated with repeated, unsuccessful in vitro fertilization (IVF) treatments, and with increased risk of recurrent spontaneous abortions (RSA), 29 white women undergoing IVF treatments, 61 RSA women and 93 fertile controls were HLA-G genotype. The HLA-G genotype, homozygous for the presence of the 14 bp sequence in exon 8, was significantly associated with reduced fertility with respect to unsuccessful IVF treatments and increased risk of recurrent miscarriage (combined P < 0.01). The 14-bp insertion/deletion polymorphism is associated with differences in HLA-G mRNA alternative splicing and levels of HLA-G. This might affect a possible immunomodulatory role of HLA-G expression in both the mother and foetus during implantation and pregnancy.

Impact of the sex of first child on the prognosis in secondary recurrent miscarriage

BACKGROUND

The carriage of a male fetus often initiates maternal immunological reactions against male-specific minor histocompatibility (HY) antigens, which, in theory, could result in subsequent recurrent miscarriage (RM).

METHODS

Information about subsequent pregnancy outcome was procured among 182 women with RM after a birth (secondary RM) referred since 1986 using questionnaires, telephone interviews and registers.

RESULTS

Significantly more of the women had had a male first-born as compared with a female first-born (110 versus 72; P < 0.02). By January 2002, 58% of those who had a male first-born had given birth to a second live infant compared with 76% of those who previously had had a female first-born (P = 0.01). Women in the former group had a significantly lower chance of having a second child than those in the latter (adjusted hazard ratio 0.59; 95% confidence interval 0.41-0.86). The number of miscarriages after admission and the risk of secondary infertility were significantly greater in women with a male first-born than among those with a female first-born (P < 0.001 and P = 0.02; respectively).

CONCLUSIONS

A male first-born seems to be associated with a less favourable reproductive potential among women with secondary RM. Maternal immunization against HY antigens may be responsible for these findings.

A study of HLA-DR and -DQ alleles in 588 patients and 562 controls confirms that HLA-DRB1*03 is associated with recurrent miscarriage

BACKGROUND

Previous studies have demonstrated an association between recurrent miscarriage (RM) and the maternal HLA-DRB1*01 and -DRB1*03 alleles. The primary aim of the present study was to confirm or reject the hypothesis about this association in a larger case-control study.

METHODS

HLA-DRB1, -DQA1 and -DQB1 genotyping was carried out by the PCR-sequence-specific primer (SSP) method in 354 patients with unexplained RM and 202 fertile controls. These results were combined with the results from a previous study of 234 RM patients and 360 controls.

RESULTS

The prevalence of patients with HLA-DRB1*03 was significantly increased compared with controls [odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.1-1.9, P = 0.01, P corrected for the number of comparisons (Pc) = 0.02]. In patients with at least four previous miscarriages or with secondary RM, the association became even stronger (OR = 1.8, 95% CI = 1.3-2.5, P = 0.0005, Pc = 0.004; and OR = 1.8, 95% CI = 1.3-2.5, P = 0.0007, Pc = 0.006, respectively). There was no significant difference between patients and controls with regard to HLA-DRB1*01.

CONCLUSION

The HLA-DRB1*03 allele or genes in linkage disequilibrium with it confer susceptibility to RM.

Prospective, serial investigations of in-vitro lymphocyte cytokine production, CD62L expression and proliferative response to microbial antigens in women with recurrent miscarriage

BACKGROUND

Lymphocytes from pregnant women with unexplained recurrent miscarriage (RM) may be characterized by a T-helper type 1-dominated cytokine production and a higher proliferative response to microbial recall antigens compared with normal pregnant women.

METHODS

Serial blood samples were taken from 14 women with RM (at least three previous consecutive miscarriages) during the first 14 weeks of pregnancy, and one blood sample was taken from 15 control women in gestational weeks 7-8. Of the 14 pregnant RM patients, four produced a live birth and 10 miscarried. Lymphocytes were in-vitro-stimulated by mitogens, allogeneic cells and microbial antigens, and the production of a series of cytokines, the proliferative responses and lymphocytic expression of CD62L (which may be a marker of T-helper type 2 lymphocytes) were measured.

RESULTS

Repeated measurements of cytokine production were reproducible during the first trimester. The proliferative responses to herpes simplex and tetanus antigens were increased, and the ratio of CD62L-/CD62L+ expressing CD4+CD45RO+ lymphocytes was decreased in patients compared with controls (P = 0.01, P < 0.01 and P < 0.01 respectively).

