Methylenetetrahydrofolate Reductase Polymorphisms and Pregnancy Outcome

Skin disorders in women with poor obstetric history: MTHFR polymorphisms and importance of preconceptional counseling

OBJECTIVES

This study focused on the link between skin disorders and Methylenetetrahydrofolate reductase (MTHFR) polymorphisms.

METHODS

Study cases were taken from a pre-conceptional care program where patients with poor obstetric history were evaluated in terms of systemic disorders including skin diseases. This retrospective cohort (n = 472) consisted of 110 (23.3%) and 362 (76.7%) women with or without skin disorders, respectively. For ease of analysis, the history of skin diseases was classified into seven categories: (1) acne/rosacea/other acneiform disorders; (2) fungal disease; (3) pruritis/xerosis; (4) psoriasis vulgaris; (5) acrochordons and other benign skin growths; (6) urticaria/dermatitis; and (7) viral diseases.

RESULTS

In this retrospective cohort of 472 women, we explored the impact of MTHFR A1298C and C677T polymorphisms on skin disorders. Despite similar allelic frequencies, our findings revealed a statistically significant association between the presence of MTHFR polymorphisms and skin disorders (p = .027). Subgroup analysis indicated significantly higher rates of MTHFR polymorphisms in patients with psoriasis vulgaris (p = .033) and acrochordons (p = .030), highlighting their potential relevance in specific skin disorder subtypes.

CONCLUSIONS

The increased prevalence of psoriasis and acrochordons among women with MTHFR deficiency underscores the complex relationship between genetic factors and dermatological health. Our findings emphasized the critical role of MTHFR polymorphisms not only in poor obstetric history but also as significant contributors to skin disorders. This dual association highlights the importance of comprehensive preconception counseling, especially customized for women affected by skin disorders.

Impact of Prematurity on the Buccal Epithelial Cells of the Neonates via Wnt/Beta-Catenin Signaling Pathway and Apoptosis

OBJECTIVE

 Understanding the reflections of prematurity is necessary for the management of neonatal complications. We focused on the impact of prematurity and related "maternal risk factors/obstetric complications" on buccal cells of the neonates via evaluation of the Wnt/β-catenin signaling pathway and apoptosis.

STUDY DESIGN

 This study consisted of "early preterm neonates (EPN) (≤34th gestational week [gw]) (n = 36)," "late preterm neonates (LPN) (34th- < 37th gw) (n = 46)," and "term neonates (control) (≥37th gw) (n = 56)." Cohort was also subclassified according to the presence of maternal risk factors, obstetric complications, and neonatal complications. Wnt/β-catenin signaling and caspase-3 activation pathways were studied immunocytochemically.

RESULTS

 Wnt/β-catenin signaling positivity was statistically more frequent at buccal smears of the EPN and LPN groups compared with controls (p < 0.001). The cutoff for gestational age at delivery in receiver operating characteristic curve with the best balance of sensitivity (67.4%) and specificity (67.3%) was 35.8th gw for determining the reduction of Wnt/β-catenin signaling positivity (p < 0.001). The study demonstrated that obstetric complications significantly affected the activity of signaling, while maternal risk factors do not have any effect on Wnt/β-catenin signaling pathway (p = 0.003 and p = 0.828, respectively). This study also demonstrated a significant relationship between Wnt/β-catenin signaling pathway and the presence of neonatal complications (p = 0.015).

CONCLUSION

 Dynamic characteristics of buccal cells are influenced by prematurity and related obstetric and neonatal problems. Buccal smear is a good tool to investigate the impact of prematurity and obstetric problems on perinatal outcome.

KEY POINTS

· Neonatal buccal cells are affected by prematurity and related obstetric/neonatal problems.. · 35.8th gw is critical for determining the reduction of Wnt/β-catenin signaling positivity.. · Obstetric and neonatal complications significantly related to Wnt/β-catenin signaling activity..

