The interval between pregnancies and the risk of preeclampsia

Animal Models of Preeclampsia: Causes, Consequences, and Interventions

Preeclampsia is a common pregnancy complication, affecting 2% to 8% of pregnancies worldwide, and is an important cause of both maternal and fetal morbidity and mortality. Importantly, although aspirin and calcium are able to prevent preeclampsia in some women, there is no cure apart from delivery of the placenta and fetus, often necessitating iatrogenic preterm birth. Preclinical models of preeclampsia are widely used to investigate the causes and consequences of preeclampsia and to evaluate safety and efficacy of potential preventative and therapeutic interventions. In this review, we provide a summary of the published preclinical models of preeclampsia that meet human diagnostic criteria, including the development of maternal hypertension, together with new-onset proteinuria, maternal organ dysfunction, and uteroplacental dysfunction. We then discuss evidence from preclinical models for multiple causal factors of preeclampsia, including those implicated in early-onset and late-onset preeclampsia. Next, we discuss the impact of exposure to a preeclampsia-like environment for later maternal and progeny health. The presence of long-term impairment, particularly cardiovascular outcomes, in mothers and progeny after an experimentally induced preeclampsia-like pregnancy, implies that later onset or reduced severity of preeclampsia will improve later maternal and progeny health. Finally, we summarize published intervention studies in preclinical models and identify gaps in knowledge that we consider should be targets for future research.

When and Where Birth Spacing Matters for Child Survival: An International Comparison Using the DHS

A large body of research has found an association between short birth intervals and the risk of infant mortality in developing countries, but recent work on other perinatal outcomes from highly developed countries has called these claims into question, arguing that previous studies have failed to adequately control for unobserved heterogeneity. Our study addresses this issue by estimating within-family models on a sample of 4.5 million births from 77 countries at various levels of development. We show that after unobserved maternal heterogeneity is controlled for, intervals shorter than 36 months substantially increase the probability of infant death. However, the importance of birth intervals as a determinant of infant mortality varies inversely with maternal education and the strength of the relationship varies regionally. Finally, we demonstrate that the mortality-reducing effects of longer birth intervals are strong at low levels of development but decline steadily toward zero at higher levels of development. These findings offer a clear way to reconcile previous research showing that birth intervals are important for perinatal outcomes in low-income countries but are much less consequential in high-income settings.

Derivation of whole blood biomonitoring equivalents for lithium for the interpretation of biomonitoring data

INTRODUCTION

Lithium salts have numerous industrial uses and are also used in the treatment of bipolar disorders. The main source of lithium exposure to the general population is drinking water and foods. Lithium is nephrotoxic at higher doses. Thus, oral exposure guidelines for lithium have been derived, including ICH's permitted daily exposure (PDE = 0.008 mg lithium/kg-bw/day) adopted by Health Canada and the United States Environmental Protection Agency's (U.S. EPA) provisional peer reviewed toxicity value (PPRTV = 0.002 mg lithium/kg-bw/day), both based on human data.

OBJECTIVE

To derive whole blood biomonitoring equivalents (BEs) associated with PDE and PPRTV to interpret population-level biomonitoring data in health risk context.

METHOD

A simple kinetic relationship based on plasma clearance value (0.5 L/kg-bw/day) and the oral absorption fraction (100%) was used to derive blood BEs for PDE and PPRTV.

RESULTS

This analysis resulted in BE values in plasma and whole blood of 16 and 10 μg/L, respectively, based on the PDE values developed by the Health Canada and of 4.2 and 2.7 μg/L, respectively, based on the PPRTV developed by U.S. EPA.

CONCLUSION

The derived BE values can be used to interpret population-level biomonitoring data.

Thrombocytopenia in pregnancy: Diagnosis and approach to management

Thrombocytopenia during pregnancy presents unique challenges for the hematologist. Obstetricians generally manage many of the pregnancy-specific etiologies, ranging from the benign (gestational thrombocytopenia) to the life-threatening (preeclampsia; hemolysis, elevated liver enzymes and low platelets syndrome; and acute fatty liver of pregnancy). However, hematologists may be consulted for atypical and severe presentations and to help manage non-pregnancy specific etiologies, including immune thrombocytopenia, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome and antiphospholipid syndrome, among others, in which maternal and fetal risks must be considered. This review provides a general approach to the diagnosis and management of thrombocytopenia in pregnancy for the consulting hematologist.

Learning from experience: cellular and molecular bases for improved outcome in subsequent pregnancies

The frequencies of preeclampsia, fetal growth restriction, fetal demise, and low birthweight are lower in subsequent pregnancies. Enhanced maternal cardiovascular adaptation, shorter first and second stages of labor, and more robust lactation also have been observed in subsequent as compared with first pregnancies. We sought to investigate the cellular and molecular bases for better outcomes in subsequent pregnancies. Based on the knowledge that specialized immune cells at the maternal-fetal interface, decidual natural killer cells, promote development of the placental bed and conversion of the spiral arteries by secreting a myriad of angiogenic and growth factors, we asked whether decidual natural killer cells differ in subsequent as compared with first pregnancies. This idea stemmed from recent studies suggesting that natural killer cells, although part of the innate immune system, possess some features of adaptive immunity, including a certain type of immune cell memory, termed trained immunity. We found that decidual natural killer cells from parous women "remember pregnancy" and differ from decidual natural killer cells of primigravidae. Compared with the decidual natural killer cells of first pregnancy, these cells, that we termed pregnancy-trained decidual natural killer cells, express greater levels of the natural killer receptors NKG2C and leukocyte immunoglobulin-like receptor B1, which interact with ligands expressed on invasive trophoblasts. Furthermore, they secrete greater levels of several growth factors, including vascular endothelial growth factor α as well as interferon-γ, augmenting remodeling of the placental bed. We propose that this pregnancy-trained memory dwells in the epigenome, where memory of stimuli is known to persist even when the stimulus is no longer present. This epigenetic memory apparently resides in endometrial natural killer cells between pregnancies. We suggest that this trained memory, which we coined pregnancy-trained decidual natural killer cells, may be the missing link in the immune basis for enhanced subsequent pregnancy. Epigenetic memory (chromatin modification) also may afford a global explanation for additional findings of enhanced maternal cardiovascular adaptation, shorter first and second stages of labor, and more robust lactation. Understanding the molecular and cellular bases of improved outcomes of subsequent pregnancy may lead to the development of treatment modalities designed for women at high risk for pregnancy disorders originating at the maternal-fetal interface.

