Rationale and design of two prospective, multicenter, observational studies on reproductive outcome in women with recurrent failures after spontaneous or assisted conception: OTTILIA and FIRST registries

Low-molecular-weight heparin in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection: A meta-analysis

INTRODUCTION

This meta-analysis aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) on pregnancy outcomes in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

MATERIAL AND METHODS

A systematic literature search of PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure was performed to identify randomized controlled trials (RCTs) comparing LMWH with no treatment or placebo published from database inception until February 19, 2023. Primary outcomes were the clinical pregnancy rate and implantation rate, and secondary outcomes were the live birth rate, miscarriage rate, and the risk of bleeding events. The certainty of the evidence was rated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Meta-analysis was conducted using STATA 14.0.

RESULTS

Five RCTs involving 1094 thrombophilic women receiving IVF/ICSI were finally included. Administration of LMWH was associated with statistically higher clinical pregnancy rate (4 RCTs, risk ratio [RR] 1.50, 95% confidence interval [CI] 1.23-1.82, p < 0.001, low certainty evidence), implantation rate (5 RCTs, RR 1.49, 95% CI 1.25-1.78, p < 0.001, very low certainty evidence), and live birth rate (2 RCTs, RR 2.15, 95% CI 1.60-2.89, p < 0.001, very low certainty evidence), but with statistically lower miscarriage rate (2 RCTs, RR 0.36, 95% CI 0.15-0.86, p = 0.021, very low certainty evidence). However, using LMWH was linked to a higher risk of bleeding events (2 RCTs, RR 2.36, 95% CI 1.49-3.74, p < 0.001, very low certainty evidence).

CONCLUSIONS

Very low certainty evidence suggests that administration of LMWH may benefit pregnancy outcomes in thrombophilic women receiving IVF/ICSI treatment, although it may also increase the risk of bleeding events. However, before putting our findings into practice, healthcare professionals should conduct an in-depth evaluation of the available evidence and specific patient situations. Furthermore, due to the low methodological quality of the included studies, more high-quality studies are needed to validate our findings in the future.

The role of thrombophilias in reproduction: A swot analysis

Thrombophilia is a group of inherited or acquired coagulation disorders that have been associated with reproductive failure. However, there are still no clear recommendations on whether its inclusion in the initial study of the infertile couple or patients with recurrent implantation failure is necessary. In this discussion paper, based on a SWOT (strengths, weaknesses, opportunities, threats) analysis, the different aspects of the repercussions of thrombophilia screening and treatment in reproduction are evaluated. To avoid possible subjectivity in the analysis and results of this study, researchers followed Oxford criteria for the evaluation of evidence. The results from the evaluation of the reviewed bibliography seem to indicate that, pending new evidence, it would be advisable not to include thrombophilia screening in the initial baseline study of the infertile couple. There is no evidence to support a clear association between thrombophilia and implantation failure or infertility. Thrombophilia testing in this setting may increase cost, with minimal potential benefit and lead to inappropriate use of anticoagulants with possible deleterious adverse effects. Future well-designed studies are needed to assess the possible benefit of anticoagulant therapy in infertile thrombophilic patients with implantation failure.

Obstetric outcomes in pregnant COVID-19 women: the imbalance of von Willebrand factor and ADAMTS13 axis

Background

Thrombotic microangiopathy has been invoked as one of the most important mechanisms of damage in COVID-19 patients. Protease ADAMTS13 is a marker of microangiopathy responsible for controlling von Willebrand multimers size. Von Willebrand factor/ADAMTS13 ratio has been found impaired in COVID-19 patients outside pregnancy.

Methods

We prospectively investigated 90 pregnant women admitted to two tertiary academic hospitals in Italy with a laboratory-confirmed diagnosis of SARS-CoV-2 infection. Demographic, clinical information and routine laboratory data were collected at the hospital admission and until discharge. We investigated whether vonWillebrand /ADAMTS13 axis imbalance is a predictor of adverse outcomes. Logistic regression analysis, which controlled for potential confounders, was performed to evaluate the association between laboratory parameters and clinical outcomes.

Results

Most women (55.6%) were parae, with median gestational age at admission of 39 weeks. At hospital admission, 63.3% were asymptomatic for COVID-19 and 24.4% showed more than one sign or symptom of infection. Nulliparae with group O showed Willebrand / ADA MTS-13 ratios significantly lower than non-O, whereas in multiparae this difference was not observed. Logistic regression showed that ratio von Willebrand to ADAMTS13 was significantly and independently associated with preterm delivery (OR 1.9, 95%CI 1.1–3.5).

Conclusion

This study shows an imbalance of vonWillebrand /ADAMTS13 axis in pregnant women with COVID-19, leading to a significantly higher and independent risk of preterm delivery. Monitoring these biomarkers might support decision making process to manage and follow-up pregnancies in this setting.

Findings from a multicentre, observational study on reproductive outcomes in women with unexplained recurrent pregnancy loss: the OTTILIA registry

STUDY QUESTION

What evaluation and care is offered to women after unexplained recurrent pregnancy loss (RPL) or intra-uterine foetal death (IUFD) and what are the reproductive outcomes?