Association of single nucleotide polymorphisms (4G/5G) of plasminogen activator inhibitor-1 and the risk factors for placenta-related obstetric complications

BACKGROUND

Placenta-related obstetric complications (PROCs) such as miscarriage, fetal growth restriction, preeclampsia, and preterm birth are the major causes of maternal and fetal morbidity and mortality. The objective of this study was to search the relevance of plasminogen activator inhibitor-1 (PAI-1) polymorphisms and co-morbidities and the risk factors for PROCs such as miscarriage, fetal growth restriction, preeclampsia, and preterm birth.

METHOD

This retrospective study analyzed the PAI-1 genotype in a cohort of 268 multiparous women with poor obstetric history. Poor obstetric history was defined as the presence of at least one of the PROCs and/or poor gestational outcomes at the previous pregnancy/pregnancies.

RESULTS

5G allele frequency was higher than the 4G allele frequency in the cohort (0.767 vs. 0.233). The frequencies of having at least one risk factor are relatively similar among the different PAI-1 genotypes ( P  > 0.05). However, the presence of MTHFR polymorphisms (homozygous and compound heterozygous forms of C677T and A1298G) and hereditary thrombophilia (Factor V Leiden and prothrombin G20210A gene mutations, and FXIII deficiency) were found to be associated with PAI 4G/4G ( P  = 0.048) and 5G/5G ( P  = 0.022) genotypes, respectively. Significant differences were not observed in other risk factors and co-morbidities such as autoimmune disorders, chronic inflammatory diseases, history of venous thromboembolism, carbohydrate metabolism disorders, hyperlipidemia, cardiovascular and cerebrovascular diseases depending on PAI-1 genotypes ( P  > 0.05).

CONCLUSION

MTHFR polymorphisms were found to be associated with PAI 4G/4G genotype, while 5G/5G genotype was observed more frequently in hereditary thrombophilia cases.

Association of lupus anticoagulants with risk factors for obstetric complications and adverse gestational outcome

BACKGROUND

Lupus anticoagulant (LA) may be a cause of poor obstetric outcome.

OBJECTIVE

To search the association of LA with risk factors for obstetric complications and adverse gestational outcome.

METHODS

This retrospective cohort was consisted of 2 groups of pregnancies with poor obstetric history; 1) LA (+) gestations (Study Group, n= 20) and 2) LA (-) gestations (Control Group, 78). All patients were admitted to a special antenatal care program and were examined in terms of risk factors for thrombotic events, placenta-related obstetric complications, and poor gestational outcomes. Patients were administered low-dose low-molecular-weight heparin (LMWH), low-dose salicylic acid and low-dose corticosteroid (if necessary) within the framework of a prophylaxis protocol in addition to their already existing medications.

RESULTS

We have shown that adverse gestational outcome was 1.7-fold more frequent in LA (+) pregnancies with poor obstetric history (p= 0.039, 70% vs. 41%). Higher rates of autoimmune diseases and hereditary thrombophilia were observed among LA (+) patients compared to LA (-) gestations (35% vs. 10.3%, p< 0.012 and 55% vs. 19.2%, p< 0.003, respectively). To identify the effectiveness of low-dose LMWH prophylaxis protocol, we compared gestational outcomes and demonstrated that the miscarriage rate was significantly decreased to half in current pregnancies compared to the previous gestations (73.6% vs. 35%, p= 0.003).

CONCLUSIONS

Autoimmune diseases and hereditary thrombophilia are more frequent in LA (+) pregnancies, and these women are prone to obstetric problems. Low-dose LMWH and salicylic acid prophylaxis are critical in the management of LA (+) pregnant women.

Association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms with vitamin B12 deficiency and adverse perinatal outcomes among pregnant women of rural South India - a cross sectional longitudinal study

OBJECTIVES

To determine the occurrence of MTHFR gene polymorphisms and to study their association with vitamin B12 deficiency and adverse perinatal outcomes among a cohort of pregnant women from Kaniyambadi block, Tamil Nadu.

METHODS

120 consecutive pregnant women who were ≤20 weeks of gestational age from the 82 villages of Kaniyambadi block were recruited. Genomic DNA was isolated from the peripheral blood. PCR amplification was done followed by Sangers sequencing. Maternal and neonatal outcomes were extracted. Data was entered and analysed.

