The selective use of heparin/aspirin therapy, alone or in combination with intravenous immunoglobulin G, in the management of antiphospholipid antibody-positive women undergoing in vitro fertilization

Intravenous Immunoglobulins as Immunomodulators in Autoimmune Diseases and Reproductive Medicine

Intravenous administration of immunoglobulins has been routinely used for more than 60 years in clinical practice, developed initially as replacement therapy in immunodeficiency disorders. Today, the use of intravenous immunoglobulins (IVIGs) is embedded in the modern algorithms for the management of a few diseases, while in most cases, their application is off-label and thus different from their registered therapeutic indications according to the summary of product characteristics. In this review, we present the state-of-the-art use of IVIGs in various autoimmune conditions and immune-mediated disorders associated with reproductive failure, as approved therapy, based on indications or off-label. IVIGs are often an alternative to other treatments, and the administration of IVIGs continues to expand as data accumulate. Additionally, new insights into the pathophysiology of immune-mediated disorders have been gained. Therefore, the need for immunomodulation has increased, where IVIG therapy represents an option for stimulating, inhibiting and regulating various immune processes.

Aspirin for Endometrial Preparation in Patients Undergoing IVF: A Systematic Review and Meta-analysis

OBJECTIVE

To investigate the effect of aspirin on IVF success rates when used as an adjuvant treatment for endometrial preparation.

DATA SOURCES

Relevant publications were comprehensively selected from PubMed, MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to November 15, 2020.

STUDY SELECTION

Randomized controlled trials (RCTs) and retrospective cohort studies that used aspirin as an adjuvant treatment for endometrial preparation and reported subsequent pregnancy outcomes were included. Studies were excluded if aspirin was used before and/or during ovarian stimulation.

DATA EXTRACTION AND SYNTHESIS

This systematic review and meta-analysis included a total of 7 studies. Risk of bias assessment was based on the methodology and categories listed in the Cochrane Handbook for the RCTs and the Newcastle-Ottawa scale for the retrospective studies. The primary outcome was live birth rate. Summary measures were reported as odds ratios (ORs) with 95% confidence intervals (CIs). There was significant evidence that aspirin for endometrial preparation improved live birth rates (OR  1.52; 95% CI   1.15-2.00). No effect was noted for clinical pregnancy rates (OR  1.37; 95% CI   1.00-1.87); however, aspirin was associated with improved pregnancy rates in a subgroup analysis of patients receiving oocyte donation (OR 2.53; 95% CI 1.30-4.92) and in the sensitivity analysis (OR 1.3; 95% CI   1.02-1.66). No effect of aspirin was found for implantation or miscarriage rates (OR 1.31; 95% CI  0.51-3.36 and OR 0.41; 95% CI  0.02-7.42, respectively).

CONCLUSION

These findings support a beneficial effect of aspirin for endometrial preparation on IVF success rates, mainly live birth rates, outside the context of ovarian stimulation. However, this evidence is based on poor quality data and needs to be confirmed with high-quality RCTs.

Preeclampsia before fetal viability in women with primary antiphospholipid syndrome- materno-fetal outcomes in a series of 7 cases

INTRODUCTION

Preeclampsia complicates about 10-17 % of pregnancies with antiphospholipid syndrome (APS). It is often severe and might occur sometimes at early gestation. The development of preeclampsia before fetal viability is a huge challenge for obstetricians and demands an intensive discussion regarding the therapeutical options.

PATIENTS AND METHODS

We retrospectively reviewed the data of 7 women with primary APS who developed preeclampsia before 24 weeks of gestation. Plasma exchange had been performed in four of the cases and two women received corticosteroids. One of the women had received 20 mg of pravastatin daily, starting at 18 weeks of gestation. Neonatal outcome was: live birth in four cases and IUFD in three cases. The main pediatric complications were noted in a 28-week-old premature born boy, who developed severe IRDS and thrombocytopenia. At the present time, the boy continues to have a retarded status.

DISCUSSION

This retrospective analysis revealed that women with APS can develop severe preeclampsia even before 20 weeks of gestation. Several management options for prolongation of pregnancy such as plasma exchange, pravastatin, LMHW, hydroxychloroquine/HCQ, or TNF-alpha blocker should be discussed with the patients. Optimal management of preeclampsia before 24 weeks of gestation usually depends on weighing the maternal and fetal complications from expectant management with prolongation of pregnancy versus the predominant fetal and neonatal risks of extreme prematurity from "aggressive" management with immediate delivery.

An observational multicentre study on the efficacy and safety of assisted reproductive technologies in women with rheumatic diseases

Objectives

The aim was to determine whether assisted reproductive technologies (ARTs) confer additional risk in rheumatic patients (in terms of disease flare and fetal–maternal complications) and whether, if performed, their efficacy is affected by maternal disease.

Methods

Sixty infertile rheumatic women undergoing 111 ART cycles were included. Clinical pregnancy rate, live birth rate, maternal disease flares and maternal–fetal complications were recorded.

Results

One hundred and eleven ART cycles in 60 women were analysed. We reported 46 pregnancies (41.4%), 3 (3.1%) cases of ovarian hyperstimulation syndrome and no cases of thrombosis during stimulation, pregnancy and puerperium. One or more maternal complication was reported in 13 (30.2%) pregnancies, and fetal complications occurred in 11 fetuses (21.1%). The live birth rate was 98%, but we reported three (6%) perinatal deaths in the first days of life. During puerperium, we recorded one (2.5%) post-partum haemorrhage and one (2.5%) articular flare.

Conclusion

The safety and efficacy of the ARTs, demonstrated in the general population, seems to be confirmed also in rheumatic patients. No evidence was found to advise against their application, and the choice of therapy should be made depending on the patient’s risk profile, irrespective of whether the pregnancy is natural or artificial induced.

Effects of multiple inherited and acquired thrombophilia on outcomes of in-vitro fertilization

INTRODUCTION

The effects of multiple inherited and acquired thrombophilic defects on the outcome of in-vitro fertilization (IVF) remain unexplored. The aim of this study was to evaluate the association between multiple thrombophilia and clinical outcomes in a large prospective cohort of women undergoing IVF.

MATERIALS AND METHODS

Consecutive women scheduled for IVF were eligible. The primary study outcome was live birth. Secondary outcomes included spontaneous abortion, clinical pregnancy, and symptomatic venous thromboembolism.