SUMMARY ANSWER

Women are assessed for thrombophilia and often treated with low-molecular weight heparin (LMWH) and/or low-dose aspirin (ASA).

WHAT IS KNOWN ALREADY

Randomized controlled trials (RCTs) on possible efficacy of heparins and/or aspirin have been inconclusive due to limited power to detect a difference and patient heterogeneity.

STUDY DESIGN, SIZE, DURATION

Prospective multicentre cohort study performed in 12 hospitals in three countries between 2012 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All consecutive pregnant women with recurrent PL (≥3 losses or 2 losses in the presence of at least one euploid foetal karyotype) or at least one IUFD. Eligible women may have undergone thrombophilia testing before conception, at the discretion of local providers. The possible assignment of women to treatments (such as LMWH) was not decided a priori but was determined based on the responsible provider's current practice. Aims of the study were: (i) to evaluate factors associated with pregnancy outcome; (ii) to compare clinical management strategies in women with and without a subsequent successful pregnancy; and (iii) to evaluate characteristics of women who may benefit from antithrombotic therapy. A propensity score matching method was used to balance the differences in baseline characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

A matched sample of 265 pregnant women was analysed, with all undergoing thrombophilia screening; 103 out of 119 (86.6%) with and 98/146 (67.1%) without thrombophilia were prescribed with LMWH and/or ASA. Overall, live-births were recorded in 204 cases (77%), PL or IUFD in 61 (23%) pregnancies. Logistic regression showed a significant interaction between thrombophilia and treatment with LMWH (P = 0.03). Findings from sensitivity analysis showed odds ratio (OR) for pregnancy loss in women with inherited or acquired thrombophilia in absence of any treatment was 2.9 (95% CI, 1.4-6.1); the administration of LMWH (with or without ASA) was associated with higher odds of live-birth (OR, 10.6; 95% CI, 5.0-22.3). Furthermore, in women without thrombophilia, the odds of live-birth was significantly and independently associated with LMWH prophylaxis (alone or in association with ASA) (OR, 3.6; 95% CI, 1.7-7.9).

LIMITATIONS, REASONS FOR CAUTION

While the propensity score matching allows us to balance the differences in baseline characteristics, it does not eliminate all confounding.

WIDER IMPLICATIONS OF THE FINDINGS

Antithrombotic prophylaxis during pregnancy may be effective in women with otherwise unexplained PL or IUFD, and even more useful in those with thrombophilia.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Italian Ministry of Health (Ricerca Corrente 2018-2020). Dr G.P. has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr E.G. has received consultant fees from Italfarmaco and Sanofi. All other authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

NCT02385461.

Thrombophilia, Inflammation, and Recurrent Pregnancy Loss: A Case-Based Review

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies and is often multifactorial with the majority of miscarriages being due to aneuploidy and anatomic or physiological abnormalities. However, inherited or acquired thrombophilias have also been associated with RPL, albeit inconsistently. While inherited thrombophilias, such as factor V Leiden and prothrombin gene mutation, are relatively prevalent in women with RPL compared with the general population, a causal link has yet to be definitively established. Recently, systemic inflammation, as measured by high-sensitivity C-reactive protein, has also been hypothesized to play a role in infertility. Based on limited prospective trial data, antithrombotic therapy and antiplatelet agents have been proposed as possible tools for the prevention of RPL. Because of the multifactorial nature of RPL and infertility, various clinicians, as obstetricians and gynecologists, endocrinologists, hematologists, or vascular medicine specialists, may be requested to counsel these women. This, together with evidence gaps, frequently leads to distinctly different diagnostic and therapeutic recommendations, especially regarding thrombophilia testing and treatment. Using four case vignettes in this review, we critically appraise the literature and highlight how two clinicians from different subspecialties approach the relationship between RPL, inflammation, and thrombophilia.

Role of Low Molecular Weight Heparin in the Management of Unexplained Recurrent Pregnancy Loss: A Review of Literature

Recurrent pregnancy loss remains a significant challenge in gynecological practice, accounting for about 2%-4% of pregnancies. In some patients, the etiology is unknown. Unexplained recurrent pregnancy loss (URPL) refers to the spontaneous loss of three or more consecutive pregnancies without an identifiable risk factor, accounting for about 40%-50% of pregnancy losses. The review aims to understand the role of low molecular weight heparin (LMWH) in the treatment of URPL. Articles for this review have been found in the PubMed database, and studies published more than ten years before the review excluded. The articles were reviewed to determine the effect of LMWH on live birth rates, reduced late pregnancy complications, and adverse drug reactions following its use. Many studies show improved live birth rates in women treated with LMWH compared to the control, while some studies show no improvement. There was no statistically significant difference in reducing late pregnancy complications, such as preeclampsia, intrauterine growth restriction, preterm labor, and low birth weight, in either study and control groups. Adverse drug reaction was rare among women treated with LMWH and, if present, was mild and self-limiting, thus making it a safe therapy. More studies, preferably large multicenter randomized controlled trials, need to be conducted on the use of LMWH to establish a consensus guideline on the treatment of URPL.