Pregnancy loss is associated with type 2 diabetes: a nationwide case-control study

Association of spontaneous abortion and lifestyle with diabetes mellitus in women: a cross-sectional study in UK Biobank

BACKGROUND

Spontaneous abortion has been associated with higher risk of type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM), while the evidence remains equivocal. This study aimed to examine the association between spontaneous abortion and the risk of T2DM and GDM, and assesses whether lifestyle factors modified this association.

METHODS

This cross-sectional study used data from the UK Biobank, recruiting 170 599 ever-pregnant women from 22 assessment centers in England, Scotland, and Wales between 2006 and 2010. History of spontaneous abortion was self-reported and was confirmed by using medical records, categorized as none, 1, 2, or ≥3 spontaneous abortions. The primary outcomes, T2DM and GDM, were ascertained from medical records using ICD-10 codes. Multivariable logistic regression was performed to estimate the adjusted odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for sociodemographic and health factors (e.g., age, ethnicity, cancer, chronic hypertension), reproductive factors (e.g., use of oral contraceptives, use of hormone treatment, hypertensive disorders of pregnancy), and lifestyle score. The lifestyle score was constructed based on smoking status, alcohol intake, physical activity, television viewing time, sleep duration, and diet quality. Effect modification by lifestyle score was assessed using multiplicative interaction terms in the regression models.

RESULTS

Among 170 599 ever-pregnant women (mean [SD] age, 56.4 [8.0] years), a history of spontaneous abortion was associated with higher odds of T2DM (OR 1.17, 95% CI 1.10-1.24) and GDM (OR 1.38, 95% CI 1.20-1.60). The odds were higher for recurrent spontaneous abortions (for T2DM: ORs were 1.33 [95% CI 1.14-1.56] for three or more spontaneous abortions, 1.07 [95% CI 0.93-1.23] for two, and 1.09 [95% CI 1.01-1.17] for one compared with none; for GDM: the corresponding ORs were 2.01 [95% CI 1.48-2.71], 1.21 [95% CI 0.90-1.64], and 1.20 [95% CI 1.01-1.42], respectively). The odds of T2DM and GDM higher with less healthy lifestyle behaviors in both categories of spontaneous abortion, although no significant interactions between spontaneous abortion and lifestyle score were observed (P-interaction>0.05).

CONCLUSIONS

Spontaneous abortion was associated with higher odds of T2DM and GDM, with a stronger association observed in women who experienced recurrent spontaneous abortions. It is imperative to integrate reproductive history into routine diabetes risk assessment, particularly for women with a history of multiple spontaneous abortions.

Risk factors associated with pregnancy loss after single euploid blastocysts transfer

Objective

To detect primary factors influencing pregnancy loss(PL) following the transfer of euploid blastocysts?

Design

Retrospective cohort study.

Methods

To identify potential factors influencing PL, we analyzed multiple variables in both the PL group and the live birth group. In order to minimize the impact of confounding factors, various variables were included in a binary logistic regression analysis.

Results

The PL rate after the transfer of euploid embryos is 13.3% (36 cases of PL out of 270 cases of single embryo transfer). Compared to the live birth group, the PL group had lower E2 levels (2376.03 ± 1553.25 vs 3412.88 ± 2116.47, P=0.007), higher LH levels (2.66 ± 2.47 vs 1.96 ± 1.52, P=0.023) on trigger day of fresh cycle, fewer retrieved oocytes (10.08 ± 5.01 vs 12.77 ± 7.20, P=0.044), higher female BMI (23.26 ± 3.27 vs 22.05 ± 2.69, P=0.016), higher proportion of maternal smokers (50% vs 20.51%, P<0.001), and more day 6 blastocyst transfers ((38.89% vs14.53, P=0.001). Logistic regression analysis revealed that higher LH levels(OR=1.304, 95%CI=1.054-1.613, P=0.015), low E2 levels (OR=0.438, 95%CI=0.242-0.794, P=0.007) on trigger day of fresh cycle, maternal smoking(OR=4.574, 95%CI=1.974-10.601, P<0.001), and day 6 blastocyst transfer(OR=4.610, 95%CI=1.907-11.141, P=0.001) appeared to be associated with increased risk of PL following the transfer of euploid embryos.

Conclusions

Maternal smoking, day of blastocyst transferred, estradiol (E2) and Luteinizing hormone (LH) levels on trigger day of corresponding fresh cycle for transferred blastocysts are all associated with PL following transfer of euploid embryos.

Association between diabetes mellitus and miscarriage, recurrent miscarriage: A meta-study

BACKGROUND

Previous studies provided inconsistent associations between diabetes mellitus (DM) and miscarriage, recurrent miscarriage (RM). Therefore, this study aims to evaluate the association between DM and miscarriage, specifically RM, through a meta-analysis approach.

METHODS

We searched for articles published before July 2023 in PubMed and Web of Science databases. STATA 12.0 software was used to compute all the results collected from included studies.

RESULTS

DM was associated with a higher risk of miscarriage, RM (miscarriage: odds ratio [OR]/relative risk [RR] = 1.23, 95% confidence interval [CI] 1.13 to 1.34; RM: OR/RR = 1.73, 95% CI 1.55 to 1.94). T1DM was associated with a higher risk of miscarriage (OR/RR = 1.16, 95% CI 1.07 to 1.26). Similarly, T2DM showed a higher risk of miscarriage (OR/RR = 1.44, 95% CI 1.23 to 1.68). Miscarriage, RM were associated with a higher risk of DM (miscarriage: OR/RR = 1.14, 95% CI 1.08 to 1.19; RM: OR/RR = 1.14, 95% CI 1.08 to 1.20). Furthermore, miscarriage was found to be associated with a higher risk of T2DM (OR/RR = 1.08, 95% CI 1.05 to 1.11).

CONCLUSION

In conclusion, our meta-analysis findings indicate a significant association between DM and miscarriages as well as RM. As a result, women with a history of miscarriage should consider regular monitoring of their metabolic health as a potential benefit. Nevertheless, it is important to note that further research is needed to validate the results of our study and shed light on the biological mechanisms underlying these associations.