RESULTS

687 women with a mean age of 34.6 (±3.2) years were included. Overall, 22 women (3.2%) had two or more thrombophilic defects. The probability of live birth was not statistically significantly different between women with ≥2 thrombophilia (odds ratio [OR] 0.62; 95% confidence interval [CI], 0.18 to 2.11) or ≥1 thrombophilia (OR 0.67;95% CI, 0.41 to 1.09) and women without any thrombophilia. None of the individual inherited thrombophilia nor positivity to antiphospholipid antibodies or lupus anticoagulant were associated with live birth. Single positivity for lupus anticoagulant carried a more than threefold higher risk of abortion (OR 3.74; 95% CI, 1.30 to 10.75). There were no statistically significant associations between individual or multiple thrombophilic defects and clinical pregnancy or pregnancy test results. No woman had a history of venous thromboembolism and none developed a thrombotic event during the study.

CONCLUSIONS

In women undergoing IVF, the presence of two or more thrombophilic defects was rare and showed no statistically significant associations with IVF outcomes.

Pregnancy Outcome in Women with Obstetric and Thrombotic Antiphospholipid Syndrome-A Retrospective Analysis and a Review of Additional Treatment in Pregnancy

Antiphospholipid syndrome (APS) is associated with pregnancy complications such as recurrent early fetal loss (RFL), fetal death, preeclampsia (PE), and intrauterine growth restriction (obstetric APS/OAPS). Other clinical manifestations are venous and/or arterial thromboses (thrombotic APS/TAPS). The data of 37 pregnancies with OAPS and 37 pregnancies with TAPS were analyzed and compared. Overall, the most frequent APS antibodies (aPl) were LA as well as "triple-positivity"; LA antibodies were significantly more frequent in women with TAPS (67.6 % TAPS vs. 29.7 % OAPS, p < 0.010), whereas "triple-positivity" was significantly more seen in women with OAPS (40.5 % OAPS vs. 13.5 % TAPS, p < 0.010). Adequate therapy has been administered in nearly all pregnancies with TAPS, whereas in 18.9 % of pregnancies with OPS, no therapy has been given at all. One woman in OAPS and four women in TAPS were treated with plasmapheresis and immunoadsorption. There was no significant association between adverse obstetric outcome and therapy. The most frequent pregnancy complications were RFL in the OAPS group (32.4 vs. 13.5 % in TAPS) and PE in the TAPS group (18.9 % in OAPS and TAPS, respectively). The data of our study showed that pregnancies with OAPS and TAPS have a similar rate of pregnancy complications. However, pregnancies with OAPS tend to have rather RFL. Although we were not able to reveal a significant association with adverse obstetric outcome, it seems that the current adequate therapy for APS in pregnancy, consisting of LDA and LMWH, might rather prevent the development of RFL. Additionally, it might be considered to divide the obstetric APS into obstetric APS with early pregnancy complications and obstetric APS with late pregnancy complications. The division into two groups of obstetric APS might facilitate the choice of additional therapy in these women.

Aspirin for in vitro fertilisation

BACKGROUND

Aspirin is used with the aim of optimising the chance of live birth in women undergoing assisted reproductive technology (ART), despite inconsistent evidence of its efficacy and safety (in terms of intraoperative bleeding during oocyte retrieval and risk of miscarriage). The most appropriate time to commence aspirin therapy and the length of treatment required are also still to be determined. This is the second update of the review first published in 2007.

OBJECTIVES

To evaluate the effectiveness and safety of aspirin in women undergoing ART.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 4) in the Cochrane Library (searched 9 May 2016); the databases MEDLINE (1946 to 9 May 2016) and Embase (1974 to 9 May 2016); and trial registers (ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform search portal). We also examined the reference lists of all known primary studies and review articles, citation lists of relevant publications and abstracts of major scientific meetings, combined with the Cochrane Gynaecology and Fertility Group's search strategy.

SELECTION CRITERIA

Randomised controlled trials on aspirin for women undergoing ART.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias and extracted the data. The primary review outcome was live birth. Secondary outcomes included clinical pregnancy, ongoing pregnancy, multiple pregnancy, miscarriage, and other complications associated with IVF/ICSI or with pregnancy and birth. We combined data to calculate risk ratios (RRs) (for dichotomous data) and mean differences (MDs) (for continuous data) and 95% confidence intervals (CIs). Statistical heterogeneity was assessed using the I² statistic. We assessed the overall quality of the evidence for the main comparisons using GRADE methods.

MAIN RESULTS

The search identified 13 trials as eligible for inclusion in the review, including a total of 2653 participants with a mean age of 35 years. Ten studies used a dose of 100 mg and three used 80 mg of aspirin per day. In most of them, aspirin was commenced immediately at the start of down-regulation, while the duration of treatment varied widely. Eight studies provided a placebo for the control group.There was no evidence of a difference between the aspirin group and the group receiving no treatment or placebo in rates of live birth (RR 0.91, 95% CI 0.72 to 1.15, 3 RCTs, n = 1053, I² = 15%, moderate-quality evidence). In addition, clinical pregnancy rates were also similar for the two groups (RR 1.03, 95% CI 0.91 to 1.17, 10 RCTs, n = 2142, I² = 27%, moderate-quality evidence); sensitivity analysis, excluding studies at high risk of bias, did not change the effect estimate. There was no evidence of a difference between groups in terms of multiple pregnancy as confirmed by ultrasound (RR 0.67, 95% CI 0.37 to 1.25, 2 RCTs, n = 656, I² = 0%, low-quality evidence), miscarriage (RR 1.10, 95% CI 0.68 to 1.77, 5 RCTs, n = 1497, I² = 0%, low-quality evidence), ectopic pregnancy (RR 1.86, 95% CI 0.75 to 4.63, 3 RCTs, n = 1135, I² = 0%, very low quality evidence) or vaginal bleeding (RR 1.01, 95% CI 0.14 to 7.13, 1 RCT, n = 487, very low quality evidence). Data were lacking on other adverse effects.The overall quality of the evidence ranged from very low to moderate; limitations were poor reporting of study methods and suspected publication bias.

