Pregnancy support- Pathology

Miscarriage - updated: 03 November 2008

Dietary trans fatty acid intake is associated with increased fetal loss

Fertil Steril. 2008 Aug;90(2):385-90.

Morrison JA, Glueck CJ, Wang P.

OBJECTIVE: To examine whether dietary trans fatty acids (TFAs) were associated with fetal loss (no. of pregnancies - no. of live births). The basis of our inquiry derives from the facts that the PPAR-gamma receptor plays a pivotal role in placental function and that TFAs down-regulate PPAR-gamma gene mRNA expression. DESIGN: Retrospective study comparing dietary data on TFAs and total calories from Block 98 quantitative food frequency questionnaire on 104 women with insulin data and reporting one or more pregnancies. SETTING: Twenty-five- to 30-year follow-up as young adults (age 39.5 +/- 4.5 years) of schoolgirls in the Princeton School cardiovascular risk study. PATIENT(S): Former participants in school-based research program at ages 6-18 years (1973-78), screened as part of follow-up study (1998-2003). MAIN OUTCOME MEASURE(S): Fetal loss. RESULT(S): By stepwise logistic regression, with fetal loss (>or=1 vs. 0) as the dependent variable and total calories, percent calories from TFAs (linear and squared terms), diabetes (yes/no), serum insulin, age, race, body mass index, leisure and work physical activity, and education as explanatory variables, percent calories from TFAs was positively, curvilinearly, independently associated with fetal loss. For each 1-unit increase in the squared term of percent calories from TFAs, the odds of having fetal loss versus no fetal loss increased 1.106 times (odds ratio = 1.106; 95% confidence interval 1.026-1.192). CONCLUSION(S): Since PPAR-gamma plays a pivotal role in placental biology and is down-regulated by TFAs, TFAs may be a reversible risk factor for fetal loss.

Publication Types:

• Retrospective study

Role of red cell selenium in recurrent pregnancy loss

J Obstet Gynaecol. 2002 Mar;22(2):181-3

Kumar KS, Kumar A, Prakash S, Swamy K, Jagadeesan V, Jyothy A.

Selenium is an essential trace mineral required for normal human health and reproduction. In recent years selenium deficiency in humans has been implicated as a risk factor for recurrent pregnancy loss. So far the selenium status in recurrent pregnancy loss (RPL) has been evaluated only in plasma and serum samples showing discrepancies of selenium deficiency as a cause for RPL. The present pilot study from India has evaluated selenium status in red cells (as they are the better indicators of selenium levels) in 20 women with three or more unexplained recurrent pregnancy losses compared to similar number of controls. The mean+/-SD red cell selenium levels in the study group was found to be 119.55+/-32.94 ng/ml (range 55-170 ng/ml), which was significantly lower compared to the control group with a mean+/-SD of 150.85+/-37.63 ng/ml (range 87-225 ng/ml). The difference was statistically significant at the 1% level ( P <0.01). Since selenium supplementation resulted in successful pregnancy outcome in veterinary practice, we conclude that large randomised studies are needed to assess the contribution of selenium in the aetiology of RPL and the potential benefits of its supplementation.

Publication Types:

• pilot study

The selenium status of women with a history of recurrent miscarriage

BJOG. 2001 Oct;108(10):1094-7

Al-Kunani AS, Knight R, Haswell SJ, Thompson JW, Lindow SW.

OBJECTIVE: To assess the relationship between selenium levels in human blood and hair, and the risk of recurrent miscarriages. DESIGN: Case-control study. PARTICIPANTS: Two groups of non-pregnant women: 18 women with one or more successful pregnancies and no history of miscarriage (control group); 26 women with a history of recurrent miscarriage (> or = 3) with no subsequent successful pregnancies (study group). METHODS: Samples of venous blood and scalp hair were collected and the selenium content analysed by inductively coupled plasma mass spectrometry. RESULTS: No significance difference was found between the level of selenium in the blood samples of the women in each group. There was a significant reduction in the mean hair selenium level in the recurrent miscarriage group compared with the control group (0.14 microg/g vs 0.34 microg/g). Further analysis of the recurrent miscarriage group revealed no relationship between levels of serum or hair selenium with parity. There was a significantly greater proportion of women in the control group who ate cereals, vitamin supplements, and liver or kidney. CONCLUSION: There was evidence of selenium deficiency in women with recurrent miscarriages compared with a control group of women with a good reproductive performance. This difference was seen in hair samples but not serum samples and therefore may not represent a simple nutritional deficiency. The importance of selenium deficiency in miscarriage has still not been determined.

Publication Types:

• Case-control study

The importance of selenium to human health

Lancet. 2000 Jul 15;356(9225):233-41

Rayman MP.

The essential trace mineral, selenium, is of fundamental importance to human health. As a constituent of selenoproteins, selenium has structural and enzymic roles, in the latter context being best-known as an antioxidant and catalyst for the production of active thyroid hormone. Selenium is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Deficiency has been linked to adverse mood states. Findings have been equivocal in linking selenium to cardiovascular disease risk although other conditions involving oxidative stress and inflammation have shown benefits of a higher selenium status. An elevated selenium intake may be associated with reduced cancer risk. Large clinical trials are now planned to confirm or refute this hypothesis. In the context of these health effects, low or diminishing selenium status in some parts of the world, notably in some European countries, is giving cause for concern.

Publication Types:

• Review

Association of reduced selenium status in the aetiology of recurrent miscarriage

Br J Obstet Gynaecol. 1999 Nov;106(11):1188-91

Nicoll AE, Norman J, Macpherson A, Acharya U.

