A comparative study of the morphology of congenital uterine anomalies in women with and without a history of recurrent first trimester miscarriage

BACKGROUND

The true impact of congenital uterine anomalies on reproductive outcomes is unknown. The aim of this study was to examine differences in the morphology of uterine anomalies found in women with and without a history of recurrent miscarriage.

METHODS

A total of 509 women with a history of unexplained recurrent miscarriage and 1976 low risk women were examined for the presence of congenital uterine anomalies by three-dimensional ultrasound. The anomalies were classified according to the American Fertility Society classification. In addition, the size of fundal distortion (F) and the length of the remaining uterine cavity (C) were measured to calculate a distortion ratio (F/F+C). The findings were compared with the measurements obtained in low risk women with an incidental finding of uterine anomaly.

RESULTS

In all, 121 anomalies were detected in the recurrent miscarriage group and 105 in low risk women. There was no significant difference in relative frequency of various anomalies or depth of fundal distortion between the two groups. However, with both arcuate and subseptate uteri, the length of remaining uterine cavity was significantly shorter (P < 0.01) and the distortion ratio was significantly higher (P < 0.01) in the recurrent miscarriage group.

CONCLUSION

The distortion of uterine anatomy is more severe in congenital anomalies, which are found in women with a history of recurrent first trimester miscarriage.

Circulating levels of inhibin A, activin A and follistatin in missed and recurrent miscarriages

BACKGROUND

The aim of this study was to investigate the changes in circulating levels and the clinical use of inhibin A, activin A and follistatin as endocrine markers of early pregnancy loss.

METHODS

Blood samples were collected from women presenting with a sporadic missed miscarriage (n = 10), and controls having pregnancy termination at 8-12 weeks (n = 15) and from women with a history of unexplained recurrent miscarriages (n = 12) at 6-12 weeks gestation. All samples were assayed for inhibin A, inhibin B, activin A, follistatin, hCG, estradiol and progesterone.

RESULTS

Serum inhibin A, hCG, estradiol and progesterone levels were significantly ( approximately 2-3 fold) decreased in sporadic miscarriages compared with controls. In the recurrent miscarriage group, time dependent changes in plasma inhibin A and hCG levels were significantly (P < 0.05) altered in the group that had a subsequent miscarriage compared with those who had a live birth. At 6-7 weeks gestation, plasma inhibin A ( approximately 4 fold, P < 0.01), hCG ( approximately 4 fold, P < 0.01) and estradiol ( approximately 2 fold, P < 0.001) levels were significantly lower in women who went on to have another miscarriage than those with a live birth. Inhibin B levels were near the detection limit of the assay.

CONCLUSIONS

Our findings suggest that inhibin A is a specific marker of early pregnancy loss before the onset of the clinical symptoms of recurrent miscarriage. There is a high degree of association between levels of inhibin A and hCG in cases of miscarriage, indicating that these two proteins could be used in combination to predict future pregnancy outcome.

Pre-eclampsia, antiretroviral therapy, and immune reconstitution

Antiretrovirals are standard treatment for HIV-1-positive women during pregnancy in the UK, but little is known about maternal or fetal safety. In our cohort study of 214 pregnant women with HIV-1 infection, those who received no antiretroviral therapy had a rate of pre-eclampsia significantly lower (none of 61) than those on triple antiretroviral therapy (8 of 76; odds ratio 15.3, 95% CI 0.9-270, p=0.0087). However, the rate of pre-eclampsia in HIV-1-positive women on treatment did not differ from that in uninfected controls (12 of 214; p=0.2). The association of HIV-1-related immune deficiency with a low rate of pre-eclampsia, and the restoration of this rate in women treated with triple antiretroviral therapy to the expected rate indicates a pivotal role of the immune system in the pathogenesis of pre-eclampsia. The clinical presentation of pre-eclampsia and toxic effects of antiretroviral therapy could overlap and complicate diagnosis and management in these patients.

Clinical outcomes following percutaneous magnetic resonance image guided laser ablation of symptomatic uterine fibroids

BACKGROUND

Fibroids are common benign tumours of the uterus. Percutaneous magnetic resonance (MR) image guided laser ablation provides a minimally invasive, day-case alternative to surgery for the treatment of symptomatic fibroids.

METHODS

Women with symptomatic fibroids wishing to avoid surgery were treated with laser ablation. MR thermal mapping ensured that maximal safe energy was applied. Fibroid volume was measured at 3 and 12 months, menstrual blood loss was recorded before and after treatment and a menorrhagia outcomes questionnaire (MOQ) was used to assess satisfaction.

RESULTS

A total of 66 patients was treated. There was a significant (P < 0.001) reduction in mean fibroid volume of 31%. This was 41% at 1 year follow-up (P < 0.001). Measured menstrual blood loss in eight patients complaining of excessive bleeding was reduced (P = 0.012). The MOQ total outcome score was not as good as that seen in hysterectomy patients (P = 0.02) but the quality of life/satisfaction score was similar (P = 0.06).

CONCLUSION

We have used objective and subjective outcome measures to determine the efficacy of MR guided laser ablation for fibroids. Based on this limited study we are encouraged that this procedure may represent a minimally invasive alternative therapy for fibroids.

Psychiatric morbidity among patients with recurrent miscarriage

In this study 81 women with recurrent miscarriages completed questionnaires designed to assess depression, anxiety and general health. This data was matched with data from their medical notes to ascertain demographic and reproductive variables. The results indicated that 33% of patients could be classified as depressed with 9.9% of women being moderately depressed and 7.4% suffering from severe depression. Twenty-one percent of patients had levels of anxiety that were equal or higher to a typical psychiatric outpatient population. Neither age, cigarette consumption, alcohol intake, previous live birth, number of miscarriages, lateness of miscarriage nor length of time since last miscarriage were found to affect the degree of psychiatric morbidity. These findings add to our understanding of the degree to which recurrent miscarriage can affect mental health.