RESULTS

Our study found the occurrence of c.1298A>C variant in homozygous state in 14.2% and c.677C>T heterozygous state in 15%. Sanger sequencing of exon 7 identified another pathogenic variant c.1262G>T in heterozygous state in two of them. Both the mothers who harboured that variant had preterm delivery and one of them gave birth to a low-birth-weight neonate. In the entire cohort, 5% of the mothers had abortion, 4.2% of them had preterm delivery and 8.8% of the neonates had low birth weight. Presence of c.1298A>C or c.677C>T variants were associated with vitamin B12 deficiency [Pearson Chi squared value (χ²)=7.9 and 7.6 respectively; p=0.02]. Heterozygous pathogenic variant c.1262G>T was associated with both adverse maternal [χ²=11.5; p=0.001] and neonatal [χ²=18.3; p=0.009] outcomes.

CONCLUSIONS

MTHFR gene polymorphisms could be associated with several adverse perinatal outcomes and vitamin B12 deficiency. Further larger studies are needed to prove the pathogenicity of c.1262G>T variant on pregnancy.

T677T Methylenetetrahydrofolate Reductase Single Nucleotide Polymorphisms Increased Prevalence in a Subgroup of Infertile Patients with Endometriosis

<b><i>Background:</i></b> Approximately 10% (190 million) of women worldwide are affected by endometriosis, ectopic deposits of endometrial tissue that create a major source of pain that affects lifestyle and reproductive function. The pathogenesis of endometriosis is an estrogen-dependent inflammatory process, influenced/catalyzed by oxidative stress and consequently defective methylation, with biochemical features centered around the folate and one-carbon cycles. We aimed to determine whether a link could be found between the two major methylenetetrahydrofolate reductase single nucleotide polymorphisms (MTHFR SNPs), c.677C&gt;T and c.1298A&gt;C, involved in methylation process/epigenetic marking failures, and endometriosis. <b><i>Material and Methods:</i></b> We studied a population of 158 patients in a group of &gt;1500 referred for treatment of infertility. All the patients had experienced &gt;2 failed assisted reproductive technology cycles and/or &gt;2 miscarriages, a classical cohort for investigation in our group. Patients with endometriosis had at least stage 2+ disease confirmed by laparoscopy. <b><i>Results:</i></b> The prevalence of the homozygous c.677C&gt;T isoform is doubled in the endometriosis group, 21.5% versus 10.2% in the non-endometriosis group (<i>p</i> &gt; 0.01). Symmetrically, the percentage of patients in the endometriosis group with the wild type MTHFR significantly decreased by one-half (8.2%-17.2%) in the non-endometriosis group (<i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> Determination of MTHFR c.677C&gt;T should not be overlooked in patients with harmful endometriosis affecting their fertility. As folates metabolism is impaired in these MTHFR SNPs carrier patients, co-treatment with 5-methyl folate may constitute a successful (co)-treatment modality.

Impact of anti-thyroid peroxidase and anti-thyroglobulin antibodies on the gestational outcome of euthyroid pregnancies: A retrospective study

BACKGROUND

Thyroglobulin (anti-TG) and/or thyroid peroxidase (anti-TPO) autoantibodies are associated with higher rates of poor gestational outcomes.

OBJECTIVE

To demonstrate the impact of anti-TPO and anti-TG autoantibodies on the gestational outcomes of euthyroid pregnant women with a history of poor gestational outcome and thyroid gland disorders.

METHODS

This retrospective study included totally 75 euthyroid pregnant, 30 of women with high thyroid autoantibodies (Anti-TPO/Thyroglobulin-positive group) and 45 of them without autoantibodies (control group).