CONCLUSION

The results of the in-vitro assays used were reproducible in serial testing during pregnancy. The importance of CD62L expression on lymphocytes for RM and the relevance of the maternal response to microbial antigens during pregnancy should be further explored.

HLA-G polymorphisms in couples with recurrent spontaneous abortions

The etiology of a fraction of recurrent spontaneous abortions (RSA) may involve immunological mechanisms. Aberrant profiles of Th1 and Th2 cytokines have been observed which are not present in uncomplicated pregnancies. Studies of classical HLA class I and II antigens in relation to RSA have not been conclusive. Furthermore, these antigens are not expressed in the placenta with the exception of HLA-C. However, HLA-G is expressed on especially invasive cytotrophoblasts and exists in both membrane and soluble forms. HLA-G may be involved in materno-fetal tolerance. Therefore, 61 RSA couples (with three or more spontaneous abortions) and 47 fertile control couples were HLA-G genotyped by direct DNA sequencing and analyzed for specific polymorphisms. No statistically significant differences were observed in the distribution of HLA-G alleles between controls and RSA couples, however, 15% of the RSA women carried the HLA-G*0106 allele compared to 2% of the control women. The 14 bp deletion polymorphism in exon 8 was investigated separately. There were a greater number of heterozygotes for the 14 bp polymorphism in the group of fertile control women than expected, according to Hardy-Weinberg equilibrium. Furthermore, the HLA-G alleles without the 14 bp sequence were prominent in the RSA males in contrast to the RSA women in whom alleles including the 14 bp sequence were frequently observed, especially as homozygotes. These results are discussed in relation to two hypotheses concerning HLA-G and RSA. A hypothesis of HLA-G histo-incompatibility between fetus/placenta and the mother was not supported by the data. Another hypothesis concerned certain HLA-G alleles associated with an altered expression profile of HLA-G isoforms or reduced expression of certain HLA-G isoforms.

The possible role of classical human leukocyte antigens in recurrent miscarriage

PROBLEM

If immunological factors play a role in the pathogenesis of recurrent miscarriage (RM), it is likely that associations between alleles of classical human leukocyte antigen (HLA) genes and RM exist. Our aim was to investigate HLA-C alleles in RM couples and HLA-DR and -DQ polymorphism in women with unexplained RM.

METHOD OF STUDY

HLA-C alleles were investigated in 35 RM and 30 control couples and HLA-DR and -DQ allogenotypes were investigated in 234 RM patients and 360 controls. All HLA investigations were undertaken by DNA based methods.

RESULTS

We found no difference between the RM and control couples in the degree of paternal incompatibility for maternal HLA-C alleles and the distribution of the two HLA-C supertypic specificities that are recognized differently by p58 killer cell inhibitory receptor (KIR) positive natural killer (NK) cells was similar in the two groups. In 97 women with at least four previous miscarriages, significantly higher frequencies of the HLA-DR1,DQ5 and -DR3,DQ2 haplotypes were found compared with 360 controls (P < 0.05 after correction for multiple comparisons). Among 94 RM patients followed prospectively, those with HLA-DR1 and/or -DR3 had a 62% miscarriage rate compared with only 29% among those without these alleles (P < 0.05). A large family study indicated that HLA-DR1 and/or -DR3 positive sisters and brothers' wives of probands with RM had an odds ratio of 5.0 for miscarrying their pregnancies compared with corresponding HLA-DR1 and -DR3 negative relatives. Finally, a meta-analysis of relevant studies based on a MEDLINE search showed that HLA-DR1, -DR3, and -DR4 were significantly increased in Caucasian women with RM.

CONCLUSIONS

HLA-DR1, -DR3, and maybe -DR4 show association to RM in Caucasian women whereas no association to classical HLA class I genes including HLA-C can be detected in RM couples. The mechanism by which class II alleles confer susceptibility to RM might be by predisposing to hypersecretion of certain cytokines, e.g., tumor necrosis factor (TNF)-alpha at the feto-maternal interface.