The two-stage placental model of preeclampsia: An update

Early-onset preeclampsia has been linked to poor placentation and fetal growth restriction, whereas late-onset preeclampsia was suggested to result from maternal factors. We have proposed an alternative model, suggesting that both early- and late-onset preeclampsia result from placental syncytiotrophoblast stress. This stress represents a common endpoint of several Stage 1 processes, promoting the clinical stage 2 of preeclampsia (new-onset hypertension and proteinuria or other signs of end-organ dysfunction), but the causes and timing of placental malperfusion differ. We have suggested that late-onset preeclampsia, without evidence of poor spiral artery remodelling, may be secondary to intraplacental (intervillous) malperfusion due to mechanical restrictions. As the growing placenta reaches its size limit, malperfusion and hypoxia occurs. This latter pathway reflects what is observed in postmature or multiple pregnancies. Our revised two-stage model accommodates most risk factors for preeclampsia including primiparity, chronic pre-pregnancy disease (e.g. obesity, diabetic-, chronic hypertensive-, and some autoimmune diseases), and pregnancy risk factors (e.g. multiple or molar pregnancies, gestational diabetes or hypertension, and low circulating Placental Growth Factor). These factors may increase the risk of progressing to the second stage of preeclampsia (both early- and late-onset) by affecting one of or both pathways leading to Stage 1, as well as potentially accelerating the steps towards Stage 2, including priming the maternal cardiovascular susceptibility to inflammatory factors shed by the placenta. This paper reviews previous preeclampsia findings and concepts, which fit with the revised two-stage model, and argues that "maternal" preeclampsia does not exist, as all preeclampsia requires a placenta.

The mnemonic code of pregnancy: Comparative analyses of pregnancy success and complication risk in first and second human pregnancies

Obstetrical complications such as spontaneous abortion/miscarriage, fetal growth restriction, preeclampsia or preterm birth occur in approx. 15% of human pregnancies. Clinical experts often state that a previous uncomplicated pregnancy reduces the risk for complications in subsequent pregnancies. Vice versa, a prior pregnancy affected by obstetrical complications increases the risk for reoccurrence. However, published evidence directly underpinning these clinical statements is sparse. Considering that the maternal immune adaptation may be causally involved in determining the outcome of subsequent pregnancies, a comprehensive analysis of clinical data was long overdue. We here present a systematic analysis of clinical data using a PubMed-based approach to identify human studies with relevant information on birth weight and incidences of pregnancy complications in first and second pregnancies. From initially 18,592 publications, 37 studies were included in the quantitative data analysis. Women with a previous pregnancy affected by complications where a derailed immune response can be inferred have a 2.2-3.2-fold increased risk to be affected again in a subsequent pregnancy. Conversely, a normally progressing primary pregnancy reduced the risk for complications in a subsequent pregnancy by 35-65%. Moreover, an uncomplicated primary pregnancy was associated with a 4.2% increased birth weight in a following pregnancy without a difference in gestational age at delivery. In conclusion, the increased birth weight after previously uncomplicated pregnancies suggests that an immune memory is mounted during primary pregnancies. This immune memory may promote the successful outcome of subsequent pregnancies or - if missing or compromised - account for a risk perpetuation of pregnancy complications.

Preeclampsia: The Relationship between Uterine Artery Blood Flow and Trophoblast Function

Maternal uterine artery blood flow is critical to maintaining the intrauterine environment, permitting normal placental function, and supporting fetal growth. It has long been believed that inadequate transformation of the maternal uterine vasculature is a consequence of primary defective trophoblast invasion and leads to the development of preeclampsia. That early pregnancy maternal uterine artery perfusion is strongly associated with placental cellular function and behaviour has always been interpreted in this context. Consistently observed changes in pre-conceptual maternal and uterine artery blood flow, abdominal pregnancy implantation, and late pregnancy have been challenging this concept, and suggest that abnormal placental perfusion may result in trophoblast impairment, rather than the other way round. This review focuses on evidence that maternal cardiovascular function plays a significant role in the pathophysiology of preeclampsia.

Recurrent or first preeclampsia in multiparae: A case-control study of singleton pregnancies in Reunion Island

Recurrent or first preeclampsia in multiparae : a case-control study of singleton pregnancies in Reunion Island Phuong Lien Tran, Pierre-Yves Robillard, Coralie Dumont, Chloé Schweizer, Asma Omarjee, Glorianne Lazaro, Silvia Iacobelli, Malik Boukerrou OBJECTIVE: To compare multiparous women with a first occurrence of preeclampsia and those with recurrent preeclampsia in singleton pregnancies.

STUDY DESIGN

a 17.5-year (2001-2018) case-control study conducted in the University's maternity of South Reunion (Indian Ocean), comparing 125 patients with recurrent preeclampsia and 742 patients with a first episode of the disease (controls). Statistical analyses were performed with use of the Student t-test for comparison of continuous data and the Chi-square or Fisher exact test for comparison of categorical variables.

RESULTS

There was no difference between the two groups concerning socio-demographic characteristics, post-partum haemorrhage, perinatal mortality rates. Nevertheless, recurrent preeclamptic women had a higher risk to present with prior chronic hypertension (OR 2.05 [1.30-3.23], p = 0.002), and to experience an early onset preeclampsia (< 34 weeks) compared to controls (OR 1.69 [1.15-2.48], p = 0.007). Women with recurrent preeclampsia were more prone to have C-sections (OR 1.63 [1.06-2.51], p = 0.024) mainly because of maternal indications (89.2% vs 76.4%, p = 0.008). Newborns from recurrent preeclampsia were more likely to have very low birthweight < 1500 g (OR 1.79 [1.16-2.77], p = 0.001), while there was no significant difference for gestational ages (34.1 vs 34.7 weeks).

CONCLUSION

Recurrent multiparous preeclamptic women presented more severe maternal disease (with a higher rate of early onset preeclampsia). Persistent hypertension in women with a history of preeclampsia is a risk factor for developing recurrent preeclampsia, and these patients should be monitored more closely.

Pregnancy outcomes in correlation with placental histopathology in subsequent pregnancies complicated by fetal growth restriction

OBJECTIVE

In attempt to shed new light on the etiopathogenesis of fetal growth restriction (FGR) we aimed to compare pregnancy outcomes and placental histopathology in cases of first vs. subsequent FGR occurrence.

STUDY DESIGN

Pregnancy and placental reports of FGR pregnancies (defined by birth weight <10th percentile), born between 2008 and 2018 were reviewed. Included only cases with recurrent FGR, in two consecutive pregnancies, thus each subject served as her own control in two FGRs consecutive pregnancies. Neonatal outcome and placental histopathology were compared between the first FGR delivery (first FGR group) and the subsequent FGR delivery (subsequent FGR group). Composite adverse neonatal outcome was defined as one or more early neonatal complications.

RESULTS

Included in the study a total of 96 cases with recurrence of FGR pregnancies. Placentas from the first FGR group were characterized by higher rate of maternal vascular malperfusion (MVM) lesions as compared with the subsequent FGR group (71.8% versus 55.2%, respectively, p = 0 .02). Adverse neonatal outcome was more prevalent in the first FGR group as compared to the recurrent FGR group (41.6% versus 25%, respectively, p = 0.02). After controlling for confounders, using multivariate regression analysis, placental MVM lesions (aOR = 1.36, 95% CI = 1.12-1.45) and composite adverse neonatal outcome (aOR = 1.18 95% CI = 1.09-1.55) were found to be independently associated with the first FGR group.