AUTHORS' CONCLUSIONS

Currently there is no evidence in favour of routine use of aspirin in order to improve pregnancy rates for a general IVF population. This is based on available data from randomised controlled trials, where there is currently no evidence of an effect of aspirin on women undergoing ART, as there is no single outcome measure demonstrating a benefit with its use. Furthermore, current evidence does not exclude the possibility of adverse effects.

The hidden world of anti-phospholipid antibodies and female infertility: A literature appraisal

Even though the association of anti-phospholipid antibodies (aPL) with infertility is debated, infertile women are commonly screened for aPL. To review evidence, a systematic PubMed search was conducted to retrieve papers addressing (i) the association between aPL and infertility, (ii) the positivity rate of criteria and non-criteria aPL in women with infertility, (iii) the association between aPL and assisted reproduction technologies (ART) outcome, (iv) the efficacy of medical treatments on ART outcome, and (v) the effects of ART on thrombotic risk. A total of 46 papers were considered; several limitations emerged: (i) wide heterogeneity in study populations, (ii) non-prospective design in 90% of studies, and (iii) aPL cutoffs not conforming to international guidelines in more than 75% of studies; aPL positivity not confirmed in 89% of studies. Most studies evinced an association between infertility and anti-β2GPI antibodies and almost all non-criteria aPL. The association rate with infertility was below 50% for lupus anti-coagulant, anti-cardiolipin antibodies (aCL), and anti-phosphatidic acid antibodies. According to our estimates, overall positivity rates of criteria and non-criteria aPL tests are 6% and 3% among infertile women, 1% and 2% among controls, respectively. A significant difference in the positivity rate of patients versus controls emerged for aCL only. Five of 18 studies reported a detrimental effect of aPL on ART outcome. Only one of the six studies assessing the effects of treatment on ART outcome among aPL-positive infertile women reported a benefit. All relevant studies reported no increase in the rate of thrombosis among aPL-positive women undergoing ART.

Intravenous immunoglobulins and antiphospholipid syndrome: How, when and why? A review of the literature

The antiphospholipid syndrome (APS) is defined by the occurrence of venous and arterial thromboses and recurrent fetal losses, frequently accompanied by a moderate thrombocytopenia, in the presence of antiphospholipid antibodies (aPL), namely lupus anticoagulant (LA), anticardiolipin antibodies (aCL), or anti-β2 glycoprotein-I (β2GPI) antibodies. The current mainstay of treatment for thrombotic APS is heparin followed by long-term anticoagulation, while in obstetric APS, the accepted first-line treatment consists in low-dose aspirin (LDA) plus prophylactic unfractionated or low-molecular-weight heparin (LMWH). Recently, new emerging treatment modalities, including intravenous immunoglobulins (IVIG), have been implemented to manage APS refractory to conventional therapy. The objective of this review is to summarize the currently available information on the IVIG therapy in APS, focusing on the use of IVIG in the obstetric form, CAPS and on primary or secondary thromboprophylaxis. We analyzed 35 studies, reporting the effects of IVIG in APS patients, and we discussed their results. IVIG in obstetric APS seem to be very useful in selected situations (patients not responsive to the conventional treatment, concomitant autoimmune manifestations or infections or patients in whom anticoagulation is contraindicated). IVIG treatment represents an important component of the combination therapy of CAPS and they could be useful, in addition to the standard therapy, to prevent recurrent thrombosis in APS patients refractory to conventional anticoagulant treatment. Anyway, in some cases we also found controversial results that claim the need of further well-designed studies to definitely state the efficacy and tolerability of IVIG in CAPS, obstetric and non-APS.

Anticoagulation and in vitro fertilization and ovarian stimulation

Assisted reproductive technology is widely used to treat couples affected by infertility. Complications associated with assisted reproduction include venous thromboembolism, ovarian hyperstimulation syndrome, and recurrent implantation failure. It has also been proposed that thrombophilia may be associated with an increased likelihood of these events. Although data are limited, antithrombotic therapy is frequently used to enhance the likelihood of successful assisted reproduction. This chapter reviews the risks of venous and arterial thromboembolism associated with assisted reproduction, as well as available data regarding the impact of thrombophilia on the risks of thromboembolism and failure of implantation. The role of antithrombotic therapy in reducing the likelihood of these events, along with recommendations from various guidelines, are also discussed.

14th International Congress on Antiphospholipid Antibodies Task Force report on obstetric antiphospholipid syndrome

Pregnancy morbidity is one of the clinical manifestations used for classification criteria of antiphospholipid syndrome (APS). During the 14th International Congress on Antiphospholipid Antibodies (aPL), a Task Force with internationally-known experts was created to carry out a critical appraisal of the literature available regarding the association of aPL with obstetric manifestations present in actual classification criteria (recurrent early miscarriage, fetal death, preeclampsia and placental insufficiency) and the quality of the evidence that treatment(s) provide benefit in terms of avoiding recurrent adverse obstetric outcomes. The association of infertility with aPL and the effectiveness of the treatment of patients with infertility and positive aPL was also investigated. This report presents current knowledge and limitations of published studies regarding pregnancy morbidity, infertility and aPL, identifying areas that need better investigative efforts and proposing how critical flaws could be avoided in future studies, as suggested by participants of the Task Force. Except for fetal death, there are limitations in the quality of the data supporting the association of aPL with obstetric complications included in the current APS classification criteria. Recommended treatments for all pregnancy morbidity associated to APS also lack well-designed studies to confirm its efficacy. APL does not seem to be associated with infertility and treatment does not improve the outcomes in infertile patients with aPL. In another section of the Task Force, Dr. Jane Salmon reviewed complement-mediated inflammation in reproductive failure in APS, considering new therapeutic targets to obstetric APS (Ob APS).

Recurrent spontaneous abortions, Hashimoto thyroiditis and alopecia totalis: response to anticoagulation and intravenous immunoglobulin therapy

INTRODUCTION

Although numerous studies indicated a link between antithyroid antibodies and recurrent spontaneous abortions (RSA), consensus on the treatment of this condition is still lacking.

CASE REPORT

We present a case of a 35-year-old pregnant woman (gestation week 4) with primary hypothyroidism, total alopecia, high level of positive antithyroid antibodies, and history of two recurrent spontaneous abortions in early pregnancy. Along with L-thyroxin substitution, intravenous human immunoglobulin (IVIg) combined with anticoagulation and antiaggregation therapy was introduced. During pregnancy her scalp hair completely re-grew, and following gestation week 39 she delivered healthy female child.