Association between HLA-DR1 and -DR3 antigens and unexplained repeated miscarriage

Few, mostly small, studies have investigated the distribution of HLA class II antigens among women with unexplained recurrent miscarriage. Although some studies have reported statistically significant associations between this syndrome and certain HLA-DR antigens--especially the -DR1 and -DR3 antigens--other studies have been unable to demonstrate such associations. For the present meta-analysis, 18 cross-sectional or case-control studies (published or unpublished) reporting on frequencies of HLA-DR1 and -DR3 antigens among Caucasian women with unexplained repeated miscarriage were identified by searching literature databases (MEDLINE and EMBASE), reading the references of identified studies, and by contacting researchers within the field. The studies comprised a total of 1508 patients. The methodological quality of most of the studies was low, especially because of small numbers of patients and because patients with only two miscarriages were included in many studies; this is defined as repeated miscarriage. The odds ratios of repeated miscarriage for the HLA-DR1 and -DR3 antigens were calculated for the individual studies and subsequently the pooled odds ratios for the studies were calculated. The combined odds ratio for HLA-DR1 was 1.29 [95% confidence interval (CI) = 1.05-1.58] (17 studies) which is statistically significant (P <0.05). The combined odds ratio for HLA-DR3 was 1.00 (95% CI 0.80-1.24) (18 studies), which is not significant. The results of the meta-analysis suggest that the HLA-DR antigen DR1 is associated with an increased susceptibility to unexplained repeated miscarriage.

Mannan-binding lectin deficiency is associated with unexplained recurrent miscarriage

Mannan-binding lectin (MBL) is a plasma protein which, upon binding to microbial carbohydrate structures, elicits activation of the complement system. The level of MBL is genetically determined. It has been reported that the frequency of low plasma levels of MBL is increased in patients with unexplained recurrent miscarriages (RM). In the present study plasma MBL levels were determined in 146 Danish women with RM and 41 of their husbands together with 49 Scottish RM women and 41 of their husbands. In both countries MBL levels were also investigated in a total of 444 controls. Based on the control data, a cut-off MBL level < 50 ng/ml was selected to define MBL deficiency. The typical odds ratio for MBL deficiency among female patients in the two populations was 1.68 (95% confidence limits 1.01-2.80, P<0.05) whereas it was 1.57 (95% confidence limits 0.72-3.42, not significant) for the male partners of the patients. There was a significant correlation between the frequency of MBL deficiency in RM women and the number of previous miscarriages (P < 0.01), whereas no such correlation was found in the husbands. The results indicate that maternal MBL deficiency is associated with RM. Maternal MBL deficiency might impair the immune defence against microorganisms at the feto-maternal interface.

Studies on associations between human leukocyte antigen (HLA) class II alleles and antiphospholipid antibodies in Danish and Czech women with recurrent miscarriages

Autoantibody production is commonly associated with particular HLA class II phenotypes. The aim of the present study was to investigate whether the presence of antiphospholipid (APL) antibodies and other autoantibodies in women with unexplained recurrent miscarriage was associated with particular human leukocyte antigen (HLA)-DR or -DQ alleles or linked epitopes which have previously been reported as being associated with the recurrent miscarriage syndrome or the presence of APL. In a total of 123 Danish and Czech women with recurrent miscarriage, serum was investigated for six different APL antibodies including anticardiolipin (ACL) antibody. Antinuclear antibodies (ANA), anti-zona pellucida antibodies and anti-sperm antibodies were also investigated. The women were HLA-DR and -DQ typed by DNA-based methods. The frequency of HLA-DR phenotypes did not differ significantly between APL antibody positive recurrent miscarriage patients and APL antibody negative recurrent miscarriage patients or healthy controls. Among ACL antibody positive recurrent miscarriage patients, significantly more were positive for the HLA-DR3 phenotype and negative for the HLA-DR2 phenotypes compared with healthy controls (P < 0.05). Among ANA positive recurrent miscarriage women, 55% carried the HLA-DR3 phenotype compared with 28% of ANA negative patients (P < 0.05) and 21% of healthy controls (P < 0.002). In conclusion, among recurrent miscarriage women, the HLA-DR3 phenotypes seem to predispose to formation of ACL antibodies and ANA. The association between APL antibodies and particular HLA alleles and HLA-linked epitopes reported in studies of patients with lupus erythematosus (e.g. HLA-DR7 and -DR4) could not be confirmed in patients with recurrent miscarriage.