Liquid Chromatographic Determination of Ampicillin Residues in Porcine Muscle Tissue by a Multipenicillin Analytical Method: European Collaborative Study

A collaborative study involving 14 laboratories was conducted to determine residues of ampicillin in porcine muscle tissue by using a liquid chromatographic method developed for multipenicillin analysis that can quantitate 8 penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, amoxicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in muscle tissue. This method involves extraction of the penicillins with phosphate buffer, pH 9, followed cleanup and concentration on a C18 solid-phase extraction column and reaction with benzoic anhydride at 50°C and with 1,2,4-triazole and mercury(II) chloride solution, pH 9.0, at 65°C. The derivatized compounds are eluted isocratically on a C8 column with a mobile phase of acetonitrile and phosphate buffer (pH 6; 0.1M) containing sodium thiosulfate and the ion-pair reagent tetrabutylammonium hydrogen sulfate. The penicillins are detected by UV absorption at 325 nm. The limit of detection and the limit of determination (quantitation) of the method were calculated to be approximately 3–5 and 25 μg/kg, respectively, in accordance with the criteria of European Union (EU) Decision No. 93/256/EEC. In this first interlaboratory study, collaborators were instructed to monitor 4 different penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, and amoxicillin) by analyzing 8 blind samples of muscle tissue in triplicate. These samples were prepared from 2 materials containing different concentrations of incurred ampicillin (63.5 μg/kg for material No. 1 and 358.1 μg/kg for material No. 2) and 1 blank material. The repeatability relative standard deviation and the reproducibility relative standard deviation were 10.2 and 17.4%, respectively, for material No. 1 and 7.0 and 16.0%, respectively, for material No. 2. These results demonstrate that the method is suitable for the determination of ampicillin residues in muscle tissue at the EU maximum residue limit (50 μg/kg) and above. However, the identification of positives by this procedure may need additional confirmation by techniques with greater specificity, such as liquid chromatography combined with mass spectrometry, or tandem mass spectrometry. Investigations regarding the basis of interlaboratory testing studies will further demonstrate the suitability of multiresidue methodology for detecting and quantitating other compounds in the family of penicillin antibiotics.

Action of the endothelin receptor (ETA) antagonist BQ-123 on forearm blood flow in young normotensive subjects

Endothelin-1 (ET-1) has been proposed to contribute to the regulation of vascular tone in humans. BQ-123, an ET(A) receptor antagonist, has also been reported to increase forearm blood flow (FBF) in vivo; however, the efficacy of BQ-123 as an antagonist of ET-1 has not been evaluated in the forearm. The present study investigated the effects of BQ-123 on changes in FBF in response to ET-1 and noradrenaline (NA; norepinephrine), taking into account the possible influence of vasodilator effects of BQ-123 on responses to vasoconstrictors. Six subjects (age 25-34 years) participated in a double-blind randomized study. FBF was measured by forearm occlusion plethysmography. Drugs were infused intra-arterially into the non-dominant arm (study arm) on four separate occasions; the non-infused arm was used as a control. The effects of BQ-123 (50 nmol/min for 60 min, or 300 nmol/min for 5 min followed by saline for 55 min) were compared with the effects of infusion of sodium nitroprusside (SNP; 12 nmol/min for 60 min) or saline on vasoconstriction induced by ET-1 (10 pmol/min for 7 min) and NA (120 pmol/min for 7 min). Infusion of BQ-123 at either dose did not significantly increase FBF, whereas SNP increased FBF by 134% (P=0.03). ET-1 significantly reduced FBF, and this effect was almost completely inhibited by both doses of BQ-123, but was unaffected by SNP. NA also reduced FBF, and this action was unaffected by BQ-123 or SNP. The data show that BQ-123 is a selective ET-1 antagonist, but do not confirm a major role for ET-1 in influencing resting forearm vascular tone in young normotensive subjects.

Regulated expression of signal transducer and activator of transcription, Stat5, and its enhancement of PRL expression in human endometrial stromal cells in vitro

Differentiation of human endometrium during the secretory phase of the menstrual cycle is characterized by expression of a variety of genes implicated in the establishment and maintenance of pregnancy. An increased abundance of signal transducers and activators of transcription (Stats) in the secretory phase suggests Stat5 as a component of the differentiation of endometrium in response to ovarian hormone stimulation in vivo. Decidualization is initiated in a subset of endometrial stromal cells (ESC) in vivo during the secretory phase, but it is unclear whether regulated expression of Stat5 is a feature of these cells. Here, therefore, the abundance and subcellular distribution of Stat5 in ESC after a decidualization stimulus of cAMP plus medroxyprogesterone acetate (MPA) has been investigated in vitro. Western blotting revealed an increase in the apparent abundance of Stat5a and Stat5b, in the cytosolic and nuclear fractions, at 2, 3, and 4 d after stimulation. The potential functional relevance of this increase in Stat5 is suggested by the ability of transiently transfected Stat5a or Stat5b to significantly enhance the response of the decidual PRL promoter to cAMP/MPA and attenuation of the response to cAMP/MPA by dominant negative Stat5. Recent evidence suggests endometrial differentiation, including PRL production, as a possible target of antiphospholipid antibodies (aPL) prevalent in recurrent miscarriage. Monoclonal antibody, ID2, which has similar reactivity as human aPL, significantly decreased the apparent abundance of nuclear Stat5b in response to cAMP/MPA and was associated with decreased decidual PRL promoter activation and PRL secretion. Regulated expression of Stat5 is therefore a component of decidual differentiation of human ESC and contributes significantly to activation of the decidual PRL promoter. Alteration of this process by an aPL component suggests decidual differentiation as a potential clinical target in recurrent early miscarriages.

Placental massive perivillous fibrin deposition associated with antiphospholipid antibody syndrome

We present three pregnancies in which massive perivillous fibrous deposition (MPVFD) and maternal floor infarction (MFI) occurred in patients with primary antiphospholipid antibody syndrome (PAPS) attending a recurrent miscarriage clinic, and who were treated with low dose aspirin and heparin. We hypothesise that PAPS may be a predisposing factor to the development of this condition. The increased prevalence of late pregnancy complications in PAPS patients with a history of early miscarriage suggests that aspirin and heparin therapy does not eradicate the underlying pathological process but merely reduces the severity. Therefore, untreated early pregnancy losses may be converted into treated pregnancies with late antenatal complications. Some patients with PAPS may therefore be prone to suffer either the previously reported complications of the uteroplacental vasculature, such as pre-eclampsia, and/or specific complications related to the environment of the intervillus space, such as MPVFD/MFI.

Thrombophilia and pregnancy loss

Thrombophilia is defined as a tendency to thrombosis. The association between specific thrombophilic defects--both inherited and acquired--and pregnancy loss is a rapidly developing field. However, apart from antiphospholipid antibodies (aPL), an acquired thrombophilic defect, the role of other defects in the haemostatic pathways remains to be established. In this invited review we discuss the recent advances in our understanding of aPL related pregnancy loss, the association between genetic thrombophilic mutations and pregnancy outcome and the role of whole blood haemostasis testing in the investigation of women with recurrent miscarriage.

Defective endovascular trophoblast invasion in primary antiphospholipid antibody syndrome-associated early pregnancy failure

BACKGROUND

Primary antiphospholipid antibody syndrome (PAPS) is an established cause of recurrent pregnancy loss, traditionally presumed to be due to 'intraplacental thromboses'. This study examines products of conception (POC) from early pregnancy failures to investigate the mechanism of pregnancy loss.

METHODS

POC from patients attending a recurrent miscarriage clinic and from terminations of pregnancy for non-medical reasons were examined histologically with particular regard to the presence or absence of vascular or intervillous thromboses and decidual endovascular trophoblast invasion.