CONCLUSION

Thyroid antibodies could contribute to previous recurrent abortions in our patient. It is suggested that in older primiparas with Hashimoto thyroiditis and history of RSA, a combined treatment with IVIg, anticoagulation and antiaggregation therapy should be considered.

Heparin for assisted reproduction

BACKGROUND

Heparin as an adjunct in assisted reproduction (peri-implantation heparin) is given at or after egg collection or at embryo transfer during assisted reproduction. Heparin has been advocated to improve embryo implantation and clinical outcomes.  It has been proposed that heparin enhances the intra-uterine environment by improving decidualisation with an associated activation of growth factors and a cytokine expression profile in the endometrium that is favourable to pregnancy.

OBJECTIVES

To investigate whether the administration of heparin around the time of implantation (peri-implantation heparin) improves clinical outcomes in subfertile women undergoing assisted reproduction.

SEARCH METHODS

A comprehensive and exhaustive search strategy was developed in consultation with the Trials Search Co-ordinator of the Cochrane Menstrual Disorders and Subfertility Group (MDSG). The strategy was used in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress). Relevant trials were identified from both electronic databases and other resources (last search 6 May 2013).

SELECTION CRITERIA

All randomised controlled trials (RCTs) were included where peri-implantation heparin was given during assisted reproduction. Peri-implantation low molecular weight heparin (LMWH) during IVF/ICSI was given at or after egg collection or at embryo transfer in the included studies. Live birth rate was the primary outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and quality of trials and extracted relevant data. The quality of the evidence was evaluated using GRADE methods.

MAIN RESULTS

Three RCTs (involving 386 women) were included in the review.Peri-implantation LMWH administration during assisted reproduction was associated with a significant improvement in live birth rate compared with placebo or no LMWH (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.07 to 2.90, three studies, 386 women, I(2) = 51%, very low quality evidence with high heterogeneity). There was also a significant improvement in the clinical pregnancy rate with use of LMWH (OR 1.61, 95% CI 1.03 to 2.53, three studies, 386 women, I(2) = 29%, very low quality evidence with low heterogeneity).However these findings should be interpreted with extreme caution as they were dependent upon the choice of statistical method: they were no longer statistically significant when a random-effects model was used.Adverse events were poorly reported in all included studies, with no comparative data available. However, LMWH did cause adverse effects including bruising, ecchymosis, bleeding, thrombocytopenia and allergic reactions. It appeared that these adverse effects were increased if heparin therapy was used over a longer duration.

AUTHORS' CONCLUSIONS

The results of this Cochrane review of three randomised controlled trials with a total of 386 women suggested that peri-implantation LMWH in assisted reproduction treatment (ART) cycles may improve the live birth rate in women undergoing assisted reproduction. However, these results were dependent on small low quality studies with substantial heterogeneity, and were sensitive to the choice of statistical model. There were side effects reported with use of heparin, including bruising and bleeding, and no reliable data on long-term effects. The results do not justify this use of heparin outside well-conducted research trials.These findings need to be further investigated with well-designed, adequately powered, double-blind, randomised, placebo-controlled, multicentre trials. Further investigations could also focus on the effects of the local (uterine) and not systemic application of heparin during ART.

Thrombophilia and outcomes of assisted reproduction technologies: a systematic review and meta-analysis

Thrombophilia has been associated with pregnancy complications and recurrent miscarriage. The aim of this systematic review was to evaluate the controversial association between thrombophilia and failures of assisted reproduction technology (ART). A systematic search of the literature for studies reporting on thrombophilia in women undergoing ART up to April 2011 yielded 33 studies (23 evaluating anti-phospholipid antibodies, 5 inherited thrombophilia, and 5 both) involving 6092 patients. Overall, methodologic quality of the studies was poor. Combined results from case-control studies showed that factor V Leiden was significantly more prevalent among women with ART failure compared with fertile parous women or those achieving pregnancy after ART (odds ratio = 3.08; 95% confidence interval, 1.77-5.36). The prothrombin mutation, methylenetetrahydrofolate reductase mutation, deficiency of protein S, protein C, or anti-thrombin were all not associated with ART failure. Women with ART failure tested more frequently positive for anti-phospholipids antibodies (odds ratio = 3.33; 95% confidence interval, 1.77-6.26) with evidence of high degree of between-study heterogeneity (I2 = 75%; P < .00001). Prospective cohort studies did not show significant associations between thrombophilia and ART outcomes. Although case-control studies suggest that women experiencing ART failures are more frequently positive for factor V Leiden and anti-phospholipid antibodies, the evidence is inconclusive and not supported by cohort studies.

Fertility, Infertility and Thrombophilia

Hypercoagulation has been reported in some studies to be associated with reproductive failures, such as unexplained infertility, IVF implantation failure and recurrent fetal losses. Many pregnancy-related disorders have been interpreted as consequences of impaired microvascular function and might be viewed as a mild form of venous thromboembolic disease. In the absence of clinical guidelines, there is a need for an evidence base regarding thrombophilic screening and antithrombotic therapy in cases of reproductive failure. This article will focus on the controversial effect of congenital and acquired thrombophilia on human fertility, and will review the English literature for relevant studies identified by searching PubMed® results between January 1966–November 2010 using the key words: ‘thrombophilia‘, ‘fertility’ and ‘infertility‘.

Aspirin for in vitro fertilisation

BACKGROUND

Aspirin is used to improve the outcome in women undergoing in vitro fertilisation despite inconsistent evidence of its efficacy. The most appropriate time to commence aspirin therapy and the length of treatment required are also still to be determined. This is an update of the review first published in 2007.

OBJECTIVES

To determine the effectiveness and safety of aspirin for improving the outcome of in vitro fertilisation and intracytoplasmic sperm injection treatment cycles.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library January 2011), MEDLINE (1966 to January 2011) and EMBASE (1980 to January 2011) databases. We used the research terms: "(aspirin OR acetylsalicylic acid) AND (in-vitro fertilisation OR intracytoplasmic sperm injection)", combined with the Cochrane Menstrual Disorders and Subfertility Group's search strategy, in order to identify randomised controlled trials on aspirin for women undergoing in vitro fertilisation.

SELECTION CRITERIA

Randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies to include in the review, extracted data and assessed trial quality.