HLA-E polymorphism in patients with recurrent spontaneous abortion

The aim of this study was to compare the frequencies of five HLA-E alleles in 82 women with recurrent spontaneous abortions with that of 150 random Danish controls. PCR sequence-specific oligonucleotide typing was carried out to detect polymorphism in exons 2 and 3 of the HLA-E gene. In informative samples sequencing of these two exons was also undertaken to confirm the presence of the HLA-E*01031 allele. HLA-E*0101, HLA-E*01032 and HLA-E*01031 were detected with frequencies of 56.7%, 33.6% and 9.6% in controls and 58,5%, 32.9% and 8.5% in patients with recurrent abortion, respectively. No HLA-E*0102 and E*0104 alleles could be detected. Since the HLA-E allele distribution was similar in women with recurrent spontaneous abortion and controls, it is suggested that maternal HLA-E polymorphism per se does not play any role in the pathogenesis of this disorder of pregnancy.

Is the expression of classical HLA class I antigens on trophoblast of importance for human pregnancy?

PROBLEM

Human leukocyte antigen (HLA)-C and possibly also HLA-B seem to be expressed on the extravillous trophoblast. These antigens carry epitopes that function as ligands for natural killer (NK)-cell-inhibitory receptors. Antitrophoblast cytotoxicity mediated by decidual NK cells might be involved in miscarriage. We thus found it relevant to elucidate whether parental HLA-C and -Bw polymorphism play a role in recurrent miscarriage (RM).

METHOD OF STUDY

HLA-C and -Bw investigations by DNA-based techniques were undertaken in 35 couples with unexplained RM and in 30 couples with normal fecundity. The number of HLA-C- and -Bw-related supertypic specificities that can bind NK-cell-inhibitory receptors was evaluated in selected couples.

RESULTS

The proportions of couples with RM and control couples carrying four HLA-C alleles with the same NK-cell-inhibitory supertypic specificities were equal. In 46% of studied couples with RM, all four HLA-B alleles carried the HLA-Bw6 supertypic specificity, which was significantly higher than the corresponding frequency (17%) in the control couples (P < 0.02).

CONCLUSIONS

The expression of polymorphic HLA-C on trophoblasts does not seem to play a role in RM. Assuming that HLA-B is expressed on trophoblasts, we may suggest that the revealed predominance of HLA-Bw6 expression (which excludes the presence of HLA-Bw4-protective antigens) may predispose a particular couple to the RM phenomenon.

Histocompatibility antigen studies in women with recurrent miscarriages and Müllerian uterine anomalies

OBJECTIVE

To determine whether the HLA alleles DR1, DR3, DR4 and DR10 which have been suggested to be risk markers for unexplained recurrent miscarriages also play a part in women with recurrent miscarriages with Müllerian uterine fusion anomalies.

STUDY DESIGN

HLA-DR typing was undertaken in 28 women with recurrent miscarriage who had been surgically treated for Müllerian anomalies and in 360 controls. In the study group, outcome of pregnancies after surgery was correlated to the results of the HLA typing.

RESULTS

In the study group, 61% were positive for HLA-DR1, -DR3, -DR4 or -DR10 compared with 65% of the controls (not significantly different). Among patients positive for these HLA risk markers, 64% of the pregnancies after surgery miscarried compared with 13% in those negative (P<0.005, RR for miscarriage=4.8, 95% CI= 1.3-18.0).

CONCLUSION

The proposed risk HLA markers for unexplained recurrent miscarriage also seem to display a negative impact on pregnancy outcome in patients with recurrent miscarriages with Müllerian uterine anomalies.

HLA-DR typing of women with recurrent late spontaneous abortion and unsuccessful cervical cerclage

The release of certain cytokines, e.g. tumour necrosis factor (TNF)-alpha, in the amniotic fluid has been suggested to be a cause of preterm birth. The predisposition to excessive liberation of cytokines from peripheral leukocytes has been shown to depend partly on the individual's HLA-DR genotype. The HLA-DR1 and -DR3 alleles have previously been reported as being associated with a TNF-alpha high responder status and have also been associated with unexplained recurrent spontaneous abortions. In the present study, HLA-DR typing was performed in 10 women who had experienced recurrent very early preterm births resulting in perinatal death, or late spontaneous abortions under a clinical picture resembling that traditionally attributed to cervical incompetence. All patients had had at least one mid-trimester miscarriage in spite of the insertion of a cervical cerclage. Nine out of 10 (90%) patients had the HLA-DR phenotypes DR1 and/or DR3 compared with 37% in the background population (P < 0.005). The results suggest that HLA-DR-associated immunological factors might play a part in recurrent late spontaneous abortions and extremely preterm births under a cervical incompetence-like picture, at least in the subset of cases not treatable by cervical cerclage.

