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T Steck

Publications and source records attributed to T Steck.

At least 19 recordsLinked to original sources
PubMed2002

The use of a detailed zygote score after IVF/ICSI to obtain good quality blastocysts: the German experience.

BACKGROUND: Due to improvements in embryo culture, it is now possible to transfer embryos 5 days after oocyte retrieval and IVF/ICSI at the blastocyst stage, giving a better synchronization with the female reproductive tract. In Germany it is illegal to culture more than three embryos. Therefore, there is need for a sufficient selection at the pronuclear (PN) stage to select the best zygotes and exclude those of poor quality. METHODS: A prospective trial was conducted in 168 IVF and ICSI cycles including the size, number and alignment of pronuclei and nucleoli, cytoplasmic halo effect, the presence of vacuoles and granularity of ooplasm. Based on the above criteria, the best zygotes were selected (score <15) for embryo transfer on day 5. Blastocysts were classified in eight grades based on the cleavage speed. RESULTS: A total of 1450 oocytes were collected, of which 1119 reached the pronuclear stage. Of the zygotes (n = 424) selected at the PN stage, 46% achieved the blastocyst stage after 5 days (grade 1-5), 26% the morula stage (grade 6-7) and 28% were arrested (grade 8). The mean zygote score showed a significant positive correlation with the mean blastocyst quality in ICSI, but not in IVF cycles. A cut-off of 15 was calculated for ICSI cycles giving the best discrimination with blastocyst grades (6 versus 7) and number of arrested embryos (23 versus 45%) below and above this cut-off. A total of 33 clinical pregnancies was achieved (20%). Women conceiving had a significantly better mean blastocyst development than those not conceiving. Strong cytoplasmic vacuolization and an extreme or no halo effect had a negative effect on blastocyst development. CONCLUSIONS: The data show that PN stage morphology is related to blastocyst development, but the rate of arrested embryos of almost 30% limits the chance of conception under the conditions of the German Embryo Protection Law.

Adult↗
PubMed2002

Th1- and Th2-like cytokine production by first trimester decidual large granular lymphocytes is influenced by HLA-G and HLA-E.

During normal early pregnancy, a particular immune environment in the decidua and the expression of non-classical HLA-G and HLA-E molecules on the invading trophoblast are assumed to be essential for the tolerance of the fetus. To assess whether HLA-G and HLA-E influence the cytokine production of their putative target cells [large granular lymphocytes (LGL)], we analysed the concentrations of tumour necrosis factor (TNF-alpha), interferon (IFN)-gamma, interleukin (IL)-10, IL-13 and granulocyte-macrophage colony stimulating factor (GM-CSF) in supernatants of isolated first trimester LGL co-cultured with HLA-G or HLA-E transfected K-562 leukaemia cells lacking the classical HLA class I and II molecules. In comparison with that observed with untransfected K-562 cells, co-culture of LGL with HLA-G-expressing cells significantly reduced the concentration of all cytokines investigated (TNF-alpha, IL-10 and GM-CSF, P < 0.01; IFN-gamma and IL-13, P < 0.05). In contrast, co-culture of LGL with HLA-E-expressing cells significantly (P < 0.01) decreased only IL-10 production, although a strong tendency towards reduced IL-13 levels was also observed. In the co-culture system presented, membrane-bound HLA-G and, to a lesser extent, HLA-E expression affected cytokine release by decidual LGL in a manner not consistent with the Th1/Th2 paradigm. In conclusion, our data are indicative of a general immune-suppressive effect of HLA-G on LGL activity.

Cells, Cultured↗
PubMed2001

Assessment of endocrine status in patients undergoing in-vitro fertilization treatment. Is it necessary?