CONCLUSION

First event of FGR is associated with a higher rate of placental MVM lesions and adverse neonatal outcome as compared to FGR in subsequent pregnancies.

New Paradigm in the Role of Regulatory T Cells During Pregnancy

Semi-allogenic fetuses are not rejected by the maternal immune system because feto-maternal tolerance induced by CD4⁺CD25⁺FoxP3⁺ regulatory T (Treg) cells is established during pregnancy. Paternal antigen-specific Treg cells accumulate during pregnancy, and seminal plasma priming plays an important role in expanding paternal antigen-specific Treg cells in mouse models. Although paternal-antigen specific Treg cells have not been identified in humans, recent studies suggest that antigen-specific Treg cells exist and expand at the feto-maternal interface in humans. Studies have also revealed that reduction of decidual functional Treg cells occurs during miscarriage with normal fetal chromosomal content, whereas insufficient clonal expansion of decidual Treg cells is observed in preeclampsia. In this review, we will discuss the recent advances in the investigation of mechanisms underlying Treg cell-dependent maintenance of feto-maternal tolerance.

Prediction of ischemic placental diseases during the first trimester combined test period: a retrospective cohort of low-risk pregnancies in search of the link between parity and disease

Objective: To assess the predictive power of a multifactorial model established on maternal characteristics, placenta-associated plasma protein A (PAPPA), and the mean uterine artery pulsatility index (Ut A PI) levels for the development of ischemic placental diseases (IPD) during the first-trimester combined test (FTCT) period and to evaluate the strength of some generally accepted clinical risk factors.Method: The studied data were obtained from a retrospective cohort of low-risk singleton pregnancies in the FTCT between 1 August 2016 and 1 December 2017. After routine 11-13-week examinations for FTCT, the Ut A PI was measured and stored electronically. The PAPPA multiple of median (MoM) was obtained as a routine component of aneuploidy screening.Results: A sample of 2493 pregnancies with clearly documented outcomes was studied. Early-onset preeclampsia, late-onset preeclampsia and fetal growth restriction (FGR) were observed in 9 (0.36%), 27 (1.08%), and 41 (1.64%) cases, respectively. With optimum cut-off levels of 0.69 for PAPPA MoM and 2.05 for mean Ut A PI and a false positive rate of 4.9%, IPD cases could be predicted with 83.3% sensitivity and 73.7% specificity. Nulliparity, previous abortion in nulliparous women and first pregnancy from second marriage were not independent risk factors. Maternal age, an interval from the last delivery longer than 6 years, and body mass index were found to be independent risk factors.Conclusion: The IPD showed some common and distinct clinical, laboratory and Doppler findings during the FTCT and were predictable with the help of multifactorial analysis. Some widely accepted risk factors could be affected by various confounders. Because of the increased IPD frequencies, parous women with a time interval from the last delivery of 6 years or longer should be screened as a high-risk group for placental dysfunction-related diseases.

Effect of Self-care Before and During Pregnancy to Prevention and Control Preeclampsia in High-risk Women

Our aims to examine the factors influencing self-care for the prevention and control of preeclampsia in high-risk women. The current study is a review where the researcher browsed the available databases such as PubMed, Cochrane, Medline, Google Scholar, Medscape, and relevant research published between 1980 and 2016 were studied. To search for articles, relevant Medical Subject Heading keywords were first determined (Self-care, preeclampsia, prevention.) A total of 350 related articles were first selected, and the findings of 70 were used to compile the present article. The results of the study were classified under two general categories, including (1). Counseling and screening strategies and (2) self-care strategies for the prevention and control of preeclampsia in high-risk women. Screening women at risk for preeclampsia include measures such as measuring their blood pressure, checking for signs of depression, testing for thrombosis, taking a history of preeclampsia, providing preconception counseling about the appropriate age, time of pregnancy, and encouraging weight loss in obese women. This review showed a positive relationship between knowledge about self-care for preeclampsia and its control. The factors influencing preeclampsia self-care include making lifestyle changes, having a healthy diet, learning stress management, performing exercise and physical activities, taking antioxidants, dietary supplements, and calcium and adherence to aspirin and heparin regimens. There is a positive relationship between preconception counseling, screening women at risk for preeclampsia, self-care for the prevention, and control of preeclampsia.

(1) Tweetable abstract self-care in high-risk women is strongly associated with prevention and control of preeclampsia.

Preeclampsia and Hypertension During Pregnancy in Areas with Relatively Low Levels of Traffic Air Pollution

Objectives Air pollution exposure may contribute to the development of preeclampsia and hypertension during pregnancy. However, the evidence for such a relation is still limited. We investigated the associations between exposure for moderate to low levels of air pollution during pregnancy and preeclampsia and gestational hypertension in selected urban and county areas of Norway. Methods This study used a sub-group of 17,533 women in the Norwegian Mother and Child Cohort Study. Air pollution levels at residential addresses were estimated using land use regression models and back-extrapolated to the period of each pregnancy. Information on preeclampsia and gestational hypertension were obtained from the Medical Birth Registry of Norway and information on lifestyle factors was collected from questionnaires completed by the women during pregnancy. Results Moderate mean levels of NO₂ (13.6 ± 6.9 µg/m³) at residential address during pregnancy were not associated with preeclampsia and pregnancy hypertension. We found no statistically significant associations per 10 µg/m³ change in NO₂ exposure and preeclampsia (adjusted OR 0.89, 95% CI 0.74, 1.08) or hypertension during pregnancy (adjusted OR 0.91, 95% CI 0.78, 1.06). Conclusions for Practice In this large Norwegian pregnancy cohort, we found no statistically significant associations for moderate to low levels of pregnancy NO₂ exposure and preeclampsia or hypertension during pregnancy.

Short interpregnancy intervals and adverse maternal outcomes in high-resource settings: An updated systematic review

BACKGROUND

Currently, no federal guidelines provide recommendations on healthy birth spacing for women in the United States. This systematic review summarises associations between short interpregnancy intervals and adverse maternal outcomes to inform the development of birth spacing recommendations for the United States.

METHODS

PubMed/Medline, POPLINE, EMBASE, CINAHL, the Cochrane Database of Systematic Reviews, and a previous systematic review were searched to identify relevant articles published from 1 January 2006 and 1 May 2017. Included studies reported maternal health outcomes following a short versus longer interpregnancy interval, were conducted in high-resource settings, and adjusted estimates for at least maternal age. Two investigators independently assessed study quality and applicability using established methods.

RESULTS

Seven cohort studies met inclusion criteria. There was limited but consistent evidence that short interpregnancy interval is associated with increased risk of precipitous labour and decreased risks of labour dystocia. There was some evidence that short interpregnancy interval is associated with increased risks of subsequent pre-pregnancy obesity and gestational diabetes, and decreased risk of preeclampsia. Among women with a previous caesarean delivery, short interpregnancy interval was associated with increased risk of uterine rupture in one study. No studies reported outcomes related to maternal depression, interpregnancy weight gain, maternal anaemia, or maternal mortality.