RESULTS

There were 31 PAPS-positive, 50 PAPS-negative, 34 aneuploid and 20 control cases at 6-14 weeks gestation. Villous morphology and frequency of intervillous thrombosis were not different among groups. Normal intradecidual endovascular trophoblast invasion was identified significantly less frequently in PAPS+ cases (24%), compared with controls (75%), aneuploid (53%), or PAPS- cases (61%; Z = -3.0, P < 0.01). In all cases there was apparently normal interstitial extravillous trophoblast invasion.

CONCLUSIONS

Defective decidual endovascular trophoblast invasion, rather than excessive intervillous thrombosis, is the most frequent histological abnormality in PAPS+ associated early pregnancy loss. Furthermore, endovascular trophoblast invasion is not significantly reduced in the majority of fetal aneuploidy-associated pregnancy failures.

Antiphospholipid antibodies and infertility

Antiphospholipid antibodies (aPL) are an established cause of recurrent pregnancy loss. As defective embryonic implantation is a common link between unexplained infertility and recurrent miscarriage, interest has focused on the potential relationship between aPL and implantation failure after in vitro fertilization and embryo transfer (IVF-ET). This review critically examines the published data to determine whether women undergoing IVF-ET should be routinely screened for aPL. Although most studies have reported an increased prevalence of aPL among women undergoing IVF-ET, prospective studies examining the effect of aPL on the outcome of IVF-ET demonstrate that these antibodies do not significantly affect either the implantation or ongoing pregnancy rates. The increased prevalence of aPL among women with infertility is therefore likely to be part of a generalized autoimmune disturbance associated with infertility. Hence routine screening for aPL among women undergoing IVF-ET is not warranted and therapeutic interventions should be used only in well designed randomized controlled trials.

High serum luteinizing hormone and testosterone concentrations do not predict pregnancy outcome in women with recurrent miscarriage

OBJECTIVE

To investigate the relationship between Day 8 serum luteinizing hormone (LH) and testosterone (T) concentrations, and body mass index (BMI) with pregnancy outcome in women with recurrent miscarriage.

DESIGN

Prospective observational study.

SETTING

National recurrent miscarriage clinic.

PATIENT(S)

Three hundred forty-four women (median age 32 years; range 18-44) with a history of recurrent first trimester miscarriage (median 4; 3-14; <12 weeks gestation) who conceived spontaneously and who received no pharmacological treatment during pregnancy were studied. All women were antiphospholipid antibody negative and had a normal peripheral karyotype as did their partners.

INTERVENTION(S)

Outcome of untreated pregnancies.

MAIN OUTCOME MEASURE(S)

Day 8 serum LH and T concentrations and BMI were correlated with pregnancy outcome.

RESULT(S)

One hundred and ninety-two (55.8%) women had a live birth and 152 (44.2%) women miscarried. Polycystic ovarian morphology was diagnosed in 174 women (50.6%). There was no significant relationship between follicular phase LH concentrations and pregnancy outcome. Pregnancy outcome was similar in women with normal and high serum T concentrations. BMI value was not significantly different between women who had a live birth and those who miscarried.

CONCLUSION(S)

The analysis of this large cohort of women with recurrent miscarriage demonstrates that prepregnancy Day 8 serum LH and T concentrations, and BMI do not have a statistically significant relationship with pregnancy outcome.

Factor V Leiden and recurrent miscarriage-prospective outcome of untreated pregnancies

BACKGROUND

Some cases of recurrent miscarriage and later pregnancy complications have a thrombotic basis. Factor V Leiden is a common thrombophilic mutation.

METHODS

The prospective outcome of untreated pregnancies amongst 25 women heterozygous for the Factor V Leiden allele who had a history of either recurrent early miscarriages only (three or more miscarriages at <12 weeks gestation; n = 19) or of late miscarriage (>12 weeks gestation; n = 9) was studied. Control groups of women with a similar pregnancy history but who had a normal Factor V genotype were also studied.

RESULTS

The live birth rate was significantly lower amongst women with a history of recurrent early miscarriage who carried the Factor V Leiden allele (6/16; 37.5%) compared with that amongst those with a normal Factor V genotype (106/153; 69.3%; odds ratio 3.75, 95% confidence intervals 1.3-10.9). The live birth rate was 11.1% (1/9) amongst those with a history of late miscarriage carrying the Factor V Leiden allele and 48.9% (22/45) amongst those with a normal Factor V genotype.

CONCLUSIONS

Attention should be directed at screening women with recurrent miscarriage associated with placental thrombosis for Factor V Leiden and a policy of targeted thromboprophylaxis during future pregnancies should be assessed in the form of a randomized controlled trial.

'Morphs' (MRFs): metal-reversible folding domains for differential IgG binding

BACKGROUND

Selective recognition and binding of IgG molecules is the basis for a host of immunological and affinity purification techniques. Capture of an IgG in these procedures relies chiefly on its interaction with one of a variety of reengineered bacterial receptors which bind to the Fc region of IgG molecules with very high affinity. While this interaction is extremely efficient in trapping IgG molecules, the tight interaction between the binding partners often requires denaturing conditions for disruption of the complex, which can adversely affect the yield of purified IgG and also limit the lifetime of the receptor matrix. An effective receptor/IgG binding system which could be modulated by less extreme conditions is of considerable general interest.

RESULTS

We describe the properties of a series of modified Fc receptor domains which are competent to bind IgG with high affinity but which can be reversibly unfolded upon addition of modest amounts of transition metal ions. Data are presented demonstrating loss of the secondary structural content of the domains as a function of increasing metal concentration, with a concomitant decrease in IgG binding affinity. Variants of the Fc receptor differing at a single amino acid position display increased sensitivity to metal-induced unfolding, while retaining comparable IgG binding ability in the absence of metal.

CONCLUSIONS

The interaction of this series of Fc receptors with metal ions abolishes IgG binding, but removal of metal ions allows refolding of the domains with restoration of the IgG binding function. Examples of the utility and potential applications of these metal-modulated IgG binding domains are discussed.

Reproductive outcomes in women with congenital uterine anomalies detected by three-dimensional ultrasound screening

OBJECTIVE

To determine reproductive outcomes in women with congenital uterine anomalies detected incidentally by three-dimensional ultrasound.

METHODS

We studied 1089 women with no history of infertility or recurrent miscarriage who were seen for a transvaginal ultrasound scan. They were screened for uterine abnormalities using three-dimensional ultrasound. We determined prevalence of miscarriage and preterm labor in women with normal and abnormal uterine morphology.

RESULTS

We found that 983 women had a normally shaped uterine cavity, 72 an arcuate, 29 a subseptate, and five a bicornuate uterus. Women with a subseptate uterus had a significantly higher proportion of first-trimester loss (Zeta = 4.68, P <.01) compared with women with a normal uterus. Women with an arcuate uterus had a significantly greater proportion of second-trimester loss (Zeta = 5.76, P <.01) and preterm labor (Zeta = 4.1, P <.01). There were no other significant differences in pregnancy outcomes between women with normal and abnormal uterine morphology.

