J.A. van der Post

Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis

Background: Alterations in waveforms in the uterine artery are associated with the development of pre-eclampsia and intrauterine growth restriction. We investigated the predictive accuracy of all uterine artery Doppler indices for both conditions in the first and second trimesters. Methods: We identified relevant studies through searches of MEDLINE, EMBASE, the Cochrane Library and Medion databases (all records to April 2006) and by checking bibliographies of identified studies and consulting with experts. Four of us independently selected studies, extracted data and assessed study validity. We performed a bivariable meta-analysis of sensitivity and specificity and calculated likelihood ratios. Results: We identified 74 studies of pre-eclampsia (total 79 547 patients) and 61 studies of intrauterine growth restriction (total 41 131 patients). Uterine artery Doppler ultrasonography provided a more accurate prediction when performed in the second trimester than in the first-trimester. Most Doppler indices had poor predictive characteristics, but this varied with patient risk and outcome severity. An increased pulsatility index with notching was the best predictor of pre-eclampsia (positive likelihood ratio 21.0 among high-risk patients and 7.5 among low-risk patients). It was also the best predictor of overall (positive likelihood ratio 9.1) and severe (positive likelihood ratio 14.6) intrauterine growth restriction among low-risk patients. Interpretation: Abnormal uterine artery waveforms are a better predictor of pre-eclampsia than of intrauterine growth restriction. A pulsatility index, alone or combined with notching, is the most predictive Doppler index. These indices should be used in clinical practice. Future research should also concentrate on combining uterine artery Doppler ultrasonography with other tests.

Induction versus expectant monitoring for intrauterine growth restriction at term: randomised equivalence trial (DIGITAT)

Objective To compare the effect of induction of labour with a policy of expectant monitoring for intrauterine growth restriction near term. Design Multicentre randomised equivalence trial (the Disproportionate Intrauterine Growth Intervention Trial At Term (DIGITAT)). Setting Eight academic and 44 non-academic hospitals in the Netherlands between November 2004 and November 2008. Participants Pregnant women who had a singleton pregnancy beyond 36+0 weeks’ gestation with suspected intrauterine growth restriction. Interventions Induction of labour or expectant monitoring. Main outcome measures The primary outcome was a composite measure of adverse neonatal outcome, defined as death before hospital discharge, five minute Apgar score of less than 7, umbilical artery pH of less than 7.05, or admission to the intensive care unit. Operative delivery (vaginal instrumental delivery or caesarean section) was a secondary outcome. Analysis was by intention to treat, with confidence intervals calculated for the differences in percentages or means. Results 321 pregnant women were randomly allocated to induction and 329 to expectant monitoring. Induction group infants were delivered 10 days earlier (mean difference −9.9 days, 95% CI −11.3 to −8.6) and weighed 130 g less (mean difference −130 g, 95% CI −188 g to −71 g) than babies in the expectant monitoring group. A total of 17 (5.3%) infants in the induction group experienced the composite adverse neonatal outcome, compared with 20 (6.1%) in the expectant monitoring group (difference −0.8%, 95% CI −4.3% to 3.2%). Caesarean sections were performed on 45 (14.0%) mothers in the induction group and 45 (13.7%) in the expectant monitoring group (difference 0.3%, 95% CI −5.0% to 5.6%). Conclusions In women with suspected intrauterine growth restriction at term, we found no important differences in adverse outcomes between induction of labour and expectant monitoring. Patients who are keen on non-intervention can safely choose expectant management with intensive maternal and fetal monitoring; however, it is rational to choose induction to prevent possible neonatal morbidity and stillbirth. Trial registration International Standard Randomised Controlled Trial number ISRCTN10363217.

Treatment of thyroid disorders before conception and in early pregnancy: a systematic review

BACKGROUND Thyroid disorders are associated with pregnancy complications. Universal screening is currently not recommended because of a lack of evidence on the effectiveness of treatment. Women with hyperthyroidism and hypothyroidism evidently require treatment but this is less clear for women with subclinical hypothyroidism and thyroid autoimmunity. Therefore, we conducted a systematic review to provide a comprehensive overview on the available treatment interventions. METHODS Relevant studies were identified by searching Medline, EMBASE and Cochrane Controlled Trials Register, published until December 2011. RESULTS From a total of 7334 primary selected titles, 22 articles were included for the systematic review and 11 were appropriate for meta-analyses. Eight studies reported on hyperthyroidism. Propylthiouracil (PTU) and methimazole reduce the risk for preterm delivery [risk ratio (RR): 0.23, confidence interval (CI): 0.1-0.52], pre-eclampsia (RR: 0.23, CI: 0.06-0.89) and low birthweight (RR: 0.38, CI: 0.22-0.66). The nine studies that reported on clinical hypothyroidism showed that levothyroxine is effective in reducing the risk for miscarriage (RR: 0.19, CI: 0.08-0.39) and preterm delivery (RR: 0.41, CI: 0.24-0.68). For treatment of subclinical hypothyroidism, current evidence is insufficient. The five studies available on thyroid autoimmunity showed a not significant reduction in miscarriage (RR: 0.58, CI: 0.32-1.06), but significant reduction in preterm birth by treatment with levothyoxine (RR: 0.31, CI: 0.11-0.90). CONCLUSION For hyperthyroidism, methimazole and PTU are effective in preventing pregnancy complications. For clinical hypothyroidism, treatment with levothyroxine is recommended. For subclinical hypothyroidism and thyroid autoimmunity, evidence is insufficient to recommend treatment with levothyroxine. The overall lack of evidence precludes a recommendation for universal screening and is only justified in a research setting.