CONCLUSIONS

In studies from high-resource settings, short interpregnancy intervals are associated with both increased and decreased risks of adverse maternal outcomes. However, most outcomes were evaluated in single studies, and the strength of evidence supporting associations is low.

Fetal human leukocyte antigen-C and maternal killer-cell immunoglobulin-like receptors in cases of severe preeclampsia

INTRODUCTION

The pathogenesis of preeclampsia may involve inadequate trophoblast invasion caused by excessive inhibition of uterine natural killer cells (uNK) by extravillous trophoblast cells (EVT). This may be the result of a combination of maternal killer-cell immunoglobin-like receptor (KIR) AA genotype and fetal human leukocyte antigen-C2 (HLA-C2) genotype. A few studies have reported a significantly increased frequency of the maternal KIR AA/fetal HLA-C2 combination in cases of preeclampsia compared to controls.

METHODS

Study subjects were 259 cases of severe preeclampsia/eclampsia and 259 matched pregnant women without preeclampsia or eclampsia. All pregnancies were singleton pregnancies, and mothers were preferentially primigravidae. Blood samples from women and their newborns were obtained from the Danish National Birth Cohort (DNBC) and the Danish Neonatal Screening Biobank. Significant differences in the frequencies of KIR AA and HLA-C2 between cases and controls were investigated.

RESULTS

No significant difference was observed between cases and controls in the frequency of maternal KIR AA (OR = 0.86, 95%CI = 0.60-1.23, P = 0.41), neither when the fetus carried an HLA-C2 allele (OR = 0.85, 95%CI = 0.52-1.38, P = 0.51), nor when the fetus carried an HLA-C2 allele more than its mother (OR = 0.75, 95%CI = 0.34-1.64, P = 0.47).

CONCLUSION

The Results show no influence of HLA-C/KIR genetic variation on the risk of severe preeclampsia, contrary to what some previous studies have observed. An explanation could be that severe preeclampsia represents a separate pathological entity compared to mild preeclampsia.

Primipaternity and birth interval; independent risk factors for preeclampsia

Background: The exact cause of preeclampsia remains unknown. The past decade has seen an ongoing debate on the relative importance of primipaternity versus prolonged birth/pregnancy interval.Aims: The aim of the current study was to analyze these two major potential risk factors in a high risk population in the Northern suburbs of Adelaide; a socioeconomically disadvantaged area characterized by instable relationships and overall poor health and lifestyle.Methods: A retrospective cohort study was performed on all multigravid women birthing at the Lyell McEwin Hospital, Adelaide, from July 2011 to August 2012; 2003 patients were included in this analysis. Basic demographic data, previous pregnancy outcomes, paternity, and birth and pregnancy intervals were recorded.Results: Women with a previously normal pregnancy had a significantly increased risk of developing preeclampsia in subsequent pregnancy with a new paternity (OR: 2.27 [p = .015]). Increasing birth and pregnancy intervals were associated with a significantly increased risk of developing preeclampsia in later pregnancies, with OR 1.39 at 3 years (p = .042) and OR 2.05 at 4 years (p = .002).Conclusions: The results of this study indicate that both prolonged birth interval and primipaternity are independent risk factors for preeclampsia in multigravidae.

Evaluation of sFlt-1/PlGF Ratio for Predicting and Improving Clinical Management of Pre-eclampsia: Experience in a Specialized Perinatal Care Center

Background

Management of pregnant women at high risk of pre-eclampsia (PE) requires frequent monitoring, with referral to specialized perinatal care centers. Reliable tests are necessary to improve prediction of PE and related complications and to assess disease severity and progression. An imbalance in two biomarkers, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF), is involved in PE pathogenesis. The sFlt-1 to PlGF ratio is increased in pregnant women before the onset of PE. An elevated ratio is highly predictive of PE, whereas the diagnosis of PE can be ruled out within one week for low ratios. The main objective of this study was to assess whether a low sFlt-1/PlGF ratio, below a cutoff of 38, can predict the absence of PE within one week.

Methods

We performed a prospective, monocentric, observational study to evaluate serum sFlt-1/PlGF ratio (Roche Diagnostics Cobas e411 system) for predicting -PE in a group of 67 high-risk pregnant women (20–37 gestation weeks).

Results

Among the 67 patients included, 53 had a sFlt-1/PlGF ratio lower than 38; none developed subsequent PE leading to a negative predictive value of 100%. Eight patients developed clinical PE. The positive predictive value was 21% at one week and 18% at four weeks, in accordance with previous studies.

Conclusions

The serum sFlt-1/PlGF ratio showed highly predictive performances for ruling out PE. Using these biomarkers in routine management of PE may improve clinical care and avoid inappropriate hospitalization, which has a significant economic impact.

Effects of a novel exercise training protocol of Wingate-based sprint bouts dispersed over a day on selected cardiometabolic health markers in sedentary females: a pilot study

PURPOSE

Sprint interval training (SIT) provides a strong stimulus for improving cardiovascular fitness, which is among the key markers for premature mortality. Recent literature demonstrated that SIT protocols with as few as two stacked 20 s Wingate Anaerobic Test (WAnT) cycle sprints provide sufficient training stimulus for a robust increase in maximal aerobic power. However, this effect is lost when only one bout is performed. This suggests training adaptation is still dependent on the volume of SIT. Therefore, the purpose of this study was to determine the effects of three dispersed 30 s WAnT bouts, done over a day but interspersed with 4 hours of recovery time, on selected cardiometabolic health markers.

METHODS

Eighteen sedentary women, age 36±8 years, were recruited and underwent 8 weeks of supervised training using the WAnT protocol, 3 days a week. Criterion measure of cardiovascular fitness (ie, V̇O2peak), skinfolds and blood lipids such as triglyceride, low density lipoprotein (LDL) and high density lipoprotein (HDL) were measured before and after training intervention.

RESULTS

V̇O2peak improved by a mean of 14.0% after training (21.7±5.7 vs 24.7±5.7 mL/kg/min, p<0.01). No significant change was observed for body fat and lipid profile.

CONCLUSION

Performing three dispersed WAnT bouts with a 4-hour recovery period between bouts throughout a day, 3 days per week for 8 weeks provides sufficient training stimulus for a robust increase in V̇O2peak, which is comparable with other previous SIT protocols with very short recovery intervals. However, no other changes in the other cardiometabolic health markers were detected.