CONCLUSION

This study shows the potential value of three-dimensional ultrasound and confirmed that women with congenital uterine anomalies were more likely to have adverse pregnancy outcomes than women with a normal uterus.

Recurrent miscarriage and variant alleles of mannose binding lectin, tumour necrosis factor and lymphotoxin alpha genes

Variant alleles of the mannose binding lectin (MBL) gene are associated with increased susceptibility to infection and polymorphisms of tumour necrosis factor and lymphotoxin alpha genes (TNF, LTA) are associated with increased severity of infection. Studies have associated recurrent miscarriage with low serum mannose binding lectin concentrations and premature membrane rupture and preterm delivery with elevated maternal and fetal levels of TNF and the TNF (- 308) polymorphism. In this study the frequencies of variant MBL, TNF and LTA alleles in 76 Caucasian couples with idiopathic recurrent miscarriage were compared with those in 69 Caucasian control couples with no history of miscarriage and at least one previous live birth. A new assay based on hybridization to immobilized sequence-specific oligonucleotides (SSO) was used to rapidly detect nine MBL, two TNF and two LTA sequence variants. The assay genotyped all the structural and promoter MBL variants known to influence serum MBL concentrations. This assay was more reliable than restriction digestion or nested allele-specific PCR for the structural variants at codon 54 or 52, respectively. Reliability for codon 57 alleles was not assessed because of the low frequency in this population. The MBL haplotype frequencies in antenatal controls were similar to those reported in other control populations. The frequencies of structural variant MBL genes and of low, medium and high MBL level haplotypes were similar in the recurrent miscarriage and control couples. The TNF and LTA haplotype frequencies were similar in the recurrent miscarriage and control couples. In this carefully defined population no association has been found between recurrent miscarriage and variant alleles of the MBL, TNF or LTA genes.

Reengineering granulocyte colony-stimulating factor for enhanced stability

Granulocyte colony-stimulating factor is a long-chain cytokine that has both biological and therapeutic applications. It is involved in the production and maturation of neutrophilic progenitor cells and neutrophils and is administered to stimulate the production of white blood cells to reduce the risk of serious infection in immunocompromised patients. We have reengineered granulocyte colony-stimulating factor to improve the thermodynamic stability of the protein, focusing on enhancing the alpha-helical propensity of residues in the antiparallel 4-helix bundle of the protein. These redesigns resulted in proteins with substantially enhanced stability while retaining wild-type levels of biological activity, measured as the ability of the reengineered proteins to stimulate the proliferation of murine myeloid cells transfected with the granulocyte colony-stimulating factor receptor.

Intrauterine haematomas in a recurrent miscarriage population

BACKGROUND

This study examines the effect of intrauterine haematomas (IUH) discovered during early pregnancy ultrasound scanning in patients with recurrent miscarriage. Previous studies of IUHs have reported conflicting findings, and none studied women with recurrent miscarriage.

METHODS

A total of 341 women with a viable pregnancy was included. Women with an IUH (n = 41) were compared with those without (n = 300).

RESULTS

An IUH was identified by ultrasound in 12% (41/341) women. There were no differences in the number of live births between the two groups (25/41, 61% in the IUH group compared with 169/300, 56% without an IUH) or the number of miscarriages (6/41, 15% with an IUH compared with 72/300, 24% without an IUH). Anti-phospholipid antibodies were more common in the IUH group (21/31, 68% compared with 103/244, 42% P < 0.01). More women with haematomas experienced vaginal bleeding (16/31, 52% compared with 47/244, 19%, P < 0.01). These associations did not affect pregnancy outcome. Also, no increase in the rate of pregnancy complications was observed in the IUH group.

CONCLUSIONS

The presence of an IUH in this potentially high risk patient group does not have a deleterious effect on pregnancy outcome.

Maternal obesity and pregnancy outcome: a study of 287,213 pregnancies in London

OBJECTIVE

To examine the maternal and foetal risks of adverse pregnancy outcome in relation to maternal obesity, expressed as body mass index (BMI, kg/m(2)) in a large unselected geographical population.

DESIGN

Retrospective analysis of data from a validated maternity database system which includes all but one of the maternity units in the North West Thames Region. A comparison of pregnancy outcomes was made on the basis of maternal BMI at booking.

SUBJECTS

A total of 287,213 completed singleton pregnancies were studied including 176,923 (61.6%) normal weight (BMI 20--24.9), 79 014 (27.5%) moderately obese (BMI 25--29.9) and 31,276 (10.9%) very obese (BMI> or =30) women.

MEASUREMENTS

Ante-natal complications, intervention in labour, maternal morbidity and neonatal outcome were examined and data presented as raw frequencies and adjusted odds ratios with 99% confidence intervals following logistic regression analysis to account for confounding variables.

RESULTS

Compared to women with normal BMI, the following outcomes were significantly more common in obese pregnant women (odds ratio (99% confidence interval) for BMI 25--30 and BMI> or =30 respectively): gestational diabetes mellitus (1.68 (1.53--1.84), 3.6 (3.25--3.98)); proteinuric pre-eclampsia (1.44 (1.28--1.62), 2.14 (1.85--2.47)); induction of labour (2.14 (1.85--2.47), 1.70 (1.64--1.76)); delivery by emergency caesarian section (1.30 (1.25--1.34), 1.83 (1.74--1.93)); postpartum haemorrhage (1.16 (1.12--1.21), 1.39 (1.32--1.46)); genital tract infection (1.24 (1.09--1.41), 1.30 (1.07--1.56)); urinary tract infection (1.17 (1.04-1.33), 1.39 (1.18--1.63)); wound infection (1.27 (1.09--1.48), 2.24 (1.91--2.64)); birthweight above the 90th centile (1.57 (1.50--1.64), 2.36 (2.23--2.50)), and intrauterine death (1.10 (0.94--1.28), 1.40 (1.14--1.71)). However, delivery before 32 weeks' gestation (0.73 (0.65--0.82), 0.81 (0.69--0.95)) and breastfeeding at discharge (0.86 (0.84--0.88), 0.58 (0.56--0.60)) were significantly less likely in the overweight groups. In all cases, increasing maternal BMI was associated with increased magnitude of risk.

CONCLUSION

Maternal obesity carries significant risks for the mother and foetus. The risk increases with the degree of obesity and persists after accounting for other confounding demographic factors. The basis of many of the complications is likely to be related to the altered metabolic state associated with morbid obesity.

Uterine artery Doppler in predicting pregnancy outcome in women with antiphospholipid syndrome

OBJECTIVE

To assess midtrimester uterine artery Doppler in the prediction of preeclampsia and small for gestational age (SGA) infants in women with primary antiphospholipid syndrome.

METHODS

One hundred seventy pregnant women with histories of recurrent miscarriage in association with antiphospholipid antibodies (32 lupus anticoagulant positive, 47 IgG anticardiolipin positive, 78 IgM anticardiolipin positive, and 13 lupus anticoagulant and anticardiolipin antibodies positive) treated with low-dose aspirin and heparin were recruited prospectively. Doppler assessment of the uterine arteries (presence or absence of notches and pulsatility index) were performed at 16-18 and 22-24 weeks. The main outcome measures were the delivery of a SGA infant and the development of preeclampsia.