Evaluating risk factors in recurrent pregnancy loss: A prospective cohort study and its impact on live birth outcomes

Recurrent pregnancy loss (RPL) affects 1-2 % of all couples trying to conceive and is a challenging heterogeneous condition. This study aimed to evaluate the prevalence and impact of various risk factors in patients suffering from RPL. We performed a prospective cohort study including patients at the tertiary RPL Unit in the Capital Region of Denmark between 1st January 2000 and 1st January 2023. The main outcome of the study was the first pregnancy after referral and whether the pregnancy was ongoing at least to the 22nd gestational week. A total of 2555 patients were included in the study, out of whom 1892 patients achieved a pregnancy after referral to the RPL Unit. This resulted in 1103 live births (58.3 %) and 718 pregnancy losses (37.9 %). Maternal age, BMI, smoking status and the number of prior pregnancy losses were negatively correlated with the likelihood of achieving pregnancy. Furthermore, maternal age, prior pregnancy losses, antiphospholipid syndrome (APS) and uterine malformations were associated with reduced birth rates. Patients with secondary RPL had a higher birth rate compared to those with primary RPL, and patients with APS treated with low-molecular-weight heparin (LMWH) demonstrated a significantly increased birth rate compared to untreated APS patients. These findings suggest that certain risk factors significantly impact the likelihood of achieving pregnancy and live birth following RPL, which can be used in patient guidance.

Diabetic and hypertensive disorders following early pregnancy loss: a systematic review and meta-analysis

Background

Spontaneous and induced abortions are common outcomes of pregnancy. There is inconsistent evidence of an association between early pregnancy loss and subsequent diabetic and hypertensive disorders in women. This systematic review and meta-analysis evaluated evidence on the risk of the subsequent development of pregnancy and non-pregnancy related diabetic and hypertensive disorders in women who experienced an early pregnancy loss.

Methods

Systematic searches were conducted in seven electronic databases (CINAHL Plus, Ovid/EMBASE, Ovid/MEDLINE, ProQuest, PubMed, Scopus, and Web of Science) from inception to 22nd December 2023. Studies were included if they reported an exposure of spontaneous abortion (SAB), induced abortion (IA) or recurrent pregnancy loss (RPL) with an outcome of gestational diabetes mellitus, pre-eclampsia, gestational hypertension, and non-pregnancy related diabetic and hypertensive disorders. Risk of bias was assessed using Risk of Bias Instrument for Non-Randomized Studies of Exposures (ROBINS-E). Random effects meta-analysis was used to pool odds of developing diabetic and hypertensive disorders following an early pregnancy loss. This study is registered with PROSPERO (CRD42022327689).

Findings

Of 20,176 records, 60 unique articles were identified for full-text review and 52 met the inclusion criteria, representing a total population of 4,132,895 women from 22 countries. Thirty-five studies were suitable for meta-analysis, resulting in a pooled odds ratio (OR) of 1.44 (95% confidence interval (CI) 1.23-1.68) for gestational diabetes mellitus following a prior SAB and a pooled OR of 1.06 (95% CI 0.90-1.26) for pre-eclampsia following a prior SAB. RPL increased the odds of developing pre-eclampsia (OR 1.37 95% CI 1.05-1.79). There was no association between IA and diabetic and hypertensive disorders.

Interpretation

A prior SAB was associated with increased odds of gestational diabetes mellitus, but not pre-eclampsia. However, women who experienced RPL had an increased risk of subsequent pre-eclampsia. Future research is required to establish evidence for an association between early pregnancy loss with non-pregnancy related diabetic and hypertensive disorders.

Funding

National Health and Medical Research Council.

"Translation, cultural adaptation, and validation of perinatal grief scale in Urdu: Addressing a gap in the research of perinatal loss in Pakistan-Cross-sectional validation study"

Background and Aims

Perinatal grief have a significant influence on maternal mental health, hence appropriate tools for assessment are necessary. In this study, we translated and validated the Perinatal Grief Scale in Urdu (PGS-Urdu) for use in Pakistan, therefore filling the gap in validated tools.

Methods

Data was collected from 165 women using consecutive sampling. Initially, "forward/backward" translation was used. For validity, content validity index and confirmatory factor analysis (CFA) were used respectively, and "Cronbach's-Alpha" for reliability. In the validity stage, items 8, 11, 23, and 32 of the original scale were eliminated based on feedback from the target groups and the expert panel. For data-analysis, SPSS 26 and Amos 26 were used.

Results

In analyzing the "Confirmatory factor analysis", the "all-fitness indicators" validated the three-factor structure of 29-item main scale. Cronbach alpha value was 0.83 for the entire scale The CFA results showed that all fitness indicators, with the exception of four, had loadings greater than 0.20, supporting the main scale's three-factor structure. With a Cronbach's Alpha value of 0.83 for overall reliability, and varied from 0.81 to 0.87 for the PGS-U variables. the PGS-U exhibits an acceptable level of internal consistency.

Conclusion

The PGS-U identifies women in perinatal grief for medical and social care. This research supports using the Urdu perinatal grief scale in obstetrics and bereavement counseling to reduce maternal mental health issues.

Adverse outcomes in subsequent pregnancies in women with history of recurrent spontaneous abortion: A meta-analysis

OBJECTIVE

This study aimed to investigate the association between a history of recurrent spontaneous abortion (RSA) and adverse outcomes in women with spontaneous conception.

METHODS

A search strategy from the inception to March 3, 2023 was run in PubMed, Embase, Cochrane Library, and Web of Science databases. The odds ratio (OR), and the 95% confidence interval (CI) or point estimation were used as the evaluation indexes. Each outcome measure tested was assessed for heterogeneity using the Cochran Q test. Sensitivity analyses were performed to test the credibility of the meta-analysis results.

RESULTS

Fifteen studies involving 1 475 389 pregnant women were included. A history of RSA was associated with gestational diabetes (OR: 2.21, 95% CI: 1.70-2.87, p < 0.001), preeclampsia (OR: 2.06, 95% CI: 1.49-2.86, p < 0.001), placenta previa (OR: 1.82, 95% CI: 1.09-3.02, p = 0.021), placental abruption (OR: 1.67, 95% CI: 1.36-2.06, p < 0.001), miscarriage (OR: 6.37, 95% CI: 3.83-10.57, p < 0.001), preterm birth (OR: 1.80, 95% CI: 1.36-2.37, p < 0.001), cesarean section (OR: 1.47, 95% CI: (1.13-1.91, p = 0.004), perinatal death (OR: 2.24, 95% CI: 1.39-3.60, p = 0.001), and neonatal intensive care unit admission (OR: 1.39, 95% CI: 1.01-1.92, p = 0.047). However, the associations of a history of RSA with gestational hypertension, small for gestational age, fetal anomalies, fetal growth restriction, and postpartum hemorrhage were not observed.