Endocrine evaluation as a prerequisite for every patient undergoing routine in-vitro fertilization (IVF) and embryo transfer for tubal or male factor infertility is still a matter of debate. The aim of this study was to determine if a full endocrine work-up, including the measurement of androgens, gonadotropins, prolactin and TSH, is conclusive for the subsequent success in IVF/ET. 71 infertile women without known endocrinopathies (e.g., polycystic ovarian disease), who were scheduled to enter the IVF/ET program were studied under strictly standardized conditions during the follicular phase of a natural cycle. Fasting serum concentrations of follicle stimulating hormone, luteinizing hormone, oestradiol, progesterone, prolactin, testosterone (T), dehydroepiandrosterone, 17-OH-progesterone, androstenedione and thyroid stimulating hormone (TSH) were measured using commercially available radioimmunoassays. Ovarian stimulation was performed by a long gonadotrophin-releasing hormone agonist/human menopausal gonadotrophin protocol. The overall clinical pregnancy rate was 15.5% in the first started IVF cycle. While patients who conceived in the first treatment cycle had significantly lower T levels (368 +/- 49 pg/ml) than those who did not (518 +/- 27 pg/ml, p=0.042, Kruskal & Wallis H-test), but the percentage of women with elevated T concentrations was not different. Similarly, TSH concentrations were significantly higher in women with a clinical pregnancy (1.9 +/- 0.2 mU/ml) than in non-pregnant women (1.4 +/- 0.3 mU/ml, p=0.046), but levels were still within the normal range. There were no further significant differences in hormone levels between pregnant and non-pregnant patients. These results do not suggest the measurement of a full hormonal profile in all infertile women before IVF/ET in non-endocrine infertility, taking into account the low likelihood to identify endocrinological disturbances, the considerable cost of endocrine testing and the paucity of therapeutic consequences.

17-alpha-Hydroxyprogesterone↗
PubMed2001

Octreotide LAR treatment throughout pregnancy in an acromegalic woman.

We report a 24-year-old woman with active acromegaly despite pituitary surgery and irradiation who received continuous octreotide LAR treatment for the control of GH excess throughout her pregnancy. The patient delivered a healthy girl following an uneventful pregnancy. Despite a substantial materno-fetal transfer of octreotide, postnatal development was normal with length parameters around the 50th percentile at 3 months of age. In almost all previously described cases (n = 13) octreotide was stopped after the diagnosis of pregnancy was established. No side-effects of mother or fetus have been reported. Octreotide treatment in pregnancy seems to be feasible and safe. Due to the still-limited number of reported cases, the potential benefits of octreotide treatment should be weighed carefully against its possible risks.

Acromegaly↗
PubMed2001

[Immunotherapy for prevention of abortion and for improving implantation in extracorporeal fertilization].

In women with a history of recurrent in-vitro fertilization failure (at least three transfers of good quality embryos), there is an increased prevalence of organo-specific and not organo-specific autoantibodies, similar to women with a history of recurrent miscarriage. It is still unknown whether these autoantibodies are causally related to the failure of implantation or merely reflect an underlying systemic disorder. Several therapeutic intervention for the improvement of implantation after in-vitro fertilization and embryo transfer have been tried, including prednisolone (10 mg/d), heparin and aspirin (80-100 mg/d) alone or in combination with immunoglobulins and active immunotherapy using partner's leukocytes. At present, these interventions in combination with IVF should be regarded as experimental, as controlled, randomized and prospective trials in a large number of couples are still lacking.

Abortion, Habitual↗
PubMed2001

Semen sample collection in medium enhances the implantation rate following ICSI in patients with severe oligoasthenoteratozoospermia.

Ejaculation in medium increases the proportion of antibody-free spermatozoa in semen samples containing anti-sperm antibodies and thereby enhances the fertilization rate in vitro. The aim of this study was to investigate whether this technique is also beneficial in semen samples with severe oligoasthenoteratozoospermia (OAT) where bacteria and detritus are often present. A prospective randomized controlled trial was carried out to study the results of sperm preparation and fertilization and pregnancy rates after intracytoplasmic sperm injection (ICSI) for OAT. Of the 114 couples (one cycle per couple) studied between 1998 and 2000, 55 men were randomized to have semen collection into sterile dry pots (group A) and the remaining 59 had samples collected into 20 ml HEPES buffered Ham's F-10 medium with 10% human serum albumin (group B). In group B the ejaculates were incubated for 30 min and mixed gently. The samples were then processed by mild centrifugation and washing followed by a mini-swim-up technique. The ejaculates in group A were prepared by the swim-up procedure only. The overall fertilization rate was 71.8% and was similar in groups A (fertilization rate = 66.7%) and B (fertilization rate = 64.3%). In group A, 10/55 clinical pregnancies were recorded (pregnancy rate 18%), with an implantation rate (IR) of 6.9% per embryo. In group B, 16 of 59 patients conceived leading to significantly higher implantation (9.9%, P < 0.001) and clinical pregnancy rates (27%, P < 0.001). It is postulated that the addition of medium before liquefaction could inhibit the binding of bacteria and detritus to the sperm surface and may diminish DNA damage caused by reactive oxygen species, leading to improved efficiency of fertilization. The results demonstrate that the addition of HEPES buffered Ham's F-10 medium to sample collection pots significantly improves the pregnancy rate after ICSI in patients with severe OAT.