RESULTS

There were 164 live births and six midtrimester losses. The prevalence of preeclampsia and SGA was similar at 10%. In predicting preeclampsia or SGA, uterine artery pulsatility index at either interval was of no value, and the diagnostic accuracy of the Doppler was limited to bilateral uterine artery notches at 22-24 weeks in the subgroup of women with positive lupus anticoagulant. In this subgroup, bilateral uterine artery notches at 22-24 weeks in predicting preeclampsia generated a high likelihood ratio for positive test (12.8, 95% confidence interval 2.2, 75), sensitivity (75%), specificity (94%), positive (75%) and negative (94%) predictive value. In predicting SGA, the corresponding figures were respectively 13.6 (95% confidence interval 1.9, 96), 80%, 94%, 80%, 94%. Uterine artery Doppler was of limited value in pregnancies associated with anticardiolipin antibodies in isolation.

CONCLUSION

In pregnancies associated with lupus anticoagulant, uterine artery Doppler at 22-24 weeks is a useful screening test in predicting preeclampsia and SGA infants.

Dynamic imaging of the pelvic floor using an open-configuration magnetic resonance scanner

The aims of this study were to develop a noninvasive, erect, gravity-dependent method for assessing movements of the female pelvic floor, to describe the range of movements in pelvic floor ascent and descent in asymptomatic and symptomatic women, and to quantify any differences. A total of 102 women, 28-86 years of age, 35 symptomatic and 67 asymptomatic, were included in the study. They were scanned in a sitting position in an open scanner with good vertical access using fast-gradient echo sequences fast spoiled grass (FSPGR). Measurements of the bladder base, uterocervical junction, and anorectal junction were taken in the sagittal plane. The levator ani (LA) muscle insertion was assessed in the coronal plane with the patients at rest, during maximal strain, and during maximum contraction of the pelvic floor. Premenopausal multiparous women have a significantly lower bladder base (8/0 mm above the baseline; P value = 0.009) and uterocervical junction (15.5/3.5 mm; P value = 0.03) at rest than nulliparous women, and this becomes more apparent on straining. Parity confers a more significant effect on the position and function of the pelvic floor than menopausal status. All pelvic organs are lower at rest and on straining in women with defecation difficulties (0/-24 mm; P value = 0.001). These differences are also seen when comparing women with and without urinary incontinence. Dynamic seated magnetic resonance imaging (MRI) shows that all the pelvic organs are lower at rest and on straining in multiparous women and in those with urinary incontinence than in a group of asymptomatic nulliparous volunteers. This difference is also seen in the position of the bladder base and anorectal junction during pelvic floor contraction. These findings suggest general pelvic floor weakness in women who present with symptoms in one compartment and indicate the need for evaluation of the entire pelvic floor particularly prior to surgery. J. Magn. Reson. Imaging 2001;13:923-929.

Anti-beta 2 glycoprotein 1 and anti-annexin V antibodies in women with recurrent miscarriage

While it has been established that anti-phospholipid antibodies (aPL) are associated with recurrent miscarriage (RM), the importance of anti-beta2 glycoprotein 1 (GP1) IgG and anti-annexin V IgG antibodies as risk factors for RM is undefined. We have investigated the prevalence of anti-beta2 GP1 IgG and anti-annexin V IgG antibodies in 54 aPL-positive and 48 aPL-negative women with RM. The prevalence of IgG anti-beta2 GP1 antibodies was not significantly different in persistently aPL-positive women with RM (7%), aPL-negative women with RM (6%) and the normal parous control group (3%). Anti-annexin V IgG antibody prevalence was significantly increased in aPL-positive women with RM compared with aPL-negative women with RM (P = 0.01). The elevations were found in 35%, 19% and 16% of aPL-positive women with RM, aPL-negative women with RM and the control group respectively. No women showed positivity for both anti-beta2 GP1 IgG and anti-annexin V antibodies. Anti-beta2 GP1 IgG antibodies do not appear to be contributory to the investigation of women with RM. Anti-annexin V antibody positivity, although associated with aPL positivity in women with RM, is not an independent risk marker.

Histological chorioamnionitis in relation to clinical presentation at 14-40 weeks of gestation

This study examines the prevalence of histological inflammation of the fetal membranes according to gestational age and mode of clinical presentation in a series of 179 consecutive placentas evaluated in a single centre. The frequency of histological inflammation between clinical groups was compared and relation between the prevalence of inflammation and gestational age examined using regression analysis. One hundred and seventy-nine placentas were examined. Histological inflammation was present in 65 (38%) cases including 37/52 (71%) pregnancies presenting with spontaneous preterm labour and delivery (PTL), 23/36 (64%) with preterm prelabour rupture of membranes (PPROM), 1/20 (5%) with vaginal bleeding but no contractions (PVB), 1/13 (8%) with intrauterine death but no labour (IUD), 1/28 (4%) with iatrogenic delivery, 0/4 with termination of pregnancy and 2/20 (10%) delivering spontaneously at term. The prevalence of histological inflammation was significantly higher in those with PTL or PPROM compared to the other groups (P<0.0001). The frequency of histological inflammation was associated with gestational age (F=57.2, P<0.0001, R=0.91), with a peak prevalence (>90%) at 20-24 weeks' gestation.

Factor V Leiden and acquired activated protein C resistance among 1000 women with recurrent miscarriage

Activated protein C (APC) resistance, both in its congenital form, due to the factor V Leiden mutation, and in its acquired form, are important risk factors for systemic venous thrombosis. In view of the suspected thrombotic aetiology of some cases of recurrent miscarriage, the prevalence of APC resistance was determined among 1111 consecutive Caucasian women with a history of either recurrent early miscarriage (three or more consecutive pregnancy losses at <12 weeks gestation; n = 904) or a history of at least one late miscarriage (>12 weeks gestation; n = 207). A control group of 150 parous Caucasian women with no previous history of adverse pregnancy outcome was also studied. Acquired APC resistance was significantly more common among both women with recurrent early miscarriage (8.8%: 80/904; P = 0.02) and those with late miscarriage (8.7%: 18/207; P = 0.04) compared with controls (3.3%: 5/150). In contrast, the frequency of the factor V Leiden allele was similar among (i) women with recurrent early miscarriage (3.3%:60/1808; 58 heterozygotes and one homozygote), (ii) those with late miscarriage (3.9%:16/414; 14 heterozygotes and one homozygote) and (iii) the control group (4.0%:12/300; 12 heterozygotes). Acquired but not congenital APC resistance (due to the factor V Leiden mutation) is associated with both early and late miscarriage.