CONCLUSION

This meta-analysis indicates a history of RSA was associated with increased risks of several adverse outcomes in pregnant women with spontaneous conception.

Fetal loss and long-term maternal morbidity and mortality: A systematic review and meta-analysis

BACKGROUND

Evidence suggests common pathways between pregnancy losses and subsequent long-term maternal morbidity, rendering pregnancy complications an early chronic disease marker. There is a plethora of studies exploring associations between miscarriage and stillbirth with long-term adverse maternal health; however, these data are inconclusive.

METHODS AND FINDINGS

We systematically searched MEDLINE, EMBASE, AMED, BNI, CINAHL, and the Cochrane Library with relevant keywords and MeSH terms from inception to June 2023 (no language restrictions). We included studies exploring associations between stillbirth or miscarriage and incidence of cardiovascular, malignancy, mental health, other morbidities, and all-cause mortality in women without previous pregnancy loss. Studies reporting short-term morbidity (within a year of loss), case reports, letters, and animal studies were excluded. Study selection and data extraction were performed by 2 independent reviewers. Risk of bias was assessed using the Newcastle Ottawa Scale (NOS) and publication bias with funnel plots. Subgroup analysis explored the effect of recurrent losses on adverse outcomes. Statistical analysis was performed using an inverse variance random effects model and results are reported as risk ratios (RRs) with 95% confidence intervals (CIs) and prediction intervals (PIs) by combining the most adjusted RR, odds ratios (ORs) and hazard ratios (HRs) under the rare outcome assumption. We included 56 observational studies, including 45 in meta-analysis. There were 1,119,815 women who experienced pregnancy loss of whom 951,258 had a miscarriage and 168,557 stillbirth, compared with 11,965,574 women without previous loss. Women with a history of stillbirth had a greater risk of ischaemic heart disease (IHD) RR 1.56, 95% CI [1.30, 1.88]; p < 0.001, 95% PI [0.49 to 5.15]), cerebrovascular (RR 1.71, 95% CI [1.44, 2.03], p < 0.001, 95% PI [1.92, 2.42]), and any circulatory/cardiovascular disease (RR 1.86, 95% CI [1.01, 3.45], p = 0.05, 95% PI [0.74, 4.10]) compared with women without pregnancy loss. There was no evidence of increased risk of cardiovascular disease (IHD: RR 1.11, 95% CI [0.98, 1.27], 95% PI [0.46, 2.76] or cerebrovascular: RR 1.01, 95% CI [0.85, 1.21]) in women experiencing a miscarriage. Only women with a previous stillbirth were more likely to develop type 2 diabetes mellitus (T2DM) (RR: 1.16, 95% CI [1.07 to 2.26]; p < 0.001, 95% PI [1.05, 1.35]). Women with a stillbirth history had an increased risk of developing renal morbidities (RR 1.97, 95% CI [1.51, 2.57], p < 0.001, 95% [1.06, 4.72]) compared with controls. Women with a history of stillbirth had lower risk of breast cancer (RR: 0.80, 95% CI [0.67, 0.96], p-0.02, 95% PI [0.72, 0.93]). There was no evidence of altered risk of other malignancies in women experiencing pregnancy loss compared to controls. There was no evidence of long-term mental illness risk in women with previous pregnancy losses (stillbirth: RR 1.90, 95% CI [0.93, 3.88], 95% PI [0.34, 9.51], miscarriage: RR 1.78, 95% CI [0.88, 3.63], 95% PI [1.13, 4.16]). The main limitations include the potential for confounding due to use of aggregated data with variable degrees of adjustment.

CONCLUSIONS

Our results suggest that women with a history of stillbirth have a greater risk of future cardiovascular disease, T2DM, and renal morbidities. Women experiencing miscarriages, single or multiple, do not seem to have an altered risk.

Pregnancy Loss and the Risk of Myocardial Infarction, Stroke, and All-Cause Mortality: A Nationwide Partner Comparison Cohort Study

Background Pregnancy loss has been associated with myocardial infarction, stroke, and all-cause mortality in women through unknown mechanisms. The aim of this study was to examine these associations in women and their male partners. Methods and Results In this register-based cohort study, all people born between 1957 and 1997, residing in Denmark between 1977 and 2017, and with a registered partner of the opposite sex were eligible for inclusion. Male partners through cohabitation, marriage, or paternity constituted the male cohort. Exposure to pregnancy loss was categorized as follows: 0, 1, 2, or ≥3 pregnancy losses. The outcomes of interest were myocardial infarction, stroke, and all-cause mortality. The Cox proportional hazards model estimated hazard ratios (HRs), adjusted for age, calendar year, parity, and parental history of myocardial infarction or stroke. During follow-up, 1 112 507 women experienced 4463 events of myocardial infarction compared with 13 838 events among 1 120 029 male partners. With the no pregnancy loss group as reference, the adjusted HRs of myocardial infarction in the female cohort after 1, 2, and ≥3 pregnancy losses were as follows: 1.1 (95% CI, 1.0-1.2), 1.3 (95% CI, 1.1-1.5), and 1.4 (95% CI, 1.1-1.8), respectively. In the male partner cohort, the corresponding estimates were 1.0 (95% CI, 1.0-1.1), 1.1 (95% CI, 1.0-1.2), and 1.0 (95% CI, 0.8-1.2), respectively. The outcome of stroke showed similar results. Pregnancy loss was not significantly associated with increased mortality in either sex. Conclusions Pregnancy loss or stillbirth was significantly associated with myocardial infarction and stroke in women but not their male partners. Pregnancy loss or stillbirth was not significantly associated with all-cause mortality in women or male partners.

Perinatal outcomes in nulliparous women with a history of multiple pregnancy losses according to number of previous pregnancy losses

BACKGROUND

While it is widely acknowledged that pregnancy losses can lead to negative outcomes for both mothers and fetuses, there is limited information available on the specific levels of risk associated with each additional pregnancy loss.