RESULTS

We could not demonstrate significant differences between two groups in terms of risk factors/co-morbidities, obstetric complications, gestational outcomes, and birth data (p> 0.05). However, enhanced miscarriage rates were observed among the Anti-TPO/Thyroglobulin-positive and control groups without significance (36.7% and 17.8% respectively, p= 0.116). High neonatal intensive care unit (NICU) admission rates were found for control and Anti-TPO/Thyroglobulin-positive groups (16.2% and 21.1%, respectively) (p= 0.720). Clinically, we compared the two groups in terms of the existence and the types of goiter (diffuse and nodular), and demonstrated that nodular goiter was statistically more frequent in the control group (40.0% vs. 8.7%, p= 0.015). Alongside, relatively high hereditary thrombophilia and type-2 diabetes mellitus rates were found in the Anti-TPO/Thyroglobulin-positive group (20.0% and 20.0%).

CONCLUSION

Thyroid autoantibody positivity is likely a risk factor for early pregnancy loss and NICU admission.

Association of Fetal MTHFR C677T Polymorphism with Susceptibility to Neural Tube Defects: A Systematic Review and Update Meta-Analysis

Background MTHFR gene may be a key epigenetic regulation-related factor crucial during embryogenesis. We performed a meta-analysis to determine the association of fetal MTHFR C677T polymorphism with neural tube defects (NTDs).Methods A comprehensive literature search of the PubMed, Embase, and CNKI database was performed up to April 10, 2020.Results A total of 19 case-control studies with 2,228 NTDs cases and 4,220 controls were identified. Pooled data revealed that the fetal MTHFR C677T polymorphism was significantly highly correlated with development of NTDs in the overall population. Stratified analysis showed a significant association among Caucasians and Asians, but not in mixed populations. There was a significant association between the MTHFR C677T polymorphism and spina bifida risk. No publication bias was found under any genetic model.Conclusions Our pooled data support the fetal MTHFR C677T polymorphism association with risk of NTDs, especially among Caucasians and Asians.

MTHFR 677TT is associated with decreased number of embryos and cumulative live birth rate in patients undergoing GnRHa short protocol: a retrospective study

Background

Whether MTHFR C677T genotype affects pregnancy outcomes following assisted reproductive technology is conflicting. And the role of MTHFR C677T genotype on cumulative live birth has not been reported. This study aims to investigate the effect of MTHFR C677T genotype on cumulative live birth following in-vitro fertilization and embryo transfer (IVF-ET).

Methods

This is a retrospective cohort study that includes 1173 women undergoing their first IVF-ET. We retrospectively compared the reproductive outcomes among the groups stratified by MTHFR C677T genotypes (677CC, 677CT, 677TT). We performed interaction analysis to detect the factor that interacts with the MTHFR C677T genotype. Poisson regression analyses were used to evaluate the associations between MTHFR C677T genotypes with the number of transferable embryos and the number of good-quality embryos. Cox regression analysis was used to evaluate the association between MTHFR C677T genotypes with cumulative live birth. All regression analyses were adjusted with the confounding factors which may independently impact reproductive outcomes.

Results

There is a significant interactive effect of MTHFR 677TT genotype with GnRHa protocol on reproductive outcomes (P for interaction<0.05). MTHFR 677TT homozygous mutation was found to impact reproductive outcomes under GnRHa short protocol but not GnRHa long protocol. MTHFR 677TT is significantly associated with decreased number of transferable embryos (p-value=0.028), decreased number of good-quality embryos (p-value=0.005), and decreased cumulative live birth rate (p-value=0.024) in patients undergoing GnRHa short protocol. However, the clinical pregnancy rate, miscarriage rate and live birth rate at the first embryo transfer cycle were not significantly different between the groups under both protocols (p-values>0.05).

Conclusions

MTHFR 677TT genotype is associated with decreased number of transferable embryos, decreased number of good-quality embryos, and decreased cumulative live birth rate in the first complete cycle in patients undergoing GnRHa short protocol.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04506-4.

Singleton pregnancy losses before gestational week 22 among patients with autoimmune disorders and Methylenetetrahydrofolate reductase polymorphisms

BACKGROUND

The rates of pregnancy losses (PLs) are increased by maternal risk factors such as autoimmune disorders (AD) and methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms.