Renal complications during pregnancy: In the hypertension spectrum

In pregnancy, there are numerous changes which occur to accommodate the needs of both the fetus and placenta. These changes present us with a unique set of clinical challenges particularly in the setting of any disease processes occurring during pregnancy. It is essential to understand that the systems profoundly affected are the cardiovascular and renal systems. The most predominant disease process occurring in pregnancy affecting both the cardiovascular and renal system is the spectrum of hypertensive disorders specifically pre-eclampsia. Due to its high incidence worldwide, it is considered as the most common cause of infant and maternal morbidity and mortality. While the international definition, classification scheme and diagnostic criteria for Hypertensive Disorders of Pregnancy still must be agreed upon, hypertension has been the mandatory feature for all established guidelines. Pre-eclampsia particularly the severe form which is recognized as HELLP (Hemolysis, Elevated Liver enzymes and Low Platelet count) syndrome is the primary cause of acute kidney injury in pregnancy. In this review, we would primarily discuss the hemodynamic and vascular changes, anatomical and physiologic renal adaptations occurring during normal pregnancy and the complications which arise in the setting of hypertensive diseases. Mainly focusing on the pre-eclampsia spectrum, since knowledge of these is of clinical importance not only in understanding its role in the disease process but more so its implications for prevention, screening, diagnosis, and management.

The duration of sexual relationship and its effects on adverse pregnancy outcomes

This study aims to determine if a short duration of sexual relationship is more common among women who experience adverse pregnancy outcomes including gestational hypertension (GHT), preeclampsia, small for gestational age (SGA) pregnancies and spontaneous preterm birth (sPTB) with or without abnormal uterine artery Doppler compared to women who have uncomplicated pregnancies. 5591 nulliparous women from the Screening for Pregnancy Endpoints (SCOPE) study were included. The risk for pregnancy complications for women who had a duration of sexual relationship of ≤3 months, 4-6 months, 7-9 months, 10-12 months was compared with women who had a duration of sexual relationship of >12 months. Uterine artery Doppler was performed at 20 ± 1 weeks' gestation. A short duration of sexual relationship (≤3 months) was more common among women with SGA in the presence of abnormal uterine artery Doppler [9.8% vs 3.0%, aOR (95% CI) 3.4 (1.6-7.08] compared to women who had uncomplicated pregnancies. A short duration of sexual relationship (≤3 months) was also more common among women who had abnormal uterine artery Doppler compared to those with normal uterine artery Doppler [6.1% vs 3.1%, aOR (95% CI) = 2.1 (1.4-3.2)]. A short duration of sexual relationship was not associated with preeclampsia after adjusting for confounders. A short duration of sexual relationship is more common among women who deliver SGA infants with features of placental insufficiency as indicated by abnormal uterine artery Doppler.

A computerized algorithm to capture patient's past preeclampsia and eclampsia history from prenatal clinical notes

Prenatal clinical notes in electronic medical records contain a wealth of information on pregnancy complications and outcomes. Extracting this critical information provides a unique opportunity for risk assessment to identify at-risk patients who may benefit from early monitoring and intervention. We developed and validated a rule-based computerized algorithm called PregHisEx to characterize past obstetrical history (preeclampsia/eclampsia) by mining prenatal clinical notes for women delivered in 2012 within a large healthcare maintenance organization. The algorithm successfully identified cases with past history of preeclampsia/eclampsia: 2984 definite and 479 probable cases at sentence level; 2419 definite and 348 probable cases at note level; and 762 definite and 82 probable cases at pregnancy episode level. Validation conducted on a random sample of 200 notes using PregHisEx yielded 88.0 percent sensitivity, 98.9 percent specificity, 91.7 percent positive predictive value, 98.3 percent negative predictive value, and F-score of 0.90. The high-performing PregHisEx can be applied for other prenatal conditions.

The impact of parity on life course blood pressure trajectories: the HUNT study in Norway

The drop in blood pressure during pregnancy may persist postpartum, but the impact of pregnancy on blood pressure across the life course is not known. In this study we examined blood pressure trajectories for women in the years preceding and following pregnancy and compared life course trajectories of blood pressure for parous and nulliparous women. We linked information on all women who participated in the population-based, longitudinal HUNT Study, Norway with pregnancy information from the Medical Birth Registry of Norway. A total of 23,438 women were included with up to 3 blood pressure measurements per woman. Blood pressure trajectories were compared using a mixed effects linear spline model. Before first pregnancy, women who later gave birth had similar mean blood pressure to women who never gave birth. Women who delivered experienced a drop after their first birth of − 3.32 mmHg (95% CI, − 3.93, − 2.71) and − 1.98 mmHg (95% CI, − 2.43, − 1.53) in systolic and diastolic blood pressure, respectively. Subsequent pregnancies were associated with smaller reductions. These pregnancy-related reductions in blood pressure led to persistent differences in mean blood pressure, and at age 50, parous women still had lower systolic (− 1.93 mmHg; 95% CI, − 3.33, − 0.53) and diastolic (− 1.36 mmHg; 95% CI, − 2.26, − 0.46) blood pressure compared to nulliparous women. The findings suggest that the first pregnancy and, to a lesser extent, successive pregnancies are associated with lasting and clinically relevant reductions in systolic and diastolic blood pressure.

Pre-Eclampsia and Eclampsia: An Update on the Pharmacological Treatment Applied in Portugal

Pre-eclampsia and eclampsia are two hypertensive disorders of pregnancy, considered major causes of maternal and perinatal death worldwide. Pre-eclampsia is a multisystemic disease characterized by the development of hypertension after 20 weeks of gestation, with the presence of proteinuria or, in its absence, of signs or symptoms indicative of target organ injury. Eclampsia represents the consequence of brain injuries caused by pre-eclampsia. The correct diagnosis and classification of the disease are essential, since the therapies for the mild and severe forms of pre-eclampsia are different. Thus, this review aims to describe the most advisable antepartum pharmacotherapy for pre-eclampsia and eclampsia applied in Portugal and based on several national and international available guidelines. Slow-release nifedipine is the most recommended drug for mild pre-eclampsia, and labetalol is the drug of choice for the severe form of the disease. Magnesium sulfate is used to prevent seizures caused by eclampsia. Corticosteroids are used for fetal lung maturation. Overall, the pharmacological prevention of these diseases is limited to low-dose aspirin, so it is important to establish the safest and most effective available treatment.

Exposure to vitamin D from fortified margarine during fetal life and later risk of pre-eclampsia: the D-tect Study

OBJECTIVE

To examine if fetal exposure to a small dosage of extra vitamin D from food fortification was associated with a decrease in the risk of pre-eclampsia later in life.

DESIGN

Cancellation of the mandatory vitamin D fortification of margarine in 1985 created a societal experiment, with entire adjacent birth cohorts exposed or unexposed to extra vitamin D during fetal development. The Danish national medical health registries allowed the identification of pre-eclampsia cases later in life among all exposed and unexposed female individuals.

SETTING

Denmark.

SUBJECTS

Women born between June 1983 and August 1988, who gave birth to their first child at age 14·5-27·5 years (n 32 621).

RESULTS

OR (95 % CI) for pre-eclampsia among women exposed v. unexposed to extra vitamin D from fortification during fetal development was 0·86 (0·76, 0·97). Exposure to extra vitamin D was associated with further reduced odds of pre-eclampsia (0·49 (0·34, 0·72)) among current smokers, but not among former smokers and non-smokers.