Is maternal underweight really a risk factor for adverse pregnancy outcome? A population-based study in London

OBJECTIVE

To determine the maternal and fetal risk of adverse outcome during pregnancy in relation to low maternal body mass index in an unselected population.

DESIGN

Retrospective analysis.

METHODS

Information for the years between 1988 and 1997 was extracted from a validated maternity database, including all but one of the maternity units in the North West Thames Region; 215,105 completed singleton pregnancies were studied. Comparison of pregnancy outcome was made on the basis of maternal body mass index at booking. There were 176,923 with a normal weight body mass index ( = 20 < 25). There were 38,182 with an underweight body mass index (< 20). Comparisons included antenatal complications (e.g. gestational diabetes, pre-eclampsia); intervention in labour, maternal morbidities (e.g. infection, postpartum haemorrhage, pulmonary thromboembolism); and neonatal outcome (admitted to special care baby unit at 24 hour of age, gestation at delivery, birthweight, stillbirth). Data are presented as percentages of outcomes in the normal and underweight groups with adjusted odds ratios and confidence intervals according to body mass index group.

RESULTS

In the underweight group only antenatal anaemia, preterm delivery and birthweight below the 5th centile were more frequent than in women of normal body mass index. The prevalence of certain complications, including development of gestational diabetes mellitus, pre-eclampsia, obstetric intervention and postpartum haemorrhage, were significantly lower in those with low body mass index.

CONCLUSION

Low maternal body mass index is associated with increased prevalence of some pregnancy complications, notably preterm delivery and low birthweight, but overall the outcome is favourable and several adverse outcomes are less common in this group of women.

G20210A prothrombin gene mutation: prevalence in a recurrent miscarriage population

Many recurrent pregnancy losses appear to have a thrombotic etiology. We have investigated the prevalence of the G20210A prothrombin gene mutation in 122 women with a history of three or more early (< or = 12 weeks gestation; n = 91), late (> 12 weeks gestation: n = 2), or mixed (n = 29) consecutive pregnancy losses. A control group of 66 healthy parous women with no history of thrombosis or miscarriage was also studied. Four heterozygotes that suffered only early pregnancy losses were detected in the patient group giving a prevalence of 3.3%. Three of the control group women were heterozygous for the mutation. giving a prevalence of 4.5% (p = 0.32: odds ratio 0.71: 95% confidence interval [CI] 0.15-3.27). When only Caucasians were analyzed, a prevalence of 3.9% (4/103) was observed in the patient group and 4.2% (2/48) in the control group (p = 0.28; odds ratio 0.89; 95% CI 0.16-5.05). The prevalence of the G20210A prothrombin gene mutation is not increased in women with recurrent miscarriage, although it was only found in women who had suffered early pregnancy losses. However, it remains possible that this mutation is relevant in a selected subgroup of women with recurrent miscarriage, additional thrombophilic defects, and in whom fetal loss is associated with placental infarction and thrombosis.

Dramatic structural and thermodynamic consequences of repacking a protein's hydrophobic core

BACKGROUND

Rop is an RNA binding, dimeric, four-helix bundle protein with a well-defined, regular hydrophobic core ideally suited for redesign studies. A family of Rop variants in which the hydrophobic core was systematically redesigned has previously been created and characterized.

RESULTS

We present a structural and thermodynamic analysis of Ala2Ile2-6, a variant of Rop with an extensively redesigned hydrophobic core. The structure of Ala2Ile2-6 reveals a completely new fold formed by a conformational "flip" of the two protomers around the dimeric interface. The free-energy profile of Ala2Ile2-6 is also very different from that of wild-type Rop. Ala2Ile2-6 has a higher melting temperature than Rop, but undergoes a slightly smaller free-energy change on unfolding.

CONCLUSIONS

The structure of Ala2Ile2-6, along with molecular modeling results, demonstrate the importance of tight packing of core residues and the adoption of favorable core side chain rotamer values in determining helix-helix interactions in the four-helix bundle fold. Structural disorder at the N and C termini of Ala2Ile2-6 provides a basis for the large differences in the enthalpy and entropy of Ala2Ile2-6 folding compared with wildtype Rop.

Obstetric risks of pregnancy in women less than 18 years old

OBJECTIVE

To quantify the age-related risks of adverse outcome during pregnancy in women less than 18 years old.

METHODS

We analyzed data from 341,708 completed singleton pregnancies in the North West Thames region between 1988 and 1997. Pregnancy outcomes were compared by age at delivery in women less than 18 years old (n = 5246) and 18-34 years old (n = 336,462); women 35 years old or older (n = 48,658) were excluded. Data are presented as percentages of women less than 18 and 18-34-year-old women, with adjusted odds ratios (OR) and 99% confidence intervals (CI).

RESULTS

Pregnancy in women less than 18 years old was associated with increased risk of preterm labor before 32 weeks' gestation (OR 1.41, CI 1.02, 1.90), maternal anemia (OR 1.82, CI 1.63, 2.03), chest infection (OR 2.70, CI 1.21, 6.70), and urinary tract infection (OR 1.60, CI 1.11, 2.31), but less obstetric intervention. Operative vaginal delivery (OR 0. 46, CI 0.41, 0.56), elective cesarean (OR 0.47, CI 0.35, 0.65), or emergency cesarean (OR 0.45, CI 0.38, 0.53) were all less likely in women aged less than 18 years. Women less than 18 years old were no more likely to have stillbirths (OR 0.75, CI 0.42, 1.34) or small-for-gestational-age infants (OR 0.95, CI 0.82, 1.09) than women aged 18-34 years.

CONCLUSION

Pregnant women less than 18 years old were more likely to deliver preterm than older women. In most other respects they have less maternal and perinatal morbidity and were more likely to have normal vaginal deliveries.

The risks associated with pregnancy in women aged 35 years or older

The obstetric risks of adverse outcome during pregnancy in women aged > or =35 years were quantified using a retrospective analysis of data from 385 120 singleton pregnancies in the North West Thames Region, UK, between 1988 and 1997. A comparison of pregnancy outcome was made on the basis of maternal age at delivery: 18-34 years (n = 336 462), 35-40 years (n = 41 327) and women aged > 40 years (n = 7331). Women aged <18 years (n = 5246) were excluded from the study. Data are presented as percentages of 18-34 year old women, 35-40 year old and > 40 year old women, with adjusted odds ratios (OR) according to age group. Pregnant women aged 35-40 years were at increased risk of: gestational diabetes, OR = 2.63 [99% confidence interval (CI) 2.40-2.89]; placenta praevia = 1.93 (1.58-2.35); breech presentation = 1.37 (1.28-1.47); operative vaginal delivery = 1.5 (1.43-1.57); elective Caesarean section = 1.77 (1.68-1.87); emergency Caesarean section = 1.59 (1.52-1.67); postpartum haemorrhage = 1.14 (1.09-1.19); delivery before 32 weeks gestation = 1.41 (1.24-1.61); birthweight below the 5th centile = 1.28 (1.20-1. 36); and stillbirth = 1.41 (1.17-1.70). Women aged >40 years had higher OR for the same risks. Pregnant women aged >/=35 years are at increased risk of complications in pregnancy compared with younger women.