OBJECTIVE

To evaluate singleton PLs before gestational week (gw) 22 among patients with AD and MTHFR polymorphisms.

METHODS

Totally, 1108 singleton pregnancies in 243 women were categorized as: 1) 148 pregnancies in 33 patients with AD, 2) 316 pregnancies in 66 patients with MTHFR polymorphisms, 3) 644 pregnancies in 144 patients with AD +MTHFR polymorphisms. PLs were classified into subgroups: a) Chemical Pregnancy(CP), b) Blighted Ovum(BO), c) gw ⩽ 10, d) gw11-14 e) gw15-22, f) Ectopic Pregnancy(EP), g) Trophoblastic Disease(TD). Obstetric histories were compared using Beksac Obstetrics Index (BOI): [number of living child + (π/10)]/gravida.

RESULTS

PL rates before gw22 were 39.2% (58/148), 33.2% (105/316), and 36.3% (234/644) in AD, MTHFR, and AD +MTHFR groups, respectively (p= 0.421). The rate of Pre-Prenatal Screening Period fetal losses (CP + BO + gw ⩽ 10 fetal losses + EP + TD) were 84.8%, 75.9%, and 77.8% in AD, MTHFR, and AD +MTHFR, respectively (p= 0.264). Gravidity ⩽ 4 versus those with gravidity ⩾ 5 had statistically significant differences in BOI (p< 0.001).

CONCLUSIONS

PL rate before gw22 among singleton pregnancies with AD and/or MTHFR polymorphisms was 35.8%. The clinical findings seem to be more complicated in patients with gravidity ⩾ 5.

Significance of inhibitory maternal killer-cell immunoglobulin-like receptor (KIR) and fetal KIR ligand genotype combinations in placenta related obstetric complications

Some maternal killer-cell immunoglobulin-like receptor (KIR) and fetal KIR ligand genotypes are associated with obstetric complications, such as recurrent miscarriage, fetal growth restriction, preeclampsia, and preterm birth. However, how KIR/KIR ligand genotypes affect these placenta-related obstetric complications has not been fully understood. We aimed to demonstrate the association of maternal KIR-fetal KIR ligand genotype combinations with immunological/metabolic risk factor associated placenta-related obstetric complications. This study consisted of three groups of pregnant women: 1) Miscarriage group (n = 30), 2) Complicated Pregnancy (CP) group (n = 30), and 3) Control group (n = 30). The observed maternal genotype frequencies of all inhibitory and activating KIRs were similar in all groups (p > 0.05). However, inhibitory 2DL3 was quite frequent in the miscarriage group (p = 0.052). There was no difference between groups in terms of centromeric and telomeric maternal haplotypes (p > 0.05). The fetal group 1 HLA-C genotype was frequently detected in the miscarriage and CP groups with rates of 83.3 % and 93.3 % respectively, while the observed frequency was 70 % in the control group. The fetal group 2 HLA-C genotype was the same in all groups. The results demonstrated significantly less fetal group 2 HLA-C homozygosity in the CP groups when compared to the control group (p = 0.020). The fetal HLA-Bw4 genotype was detected more frequently in the miscarriage and CP groups (p = 0.028 and p = 0.001, respectively). The inhibitory KIR/KIR ligand genotype combinations of 2DL3-C1 and 3DL1-Bw4 were more frequent in the miscarriage and CP groups (p = 0.045 and p = 0.002, respectively). Enhanced NK cell inhibition may be one of the mechanisms underlying placenta-related obstetric complications.