MAIN RESULTS

The searches identified 13 trials which were eligible for inclusion in the review, including a total of 2653 participants. No significant differences were found between the treatment and control groups for any of the outcomes assessed. No significant differences were found in the meta-analysis of studies investigating the effect of aspirin compared with control on live birth rate (RR 0.91, 95% CI 0.72 to 1.15; three studies and 1053 participants), clinical pregnancy rate (RR 1.03, 95% CI 0.91 to 1.17; 10 studies and 2142 participants), ectopic and miscarriage rates (RR 1.86, 95% CI 0.75 to 4.63; RR 1.10, 95% CI 0.68 to 1.77) respectively (three and five studies involving 1135 and 1497 participants).

AUTHORS' CONCLUSIONS

Use of aspirin for women undergoing in vitro fertilisation cannot be recommended due to lack of evidence from the current trial data. Adequately powered trials are needed. It was proposed in the initial version of this review that a sample size of 350 women in each group would be required in order to demonstrate a 10% improvement from the use of aspirin, with 80% power at the 5% significance level. Until such evidence is available, this treatment can not be recommended.

Low-Molecular-Weight Heparin in Women with Repeated Implantation Failure

Implantation failure is common in assisted reproduction techniques (ART). The role of low-molecular-weight heparin (LMWH) is a matter of debate as a potential factor to improve implantation. Aim: To evaluate the pregnancy rate in patients with or without heparin administration. Materials & methods: We performed a retrospective observational analysis of patients with at least two IVF/intracytoplasmic sperm injection cycles with implantation failure, screened for inherited thrombophilia and submitted to further ART cycles with or without administration of LMWH. A total of 265 patients fulfilled the enrollment criteria. Of these 149 (56%) were primary infertile and 116 (44%) were secondary infertile. Their mean age was 36.3 ± 3.6 years. We analyzed basal FSH, smoking habit, gene variants for inherited thrombophilia (i.e., MTHFR C677T, prothrombin G202A10G and factor V Leiden). The patients underwent 569 new ART cycles: 512 (90%) without and 57 (10%) with LMWH. Results: In total 105 clinical pregnancies were observed in 569 cycles (18.8%). The pregnancy rate was 17.19% (88/512) in patients not treated with LMWH and 29.52% (17/57) in the LMWH-treated group (p = 0.006). In women over 36 years of age the pregnancy rate was 15.53% (50/322) in nontreated versus 35.71% (10/28) in treated cycles (p = 0.007), while no difference was found in younger women. No statistical difference was found between the presence of inherited thrombophilia and pregnancy rate in treated and untreated cycles. Discussion: significantly higher pregnancy rate in patients with previous ART implantation failures was observed with LMWH. Our results confirm no relation among inherited thrombophilia and pregnancy rate in patients with previous IVF implantation failures. These findings should be confirmed by randomized controlled trials before use of LMWH for ART cycles is recommended.

Intravenous immunoglobulin therapy in rheumatic diseases

Prepared from the collective plasma of several thousand people, therapeutic intravenous immunoglobulin (IVIg) consists mostly of human polyspecific IgG. In addition to its use in primary and secondary immune deficiencies, IVIg is used in the treatment of several rheumatic conditions, including Kawasaki disease, dermatomyositis and antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. In these diseases, IVIg therapy generally involves the use of 2 g/kg administered over either 2 or 5 consecutive days. However, dosage regimens have not been thoroughly explored, and indications for IVIg in most rheumatic diseases, such as systemic lupus erythematosus, polymyositis and catastrophic antiphospholipid syndrome, derive from its off-label usage. Randomized clinical trials are warranted to support the evidence-based use of IVIg, and to identify the ideal administration protocols to maximize the benefits of what is a limited resource. Further research to improve the therapeutic application of IVIg relies essentially on the conception of next-generation immunoglobulin preparations and optimization of combined therapies with immunomodulatory drugs and biologic agents.

Evidence for the use of intravenous immunoglobulins--a review of the literature

Intravenous immunoglobulins (IVIg) were first introduced in the middle of the twentieth century for the treatment of primary immunodeficiencies. In 1981, Paul Imbach noticed an improvement of immune-mediated thrombocytopenia, in patients receiving IVIg for immunodeficiencies. This opened a new era for the treatment of autoimmune conditions with IVIg. Since then, IVIg has become an important treatment option in a wide spectrum of diseases, including autoimmune and acute inflammatory conditions, most of them off-label (not included in the US Food and Drug Administration recommendation). A panel of immunologists and internists with experience in IVIg therapy reviewed the medical literature for published data concerning treatment with IVIg. The quality of evidence was assessed, and a summary of the available relevant literature in each disease was given. To our knowledge, this is the first all-inclusive comprehensive review, developed to assist the clinician when considering the use of IVIg in autoimmune diseases, immune deficiencies, and other conditions.

Luteal phase empirical low molecular weight heparin administration in patients with failed ICSI embryo transfer cycles: a randomized open-labeled pilot trial

BACKGROUND

The pathology underlying recurrent implantation failures (RIF) is not clear and treatment options proposed are generally not evidence based. Although the effect of heparin on trophoblast biology has not been studied extensively, given the available data suggesting a possible beneficial effect of heparin on embryo implantation, we decided to undertake this pilot study.

METHODS

One hundred and fifty women with > or =2 failed assisted reproduction treatment cycles were included in this randomized open-label pilot trial. Participants underwent controlled ovarian stimulation with the long protocol and were randomly allocated to receive 1 mg/kg/day low molecular weight heparin (LMWH) or no treatment in addition to routine luteal phase support (LPS) on the day after oocyte retrieval. LPS and LMWH was continued up to the 12th gestational week in pregnant participants.

RESULTS

There were 26 (34.7%) live births in the LMWH group, and 20 (26.7%) in the control group (absolute difference 8.0%, 95% CI -4.2 to 24.9%, P = 0.29). There were 34 (45.3%) and 29 (38.7%) clinical pregnancies in the LMWH and control groups, respectively (absolute difference 6.6%, 95% CI -9.0 to 21.8%, P = 0.41). Implantation rates were 24.5 and 19.8% in the LMWH and control groups, respectively (absolute difference 4.7%, 95% CI -4.7 to 14.1%, P = 0.33).