OBJECTIVE

This study aimed to investigate the effect of number of previous pregnancy losses among nulliparous women on maternal and neonatal adverse outcomes.

STUDY DESIGN

This was a multicenter retrospective cohort study. The study population included all nulliparous women with singleton pregnancies who delivered in all university-affiliated obstetrical centers in a single geographic area between 2003 and 2021. Maternal and neonatal outcomes of women who delivered at our medical centers and had varying numbers of previous pregnancy losses were compared with women who had no previous pregnancy loss. The primary outcome of this study was preterm delivery rate at <37 weeks of gestation. The secondary outcomes were adverse maternal and neonatal outcomes. Univariate analysis was performed using multiple logistic regression modeling.

RESULTS

During the study period, 97,904 nulliparous women met the inclusion and exclusion criteria. Of those women, 84,245 (86%) had no previous pregnancy losses (reference group), 10,724 (11%) had 1 previous pregnancy loss, 2150 (2.2%) had 2 previous pregnancy losses, 516 (0.5%) had 3 previous pregnancy losses, 160 (0.2%) had 4 previous pregnancy losses, and 99 (0.1%) had ≥5 previous pregnancy losses. Women who had previous pregnancy losses had significantly higher rates of preterm delivery, hypertensive disorders of pregnancy, diabetes mellitus (pregestational and gestational), unplanned cesarean delivery, perinatal death, neonatal intensive care unit admissions, and neonatal hypoglycemia. The risks of preterm delivery and most other adverse obstetrical outcomes correlated with the number of previous pregnancy losses. Multivariate analyses showed that each previous pregnancy loss was associated with an additional, significant, increased risk of preterm delivery of 14% at <37 weeks of gestation, 37% at <34 weeks of gestation, 45% at <32 weeks of gestation, and 77% at <28 weeks of gestation.

CONCLUSION

A history of previous pregnancy losses increased the risk of preterm delivery and other perinatal outcomes in a dose-dependent manner. To minimize perinatal complications, obstetricians should be aware of the risks and complications in this unique population, consider close monitoring of the cervical length, and maintain high vigilance in case of complications with special attention to other potentially modifiable risks.

Assessing the efficacy and safety of Sildenafil vs. Nifedipine in improving endometrial blood flow and thickness in women with recurrent first-trimester miscarriage

Endometrial thickness and uterine blood flow influence pregnancy continuation until term. Nifedipine, a type II calcium channel blocker, and Sildenafil, a type 5-specific phosphodiesterase inhibitor, have shown the potential to improve these factors. This study aims to compare the safety and efficacy of Nifedipine and Sildenafil in improving endometrial blood flow and thickness in Iraqi women with recurrent first-trimester miscarriages. Women with unexplained recurrent pregnancy loss in the first trimester (non-pregnant during the study) were randomly assigned to two groups. Transvaginal color Doppler ultrasound assessed uterine artery pulsatility, resistance indexes, and endometrial thickness during the second phase of the menstrual cycle (day 15 to day 25). The first group received oral Nifedipine (10 mg) twice daily, while the second group received oral Sildenafil citrate (20 mg) every 8 hours from day 5 to day 25. Baseline measurements showed no significant differences in pulsatility index between the groups (2.02±0.52 for Nifedipine, 2.03±0.49 for Sildenafil, p=0.927). Sildenafil treatment resulted in a more noticeable reduction in the pulsatility index. The resistive index had a significant difference in baseline readings (0.98±0.14 for Nifedipine, 1.06±0.14 for Sildenafil, p=0.033), with Sildenafil showing a more pronounced reduction. Post-treatment, Sildenafil demonstrated a greater improvement in endometrial thickness than Nifedipine (10.09±0.74 mm vs. 9.34±0.50 mm, respectively; p<0.001). Both medications were safe and effective in improving endometrial blood flow and thickness in women with recurrent pregnancy miscarriages, with Sildenafil showing greater efficacy.

Cell-free fetal DNA for genetic evaluation in Copenhagen Pregnancy Loss Study (COPL): a prospective cohort study

BACKGROUND

One in four pregnancies end in a pregnancy loss. Although the effect on couples is well documented, evidence-based treatments and prediction models are absent. Fetal aneuploidy is associated with a higher chance of a next successful pregnancy compared with euploid pregnancy loss in which underlying maternal conditions might be causal. Ploidy diagnostics are therefore advantageous but challenging as they require collection of the pregnancy tissue. Cell-free fetal DNA (cffDNA) from maternal blood has the potential for evaluation of fetal ploidy status, but no large-scale validation of the method has been done.

METHODS

In this prospective cohort study, women with a pregnancy loss were recruited as a part of the Copenhagen Pregnancy Loss (COPL) study from three gynaecological clinics at public hospitals in Denmark. Women were eligible for inclusion if older than 18 years with a pregnancy loss before gestational age 22 weeks (ie, 154 days) and with an intrauterine pregnancy confirmed by ultrasound (including anembryonic sac), and women with pregnancies of unknown location or molar pregnancies were excluded. Maternal blood was collected while pregnancy tissue was still in situ or within 24 h after pregnancy tissue had passed and was analysed by genome-wide sequencing of cffDNA. Direct sequencing of the pregnancy tissue was done as reference.

FINDINGS

We included 1000 consecutive women, at the time of a pregnancy loss diagnosis, between Nov 12, 2020, and May 1, 2022. Results from the first 333 women with a pregnancy loss (recruited between Nov 12, 2020, and Aug 14, 2021) were used to evaluate the validity of cffDNA-based testing. Results from the other 667 women were included to evaluate cffDNA performance and result distribution in a larger cohort of 1000 women in total. Gestational age of fetus ranged from 35-149 days (mean of 70·5 days [SD 16·5], or 10 weeks plus 1 day). The cffDNA-based test had a sensitivity for aneuploidy detection of 85% (95% CI 79-90) and a specificity of 93% (95% CI 88-96) compared with direct sequencing of the pregnancy tissue. Among 1000 cffDNA-based test results, 446 (45%) were euploid, 405 (41%) aneuploid, 37 (4%) had multiple aneuploidies, and 112 (11%) were inconclusive. 105 (32%) of 333 women either did not manage to collect the pregnancy tissue or collected a sample classified as unknown tissue giving a high risk of being maternal.