Epidemiology and the medical causes of miscarriage

Human reproduction is extraordinarily wasteful. The reasons for this have taxed all of the contributors to this book. As we move into the 21st century it is sobering to reflect on the fact that we have failed to harness the power of the evolving revolution in molecular medical biology to answer the fundamental question: why is the fate of a fertilized egg so hazardous and so unsuccessful? The following account summarizes our limited knowledge of the epidemiology of miscarriage and then moves on to consider some of the medical causes of miscarriage. The contribution of genetic abnormalities to the problem of pregnancy wastage is discussed elsewhere in this volume.

The use of whole rat embryo culture as a technique for investigating potential serum toxicity in recurrent miscarriage patients

Previously, the rat embryo model has been used as an experimental technique in investigations of the aetiology of idiopathic recurrent miscarriage. The aim of the present study was to validate it as a tool in the investigation of the aetiology of this condition. Subjects (n = 36) with a history of recurrent miscarriage were recruited from two dedicated recurrent miscarriage clinics and compared with control women with at least one previous pregnancy resulting in a live birth (n = 23). Serum from each woman was used as culture medium in the rat embryo model. Cultured embryos were scored for growth and differentiation. No statistical difference was found in any parameter between the two groups. Furthermore, patients from the recurrent miscarriage group whose serum demonstrated a trend towards lower scores, subsequently conceived and underwent uncomplicated pregnancies.

Magnetic resonance-guided percutaneous laser ablation of uterine fibroids

Laser ablation of uterine fibroids using a percutaneous approach under local anesthetic in an open magnetic resonance (MR) scanner was performed in 12 symptomatic women awaiting hysterectomy. Accurate laser fiber placement was assisted by the use of an MR needle tracking system, as well as laser heat dissipation monitored during treatment by a real-time imaging processor. This day case procedure was well tolerated by all women, with eight women subsequently declining their planned surgery. Follow-up measurements of treated fibroid volume by MRI demonstrated a mean decrease of 37.5% at 3 months. This novel minimally invasive approach offers an alternative to surgery for women with fibroids, but longer follow-up is required to ascertain maximal fibroid shrinkage and to compare outcome with traditional surgery.

Recurrent miscarriage--an aspirin a day?

Recurrent miscarriage and later pregnancy complications are in some cases associated with placental thrombosis and infarction. The aim of this study was to assess the value of low dose aspirin (75 mg daily) in improving the subsequent livebirth rate amongst women with either unexplained recurrent early miscarriage (<13 weeks gestation; n = 805) or unexplained late pregnancy loss (n = 250). Amongst women with recurrent early miscarriages, there was no significant difference in the livebirth rate between those who took aspirin (251/367; 68.4%) compared with those who did not take aspirin [278/438; 63.5%; odds ratio (OR) 1.24; 95% confidence interval (CI) 0.93-1.67]. This relationship was independent of the number of previous early miscarriages. In contrast, women with a previous late miscarriage who took aspirin had a significantly higher livebirth rate (122/189; 64.6%) compared with those who did not take aspirin (30/61; 49.2%: OR 1.88; 95% CI 1.04-3.37). The empirical use of low dose aspirin amongst women with unexplained recurrent early miscarriage is not justified. We are currently investigating the role of incremental doses of aspirin in the treatment of women both with early miscarriages associated with thrombophilic abnormalities and in those with late pregnancy losses.

Modulating protein folding rates in vivo and in vitro by side-chain interactions between the parallel beta strands of green fluorescent protein

We have identified pairs of residues across the two parallel beta strands of green fluorescent protein that facilitate native strand register of the surface-exposed beta barrel. After constructing a suitable host environment around two guest residues, minimizing interactions of the guest residues with surrounding side-chains yet maintaining the wild-type protein structure and the chromophore environment, we introduced a library of cross-strand pairings by cassette mutagenesis. Colonies of Escherichia coli transformed with the library differ in intracellular fluorescence. Most of the fluorescent pairs have predominantly charged and polar guest site residues. The magnitude and the rate of fluorescence acquisition in vivo from transformed E. coli cells varies among the mutants despite comparable levels of protein expression. Spectroscopic measurements of purified mutants show that the native protein structure is maintained. Kinetic studies using purified protein with fully matured chromophores demonstrate that the mutants span a 10-fold range in folding rates with undetectable differences in unfolding rates. Thus, green fluorescent protein provides an ideal system for monitoring determinants of in vivo protein folding. Cross-strand pairings affect both protein stability and folding kinetics by favoring the formation of native strand register preferentially to non-native strand alignments.

Understanding the sequence determinants of conformational switching using protein design

An important goal of protein design is to understand the forces that stabilize a particular fold in preference to alternative folds. Here, we describe an extension of earlier studies in which we successfully designed a stable, native-like helical protein that is 50% identical in sequence to a predominantly beta-sheet protein, the B1 domain of Streptococcal IgG-binding protein G. We report the characteristics of a series of variants of our original design that have even higher sequence identity to the B1 domain. Their properties illustrate the extent to which protein stability and conformation can be modulated through careful manipulation of key amino acid residues. Our results have implications for understanding conformational change phenomena of central biological importance and in probing the malleability of the sequence/structure relationship.

Proteomics of Mycoplasma genitalium: identification and characterization of unannotated and atypical proteins in a small model genome

We present the results of a comprehensive analysis of the proteome of Mycoplasma genitalium (MG), the smallest autonomously replicating organism that has been completely sequenced. Our aim was to identify and characterize all soluble proteins in MG that are structurally and functionally uncharacterized. We were particularly interested in identifying proteins that differed significantly from typical globular proteins, for example, proteins which are unstructured in the absence of a 'partner' molecule or those that exhibit unusual thermodynamic properties. This work is complementary to other structural genomics projects whose primary aim is to determine the three-dimensional structures of proteins with unknown folds. We have identified all the full-length open reading frames (ORFs) in MG that have no homologs of known structure and are of unknown function. Twenty-five of the total 483 ORFs fall into this category and we have expressed, purified and characterized 11 of them. We have used circular dichroism (CD) to rapidly investigate their biophysical properties. Our studies reveal that these proteins have a wide range of structures varying from highly helical to partially structured to unfolded or random coil. They also display a variety of thermodynamic properties ranging from cooperative unfolding to no detectable unfolding upon thermal denaturation. Several of these proteins are highly conserved from mycoplasma to man. Further information about target selection and CD results is available at http://bioinfo.mbb.yale.edu/genome

Interstitial thermo-ablation under MRI guidance for the treatment of fibroids

Women with symptomatic uterine fibroids are increasingly seeking alternatives to open surgery. The combination of high resolution magnetic resonance imaging and the application of laser heat permit percutaneous treatment of fibroids under local anaesthetic. This article reviews the technique of interstitial thermo-ablation and other current minimally invasive therapies for symptomatic fibroids.