CONCLUSION

Despite lack of statistical significance, observed relative increase by 30% in live birth rates with LMWH may be regarded as a clinically significant trend necessitating further research on the use of empirical LMWH in women with RIF and possibly in all women undergoing assisted reproduction treatment. Failure to demonstrate statistical significance of the observed treatment difference may be due to limited sample size of this pilot study.

Low-molecular-weight heparin in the treatment of recurrent IVF-ET failure and thrombophilia: a prospective randomized placebo-controlled trial

INTRODUCTION

Recently, thrombophilia (acquired and inherited) has been implicated in recurrent IVF-ET failure. The objective of this study was to determine the effect and safety of thromboprophylaxis using low-molecular-weight heparin (LMWH) in women with recurrent in vitro fertilization (IVF)-embryo transfer (ET) failure and thrombophilia.

METHODS

Eighty-three women with history of three or more previous IVF failures and who had at least one thrombophilic defect were eligible for this study. Patients were randomly allocated into two groups: Group A (n = 42) received enoxaparin 40 mg/day, and group B (n = 41) received placebo (NaCl 0.9%). Both treatments started on the day of ET and continued until delivery or foetal demise was diagnosed. The primary outcomes were the implantation, pregnancy and live birth rates.

RESULTS

Patients who received LMWH for thromboprophylaxis had a significant increase in the implantation and pregnancy rates compared with the placebo group (20.9% vs. 6.1% and 31% vs. 9.6%, respectively; p < 0.001 and p < 0.05, respectively). A significant increase in the live birth rate was observed in the heparin-treated group compared with placebo (23.8% vs. 2.8%, respectively; p < 0.05). The abortion rate was significantly higher in the placebo-treated group compared to the heparin-treated group (p < 0.05). The frequency of treatment complications did not differ between the two study groups.

CONCLUSIONS

LMWH is a safe and effective thromboprophylactic treatment for women with thrombophilia and recurrent IVF-ET failures. The implantation rate, pregnancy and live birth rates are significantly increased with such treatment.

Anticoagulant therapy and pregnancy

Low dose aspirin therapy is one of the anticoagulant treatments used during pregnancy. Anticoagulant agents may be useful for several disorders, such as recurrent miscarriage, pre-eclampsia, fetal growth restriction and infertility. However, it is unclear whether anticoagulant therapy can increase the live birth rate in all of these cases. Recent data suggest that a low-dose aspirin and heparin combination therapy is effective in the prevention of recurrent pregnancy loss in women with antiphospholipid syndrome. Thrombogenic diseases, for example, protein C deficiency, protein S deficiency, factor XII deficiency and hyperhomocysteinemia, may cause pregnancy loss. The etiology of recurrent miscarriage is often unclear and may be multifactorial, with much controversy regarding diagnosis and treatment. Although 70% of recurrent pregnancy losses are unexplained, anticoagulant therapy is effective in maintaining pregnancy without antiphospholipid antibody syndrome. We conclude that a low-dose aspirin and heparin combination therapy can be useful for unexplained cases of recurrent pregnancy loss without antiphospholipid antibody syndrome. (Reprod Med Biol 2008; 7: 1-10).

Low-dose aspirin for in vitro fertilisation

BACKGROUND

Low-dose aspirin is sometimes used to improve the outcome in women undergoing in vitro fertilisation, despite inconsistent evidence of efficacy and the potential risk of significant side affects. The most appropriate time to commence aspirin therapy and length of treatment required is also still to be determined.

OBJECTIVES

To determine the effectiveness of low-dose aspirin for improving the outcome of in vitro fertilisation and intracytoplasmic sperm injection treatment cycles.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (April 2007), MEDLINE (1966 to March 2007) and EMBASE (1980 to March 2007) databases using the following research terms: "(aspirin OR acetylsalicylic acid) AND (in-vitro fertilisation OR intracytoplasmic sperm injection)" combined with the Cochrane Menstrual Disorders and Subfertility Group's search strategy for identifying randomised controlled trials for reports which appeared to describe randomised controlled trials of low-dose aspirin for women undergoing in vitro fertilisation.

SELECTION CRITERIA

Prospective randomised controlled trials, published or unpublished, which addressed the objectives of the review. Quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies to include in the review, extracted data and assessed trial quality.

MAIN RESULTS

The searches identified nine trials which were eligible for inclusion in the review, including a total of 1449 participants. No significant differences were found between the treatment and control groups for any of the outcomes assessed. Only two studies (involving 401 participants) investigated the effect of low-dose aspirin on live birth rate, and no significant difference was found between the treatment and control groups (RR 0.94, 95% CI 0.63 to 1.39). No significant difference was found in clinical pregnancy rate between treatment and control groups, based on results from 1240 participants in seven studies (RR 1.09, 95% CI 0.83 to 1.43). No data were reported on adverse events related to aspirin treatment in any of the included studies.

AUTHORS' CONCLUSIONS

Use of low-dose aspirin for women undergoing in vitro fertilisation cannot currently be recommended due to lack of adequate trial data. There is a need for randomised controlled trials investigating the use of low-dose aspirin for different patient groups undergoing in vitro fertilisation. We used control group data from the largest trial included in this review to determine that a sample size of 350 women in each group would be required in order to demonstrate a 10% improvement from the use of aspirin with 80% power at the 5% significance level. Until evidence from appropriately powered trials is available, this treatment can not be recommended.

IgG-antiphospholipid antibodies in follicular fluid of IVF-ET patients are related to low fertilization rate of their oocytes

PROBLEM

Patients undergoing in vitro fertilization and embryo transfer (IVF-ET) failures show an increased incidence of antiphospholipid antibodies (aPL) in their blood. The physiological manifestations of aPL in this patient group are nonetheless controversial. Pathological effects of aPL on embryos in vitro have been documented. We questioned whether aPL if found in follicular fluids (FFs) could result in embryonic damage.

METHOD OF STUDY

Blood from 44 patients with three or more IVF-ET failures were tested by enzyme-linked immunosorbent assays (ELISA) for the presence of immunoglobulin (Ig)G, IgM and IgA aPL. Both the 29 aPL-positive and 15 aPL-negative patients gave permission for FF collection during their next IVF-ET attempt for additional aPL determinations.

RESULTS

Patients with no aPL in their blood, had no aPL in their FFs. Patients with IgG and/or IgM aPL in their blood had IgG but not IgM in their respective FFs.