INTERPRETATION

This validation of cffDNA-based testing in pregnancy loss shows the potential and feasibility of the method to distinguish euploid and aneuploid pregnancy loss for improved clinical management and benefit of future reproductive medicine and women's health research.

FUNDING

Ole Kirks Foundation, BioInnovation Institute Foundation, and the Novo Nordisk Foundation.

The association between offspring birthweight and future risk of maternal diabetes: A population-based study

AIMS

As an indicator of maternal cardiometabolic health, newborn birthweight may be an important predictor of maternal type 2 diabetes mellitus (diabetes). We evaluated the relation between offspring birthweight and onset of maternal diabetes after pregnancy.

METHODS

This retrospective cohort study used linked population-based health databases from Ontario, Canada. We included women aged 16-50 years without pre-pregnancy diabetes, and who had a live birth between 2006 and 2014. We used Cox proportional hazard regression to evaluate the association between age- and sex-standardized offspring birthweight percentile categories and incident maternal diabetes, while adjusting for maternal age, parity, year, ethnicity, gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP). Results were further stratified by the presence of GDM in the index pregnancy.

RESULTS

Of 893,777 eligible participants, 14,329 (1.6%) women were diagnosed with diabetes over a median (IQR) of 4.4 (1.5-7.4) years of follow-up. There was a continuous positive relation between newborn birthweight above the 75th percentile and maternal diabetes. Relative to a birthweight between the 50th and 74.9th percentiles, women whose newborn had a birthweight between the 97th and 100th percentiles had an adjusted hazards ratio (aHR) of diabetes of 2.30 (95% CI 2.16-2.46), including an aHR of 2.01 (95% CI 1.83-2.21) among those with GDM, and 2.59 (2.36-2.84) in those without GDM.

CONCLUSIONS

A higher offspring birthweight signals an increased risk of maternal diabetes, offering another potentially useful way to identify women especially predisposed to diabetes.

Miscarriage, stillbirth and the risk of diabetes in women: A systematic review and meta-analysis

AIMS

Whether women with a history of miscarriage or stillbirth have an increased risk of diabetes is inconclusive. We aimed to systematically assess the association between them.

METHODS

We searched PubMed, Web of Science and Scopus through November 2022. Random-effect model for meta-analysis was applied to calculate pooled odds ratios and corresponding 95 % confidence intervals (CIs) when heterogeneity was > 40 %.

RESULTS

Thirteen cohort studies and eight case-control studies with a total of 529,990 participants were included. Women ever experiencing a miscarriage had a 1.15-fold risk of non-gestational diabetes (95% CI: 1.02-1.28) and a 1.62-fold risk of gestational diabetes (95% CI: 1.32-1.98) compared to those never experiencing a miscarriage. Of them, women with three or more miscarriages had a 1.99-fold risk of non-gestational diabetes (95% CI: 1.36-2.91). The risk of non-gestational diabetes among women ever experiencing a stillbirth was 1.21 times compared with those never experiencing a stillbirth (95% CI: 1.03-1.41). Pooled results did not support a stable association between stillbirth and gestational diabetes risk (odds ratio:1.91, 95% CI: 1.00-3.64).

CONCLUSIONS

A history of miscarriage or stillbirth was associated with an increased risk of diabetes in women. Future studies are needed to explore whether prediabetic metabolic conditions contribute to this association.

Previous pregnancy loss and gestational cardiovascular health: A prospective cohort of nulliparous women

Objectives

To estimate the association of previous pregnancy loss with subsequent cardiovascular health during gestation and to examine the role of high-sensitivity C reactive protein (hs-CRP) in the association.

Methods

A total of 2,778 nulliparous pregnant women were recruited between March 2015 and November 2020 in Hefei city, China. Their cardiovascular health (CVH) including prepregnancy body mass index (BMI), blood pressure, total cholesterol, fasting plasma glucose, and smoke status were recorded at 24-28 weeks' gestation, as well as their reproductive history. Multivariate linear and logistic regression were performed to examine the association of pregnancy loss with cardiovascular health. And the role of hs-CRP between pregnancy loss and CVH was assessed by the mediation analysis.

Results

Compared with women who have no pregnancy loss, women with a history of spontaneous or induced abortions had higher BMI (β, 0.72, 95% CI, 0.50 to 0.94) and fasting plasma glucose (β, 0.04, 95% CI, 0.01 to 0.07), and had lower total CVH scores after adjusting for confounders (β, -0.09, 95% CI, -0.18 to -0.01). CVH scores were most significantly decreased among women with 3 or more induced abortions (β, -0.26, 95% CI, -0.49, -0.02). The contribution of pregnancy loss to poorer gestational CVH mediated by increased hs-CRP levels was 23.17%.

Conclusion

Previous pregnancy loss was associated with poorer cardiovascular health during gestation, which may be mediated by their gestational inflammatory status. Exposure to miscarriage alone was not a significant predictor of poorer CVH.

Pregnancy loss is related to body mass index and prediabetes in early adulthood: Findings from Add Health

Pregnancy loss, including miscarriage and stillbirth, affects 15-20% of pregnancies in the United States (US) annually. Accumulating evidence suggests that pregnancy loss is associated with a greater cardiovascular disease (CVD) burden later in life. However, few studies have evaluated the impact of pregnancy loss on CVD risk factors in early adulthood (age <35 years). The aim of this study was to examine associations between pregnancy loss and CVD risk factors (body mass index, blood pressure, hyperlipidemia, diabetes status) in early adulthood. We conducted a cross-sectional analysis using the public-use dataset for Wave IV (2007-2009) of the National Longitudinal Study of Adolescent to Adult Health (Add Health). Our sample consisted of women, ages 24-32 years, with a previous pregnancy who completed biological data collection (n = 2,968). Pregnancy loss was assessed as any history of miscarriage or stillbirth; and quantified as none, one, or recurrent (≥2) pregnancy loss. Associations between pregnancy loss and each CVD risk factor were tested using linear and logistic regression adjusting for sociodemographic factors, parity, health behaviors during pregnancy, and depression. We tested for interactions with race/ethnicity. A total of 670 women reported a pregnancy loss, of which 28% reported recurrent pregnancy loss. A prior pregnancy loss was related to a 3.79 (kg/mm2) higher BMI in non-Hispanic Black women, but not white women. Women with recurrent pregnancy loss were more likely to have prediabetes (AOR, 1.93; 95% CI, 1.10-3.37, p<0.05) than women with all live births. Findings suggest that pregnancy loss may be associated with a more adverse CVD risk profile in early adulthood, particularly for women who experience recurrent pregnancy loss. This highlights the need for CVD risk assessment in young women with a prior pregnancy loss. Further research is necessary to identify underlying risk factors of pregnancy loss that may predispose women to CVD.