CONCLUSIONS

Additional vitamin D in fetal life from food fortification seems to reduce the risk of pre-eclampsia later in life. The risk reduction may be particularly strong among women who smoke during pregnancy.

Heart rate variability and baroreceptor reflex sensitivity in early- versus late-onset preeclampsia

OBJECTIVE

To determine whether there are differences in autonomic nervous system function in early- versus late-onset preeclampsia.

METHODS

Matched case-control study. Cases were defined as singleton pregnancies with preeclampsia at < 34+0 weeks of gestation (early-onset preeclampsia) and ≥ 34+0 weeks of gestation (late-onset preeclampsia). For each case in each of the preeclampsia subgroups, three "control"uncomplicated singleton pregnancies were matched by maternal age, height, and week of gestation. Blood pressure and heart rate were measured continuously for 30 minutes in each participant. Baroreceptor reflex sensitivity (assessed using sequence technique), time and frequency domain heart rate variability measures, as SDNN, RMSSD, LFRRI, HFRRI and LF/HFRRI of R-R intervals, were compared between groups (p<0.05 significant).

RESULTS

24 women with preeclampsia (10 with early-onset and 14 with late-onset preeclampsia) and 72 controls were included in the study. SDNN, RMSSD and HFRRI were significantly higher in the late-onset preeclampsia group compared to gestational age matched controls (p = 0.033, p = 0.002 and p = 0.018, respectively). No significant differences in SDNN RMSSD and HFRRI between early-onset preeclampsia group and gestational age matched controls were observed (p = 0.304, p = 0.325 and p = 0.824, respectively). Similarly, baroreceptor reflex sensitivity was higher in late-onset preeclampsia compared to controls at ≥ 34 weeks (p = 0.037), but not different between early-onset preeclampsia compared to controls at < 34 weeks (p = 0.50).

CONCLUSIONS

Heart rate variability and baroreceptor reflex sensitivity are increased in late- but not early-onset preeclampsia compared to healthy pregnancies. This indicates a better autonomic nervous system mediated adaptation to preeclampsia related cardiovascular changes in late-onset disease.

sFlt-1/PlGF for prediction of early-onset pre-eclampsia: STEPS (Study of Early Pre-eclampsia in Spain)

OBJECTIVE

A high ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) has been linked to pre-eclampsia (PE). We evaluated the sFlt-1/PlGF ratio as a predictive marker for early-onset PE in women at risk of PE.

METHODS

This prospective, Spanish, multicenter study included pregnant women with a risk factor for PE, including intrauterine growth restriction, PE, eclampsia or hemolysis, elevated liver enzymes and low platelet count syndrome in previous pregnancy, pregestational diabetes or abnormal uterine artery Doppler. The primary objective was to show that the sFlt-1/PlGF ratio at 20, 24 and 28 weeks' gestation was predictive of early-onset PE (< 34 + 0 weeks). Serum sFlt-1 and PlGF were measured at 20, 24 and 28 weeks. Multivariate logistic regression was used to develop a predictive model.

RESULTS

A total of 819 women were enrolled, of which 729 were suitable for analysis. Of these, 78 (10.7%) women developed PE (24 early onset and 54 late onset). Median sFlt-1/PlGF ratio at 20, 24 and 28 weeks was 6.3 (interquartile range (IQR), 4.1-9.3), 4.0 (IQR, 2.6-6.3) and 3.3 (IQR, 2.0-5.9), respectively, for women who did not develop PE (controls); 14.5 (IQR, 5.5-43.7), 18.4 (IQR, 8.2-57.9) and 51.9 (IQR, 11.5-145.6) for women with early-onset PE; and 6.7 (IQR, 4.6-9.9), 4.7 (IQR, 2.8-7.2) and 6.0 (IQR, 3.8-10.5) for women with late-onset PE. Compared with early-onset PE, the sFlt-1/PlGF ratio was significantly lower in controls (P < 0.001 at each timepoint) and in women with chronic hypertension (P < 0.001 at each timepoint), gestational hypertension (P < 0.001 at each timepoint) and late-onset PE (P < 0.001 at each timepoint). A prediction model for early-onset PE was developed, which included the sFlt-1/PlGF ratio plus mean arterial pressure, being parous and previous PE, with areas under the receiver-operating characteristics curves of 0.86 (95% CI, 0.77-0.95), 0.91 (95% CI, 0.85-0.97) and 0.93 (95% CI, 0.86-0.99) at 20, 24 and 28 weeks, respectively, and was superior to models using the sFlt-1/PlGF ratio alone or uterine artery mean pulsatility index.

CONCLUSIONS

The sFlt-1/PlGF ratio can improve prediction of early-onset PE for women at risk of this condition. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Effect of Pregnancy Interval on Second Pregnancy Blood Pressure Following Prior Preeclampsia

OBJECTIVE

Preeclampsia generally occurs in first pregnancies and tends not to recur when the interpregnancy interval (IPI) is short. We hypothesized that, in women experiencing preeclampsia in their first pregnancy, the difference in mean arterial pressure (MAP) across pregnancy between their index and subsequent pregnancy would be inversely associated with the length of time between pregnancies and that the interval between pregnancies will be directly associated with the likelihood of preeclampsia recurrence.

METHODS

This was a retrospective chart review evaluating 171 women diagnosed with preeclampsia during their first pregnancy who had a subsequent pregnancy at our institution. Blood pressures were collected from each pregnancy, marking the recurrence of hypertensive disorders, including preeclampsia. Antepartum MAP was compared between pregnancies, examining differences as a function of IPI.

RESULTS

There was a significant association of IPI with the reduction in MAP between pregnancies across trimesters ( P = .04), but this reduction became smaller over time. The MAP during the third trimester decreased significantly between pregnancies across all patient groups (IPI <24 months: -5.7 mm Hg, P < .0001; IPI 24-48 months: -4.5 mm Hg, P < .0001; IPI >48 months -3.4 mm Hg, P = .03). The recurrence rate of preeclampsia did not vary significantly with IPI ( P = .21).

CONCLUSION

The IPI influences the MAP of the second pregnancy in women with prior preeclampsia. Shorter IPI is associated with a greater reduction in MAP when compared to the longer IPI. Although there was a trend toward higher preeclampsia recurrence with longer IPI, this trend did not reach statistical significance.

Immunological implications of pregnancy-induced microchimerism

Immunological identity is traditionally defined by genetically encoded antigens, with equal maternal and paternal contributions as a result of Mendelian inheritance. However, vertically transferred maternal cells also persist in individuals at very low levels throughout postnatal development. Reciprocally, mothers are seeded during pregnancy with genetically foreign fetal cells that persist long after parturition. Recent findings suggest that these microchimeric cells expressing non-inherited, familially relevant antigenic traits are not accidental 'souvenirs' of pregnancy, but are purposefully retained within mothers and their offspring to promote genetic fitness by improving the outcome of future pregnancies. In this Review, we discuss the immunological implications, benefits and potential consequences of individuals being constitutively chimeric with a biologically active 'microchiome' of genetically foreign cells.