CONCLUSIONS

The presence of IgG aPL in FFs and increased infertility length were significantly related to lower fertilization rates, independently. Follicular fluid IgG aPL appears as a risk factor in association with successful IVF-ET outcomes.

[Hormone therapy, fertility and pregnancy in antiphospholipid syndrome]

Antiphospholipid syndrome (APS) carries a risk of thrombosis and infertility. Consequently the use of any type of hormone therapy and pregnancy in APS requires special considerations. The present article provides a broad review of all these issues. The use of contraception, hormone replacement therapy and selective estrogen receptor modulators in APS are described. In vitro fertilization/embryo transfer and ovarian induction in these patients are reviewed. Lastly, the possible fetal and maternal complications that can occur during pregnancy are described and, based on the literature, recommendations for the management of pregnancy in women with APS are provided.

Is intravenous immunoglobulins (IVIG) efficacious in early pregnancy failure? A critical review and meta-analysis for patients who fail in vitro fertilization and embryo transfer (IVF)

PROBLEM

Intravenous Immunoglobulins (IVIG) are widely used off label in the treatment of early reproductive failure. As IVIG is expensive, and may have side-effects, evidence of efficacy is needed. Previous results have suggested that the pre-conception treatment of primary recurrent abortion patients might be effective, but the data set has been too small for adequate statistical power. More recently it has been suggested that IVIG may improve the success rate of in vitro fertilization and embryo transfer (IVF) in patients with prior IVF failures, but clinical trials have given conflicting results that need explanation. Systematic reviews generating inconclusive results have focused on methodological rigor to the exclusion of biological plausibility.

METHODS

Review of current basic science of design, measurement, and evaluation of clinical trials and basic science mechanisms providing a rationale for treatment. Meta-analysis of published randomized controlled and cohort-controlled trials (updated with two unpublished data sets) evaluating IVIG treatment in IVF failure patients. Live birth rate was used as the most relevant endpoint. The ability of different sources of IVIG to suppress natural killer (NK) cell activity was determined using a standard (51)Cr-release assay in vitro.

RESULTS AND CONCLUSIONS

Meta-analysis of three published randomized controlled trials (RCTs) of IVIG in IVF failure patients shows a significant increase in the live birth rate per woman (p = 0.012; Number Needed to Treat for 1 additional live birth, NNT = 6.0 women). Using live birth rate per embryo transferred, and adding data from two cohort-controlled trials to the meta-analysis further supports this conclusion (overall p = 0.000015, NNT = 3.7 women). Relevant variables appear to include properties and scheduling of the IVIG, and selection of patients with abnormal immune test results. Different IVIG preparations vary significantly in their ability to suppress NK activity in vitro. A rationale for use of IVIG is provided by a review of mechanisms of IVIG action and mechanisms underlying failure of chromosomally normal embryos.

Antiphospholipid antibodies and coagulation defects in women with implantation failure after IVF and recurrent miscarriage

Evaluation of patients with IVF implantation failure or recurrent miscarriage often frustratingly fails to elicit any particular cause for their problem. Testing for antiphospholipid antibodies or thrombophilia is commonly carried out, and interpretation of results in the light of the current evidence is extremely difficult. This paper reviews the purported pathogenetic mechanisms and clinical associations between both antiphospholipid antibodies and inherited thrombophilias, and reproductive failure. The current management strategies are also critically evaluated and recommendations are made for optimal, evidence-based clinical practice.

Low-dose aspirin does not improve ovarian stimulation, endometrial response, or pregnancy rates for in vitro fertilization

Background

The purpose of this study is to determine if low-dose aspirin improved ovarian stimulation, endometrial response, or IVF pregnancy rates in our program.

Methods

Retrospective analysis of 316 consecutive IVF cycles from 1995 through 2001. Aspirin 80 mg daily was initiated at the start of luteal leuprolide in 72 cycles. The 244 controls received no aspirin during treatment.

Results

The live birth rate in aspirin users was 29%, slightly lower compared to 41% in the no aspirin control group (p = 0.07). Implantation rates were 21% with aspirin and 30% in the control population (p = 0.01). There was no difference in the maximal endometrial thickness between aspirin and non-aspirin groups. The two groups were similar regarding age, gonadotropin ampules, embryos, number of embryos transferred, prior parity, diagnosis, use of intracytoplasmic sperm injection, and stimulation protocol.

Conclusion

Low-dose aspirin was not beneficial to IVF patients in our program. Aspirin does not enhance endometrial thickness, augment the ovarian response, or improve pregnancy rates.

Prevention of recurrent miscarriage for women with antiphospholipid antibody or lupus anticoagulant

BACKGROUND

A range of treatments have been proposed to improve pregnancy outcome in recurrent pregnancy loss associated with antiphospholipid antibody (APL). Small studies have not resolved uncertainty about benefits and risks.

OBJECTIVES

To examine outcomes of all treatments given to maintain pregnancy in women with prior miscarriage and APL.

SEARCH STRATEGY

We searched the Pregnancy and Childbirth Group's Trials Register (30 May 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), MEDLINE (1966 to June 2003), EMBASE (1988 to June 2003), Lupus (volume one to eight, 1991 to 1999) and conference proceedings from the International Symposium on APL up to 1999.

SELECTION CRITERIA

Randomised or quasi-randomised, controlled trials of interventions in pregnant women with a history of pregnancy loss and APL.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed quality and extracted data for studies up to December 1999. One review author performed this for studies after 1999.

MAIN RESULTS

Thirteen studies were found (849 participants). The quality was not high; 50% had clear evidence of allocation concealment. Participant characteristics varied between trials. Unfractionated heparin combined with aspirin (two trials; n = 140) significantly reduced pregnancy loss compared to aspirin alone (relative risk (RR) 0.46, 95% confidence interval (CI) 0.29 to 0.71). Low molecular weight heparin (LMWH) combined with aspirin compared to aspirin (one trial; n = 98) did not significantly reduce pregnancy loss (RR 0.78, 95% CI 0.39 to 1.57). There was no advantage in high-dose, over low-dose, unfractionated heparin (one trial; n = 50). Three trials of aspirin alone (n = 135) showed no significant reduction in pregnancy loss (RR 1.05, 95% CI 0.66 to 1.68). Prednisone and aspirin (three trials; n = 286) resulted in a significant increase in prematurity when compared to placebo, aspirin, and heparin combined with aspirin, and an increase in gestational diabetes, but no significant benefit. Intravenous immunoglobulin +/- unfractionated heparin and aspirin (two trials; n = 58) was associated with an increased risk of pregnancy loss or premature birth when compared to unfractionated heparin or LMWH combined with aspirin (RR 2.51, 95% CI 1.27 to 4.95). When compared to prednisone and aspirin, intravenous immunoglobulin (one trial; n = 82) was not significantly different in outcomes.