OBJECTIVE: To determine whether recurrent miscarriage is associated with reduced selenium status. DESIGN: Case-control study. SETTING: Department of Obstetrics and Gynaecology, Glasgow Royal Infirmary and Glasgow Royal Maternity Hospital. POPULATION: Twenty nonpregnant women with a history of unexplained recurrent miscarriage, and 47 nonpregnant parous women with a history of at least one successful pregnancy and no more than one miscarriage. METHODS: A 7 mL blood sample from each woman was collected into lithium heparin 'vacutainer' tubes. Samples were centrifuged at 3000 g for 15 minutes, and plasma was extracted and stored at -20 degrees C. Selenium concentrations were measured using a fluorescence spectrophotometer. The selenium concentrations in the two groups were compared and the differences examined using the Student's t test. MAIN OUTCOME MEASURES: Plasma selenium concentration (microg/L). RESULTS: The mean selenium concentration for women with a history of unexplained recurrent miscarriage was 67.7 microg/L (SD 16.4). The selenium level for the women with no history of recurrent miscarriage was 70.3 microg/L (SD 12.7). There was no difference in selenium concentrations between the two groups (P = 0.53). CONCLUSIONS: In this study there is no association between unexplained recurrent miscarriage and reduced selenium status, implying that reduced selenium status is not a factor in the pathogenesis of recurrent miscarriage. We can find no rationale for a trial of selenium therapy in women with a history of recurrent miscarriage.

Publication Types:

• Clinical Trial

Selenium deficiency and miscarriage: a possible link?

Br J Obstet Gynaecol. 1996 Feb;103(2):130-2

Barrington JW, Lindsay P, James D, Smith S, Roberts A.

OBJECTIVE: To investigate a possible relationship between a deficiency in serum selenium concentration and first trimester miscarriage. DESIGN: An observational study. SETTING: A teaching hospital in South Wales. PARTICIPANTS AND METHODS: Serum selenium, albumin and total protein concentration were measured in 40 women admitted with first trimester nonrecurrent miscarriage. The results were compared with an equal number of age-matched nonpregnant healthy volunteers, and also from 40 pregnant women attending the antenatal clinic for booking in the first trimester. RESULTS: A reduction in serum selenium normally occurs in the first trimester of pregnancies that progress to term. However, a further statistically highly significant decrease in serum selenium was observed in those women who miscarried. CONCLUSION: Further studies are required to assess the potential benefits of selenium supplements.

Publication Types:

• Clinical Trial

Thyroid autoimmunity and miscarriage

Eur J Endocrinol. 2004 Jun;150(6):751-

Prummel MF, Wiersinga WM.

To ascertain the strength of the association between thyroid autoimmunity and miscarriage, we performed a meta-analysis of both case-control and longitudinal studies performed since 1990 when this association was first described. A clear association between the presence of thyroid antibodies and miscarriage was found with an odds ratio (OR) of 2.73 (95 % confidence interval (CI), 2.20-3.40) in eight case-control and ten longitudinal (OR, 2.30; 95 % CI, 1.80-2.95) studies. This association may be explained by a heightened autoimmune state affecting the fetal allograft, of which thyroid antibodies are just a marker. Alternatively, the association can be partly explained by the slightly higher age of women with antibodies compared with those without (mean+/-S.D. age difference, 0.7+/-1.0 years; P<0.001). A third possibility is mild thyroid failure, as thyroid-stimulating hormone (TSH) levels in antibody-positive but euthyroid women are higher than in antibody-negative women: difference 0.81+/-0.58 mU/l (P=0.005). Randomized clinical trials with l-thyroxine (aiming at TSH values between 0.4 and 2.0 mU/l) and with selenium (to decrease antibodies against thyroid peroxidase) are clearly needed to elucidate further the nature of this association.

Publication Types:

• Review

Influence of thyroid autoimmunity and maternal age on the risk of miscarriage

Am J Reprod Immunol. 2004 Nov;52(5):312-6

Sieiro Netto L, Medina Coeli C, Micmacher E, Mamede Da Costa S, Nazar L, Galvão D, Buescu A, Vaisman M.

OBJECTIVES: Recently, studies have shown an association between antiperoxidase for the detection of thyroid autoimmunity (TAI) and abortion. Another point to be considered is the association of high risk of abortion and maternal age. The aim of the present study was to evaluate if the association between TAI and miscarriage could also be verified whether a population of unselected pregnant young women who normally present a low risk of miscarriage. MATERIALS AND METHODS: We studied 534 pregnant women, by determining their serum thyroid antiperoxidase antibodies (TPO-Abs), thyrotropin (TSH) and free thyroxine (fT4) levels. Our end point was the pregnancy loss or live birth. RESULTS: Age ranged from 12 to 49 years (mean +/- S.D.; 23.5 +/- 5.9). Of 534 women, 29 (5.4%) were TPO-Ab positive. TSH levels were significantly higher in TPO-Ab-positive women compared with TPO-Ab negative women (median; 1.9 versus 1.1; P = 0.001). Elevated TSH levels were found in 13.8% (4 of 29) of the TPO-Ab-positive women compared with only 2.4% (12 of 505) in the TPO-Ab-negative women. There were no significant differences in fT4 levels in relation with autoimmunity and risk of miscarriage. The overall risk of miscarriage was 2.4% (13 of 534). Risk of miscarriage was significantly higher among women older than 35 years (7.7%), TPO-Ab positive (10.3%) and presenting high levels of TSH (12.5%). These factors remained independently associated with the risk of miscarriage in full multivariate analysis. CONCLUSIONS: We conclude that TAI is independently associated with is a higher risk of miscarriage in a population of unselected pregnant presenting a low risk of miscarriage.

Publication Types:

• Review

Publication Types:

• Review