Buffers↗
PubMed2000

Cholesterol movement in Niemann-Pick type C cells and in cells treated with amphiphiles.

Cholesterol accumulates to massive levels in cells from Niemann-Pick type C (NP-C) patients and in cells treated with class 2 amphiphiles that mimic NP-C disease. This behavior has been attributed to the failure of cholesterol released from ingested low density lipoproteins to exit the lysosomes. However, we now show that the rate of movement of cholesterol from lysosomes to plasma membranes in NP-C cells is at least as great as normal, as was also found previously for amphiphile-treated cells. Furthermore, the lysosomes in these cells filled with plasma membrane cholesterol in the absence of lipoproteins. In addition, we showed that the size of the endoplasmic reticulum cholesterol pool and the set point of the homeostatic sensor of cell cholesterol were approximately normal in NP-C cells. The plasma membrane cholesterol pools in both NP-C and amphiphile-treated cells were also normal. Furthermore, the build up of cholesterol in NP-C lysosomes was not a physiological response to cholesterol overload. Rather, it appeared that the accumulation in NP-C lysosomes results from an imbalance in the brisk flow of cholesterol among membrane compartments. In related experiments, we found that NP-C cells did not respond to class 2 amphiphiles (e.g. trifluoperazine, imipramine, and U18666A); these agents may therefore act directly on the NPC1 protein or on its pathway. Finally, we showed that the lysosomal cholesterol pool in NP-C cells was substantially and preferentially reduced by incubating cells with the oxysterols, 25-hydroxycholesterol and 7-ketocholesterol; these findings suggest a new pharmacological approach to the treatment of NP-C disease.

Androstenes↗
PubMed2000

Increased prevalence of thyroid antibodies in euthyroid women with a history of recurrent in-vitro fertilization failure.

This study was undertaken to evaluate whether the presence of thyroid antibodies in euthyroid women is associated with an adverse outcome in an in-vitro fertilization (IVF)-embryo transfer programme. In 24 women (study group: mean age +/- SD: 31.5 +/- 4.4 years) who failed to conceive after having three or more cycles of IVF and embryo transfer, serum concentrations of thyroglobulin (TG), thyroid peroxidase antibodies (TPO) and anticardiolipin antibodies (IgG and IgM) were measured using commercially available kits. The control group comprised 24 consecutive patients without endocrine dysfunction (mean age +/- SD: 30.3 +/- 4.1 years) seeking infertility treatment in our department of assisted reproduction. All patients in both the study and the control groups were determined to be euthyroid by demonstrating normal concentrations of thyroid-stimulating hormone (TSH). In the study and control groups respectively, 13 and two patients demonstrated positive titres of TG, TPO or both thyroid antibodies (Fisher's exact test: P = 0.002). Mean serum concentrations of TG were significantly increased in the study group compared to the control subjects (156 +/- 167 IU/ml versus 33.5 +/- 32.0 IU/ml; U-test: P = 0.009). Serum concentrations of TPO and anticardiolipin antibodies were similar in both groups. Our investigations revealed that thyroid antibodies might be independent markers for reproductive failure in an IVF-embryo transfer programme.

Adult↗
PubMed1999

Plasma endothelin and big endothelin levels in women with severe preeclampsia or HELLP-syndrome.

OBJECTIVE: To compare maternal and umbilical venous big endothelin (big ET) and endothelin-1 (ET-1) levels of pregnancies complicated by severe preeclampsia (PE) or HELLP-syndrome to those of a well-matched normotensive pregnant control group. METHODS: We measured plasma levels of ET-1 and big ET in 16 patients with severe PE and 14 patients with HELLP-syndrome by commercially available RIAs and compared them with those of well-matched normotensive pregnant controls. Additionally, the umbilical venous ET-1 and big ET levels were determined in 10 corresponding newborns. RESULTS: The plasma concentrations of ET-1 and big ET were significantly higher in patients with severe PE and especially in women with HELLP-syndrome when-compared with controls. The molar ratios of big ET to ET-1 were significantly lower in the two study groups. The levels of ET-1 and big ET were higher in umbilical venous plasma than in maternal plasma, but there were no significant differences in the umbilical venous concentrations between normotensive and by severe PE or HELLP-syndrome complicated pregnancies. CONCLUSIONS: These findings suggest that ET-1 may be considered as a marker of endothelial injury in by severe preeclampsia or HELLP-syndrome complicated pregnancies. The increase of the ET-1 plasma levels may be due, at least in part, to changes in the conversion of big ET to ET-1 by the endothelin-converting enzyme.