Intravenous immunoglobulin in the prevention of recurrent spontaneous abortion: the European experience

PROBLEM

Clinical trials of the use of intravenous immunoglobulin (IvIg) in the treatment of recurrent spontaneous abortion (RSA) in Europe were reported and discussed.

METHOD OF STUDY

A search of the published literature, combined with our own published and unpublished results, was performed.

RESULTS

Two placebo-controlled trials have been concluded in Europe. One trial found high but equal success rates in both the IvIg and the placebo group. Another trial found that IvIg treatment may increase the success rate by 24% compared with placebo but that the result was not statistically significant, which might be due to the small number of patients. Reasons for the diverse results of the two trials were discussed.

CONCLUSION

More and larger placebo-controlled trials of IvIg treatment in RSA are needed before drawing definitive conclusions.

HLA-C and -Bw typing of couples with unexplained recurrent miscarriages

There is now evidence that the classical HLA class I molecule HLA-C is expressed on extravillous trophoblasts together with non-classical HLA-G molecules. Since clones of NK-cells are inhibited differently by supertypic epitopes associated with HLA-C and -B alleles we found it of interest to study HLA-C and -Bw polymorphism in 35 couples with recurrent miscarriage and 30 control couples with normal fecundity. All HLA assignments were undertaken by DNA techniques. The distribution of HLA-C alleles or the HLA-C associated supertypic epitopes recognized by NK1 or NK2 clones was not significantly different between patients and controls. The distribution of couples according to the number of NK1 and NK2 epitopes in the couple was similar in patients and controls. With respect to the HLA-Bw epitopes recognized by NKB1 clones, in 46% of the couples with recurrent miscarriage none of the spouses carried the HLA-Bw4 epitope compared with only 17% of the control couples (P < 0.02). It is concluded that the HLA-Bw4 epitope is carried more frequently by couples with normal fecundity than couples with recurrent miscarriage. The fetuses of couples with recurrent miscarriage are thus expected to lack expression of HLA-Bw4 epitopes on the trophoblast more often than fetuses of normal couples which might be of importance for the inhibition of NK-cell mediated antitrophoblast cytotoxicity.

[Habitual abortion. A review of etiology, diagnosis and treatment with emphasis on immunonological factors]

Almost 1% of women who attempt pregnancy will experience recurrent miscarriage. The majority of traditionally accepted causes of recurrent miscarriage lack proper documentation and the evidence for the majority of treatments is sparse. An increased level of midfollicular phase luteinizing hormone seems to be associated with some cases of recurrent miscarriage. Many autoantibodies are found with increased frequency in women with recurrent miscarriage, and they seem to be associated with an increased risk of adverse pregnancy outcome. This may indicate that the autoantibodies per se or associated immunological phenomena are risk factors for the condition. Polygenically determined immunological phenomena seem to play an important role. Treatment of recurrent miscarriage by anticoagulation, allogeneic lymphocyte immunization or intravenous immunoglobulin is under evaluation in controlled trials.

A fresh look at the causes and treatments of recurrent miscarriage, especially its immunological aspects

The scientific basis for many traditionally accepted causes of recurrent miscarriage (RM) is weak. A significant proportion of RM cases with relatively few miscarriages can presumably be attributed to the random occurrence of consecutive chromosomally abnormal conceptions. New insights in the immunological interactions taking place at the feto-maternal interface provide us with the opportunity to propose detailed pathophysiological models for immunologically mediated RM. Scientific support for the theory that RM is a consequence of graft rejection-like alloimmune reactions against paternal human leukocyte antigens on the fetus is sparse. Conversely, there is considerable evidence that decidual natural killer cells play a role in the implantation and early invasion of the trophoblast and in the pathogenesis of RM. T helper (Th) cells from women with RM react against trophoblast antigens in vitro with the secretion of mainly interleukin-2 and interferon-gamma (a so-called Th1 response), which are known to inhibit trophoblast growth. The predisposition to a Th1 response against a given antigen may be determined by an individual's class II histocompatibility genes. In accordance with this, case-control, prospective and family studies indicate that maternal histocompatibility haplotypes comprising DR1 and DR3 alleles confer susceptibility to RM. The frequent occurrence of autoantibodies in women with RM is compatible with the theory of a Th1 response against trophoblast as a cause of the syndrome, but the autoantibodies themselves probably do not cause RM.