Placental weight in the first pregnancy and risk for preeclampsia in the second pregnancy: A population-based study of 186 859 women

OBJECTIVE

To study whether placental weight in the first pregnancy is associated with preeclampsia in the second pregnancy.

STUDY DESIGN

In this population-based study, we included all women with two consecutive singleton pregnancies reported to the Medical Birth Registry of Norway during 1999-2012 (n=186 859). Placental weight in the first pregnancy was calculated as z-scores, and the distribution was divided into five groups of equal size (quintiles). We estimated crude and adjusted odds ratios with 95% confidence intervals for preeclampsia in the second pregnancy according to quintiles of placental weight z-scores in the first pregnancy. The 3rd quintile was used as the reference group.

RESULTS

Among women without preeclampsia in the first pregnancy, 1.4% (2507/177 149) developed preeclampsia in the second pregnancy. In these women, the risk for preeclampsia in the second pregnancy was associated with placental weight in the first pregnancy in both lowest (crude odds ratio (cOR) 1.30, 95% confidence interval (CI); 1.14-1.47) and highest quintile (cOR 1.20, 95% CI; 1.06-1.36). The risk associated with the highest quintile of placental weight was confined to term preeclampsia. Among women with preeclampsia in the first pregnancy, 15.7% (1522/9710) developed recurrent preeclampsia, and the risk for recurrent preeclampsia was associated with placental weight in lowest quintile in the first pregnancy (cOR 1.30, 95% CI; 1.10-1.55). Adjustment for interval between pregnancies, maternal diabetes, age, and smoking in the first pregnancy did not alter these estimates notably.

CONCLUSION

Placental weight in the first pregnancy might help to identify women who could be at risk for developing preeclampsia in a second pregnancy.

Season of Conception, Smoking, and Preeclampsia in Norway

BACKGROUND

Preeclampsia (PE) is a dangerous and unpredictable pregnancy complication. A seasonal pattern of risk would suggest that there are potentially preventable environmental contributors, but prior analyses have not adjusted for confounding by PE risk factors that are associated with season of conception.

METHODS

Seasonal effects were modeled and tested by representing each day of the year as an angle on a unit circle and using trigonometric functions of those angles in predictive models, using "harmonic analysis." We applied harmonic Cox regression to model confounder-adjusted effects of the estimated day of the year of conception on risk of PE for births from the Medical Birth Registry of Norway for deliveries between 1999 and 2009. We also examined effect measure modification by parity, latitude (region), fetal sex, and smoking.

RESULTS

In adjusted models, PE risk was related to season, with higher risk in spring conceptions and lower risk in autumn conceptions, with a risk amplitude (maximum compared with minimum) of about 20%. The pattern replicated across subpopulations defined by parity, latitude (region), fetal sex, and smoking.

CONCLUSIONS

These results suggest that there is a seasonal driver for PE, with effects that are not modified by parity, latitude, fetal sex, or smoking. https://doi.org/10.1289/EHP963.

A best practice position statement on the role of the nephrologist in the prevention and follow-up of preeclampsia: the Italian study group on kidney and pregnancy

Preeclampsia (PE) is a protean syndrome causing a transitory kidney disease, characterised by hypertension and proteinuria, ultimately reversible after delivery. Its prevalence is variously estimated, from 3 to 5% to 10% if all the related disorders, including also pregnancy-induced hypertension (PIH) and HELLP syndrome (haemolysis, increase in liver enzyme, low platelets) are included. Both nephrologists and obstetricians are involved in the management of the disease, according to different protocols, and the clinical management, as well as the role for each specialty, differs worldwide. The increased awareness of the role of chronic kidney disease in pregnancy, complicating up to 3% of pregnancies, and the knowledge that PE is associated with an increased risk for development of CKD later in life have recently increased the interest and redesigned the role of the nephrologists in this context. However, while the heterogeneous definitions of PE, its recent reclassification, an emerging role for biochemical biomarkers, the growing body of epidemiological data and the new potential therapeutic interventions lead to counsel long-term follow-up, the lack of resources for chronic patients and the increasing costs of care limit the potential for preventive actions, and suggest tailoring specific interventional strategies. The aim of the present position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature and to try to identify theoretical and pragmatic bases for an agreed management of PE in the nephrological setting, with particular attention to the prevention of the syndrome (recurrent PE, presence of baseline CKD) and to the organization of the postpartum follow-up.

Maternal rubella immunity status and pre-eclampsia

PROBLEM

To determine if maternal immune maladaptation associated with pre-eclampsia is reflected in the rubella immunity status.

METHOD OF STUDY

Incidence of pre-eclampsia was compared between rubella non-immune and immune gravidae carrying a singleton pregnancy beyond 24 weeks, taking into account maternal characteristics and reported risk factors for pre-eclampsia.

RESULTS

The 9870 (10.4%) rubella non-immune gravidae among the 95 024 in the cohort exhibited no difference in incidence of underlying medical disorders, but they were slightly but significantly older, shorter, heavier, and had more pre-eclampsia (OR 1.24, 95% CI 1.05-1.47) despite having fewer nulliparas. Regression analysis confirmed an overall association between rubella non-immunity with pre-eclampsia (aOR 1.27, 95% CI 1.06-1.54), which was related to multiparas (aOR 1.42, 95% CI 1.05-1.91) and carrying a male fetus (aOR 1.37, 95% CI 1.06-1.78).

CONCLUSION

The association between rubella non-immunity and pre-eclampsia reflects immune maladaptation in multiparas and toward a male fetus.

A Comparison of 2-Methoxyestradiol Value in Women with Severe Preeclampsia Versus Normotensive Pregnancy

INTRODUCTION

Preeclampsia is a pregnancy complication characterized by high blood pressure and proteinuria. Endothelial dysfunction is a major theory suggested as its aetiology. It is caused by anti-angiogenic condition characterized by low Vascular Endothelial Growth Factor (VEGF). An estradiol metabolite, called 2-Methoxy Estradiol (2-ME), is produced with the help of Catechol-O-Methyltransferase (COMT). This substance has an important role in VEGF expression. A 2-ME is suppressed in women with preeclampsia.

AIM

To compare 2-ME in women with severe preeclampsia and normotensive pregnancy.

MATERIALS AND METHODS

A total of 80 subjects qualified the inclusion and exclusion criteria, were divided into two groups (40 each): the severe preeclampsia and the normotensive pregnancy. Blood sample was collected and examined with the ELISA 2-ME kit (Cayman). The data were compared and calculated using Fisher-Exact test to examine 2-ME differences between the two groups.

RESULTS

Women age, parity, and gestational age showed a non significant difference between both groups. Nonetheless, the BMI before pregnancy and the history of preeclampsia in the past pregnancy showed significant differences. In this study, the 2-ME value was lower in the severe preeclampsia group compared to the normotensive.

CONCLUSION

This study concludes that 2-ME value in severe preeclampsia is lower than normotensive pregnancy. A lower 2-ME value may indicate COMT not producing enough 2-ME which in turn may cause the pre-eclampsia.