Adult↗
PubMed1999

Endocrine abnormalities during the follicular phase in women with recurrent spontaneous abortion.

The frequency of endocrine abnormalities during the follicular phase in non-pregnant women with a history of recurrent abortion was investigated in a case-control study. A total of 42 consecutive women with recurrent spontaneous abortion (three or more consecutive abortions, mean +/- SD: 3.9 +/- 1.1 range 3-8) with no parental chromosome rearrangement or uterine abnormality were studied during the early follicular phase under standardized conditions. Serum concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, androstenedione, testosterone, dehydroepiandro-stenedione, 17-OH-progesterone, oestradiol, progesterone and thyroid stimulating hormone (TSH) were measured by commercially available radioimmunoassays. Controls were 42 nulligravid females with tubal or male factor infertility without miscarriage. Mean (SD) concentrations of prolactin and androstenedione were 14.2 +/- 6.7 ng/ml versus 10.5 +/- 3.5 ng/ml (95% CI 0.8-6.1) and 2.3 +/- 0.9 ng/ml versus 1.7 +/- 0.6 ng/ml (95% CI 0.2-0.9) in the study and control groups respectively. The other endocrine parameters were comparable in both groups. Obesity [BMI weight (kg)/height (m2) > or = 25] was more prevalent (23 versus 5 women, P = 0.0001) in the study than the control group. Recurrent spontaneous abortion is associated with abnormalities in prolactin and androgen secretion during the follicular phase, suggesting an endocrine aetiology in this disorder. Reduction of body weight and correction of hyperprolactinaemia and of hyperandrogenism may reduce the rate of miscarriage in a subsequent pregnancy in these women.

Abortion, Habitual↗
PubMed1999

Leukaemia inhibitory factor gene mutations in infertile women.

The glycoprotein leukaemia inhibitory factor (LIF) is produced by the endometrium and is involved in the control of implantation. In women with unexplained infertility reduced uterine concentrations of LIF have been reported. Studies with mice lacking a functional LIF gene have shown that the LIF protein is essential for implantation of the embryo. We have developed a method for screening of gene mutations in the coding region and critical regulatory regions of the LIF gene. Thus we could screen nulligravid infertile women (n = 74), fertile controls (n = 75) and as a second unrelated control group, neurological patients (n = 131) for LIF gene mutations. In infertile women, three heterozygous point mutations have been identified: one in close proximity to the start codon of exon 1 and two mutations in exon 3. These correspond to regions of the LIF protein which are thought to be highly important for interaction with the LIF receptor and thus lead to reduced biological activity of the LIF protein. Only one point mutation/polymorphism in the non-coding region between exon 2 and 3 was found in the control groups. Our results suggest that heterozygosity for a LIF gene mutation could give rise to decreased availability or biological activity of LIF in the uterus and cause implantation failure. Thus the mutations identified in our study could be responsible for infertility in a subgroup of nulligravid women.

Adolescent↗
PubMed1999

Evaluation of a cut-off value for sperm motility after different hours of incubation to select the suitable reproductive technology (IVF or ICSI).