Association of increased C-Reactive Protein and hypocomplementemia with risk factors for thrombosis in women who have susceptibility for poor gestational outcome; importance of preconceptional counseling

This study aimed to investigate the association of increased C-Reactive Protein (CRP) and hypocomplementemia with risk factors for thrombosis such as Factor V Leiden (FVLP) and Prothrombin G20210A polymorphisms (PP), increased Activated Protein C Resistance (APCR) and decreased anti-thrombin III (ATIII) activity in women who have metabolic (MTHFR polymorphisms) and immunological risk factors (autoimmune antibody positivity, autoimmune disorders, and chronic inflammatory diseases). All patients (n= 197) were evaluated in terms of risk factors for thrombosis including FVLP, PP, increased APCR, and decreased ATIII activity as well as CRP and complement (C) 3 and C4 levels within a framework of preconceptional care program. Patients with high CRP levels together with hypocomplementemia were included to the study group (n= 13), while women with normal levels of CRP, C3, and C4 were accepted as controls (n= 184). Decreased ATIII activity was found to be statistically more frequent in the study group compared to controls (p= 0.036). There were no significant differences between the study and control groups in terms of the presence of FVLP, PP and increased APCR (p= 0.386, p= 0.462, p= 0.625, respectively). Decreased ATIII activity should be the concern of preconceptional and antenatal care programs in risky patients with increased CRP levels and hypocomplementemia in order to prevent placental inflammation related gestational complications.

Obstetrical history of a family with combined oxidative phosphorylation deficiency 3 and methylenetetrahydrofolate reductase polymorphisms

Objectives

Recurrent pregnancy loss (RPL) is a devastating complication of pregnancy with various etiologic backgrounds.

Case presentation

We present a case of combined oxidative phosphorylation deficiency 3 (COXPD3) carrier pregnant woman with Methylenetetrahydrofolate reductase (MTHFR) polymorphisms. She had five pregnancy losses and a postpartum death due to COXPD3. The patient was admitted to our clinic for the first time at her seventh pregnancy with oocyte donation. The patient was registered in a special antenatal care program and delivered a healthy baby at term. Her eighth pregnancy was terminated due to COXPD3 which was prenatally diagnosed.

Conclusions

Comprehensive and individualized approaches are necessary in RPL cases to obtain optimal outcomes.

Association of MTHFR 677C>T polymorphism with IUGR and placental abruption risk: A systematic review and meta-analysis

OBJECTIVE

The effects of the MTHFR 677C > T polymorphism on the intrauterine growth restriction (IUGR) and placental abruption risk have been evaluated in some studies. However, those studies results were conflicting and ambiguous. Therefore, we carried out the current meta-analysis to evaluate the association of MTHFR 677C > T polymorphism with risk of IUGR and placental abruption from all eligible studies.

METHODS

An electronic search of the PubMed, Embase, Scopus and CNKI databases was performed up to February 25, 2020.

RESULTS

A total of 25 case-control studies including eight studies with 687 cases and 2336 controls for IUGR and 17 studies with 1574 cases and 5758 controls for placental abruption were selected. The analysis results indicated that MTHFR 677C > T polymorphism was associated with an increased risk of IUGR and placental abruption in global population. When stratified by ethnicity a significant association between the MTHFR 677C > T polymorphism and IUGR risk was found in Caucasians and Africans. However, there was no a significant association between the MTHFR 677C > T polymorphism and placental abruption risk by ethnicity.

CONCLUSIONS

Our pooled data indicated that the MTHFR 677C > T polymorphism might play a role in development of IUGR and placental abruption.

Low-dose low-molecular-weight heparin prophylaxis against obstetrical complications in pregnancies with metabolic and immunological disorder-associated placental inflammation