Asthma Is Associated With Pregnancy Loss and Recurrent Pregnancy Loss: A Nationwide Cohort Study

BACKGROUND

Women with asthma appear to have an increased risk of pregnancy loss (PL). The impact of asthma on recurrent pregnancy loss (RPL), defined as 3 consecutive losses, is, however, unknown.

OBJECTIVE

The aim of this study was to investigate whether having asthma before or during the fertile age is associated with PL and RPL.

METHODS

Based on Danish national health registers, we identified all women aged 6 to 45 years with at least 2 filled prescriptions of an antiasthma drug during the period 1977 to 2019. Women with asthma were compared with women without asthma. Pregnancy outcomes were retrieved for both groups from national health registers. Logistic regression with adjustment for the year of birth and educational level provided odds ratios (ORs) for the number of PLs. Subgroup analyses were conducted for early-onset (age 6-15 years), adult-onset (age 16-39 years), and late-onset (age 40-45 years) asthma. Lastly, we compared uncontrolled asthma (defined as ≥ 400 doses of a short-acting beta-2 agonist in a year) to controlled asthma (defined as < 400 doses of a short-acting beta-2 agonist in a year).

RESULTS

In a population of 1,309,786 women, we identified 128,553 women with asthma and 1,297,233 women without asthma. Compared with nonasthmatic women, women with asthma had ORs for 1, 2, and 3 or more PLs of 1.05 (95% CI 1.03-1.07), 1.09 (95% CI 1.05-1.13), and 1.18 (95% CI1.11-1.24), respectively, and for RPL of 1.19 (95% CI 1.12-1.27). In women with early-onset asthma, the OR of 3 or more PLs was 1.47 (95% CI 1.24-1.72). For women classified as having uncontrolled asthma compared with controlled asthma, we found a significant OR of 1.60 (95% CI 1.16-2.16) for 3 or more PLs.

CONCLUSIONS

We found a significant positive association between asthma and number of PLs and RPLs. Early-onset asthma and uncontrolled asthma were more strongly associated with PL than adult-onset and late-onset asthma and controlled asthma.

Pregnancy loss and subsequent risk of prediabetes, diabetes and metabolic syndrome in couples: Tehran lipid and glucose study

Background

There is limited evidence regarding the impact of pregnancy loss on the subsequent risk of metabolic disorders. We aimed to investigate whether history of pregnancy loss is associated with the subsequent risk of prediabetes (pre-DM), diabetes (DM), and metabolic syndrome (METs) among couples.

Method

In this population-based cohort study, 2765 couples with and without history of pregnancy loss and free of DM, pre-DM, and METs at baseline were included and followed for incidents of DM, pre-DM, and METs by 3-year intervals visits from 1999 to 2018. Detailed data of variables was collected using standard questionnaires, interviews, clinical and laboratory assessments. A modified Poisson regression for binary outcome data with a log link function and robust error variance was used to estimate relative risks (RRs) in couples with and without history of pregnancy loss. Both unadjusted and adjusted models were fitted, and effect measures were calculated.

Result

During a median follow-up of 15 years, females with history of pregnancy loss were experienced more pre-DM (50% vs. 45.5%), DM (28.9% vs. 21.3%), and METs (70% vs. 60.1%) than females without such history. Moreover, history of pregnancy loss increased the risk of METs by 8% among females. The incidence of DM in males with history of pregnancy loss in their spouses was higher than in males without it (28.8% vs. 23.5%). Among males, having a spouse with history of pregnancy loss was positively associated with the risk of pre-DM (RR = 1.12; 95%CI: 1.02, 1.23, p = 0.02); furthermore, they were more prone to the risk of METs than females with a history of pregnancy loss (RR = 1.13; 95%CI: 1.07, 1.20, p < 0.001).

Conclusion

Although pregnancy loss is a female-specific factor, may foreshadow the subsequent METs, our study identified a higher risk of subsequent pre-DM and METs in males with history of pregnancy loss in their spouses. Pregnancy loss could be considered a possible future risk factor for metabolic disorders in couples.

Diabetic and Hypertensive Disorders Following Miscarriage: A Protocol for Systematic Review and Meta-Analysis

(1) Background: Miscarriages occur in approximately 15–25% of all pregnancies. There is limited evidence suggesting an association between history of miscarriage and the development of diabetic and hypertensive disorders in women. This systematic review aims to collate the existing literature and provide up to date epidemiological evidence on the topic. (2) Methods: We will search CINAHL Plus, Ovid/EMBASE, Ovid/MEDLINE, ProQuest, PubMed, Scopus, Web of Science, and Google Scholar, using a combination of medical subject headings, keywords, and search terms, for relevant articles related to the association between miscarriage and the risk of diabetic and hypertensive disorders. Cross-sectional, case–control, nested case–control, case–cohort, and cohort studies published from inception to April 2022 will be included in the search strategy. Three reviewers will independently screen studies and the risk of bias will be assessed using the Joanna Briggs Institute Critical Appraisal tool. Where the data permit, a meta-analysis will be conducted. (3) Results: The results of this systematic review will be submitted to a peer-reviewed journal for publication. (4) Conclusions: The findings of this systematic review will instigate efforts to manage and prevent reproductive, cardiovascular, and metabolic health consequences associated with miscarriages.

H1299R Variant in Factor V and Recurrent Pregnancy Loss: A Systematic Review and Meta-Analysis Protocol

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies, affecting approximately 1 to 3% of women worldwide. Scientific data highlight a possible correlation between thrombophilic genetic variants and RPL. H1299R variant in the factor V gene would lead to an increased thrombotic risk associated with frequent miscarriages. However, the data are often conflicting, making this an interesting question for further investigations by evaluating genotype-phenotype correlations to improve the clinical management and genetic counseling of couples. A systematic review and meta-analysis will follow the preferred reporting elements for systematic review and meta-analysis protocols (PRISMA-P). The Pubmed (MEDLINE) and Embase (OVID) databases will be explored to identify suitable articles based on inclusion and exclusion criteria. Inclusion criteria are: (a) H1299R genotyping with clear data reported, referred to as Heterozygous (Het) and/or Homozygous (Hom); (b) articles written in English; (c) analyses of only RPL female patients having at least two or more previous pregnancy losses and compared with a control group. This analysis will present selected scientific evidence, addressing the questions concerning the association between the H1299R variant and RPL, hoping to clarify this still unresolved issue. PROSPERO registration number: CRD42022330077.