Maternal HLA class II alleles predispose to pregnancy losses in Danish women with recurrent spontaneous abortions and their female relatives

PROBLEM

If damage to the trophoblast mediated through autoimmune mechanisms is responsible for recurrent spontaneous abortions (RSA), maternal class II HLA antigens might be expected to be involved. We wanted to evaluate the impact of these antigens on pregnancy outcome in RSA women and their relatives.

METHOD

HLA-DR and -DQ typing using RFLP and PCR-SSP methods was carried out in 234 Danish women with unexplained RSA and 360 controls. The HLA-DR types were correlated to outcome of the next pregnancy in 94 patients. Sisters, brothers, and wives of brothers of 146 consecutive patients were HLA typed and their pregnancy outcomes were correlated to the HLA-DR types.

RESULTS

HLA-DR1/Br and -DR3 were each significantly increased in women with at least four previous pregnancy losses (both P-values < 0.05 after correction for multiple comparisons). In the prospective study, 62% of the HLA-DR1/Br and/or -DR3 positive patients miscarried the next pregnancy compared with only 29% of those negative for both allogenotypes (P = 0.025). The family studies indicated that female relatives of RSA patients had a greater risk (odds ratio = 5.0, 95% CI = 2.0-11.0) of pregnancy losses when positive for HLA-DR1/Br and/or -DR3 than those negative for the allogenotypes.

CONCLUSIONS

Maternal HLA-DR allogenotypes DR1/Br and -DR3 or closely linked genes seem to predispose to pregnancy losses in RSA patients and their first degree relatives.

Placebo-controlled trial of treatment of unexplained secondary recurrent spontaneous abortions and recurrent late spontaneous abortions with i.v. immunoglobulin

The aim of this trial was to investigate whether infusions of i.v. immunoglobulins (Ig) to women with secondary recurrent spontaneous abortions and recurrent second trimester spontaneous abortions can increase the rate of successful pregnancy. In a prospective, double-blind, placebo-controlled trial, infusions of i.v. Ig (Nordimmun) or placebo were given during pregnancy to 34 women with a history of either unexplained recurrent spontaneous abortion subsequent to a birth or including at least one second trimester miscarriage. The success rate was 52.9% in the i.v. Ig group compared with 29.4% in the placebo group (not significantly different, therapeutic gain 23.5%, 95% confidence interval -8.6 to 55.7%). No changes in autoantibody concentrations or major lymphocyte subsets were induced by i.v. Ig treatment. In conclusion, an expected 55% therapeutic gain of i.v. Ig in recurrent spontaneous abortion could not be confirmed using the treatment regimen tested. However, to determine whether the trend of therapeutic gain of i.v. Ig in these women may be statistically significant, a larger trial is in progress.

Maternal HLA class II allogenotypes are markers for the predisposition to fetal losses in families of women with unexplained recurrent fetal loss

The HLA allogenotypes DR1/Br, DR3 and DR10 (entitled risk HLA markers) have been reported as being genetic markers for the predisposition to experience unexplained recurrent fetal losses. The aim of the study was to determine whether the putative risk HLA markers might also be markers for the risk of pregnancy loss in sisters and wives of brothers of women with unexplained recurrent fetal losses. Information concerning pregnancy outcomes among the relatives of 146 consecutive women with unexplained recurrent fetal losses was collected. Ninety-five of the full sisters, 69 of the full brothers and 50 of the wives of the brothers were HLA typed. Sisters who had experienced at least one previous pregnancy loss (affected women) shared more HLA haplotypes with the proband than unaffected sisters, when the proband was positive for the risk markers (P = 0.02). More affected than unaffected sisters and brothers' wives were positive for the risk markers (P < 0.005 and P < 0.03; respectively). The lowest estimate of the odds ratio for experiencing pregnancy loss among sisters and brothers' wives who were positive compared with those negative for the risk markers was 3.5 (95% credible interval = 1.9-5.8). It is concluded that maternal DR1/Br, DR3 and DR10 allogenotypes seem to be genetic markers for the risk of pregnancy loss among relatives of women with unexplained recurrent fetal losses. The pattern of inheritance suggests a polygenic mode of inheritance with alleles linked to the risk HLA markers interacting with non-HLA linked genes expressed on the fetus or the trophoblast.