High activity of fatty acid oxidation enzymes in human placenta: Implications for fetal-maternal disease

As the human fetus and placenta are considered to be primarily dependent on glucose oxidation for energy metabolism, the cause of the remarkable association between severe maternal pregnancy complications and the carriage of a fetus with an inborn error of mitochondrial long-chain fatty acid oxidation (FAO) has remained obscure. We analysed human term placenta and chorionic villus samples for the activities of a variety of enzymes involved in FAO, and compared the results with those obtained in human liver. All enzymes were found to be expressed, with a very high activity of two enzymes involved in the metabolism of long-chain fatty acids (CPT2 and VLCAD), whereas the activity of medium-chain acyl-CoA dehydrogenase (MCAD) was found to be low, when compared to liver. These results suggest that fatty acid oxidation may play an important role in energy generation in human placenta, and that a deficiency in the placental oxidation of long-chain FAO may result in placental dysfunction, thus causing gestational complications.

Transvaginal sonographic assessment of cervical length and wedging for predicting outcome of labor induction at term: a systematic review and meta‐analysis

To perform a systematic review and meta‐analysis to assess the predictive capacity of transvaginal sonographic assessment of the cervix for the outcome of induction of labor.

Prenatal famine exposure, health in later life and promoter methylation of four candidate genes

Poor nutrition during fetal development can permanently alter growth, cardiovascular physiology and metabolic function. Animal studies have shown that prenatal undernutrition followed by balanced postnatal nutrition alters deoxyribonucleic acid (DNA) methylation of gene promoter regions of candidate metabolic control genes in the liver. The aim of this study was to investigate whether methylation status of the proximal promoter regions of four candidate genes differed between individuals exposed to the Dutch famine in utero. In addition, we determined whether methylation status of these genes was associated with markers of metabolic and cardiovascular disease and adult lifestyle. Methylation status of the GR1-C (glucocorticoid receptor), PPARγ (peroxisome proliferator-activated receptor gamma), lipoprotein lipase and phosphatidylinositol 3 kinase p85 proximal promoters was investigated in DNA isolated from peripheral blood samples of 759 58-year-old subjects born around the time of the 1944-45 Dutch famine. We observed no differences in methylation levels of the promoters between exposed and unexposed men and women. Methylation status of PPARγ was associated with levels of high-density lipoprotein cholesterol and triglycerides as well as with exercise and smoking. Hypomethylation of the GR promoter was associated with adverse adult lifestyle factors, including higher body mass index, less exercise and more smoking. The previously reported increased risk of cardiovascular and metabolic disease after prenatal famine exposure was not associated with differences in methylation status across the promoter regions of these candidate genes measured in peripheral blood. The adult environment seems to affect GR and PPARγ promoter methylation.

Circadian variation of urinary albumin excretion in pregnancy

Objective The hypothesis was tested that circadian variations in urinary albumin excretion of pregnant women in the third trimester of normal pregnancy are different from nonpregnant individuals.

Should cervical favourability play a role in the decision for labour induction in gestational hypertension or mild pre-eclampsia at term? An exploratory analysis of the HYPITAT trial

Please cite this paper as: Tajik P, van der Tuuk K, Koopmans C, Groen H, van Pampus M, van der Berg P, van der Post J, van Loon A, de Groot C, Kwee A, Huisjes A, van Beek E, Papatsonis D, Bloemenkamp K, van Unnik G, Porath M, Rijnders R, Stigter R, de Boer K, Scheepers H, Zwinderman A, Bossuyt P, Mol B. Should cervical favourability play a role in the decision for labour induction in gestational hypertension or mild pre‐eclampsia at term? An exploratory analysis of the HYPITAT trial. BJOG 2012;119:1123–1130.

Cost-effectiveness of induction of labour at term with a Foley catheter compared to vaginal prostaglandin E2 gel (PROBAAT trial)

To assess the economic consequences of labour induction with Foley catheter compared to prostaglandin E2 gel.

Recurrence risk and prediction of a delivery under 34 weeks of gestation after a history of a severe hypertensive disorder

Please cite this paper as: Langenveld J, Buttinger A, van der Post J, Wolf H, Mol B, Ganzevoort W. Recurrence risk and prediction of a delivery under 34 weeks of gestation after a history of a severe hypertensive disorder. BJOG 2011;118:589–595.