A systematic exploration of the influence of the protein stability on amyloid fibril formation in vitro

There are a number of diseases in which normally soluble proteins associate into regular, insoluble amyloid fibrils. The development of in vitro model systems in which detailed structural, kinetic, and thermodynamic characterization are feasible is of critical importance to our understanding of the amyloid fibril phenomenon. The formation of amyloid fibrils by proteins that are not associated with disease has been recently described, suggesting that this may be a common property of many proteins and not only of the few proteins associated with amyloidoses. The B1 Ig-binding domain of protein G (beta1) is an extremely well-characterized model system. We have found that under certain experimental conditions, some variants of beta1 form fibrils with high reproducibility. By controlling the stability of the protein-either by mutations or by changing experimental conditions-we are able to modulate the ability of the protein to form fibrils. For all of the variants, we find that the key requirement for fibril formation is to choose conditions in which the population of intermediate conformations present during the unfolding transition is maximized.

Prevalence of hepatitis C among pregnant women attending an inner London obstetric department: uptake and acceptability of named antenatal testing

OBJECTIVE

To examine the value of universal antenatal screening for hepatitis C virus (HCV) infection among an inner London population, with regard to prevalence, uptake, and acceptability of testing, and identification of new cases.

DESIGN

Serum analysis for antibodies against HCV in pregnant women following informed consent ("opt out" policy). Samples positive for HCV antibodies were tested for the presence of HCV RNA by polymerase chain reaction. Information on hepatitis C was provided for all women. Acceptability of antenatal HCV testing and identification of risk factors for infection were assessed through the use of questionnaires randomly distributed among a cohort of 300 pregnant women.

SETTING

Antenatal clinics at St Mary's Hospital, London, serving a multiethnic population.

SUBJECTS

A total of 4825 pregnant women booking for antenatal care between November 1997 and April 1999.

RESULTS

The overall prevalence of anti-HCV was 0.8% and HCV viraemia was 0.6%. Ninety eight per cent of samples (n=4729) were tested; 0.2% of women had a false positive result. In 207 women who completed a questionnaire regarding our testing policy, 84% made a positive decision to be tested for anti-HCV and 92% said that HCV testing should be offered to all pregnant women. The majority (22/32-69%) of HCV infected women were newly diagnosed and although HCV positive women were significantly more likely to have a history of drug abuse, most (16/22-73%) new cases had no identified risk factors for HCV infection at booking.

CONCLUSION

The prevalence of anti-HCV in an inner London multiethnic antenatal population is high (0.8%). Routine screening for HCV is acceptable to pregnant women. The majority of women diagnosed during their current pregnancy would not have been identified as HCV infected by epidemiological risk factors at the time of booking.

Prospective pregnancy outcome in untreated recurrent miscarriers with thyroid autoantibodies

The purpose of this study was to determine the prevalence of thyroid antibodies in women with recurrent miscarriage and to observe whether their presence was predictive of future pregnancy outcome. A total of 870 consecutive, non-pregnant women with a history of three or more pregnancy losses and normal parental karyotypes were investigated for the presence of thyroglobulin antibodies (TgAb) and for thyroid microsomal antibodies (TmAb). Thyroid antibodies were found in 162 (19%) women. TgAb only were found in eight women (5%); TmAb only in 98 (60%) and both TgAb and TmAb were found in 56 (35%). Thirteen women had a history of thyroid disease and a further 15 women were found to have abnormal thyroid function. All 28 were excluded from the pregnancy outcome study. Among the remaining 134 thyroid antibody positive women, 36 women were not tested and normal thyroid stimulating hormone results were obtained for 98. In the group proven euthyroid, 14 of 24 untreated pregnancies resulted in live births (58%). Among the 710 thyroid antibody negative women, 47 of 81 untreated pregnancies resulted in live births (58%). The future risk of pregnancy loss in women with unexplained recurrent miscarriage is not affected by their thyroid antibody status.

The role of backbone conformational heat capacity in protein stability: temperature dependent dynamics of the B1 domain of Streptococcal protein G

The contributions of backbone NH group dynamics to the conformational heat capacity of the B1 domain of Streptococcal protein G have been estimated from the temperature dependence of 15N NMR-derived order parameters. Longitudinal (R1) and transverse (R2) relaxation rates, transverse cross-relaxation rates (eta(xy)), and steady state [1H]-15N nuclear Overhauser effects were measured at temperatures of 0, 10, 20, 30, 40, and 50 degrees C for 89-100% of the backbone secondary amide nitrogen nuclei in the B1 domain. The ratio R2/eta(xy) was used to identify nuclei for which conformational exchange makes a significant contribution to R2. Relaxation data were fit to the extended model-free dynamics formalism, incorporating an axially symmetric molecular rotational diffusion tensor. The temperature dependence of the order parameter (S2) was used to calculate the contribution of each NH group to conformational heat capacity (Cp) and a characteristic temperature (T*), representing the density of conformational energy states accessible to each NH group. The heat capacities of the secondary structure regions of the B1 domain are significantly higher than those of comparable regions of other proteins, whereas the heat capacities of less structured regions are similar to those in other proteins. The higher local heat capacities are estimated to contribute up to approximately 0.8 kJ/mol K to the total heat capacity of the B1 domain, without which the denaturation temperature would be approximately 9 degrees C lower (78 degrees C rather than 87 degrees C). Thus, variation of backbone conformational heat capacity of native proteins may be a novel mechanism that contributes to high temperature stabilization of proteins.

Pregnancy outcome is not affected by antiphospholipid antibody status in women referred for in vitro fertilization

OBJECTIVE

To determine the prevalence of antiphospholipid (aPL) and anti-beta 2 glycoprotein I (anti-beta2-GPI) antibodies in women referred for IVF and to prospectively evaluate the effect of these antibodies on IVF outcome.

DESIGN

Prospective observational study.

SETTING

A university hospital and IVF unit.

PATIENT(S)

Three hundred eighty consecutive women referred for IVF.

INTERVENTION(S)

Blood samples taken before commencement of IVF cycles were tested for the presence of aPL (lupus anticoagulant [LA], anticardiolipin [aCL], and antiphosphatidyl serine antibodies [aPS]) and anti-beta2-GPI antibodies.

MAIN OUTCOME MEASURE(S)

Antibody prevalence, pregnancy rates, and live birth rates.

RESULT(S)

Of the total 380 women, 89 tested persistently positive for aPL (23.4%). None of 176 women tested for IgG aPS antibodies had a positive titer. Only 3.3% (11 of 329) tested positive for anti-beta2-GPI antibodies. Pregnancy rate, live birth rate, gestational age at delivery, and birth weight were not affected by aPL status.

CONCLUSION(S)

Although women referred for IVF have a high prevalence of aPL, these antibodies do not affect the outcome of treatment. Screening women undergoing IVF for aPL is not justified.