HLA class II alleles confer susceptibility to recurrent fetal losses in Danish women

HLA-DR and -DQ typings were performed by a combination of RFLP and PCR-SSP techniques in 234 Danish women with at least three consecutive unexplained fetal losses (recurrent fetal losses) and 360 controls and the DRB1, DQA1 and DQB1 alleles were deduced. In the total group of patients, the frequency of no DRB1-DQA1-DQB1 haplotype was significantly increased compared with controls. In the subgroup of 97 women with four or more fetal losses (multiple fetal loss group), the frequency of women carrying the DRB1*0101, DQA1*0101, DQB1*0501; DRB1*0102, DQA1*0101, DQB1*0501 and DRB1*0103, DQA1*0101, DQB1*0501 haplotypes or the DRB1*0301, DQA1*0501, DQB1*0201 haplotype were significantly increased compared with controls (RR = 2.1; pc < 0.05 with regard to former three haplotypes combined and RR = 2.2; pc < 0.05 for the latter). The frequency of women with at least one of the four haplotypes was significantly (p < 0.002) increased with the number of previous fetal losses in the women's history. Analysis of the DQA1 and DQB1 phenotypes in women with at least four fetal losses showed that DQA1*0501 and DQB1*0501 were increased compared with controls (RR = 1.9; pc < 0.05 and RR = 2.2; pc < 0.025, respectively). Analysis of DRB1-DQA1-DQB1/DRB1-DQA1-DQB1 genotypes suggested that genotypes comprising both DQA1*0501 and DQB1*0501 alleles (in trans) exhibited a higher RR for experiencing at least four fetal losses (RR = 3.4, p = 0.002) than each of the alleles did alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Placebo-controlled trial of active immunization with third party leukocytes in recurrent miscarriage

OBJECTIVE

To investigate whether active immunization with third party leukocytes improves pregnancy outcome in women with unexplained recurrent miscarriages.

DESIGN

A double-blind prospective placebo-randomized trial.

PATIENTS

Sixty-six patients with unexplained recurrent miscarriages achieved pregnancy after having received active immunization or placebo.

INTERVENTIONS

Among the patients who achieved pregnancy, 43 were immunized with third party leukocytes and 23 received autologous leukocytes.

MAIN OUTCOME MEASURES

Frequency of new miscarriages in actively immunized women compared with placebo.

RESULTS

In the total group of patients, 71% of the actively immunized patients had a successful pregnancy compared with 48% of the placebo treated patients (not significant, RR = 0.6; 95% confidence limits = 0.3-1.1). In a subgroup of patients with primary recurrent miscarriages the success rate was 76% compared with 38% in the placebo group (p < 0.02, RR = 0.4; 95% confidence limits = 0.2-0.9). In this subset of patients, median birthweight was also significantly higher in actively immunized patients than in placebo treated patients (3445 g versus 3000 g; p < 0.05).

CONCLUSIONS

Active immunization did not provide any benefit in the overall group of women with recurrent miscarriages. However, among women with primary recurrent miscarriages it may improve outcome with respect to the number of livebirths and birthweight.

Prognostic significance of maternal DR histocompatibility types in Danish women with recurrent miscarriages

In a previous case-control study of women with unexplained recurrent miscarriages we reported that the frequency of women positive for each of the two histocompatibility (HLA) types HLA-DR1, Br and HLA-DR3 was increased in a subset of patients with a history of four or more miscarriages. In the present study we examined whether the increased frequency of the two HLA types in this subset of patients indicated that they would result in a poor pregnancy prognosis. We related pregnancy outcomes to the mothers' HLA-DR type in a prospective study of a well-defined, closely supervised group of 94 women with unexplained recurrent miscarriages who had achieved intra-uterine pregnancy in the course of one of two prospective placebo-controlled trials concerning the efficacy of immunotherapy. Of the patients who were HLA-DR1, Br and/or HLA-DR3 positive 62% miscarried their next pregnancy compared with 29% of the patients negative for the two HLA types [relative risk of miscarriage in the former group = 2.2 (P < 0.002) unadjusted, and 1.8 (P = 0.025) when adjusted for the number of previous miscarriages]. The results suggest that Danish women with unexplained recurrent miscarriages who are positive for HLA-DR1, Br and/or -DR3 display a poorer pregnancy outcome than patients negative for these types.