AUTHORS' CONCLUSIONS

Combined unfractionated heparin and aspirin may reduce pregnancy loss by 54%. Large, randomised controlled trials with adequate allocation concealment are needed to explore potential differences between unfractionated heparin and LMWH.

Drug intervention in early pregnancy after assisted reproductive technology

Implantation in humans is a complex, closely regulated, highly selective and relatively poorly understood process. Humans have the highest rate of miscarriage in mammals and various pharmacological manipulations have been used to minimize pregnancy losses in both spontaneous pregnancies and pregnancies resulting from assisted reproduction technology. The widespread application of protocols using numerous drugs in assisted reproduction treatment has led to an increasing number of pregnancies exposed to these drugs. The vast majority of these protocols have been based on data from a few observational and often retrospective clinical studies. This paper reviews the recent literature on drug interventions in early pregnancy after assisted reproduction treatment. It is concluded that there are still numerous issues about the safety of most drugs for both the women and their fetus. In many cases, the benefits are theoretical and the possible long-term side-effects are untested. There is an urgent need for more epidemiological studies and randomized controlled trials to explore the use, efficacy and side-effects of both old and new drugs in early pregnancy after assisted reproduction treatment.

Low-dose aspirin in a short regimen as standard treatment in in vitro fertilization: a randomized, prospective study

OBJECTIVE

To determine if treatment with low-dose aspirin in a short regimen improves the outcome in a nonselected IVF population as compared with no treatment.

DESIGN

Prospective, randomized study where IVF patients were given aspirin or received no treatment.

SETTING

IVF clinic.

PATIENT(S)

The study included 1380 consecutive IVF cycles.

INTERVENTION(S)

Women undergoing IVF were randomly assigned to treatment with aspirin 75 mg daily from the day of embryo transfer (ET) until pregnancy test or no treatment in an open study.

MAIN OUTCOME MEASURE(S)

Birth rate per ET.

RESULT(S)

Background characteristics were similar in the two groups studied except for a minor difference in number of embryos transferred (2.1 vs. 2.0). Birth rate was 27.2% in the aspirin group as compared with 23.2% in the nontreated group, giving an odds ratio, adjusted for number of embryos transferred, of 1.2 (95% confidence interval, 1.0-1.6).

CONCLUSION(S)

The increased birth rate with aspirin compared with no treatment was significant. Given the importance of every birth in IVF, especially when taking into account the limited number of IVF cycles that are normally performed in an individual woman, any treatment to improve birth rate is important.

[So-called antiphospholipid antibodies and infertility: biological data]

Recurrent early and late foetal losses are common problems found in women with antiphospholipid syndrome, with therapeutic implication and improvement of the prognosis for the next pregnancies with antithrombotic therapy. After these results, some groups propose to extend the antiphospholipid investigations to infertility and failure of in vitro fertilization embryo transfer, but actually without demonstration of a real utility in the management of these women.

A randomized, double-blind, placebo-controlled trial of heparin and aspirin for women with in vitro fertilization implantation failure and antiphospholipid or antinuclear antibodies

OBJECTIVE

To investigate whether heparin and low-dose aspirin increase the pregnancy rate in antiphospholipid antibody or antinuclear antibody-seropositive women with IVF implantation failure.

DESIGN

A double-blind, randomized, transfer-by-transfer of fresh or cryopreserved embryos, crossover trial.A hospital infertility clinic and associated IVF service.

PATIENT(S)

Women seropositive for at least one antiphospholipid (APA), antinuclear (ANA), or beta(2) glycoprotein I autoantibody and >or=10 embryos transferred without achieving pregnancy (n = 143).

INTERVENTION(S)

Subcutaneous unfractionated heparin (5000 IU b.i.d.) and aspirin (100 mg daily) (158 transfers of 296 embryos) or placebo (142 transfers of 259 embryos) from the day of embryo transfer.

MAIN OUTCOME MEASURE(S)

Fetal heart per embryo transferred (implantation rate).

RESULT(S)

There was no significant difference in pregnancy rates or implantation rates between treated and placebo cycles; for example, fetal hearts per embryo transferred implantation rates were 6.8% (20/296) and 8.5% (22/259), respectively, and the generalized estimating equation covariate adjusted relative pregnancy rate was 0.65 (95% confidence interval, 0.33-1.28). The implantation rate for seropositive trial participants (42/555, 7.6%) compared favorably with that for IVF implantation-failure patients continuing treatment outside the trial (147/3237, 4.5%).

CONCLUSION(S)

Heparin and aspirin did not improve pregnancy or implantation rates for APA-positive or ANA-positive patients with IVF implantation failure.

Is there any evidence for immunologically mediated or immunologically modifiable early pregnancy failure?

PURPOSE

Human reproduction is an inefficient process. There is a high rate of loss of early pregnancies, often before the mother (or physician) knows she is pregnant. Genetic abnormalities can explain much of the wastage, but can it explain all of the failures? As embryos bear paternal and embryonic antigens foreign to the maternal immune system, could some otherwise normal embryos be "rejected"?

METHODS

Critical review of existing data.

RESULTS AND CONCLUSIONS

Otherwise normal embryos can fail prior to implantation, at implantation, in the periimplantation period as occult/chemical pregnancies, and as clinically evident miscarriages. The maternal immune system and its products (e.g., cytokines) can have innocent bystander effects, and a good case for direct recognition and "rejection" can also be made. The tools needed for accurate clinical diagnosis of such situations require further development and validation. Deliberate modification of the maternal host defence system can improve the chance of success, but the best evidence for efficacy of immunotherapeutic interventions is the situation of recurrent spontaneous abortions, which constitutes only a small percentage of losses. There is also evidence of clinical efficacy for several types of treatment to improve implantation and early pregnancy success.