BACKGROUND: The aim of this study was to enhance the predictability of conventional semen parameters for in-vitro fertilization outcome. The utility of late sperm motility in presence of a cumulus-oocyte complex after different hours of incubation was investigated to predict the outcome of IVF in borderline and normal ejaculates (at least 5 x 10(6) motile sperm). METHODS: The study was done on 52 infertile couples undergoing conventional in-vitro fertilization and embryo transfer. Sperm were prepared by the Percoll cushion centrifugation with swim-down. Cocultures were established by inseminating the cumulus-oocyte complexes with 100000 motile spermatozoa and incubating them for 48 hours. Another 100000 spermatozoa were incubated in culture medium for 48 hours. Sperm motility (WHO a+b) was determined at 0, 4, 24 and 48 hours of incubation. RESULTS: The fertilization rate was 65.5% (42.9-88.1). The conventional semen parameters did not correlate with the fertilization rate. Sperm motility measured after different hours of incubation was found to be significantly positively correlated with the fertilizing ability of sperm in vitro in Spearman's rank correlation test: motility after 0 h (p<0.02), after 4 h (p=0.0025). after 24 h (n.s.) and after 48 h (p=0.0071). Cut-off values for late sperm motility were determined and differences in fertilization rates were calculated for these cut-off values after different hours of incubation. A cut-off value of 20% progressive motile spermatozoa after 48 hours gave the best statistical power (fertilization rate 71.7 vs. 50.2%, p<0.001). Significant differences in the fertilization rates were also observed for a cut-off value of 35% after 24 hours of incubation (70.1 vs. 46.2%, p=0.001) and for a cut-off point of 60% after 4 hours (72.4 vs. 51.5%, p=0.001). CONCLUSIONS: The predictive power of sperm motility after 48 h for fertilization outcome provides support in the decision-making process within the assisted reproduction setting. If less than 20% of sperm are motile after 48 h micromanipulatory techniques should be considered.

Adult↗
PubMed1998

Risk factors associated with preterm (<37+0 weeks) and early preterm birth (<32+0 weeks): univariate and multivariate analysis of 106 345 singleton births from the 1994 statewide perinatal survey of Bavaria.

OBJECTIVE: The study was conducted to identify medical, obstetrical and social risk factors associated with early preterm births (<32+0 gestational weeks). STUDY DESIGN: The Statewide Perinatal Survey of Bavaria is a collection of perinatal data from all Bavarian maternity units using a uniform numbered questionnaire. Data on 106345 singleton births from the 1994 Survey were analysed using univariate and multivariate logistic regression analysis. RESULTS: In the multivariate analysis, early preterm birth was associated with premature rupture of the membranes (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.37-1.86), treatment for infertility (OR 1.7, 95% CI 1.19-2.34), previous induced abortion (OR 1.8, 95% CI 1.57-2.13), maternal age >35 years (OR 1.8, 95% CI 1.47-2.16), premature cervical dilatation (OR 2.3, 95% CI 1.86-2.94), a history of stillbirth (OR 3.2, 95% CI 2.13-4.83), a history of preterm birth (OR 3.3, 95% CI 2.45-4.48), maternal age <18 years (OR 3.4, 95% CI 2.03-5.61), malpresentation (OR 3.9, 95% CI 3.10-4.93), preeclampsia (OR 4.0, 95% CI 3.20-4.94), uterine bleeding (OR 5.0, 95% CI 4.08-6.02), preterm labour (OR 7.0, 95% CI 5.94-8.22), and chorioamnionitis (OR 22.3, 95% CI 17.40-28.66). CONCLUSION: These data identify a subgroup of women at an increased risk for early preterm birth and may benefit from an intensified prenatal care. Risk factors related to the obstetrical history, genital infections, preeclampsia and maternal age are the most relevant for early preterm birth.

Abortion, Induced↗
PubMed1998

Plasma renin activity and aldosterone serum concentration are decreased in severe preeclampsia but not in the HELLP-syndrome.

BACKGROUND: To investigate plasma renin activity and aldosterone serum concentrations in severe preeclampsia (PE) or HELLP-syndrome. METHODS: We measured plasma renin activity and serum concentrations of aldosterone, progesterone, estradiol and estriol in 16 patients with PE and 14 patients with HELLP-syndrome and in well-matched normotensive pregnant controls. Additionally, the umbilical venous levels of aldosterone and plasma renin activity were determined in ten corresponding newborns. RESULTS: Serum aldosterone levels as well as plasma renin activity were significantly lower in patients with PE but not in women with HELLP-syndrome when compared to controls. We did not find any relationship either between aldosterone serum concentration or plasma renin activity and progesterone, estradiol or estriol levels in PE or in the HELLP-syndrome. Umbilical venous renin activity and aldosterone levels were higher than in maternal blood, but there were no significant differences in the umbilical venous levels between normotensive pregnancies and pregnancies complicated by either severe PE or HELLP-syndrome. CONCLUSION: It is concluded that in patients with PE well-known changes in the renin-angiotensin-aldosterone system cannot be found in patients with HELLP- syndrome. This finding is not related to alterations in sex steroid levels.