Number of Births and Risk of Diabetes in China's Older Women

As an important life event in individuals' life, childbirth will affect the health of women to different degrees. More and more attention has been paid to whether the number of births will affect the incident diabetes in elderly women, but there are few related studies. Based on the data of the Chinese Longitudinal Healthy Longevity Survey in 2018, 6,159 older women are selected as the study population. Logistic regression analyses are used to estimate the relationship between the number of births and diabetes risk. For each additional birth, the odds ratio of maternal diabetes will decrease by 6.9% and the result is significant at the 1% level, especially among mothers having four children or less. The conclusion is equally applicable in the sample of fathers and urban mothers, but the increase in the number of births will increase the risk of diabetes in rural mothers, although this result is not statistically significant. Later age at first birth, later age at last birth, the longer childbearing period, and birth interval will significantly reduce the risk of diabetes.

Associations between parity, pregnancy loss, and breastfeeding duration and risk of maternal type 2 diabetes: An observational cohort study

BACKGROUND

Parity, pregnancy loss, and breastfeeding duration were found to be associated with diabetes. However, the results are inconsistent. Also, no epidemiological studies have examined the association of these reproductive factors with diabetes in the same large population. We aim to investigate the associations between parity, pregnancy loss, breastfeeding duration, and the risk of maternal diabetes in middle-aged and elderly Chinese females.

METHODS

We included 131 174 females aged ≥40 years from the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study). Multivariable linear regression and logistic regression were used to assess the association between parity, pregnancy loss, and breastfeeding duration and type 2 diabetes.

RESULTS

The number of parities and breastfeeding duration were positively related to fasting plasma glucose, 2-hour postload glucose, glycosylated hemoglobin, and homeostatic model assessment of insulin resistance. Compared with those with one birth, nulliparous women or women with 2 or ≥3 births had a significantly increased risk of diabetes. The odds ratios (OR) and 95% confidence intervals (CI) were 1.27 (1.10-1.48), 1.17 (1.12-1.22), and 1.28 (1.21-1.35), respectively. Compared with women without pregnancy loss, those who underwent 2 (OR 1.09; 95% CI, 1.04-1.14) or ≥3 pregnancy losses (OR 1.11; 95% CI, 1.04-1.18) had an increased risk of diabetes. Moreover, women with a breastfeeding duration ≥0 to 6 months (OR 0.82; 95% CI, 0.75-0.90) and ≥6 to 12 months (OR 0.94; 95% CI, 0.89-0.99) had a significantly lower risk of diabetes.

CONCLUSIONS

Nulliparous women or women with multiparity or more than one pregnancy loss have an increased risk of diabetes in later life, while women who breastfeed more than 0 to 12 months have a lower risk of diabetes.

The impact of early pregnancy complications on completed family size-A nationwide, registry-based cohort study with 40 years of data

INTRODUCTION

The impact of early pregnancy complications on completed family size is unknown. Here, we hypothesize that early pregnancy complications and adverse outcomes may influence family size.

MATERIAL AND METHODS

In this nationwide, registry-based study we included all 458 475 women born 1957-1972 who lived in Denmark from age 20-45 years with at least one registered pregnancy. The main outcome of the study was number of children per woman by age 45, estimated using a Generalized Linear Mixed Model. Exposures were: (a) total number of pregnancy losses experienced (0, 1, 2, ≥3); (b) highest number of consecutive pregnancy losses (0, 1, 2, ≥3); (c) sex of firstborn child; (d) outcome of first pregnancy (live birth, stillbirth, pregnancy loss, ectopic pregnancy, or molar pregnancy).

RESULTS

Number of live births was negatively influenced by maternal age and adverse first pregnancy outcomes, especially ectopic pregnancies. A 30-year-old woman with a first ectopic pregnancy was expected to have 1.16 children (95% CI 1.11-1.22) compared with 1.95 children (95% CI 1.86-2.03) with a first live birth. Three or more consecutive losses also decreased number of live births significantly: 1.57 (95% CI 1.50-1.65) compared with 1.92 (95% CI 1.84-2.0) with only live births. The total number of pregnancy losses had no effect before the age of 35 years. Sex of firstborn had no effect.

CONCLUSIONS

Previous pregnancy history has a significant effect on number of children per woman, which is important at both individual and societal levels. Pathophysiological research of adverse pregnancy outcomes should be an urgent priority as the causes remain poorly understood.

Recurrent Pregnancy Loss and Concealed Long-QT Syndrome

Background

Recurrent pregnancy loss affects 1% to 2% of couples attempting childbirth. A large fraction of all cases remains idiopathic, which warrants research into monogenic causes of this distressing disorder.

Methods and Results

We investigated a nonconsanguineous Estonian family who had experienced 5 live births, intersected by 3 early pregnancy losses, and 6 fetal deaths, 3 of which occurred during the second trimester. No fetal malformations were described at the autopsies performed in 3 of 6 cases of fetal death. Parental and fetal chromosomal abnormalities (including submicroscopic) and maternal risk factors were excluded. Material for genetic testing was available from 4 miscarried cases (gestational weeks 11, 14, 17, and 18). Exome sequencing in 3 pregnancy losses and the mother identified no rare variants explicitly shared by the miscarried conceptuses. However, the mother and 2 pregnancy losses carried a heterozygous nonsynonymous variant, resulting in p.Val173Asp (rs199472695) in the ion channel gene KCNQ1. It is expressed not only in heart, where mutations cause type 1 long‐QT syndrome, but also in other tissues, including uterus. The p.Val173Asp variant has been previously identified in a patient with type 1 long‐QT syndrome, but not reported in the Genome Aggregation Database. With heterologous expression in CHO cells, our in vitro electrophysiologic studies indicated that the mutant slowly activating voltage‐gated K+ channel (I_Ks) is dysfunctional. It showed reduced total activating and deactivating currents (P<0.01), with dramatically positive shift of voltage dependence of activation by ≈10 mV (P<0.05).