Objective: We investigated the importance of prophylactic administration of low-dose low-molecular-weight heparin (LMWH) in women with risk factors associated with placental inflammation.Materials and methods: This retrospective cohort study included 300 pregnant women with a singleton pregnancy (30 primigravidas and 270 multigravidas) who received prophylactic low-dose LMWH to prevent placental inflammation. Based on maternal risk factors, patients were categorized into 3 groups as follows: Group 1: Patients with metabolic risk factors for placental inflammation (n = 205), Group 2: Patients with immunological risk factors for placental inflammation (n = 42), Group 3: Patients with metabolic and immunological risk factors for placental inflammation (n = 53). Obstetric histories, demographic features, clinical characteristics, and present pregnancy outcomes were compared between groups. Live birth rates, composite adverse obstetric outcomes, and the Beksac obstetric index were compared between present and previous pregnancies in multigravidas.Results: Pregnancy outcomes were significantly better in the present pregnancy than in previous pregnancies. A significant increase was observed in live birth rates (33.4% vs. 69.9%, 27.5% vs. 60.5%, and 30.1% vs. 69.4% in groups 1, 2, and 3, respectively) and in the Beksac obstetric index (0.32 vs. 0.43, 0.33 vs. 0.47, and 0.38 vs. 0.57 in groups 1, 2, and 3 respectively) (p < .001 for all). A significant decrease in composite adverse pregnancy outcome rates was observed during the present pregnancy (23.5% vs. 100%, 28.9% vs. 100%, and 24.5% vs. 100% in groups 1, 2, and 3, respectively) (p < .001 for all). Live birth and composite adverse obstetric outcome rates were 70% and 33.3%, respectively in primigravidas.Conclusion: Low-dose low-molecular-weight heparin prophylaxis is useful to prevent metabolic and immunological disorders causing placental inflammation, which is the most likely pathophysiological mechanism contributing to various obstetrical complications.

Folic acid – role in the body, recommendations and clinical significance

Introduction. Folic acid is a compound classified as B group vitamins. In the body it is subject to processes that transfer its inactive form into a form responsible for biological effects of folic acid, i.e. 5-methyltetrahydrofolate (5-MTHF). It is, in particular, responsible for processes of the correct biosynthesis of purine and pyridine bases present in the formation of DNA and RNA molecules. Humans do not synthesize the endogenous form of folic acid; therefore, it is vital to supplement this vitamin in its natural form or multivitamin preparations. The most folic acid is found in the green leafy vegetables (spinach, peas, asparagus) and in offal (liver). An adequate supply of folic acid is especially indicated in pregnant women with a reduced amount of folic acid due to its use by an intensively developing foetus. The recommended dose of folic acid during this period is 0.4 mg/24h and this dose varies depending on the patient’s and her family’s medical history. The updated state of knowledge on the role of vitamin B9 in the body has been presented. The importance of its supplementation in specific clinical cases was analyzed.

Summary. Many studies indicate an important role of the folic acid in the prevention of congenital defects of the nervous, cardiovascular and urogenital systems. Its deficiency increases the risk of complications in pregnancy, such as recurrent miscarriages, pre-eclampsia or postpartum haemorrhage. For this reason, a prophylactic folic acid supplementation is recommended, in women with increased risk of its deficiency, in particular.

Comparison of different types of twin pregnancies in terms of obstetric and perinatal outcomes: association of vanished twins with methylenetetrahydrofolate reductase (MTHFR) polymorphism(s)

PURPOSE

Vanished twin (VT) has been associated with poor perinatal outcomes. Our research aimed to investigate the outcomes of pregnancies with vanished twin and its possible association with methylenetetrahydrofolate reductase (MTHFR) polymorphisms.

METHODS

This study consisted of 30 of 38 VT pregnancies (group 1, VT group), 109 singletons (group 2), 70 spontaneous twins (group 3), and 101 in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) twins (group 4).

RESULTS

Most patients in group 1 (28/30) were tested for MTHFR genes (C677T or A1298C polymorphisms). Eight of the 38 pregnancies with VT (21.1%) resulted in miscarriage. The prevalence of "2 or more pregnancy losses" in the "obstetric history" in group 1 was higher (23.3%) than those in the other groups (p = 0.007, χ² = 17.8). The allelic frequencies of MTHFR 677 and MTHFR 1298 in group 1 were 0.268 and 0.429, respectively (higher than those in healthy population). The median birthweights in groups 1, 2, 3, and 4 were 2940, 3200, 2300, and 2095 g, respectively. The prevalence of respiratory distress syndrome was significantly higher in the IVF/ICSI twin pregnancy group (p < 0.001, χ² = 21.2). Early pregnancy loss and the presence of "2 or more miscarriages" in the obstetric history of pregnancies with VT were more frequent.

CONCLUSION

The coincidence of VT and MTHFR polymorphisms might play an incidental or factual role in this connection.