Adult↗
PubMed1998

Prophylactic intravenous hydroxyethyle starch solution prevents moderate-severe ovarian hyperstimulation in in-vitro fertilization patients: a prospective, randomized, double-blind and placebo-controlled study.

A prospective, randomized, double-blind and placebo-controlled study was conducted to assess the effectiveness of i.v. administration of 6% hydroxyethyle starch solution (HES) in preventing moderate and severe ovarian hyperstimulation syndrome (OHSS) in patients in an in-vitro fertilization programme. A total of 101 women who had serum oestradiol concentrations >1500 pg/ml and/or more than 10 follicles on day of human chorionic gonadotrophin (HCG) administration were recruited into two groups: HES group (n = 51) received 1000 ml 6% HES; and the placebo group (n = 50) received 1000 ml of sodium chloride 0.9% solution at the time shortly after embryo transfer. Follow-up examinations 7 +/- 1 and 14 +/- 1 days after embryo transfer included transvaginal ultrasound (diameters of each ovary and maximum cysts, number of cysts, ascites), blood tests (serum oestradiol, progesterone, beta-HCG, C-reactive protein, blood count, plasma proteins, electrolytes, kidney function tests) and evaluation of abdominal pain, nausea, diarrhoea, abdominal swelling and weight gain. Only one moderate OHSS developed in the HES group whereas seven moderate-severe cases were observed in the placebo group (P = 0.031). Furthermore, serum oestradiol concentration, leukocyte count, increase in abdominal circumference and weight gain 14 days after embryo transfer were significantly higher in the placebo group. There were no differences between the two groups in terms of age, oestradiol concentration and number of follicles at time of HCG injection. Administration of 6% HES prevents the development of moderate-severe OHSS in risk patients.

Adult↗
PubMed1997

Thyroid antibodies and their relation to antithrombin antibodies, anticardiolipin antibodies and lupus anticoagulant in women with recurrent spontaneous abortions (antithyroid, anticardiolipin and antithrombin autoantibodies and lupus anticoagulant in habitual aborters).

OBJECTIVE: This study was undertaken to evaluate the incidence of thyroid autoantibodies in women with a history of recurrent spontaneous abortions (RSA) and to investigate their relationship to non-organ specific autoantibodies. STUDY DESIGN: 28 euthyroid non-pregnant habitual aborters were analysed for thyreoglobulin (TG), thyroid peroxidase antibodies (TPO), and autoantibodies to thromboplastin, cardiolipin and lupus anticoagulant. 28 multigravidae without previous abortions or endocrine dysfunctions served as controls. RESULTS: 11 of 28 women with recurrent spontaneous miscarriage (39%), but only 2 of 28 controls (7%) (Chi square test: p < 0.01) demonstrated positive titres of TG, TPO, or both antibodies, 12 patients were positive for antithrombin antibodies and 3 for anticardiolipin. Only one women was lupus anticoagulant positive. No significant correlation between thyroid antibody positivity and positivity for antiphospholipids (Fisher's exact test: p = 0.441), anticardiolipin (p = 0.664) or lupus coagulant (p = 0.607) was found. CONCLUSIONS: The incidence of thyroid antibodies in euthyroid women with recurrent pregnancy loss appears to be significantly increased compared with controls of reproductive age without previous abortions. No correlation between the presence of thyroid autoantibodies and non-organ specific autoantibodies could be established.

Abortion, Habitual↗
PubMed1997

Serum levels of folate and cobalamin in women with recurrent spontaneous abortion.

We evaluated the folate and cobalamin status in 29 non-pregnant women with a history of recurrent spontaneous abortion (three or more consecutive) of unknown aetiology in comparison to 29 healthy nulligravidae of similar reproductive age (controls). Serum concentrations of folate and cobalamin showed no significant differences between the two groups. No correlation between age and vitamin concentrations was found. In the study group there was a significant negative correlation of the number of previous abortions and the concentration of serum folate. Patients with at least four previous miscarriages had significantly lower serum values of folic acid than women with three abortions, but not than controls. The underlying cause of this finding remains unclear. In conclusion, the serum concentrations of folic acid and vitamin B12 are not significantly altered in women with unexplained recurrent spontaneous abortions, and an association between a deficiency of these vitamins and an increased risk of pregnancy loss appears to be questionable in the majority of gestations.

Abortion, Habitual↗