Conclusions

The current study uncovered concealed maternal type 1 long‐QT syndrome as a potential novel cause behind recurrent fetal loss.

The diagnosis of Gestational Diabetes Mellitus and its impact on In Vitro Fertilization pregnancies. A pilot study

BACKGROUND

In Vitro Fertilization (IVF) is increasingly becoming a necessary mode of reproduction. This high risk group is prone to Gestational Diabetes Mellitus (GDM) which further exposes these pregnancies to an increased risk of adverse outcomes. In light of the limited data in the current literature, further investigation is needed regarding the time of GDM diagnosis in IVF pregnancies as well as the outcome of IVF pregnancies complicated by GDM.

METHODS

In this three center pilot cross sectional study, the data of 101 singleton IVF pregnancies complicated by GDM were analyzed. Prompt GDM diagnosis in IVF pregnancies was accomplished by self-blood glucose monitoring (SMBG) from the first antenatal visit and confirmed by an OGTT. To evaluate pregnancy outcome, maternal and fetal complications in the 101 GDM IVF group was compared to 101 IVF as well as 101 spontaneous conceptions (SC). The three groups were matched by age. The effect of demographic and glycemic parameters on the outcome of GDM IVF pregnancies was investigated.

RESULTS

GDM diagnosis was made before the 24th week in 37.6% of the GDM IVF group. The week of delivery was earlier for the GDM IVF group (37 ± 1.7) relative to the IVF (37.9 ± 0.9, p < 0.001) and the SC group (38.1 ± 0.8, p < 0.001). GDM IVF pregnancies exhibited greater preeclampsia rates and 84.8% underwent caesarian section. No significant difference regarding LGA and SGA birth weights was found. Complications of GDM IVF pregnancies were associated with the 1-h postprandial BG (r = 0.267, p = 0.007).

CONCLUSION

GDM screening in IVF pregnancies may be considered earlier than the 24th week. IVF pregnancies affected by GDM are prone to increased maternal and fetal complications which are associated with 1-h postprandial BG.

Chance of live birth: a nationwide, registry-based cohort study

STUDY QUESTION

Does the sequence of prior pregnancy events (pregnancy losses, live births, ectopic pregnancies, molar pregnancy and still birth), obstetric complications and maternal age affect chance of live birth in the next pregnancy and are prior events predictive for the outcome?

SUMMARY ANSWER

The sequence of pregnancy outcomes is significantly associated with chance of live birth; however, pregnancy history and age are insufficient to predict the outcome of an individual woman's next pregnancy.

WHAT IS KNOWN ALREADY

Adverse pregnancy outcomes decrease the chance of live birth in the next pregnancy, whereas the impact of prior live births is less clear.

STUDY DESIGN, SIZE, DURATION

Nationwide, registry-based cohort study of 1 285 230 women with a total of 2 722 441 pregnancies from 1977 to 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All women living in Denmark in the study period with at least one pregnancy in either the Danish Medical Birth Registry or the Danish National Patient Registry. Data were analysed using logistic regression with a robust covariance model to account for women with more than one pregnancy. Model discrimination and calibration were ascertained using 20% of the women in the cohort randomly selected as an internal validation set.

MAIN RESULTS AND THE ROLE OF CHANCE

Obstetric complications, still birth, ectopic pregnancies and pregnancy losses had a negative effect on the chance of live birth in the next pregnancy. Consecutive, identical pregnancy outcomes (pregnancy losses, live births or ectopic pregnancies) immediately preceding the next pregnancy had a larger impact than the total number of any outcome. Model discrimination was modest (C-index = 0.60, positive predictive value = 0.45), but the models were well calibrated.

LIMITATIONS, REASONS FOR CAUTION

While prior pregnancy outcomes and their sequence significantly influenced the chance of live birth, the discriminative abilities of the predictive models demonstrate clearly that pregnancy history and maternal age are insufficient to reliably predict the outcome of a given pregnancy.

WIDER IMPLICATIONS OF THE FINDINGS

Prior pregnancy history has a significant impact on the chance of live birth in the next pregnancy. However, the results emphasize that only taking age and number of losses into account does not predict if a pregnancy will end as a live birth or not. A better understanding of biological determinants for pregnancy outcomes is urgently needed.

STUDY FUNDING/COMPETING INTEREST(S)

The work was supported by the Novo Nordisk Foundation, Ole Kirk Foundation and Rigshospitalet's Research Foundation. The authors have no financial relationships that could appear to have influenced the work.

TRIAL REGISTRATION NUMBER

N/A.

Maternal-foetal complications in pregnancy: a retrospective comparison between type 1 and type 2 diabetes mellitus

BACKGROUND

The aim of the study was a retrospective comparison of the differences in maternal-foetal outcomes between women with type 1 and type 2 diabetes mellitus (T1DM and T2DM).

METHODS

A cohort of 135 patients with pregestational diabetes, 73 with T1DM (mean age 29 ± 5 years) and 62 with T2DM (mean age 33 ± 6 years), in intensive insulin treatment throughout pregnancy were evaluated. Clinical and metabolic parameters and the prevalence of maternal and foetal complications were assessed.

RESULTS

Women with T1DM showed lower pregestational BMI (p < 0.001), pregestational weight (p < 0.001), weight at delivery (p < 0.001), ∆_total_insulin requirement (IR) at the first, second and third trimesters (all p < 0.001) and higher weight gain during pregnancy (p < 0.001), pregestational HbA1c (p = 0.040), HbA1c in the first (p = 0.004), second (p = 0.020) and third (p = 0.010) trimesters compared to T2DM. Women with T1DM had a higher risk of macrosomia (p = 0.005) than T2DM, while women with T2DM showed higher prevalence of abortion (p = 0.037) than T1DM. At multivariate analysis, pregestational BMI and ∆_total_IR of the first trimester were independently associated with abortion in T2DM, while weight gain during pregnancy was independently associated with macrosomia in T1DM.

CONCLUSION

Women with T1DM have a higher risk of macrosomia than T2DM due to weight gain throughout pregnancy. By contrast, women with T2DM have a higher risk of spontaneous abortion than T1DM, due to pregestational BMI and ∆_total_IR in the first trimester.

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.