Early-onset preeclampsia appears to discourage subsequent pregnancy but the risks may be overestimated

BACKGROUND

Early-onset preeclampsia is associated with adverse maternal and perinatal outcomes. For women who consider another pregnancy after one complicated by early-onset preeclampsia, the likelihood of recurrence and the subsequent pregnancy outcome for themselves and their babies are pertinent considerations.

OBJECTIVES

The purpose of this study was to determine the subsequent pregnancy rate after a nulliparous pregnancy that was complicated by early-onset preeclampsia and among those who have a subsequent pregnancy, the risk of recurrence by gestational week, and adverse pregnancy outcomes.

STUDY DESIGN

This was a population-based record linkage cohort study. The study population included nulliparous women with a singleton pregnancy and early-onset preeclampsia (<34 weeks gestation) who gave birth in New South Wales Australia from 2001-2010 (the index birth), with follow-up data for a subsequent birth through 2012. Early-onset in the index birth was further categorized as <28 vs 28-33 weeks gestation. Subsequent pregnancy outcomes that were assessed included the pregnancy rate, preeclampsia recurrence, and maternal and perinatal morbidity and mortality rates. The risk of preeclampsia necessitating delivery at each gestational week for women who were at risk was plotted, and the net gain or loss of gestational age when comparing the index with the subsequent pregnancy was calculated.

RESULTS

Among 361,031 nulliparous women with singleton pregnancies, 1473 (0.4%) had early-onset preeclampsia. Women with early-onset preeclampsia in their first pregnancy had a lower subsequent pregnancy rate (59.7%) than women without preeclampsia (67.7%). Of the 758 women with a subsequent singleton birth, 256 (33.8%) experienced preeclampsia in the next pregnancy; 57 women (7.5%) with recurrent early-onset preeclampsia were included. Cumulative rates of preeclampsia in the subsequent pregnancy were higher at every gestation from 23 weeks gestation when the index birth was <28 weeks compared with 28-33 weeks gestation. The cumulative rate and gestation-specific risk of recurrent preeclampsia rose most steeply at 32-38 weeks gestation. Most women (94.6%) progressed to a later gestational age in their subsequent pregnancy. The median overall increase in gestational age at delivery was 6 weeks (interquartile range, 4-8); among women with recurrent preeclampsia, the median increase was 5 weeks (interquartile range, 2-7). Women with index birth <28 weeks gestation compared with 28-33 weeks gestation were more likely to deliver preterm (38.8% vs 28.7%; relative risk, 1.35; 95% confidence interval, 1.04-1.75) and have a perinatal death (4.3% vs 1.2%; relative risk, 3.46; 95% confidence interval, 1.15-10.39) at the subsequent birth, but live born infants had similar rates of severe morbidity (17.1% vs 15.0%; relative risk, 1.14; 95% confidence interval, 0.73-1.79).

CONCLUSION

Women with early-onset preeclampsia in a first pregnancy appear less likely than women without preeclampsia to have a subsequent pregnancy. Maternal and perinatal outcomes in the subsequent pregnancy are generally better than in the first; most women will not have recurrent preeclampsia, and those who do usually will give birth at a greater gestational age compared with their index birth.

VEGF-A and VEGFR1 SNPs associate with preeclampsia in a Philippine population

The vascular endothelial growth factor (VEGF) family is important for establishing normal pregnancy, and related single nucleotide polymorphisms (SNPs) are implicated in abnormal placentation and preeclampsia. We evaluated the association between preeclampsia and several VEGF SNPs among Filipinos, an ethnically distinct group with high prevalence of preeclampsia. The genotypes and allelic variants were determined in a case-control study (191 controls and 165 preeclampsia patients) through SNP analysis of VEGF-A (rs2010963, rs3025039) and VEGF-C (rs7664413) and their corresponding receptors VEGFR1 (rs722503, rs12584067, rs7335588) and VEGFR3 (rs307826) from venous blood DNA. VEGF-A rs3025039 C allele has been shown to associate with preeclampsia (odds ratio of 1.648 (1.03-2.62)), while the T allele bestowed an additive effect for the maintenance of normal, uncomplicated pregnancy and against the development of preeclampsia (odds ratio of 0.62 (0.39-0.98)). VEGFR1 rs722503 is associated with preeclampsia occurring at or after the age of 40 years. The results showed that genetic variability of VEGF-A and VEGFR1 are important in the etiology of preeclampsia among Filipinos.

Prediction and prevention of hypertensive disorders of pregnancy

The most common classifications of hypertensive disorders of pregnancy consist of chronic hypertension, gestational hypertension, preeclampsia (PE) and superimposed PE. A common final pathophysiology of PE is endothelial dysfunction. The most successful translational research model for explaining the cause-effect relationship in the genesis of PE is the angiogenic/angiostatic balance theory, involving soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF) and soluble endoglin (sEng). In a systematic review of articles on the prediction of early-onset PE using angiogenesis-related factors, we revealed that the prediction of early-onset PE in the first trimester is clinically possible, but the prediction of early-onset PE in the early third trimester might be ideal. In addition, an onset threshold or a serial approach appeared to be clinically useful for predicting the imminent onset of PE, with onset at <4 weeks after blood sampling in the second and early third trimesters, because the positive likelihood ratio was >10 and the positive predictive value was >20%. The National Institute for Health and Care Excellence guidelines state that the Triage PlGF testing and Elecsys immunoassay for the sFlt-1/PlGF ratio could help to exclude PE in women with suspected PE at 20-34 weeks of gestation. Until now, we have not found any effective therapies to prevent PE. However, low-dose aspirin treatment starting at ⩽16 weeks of gestation might be associated with a marked reduction in PE. In addition, early statin treatment might prevent the occurrence of PE. Currently, a clinical trial using pravastatin for the prevention of PE is ongoing.

Inter-pregnancy interval and risk of recurrent pre-eclampsia: systematic review and meta-analysis

BACKGROUND

Women with a history of pre-eclampsia have a higher risk of developing pre-eclampsia in subsequent pregnancies. However, the role of the inter-pregnancy interval on this association is unclear.

OBJECTIVE

To explore the effect of inter-pregnancy interval on the risk of recurrent pre-eclampsia or eclampia.

SEARCH STRATEGY

MEDLINE, EMBASE and LILACS were searched (inception to July 2015).

SELECTION CRITERIA

Cohort studies assessing the risk of recurrent pre-eclampsia in the immediate subsequent pregnancy according to different birth intervals.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed screening, data extraction, methodological and quality assessment. Meta-analysis of adjusted odds ratios (aOR) with 95 % confidence intervals (CI) was used to measure the association between various interval lengths and recurrent pre-eclampsia or eclampsia.

MAIN RESULTS

We identified 1769 articles and finally included four studies with a total of 77,561 women. The meta-analysis of two studies showed that compared to inter-pregnancy intervals of 2-4 years, the aOR for recurrent pre-eclampsia was 1.01 [95 % CI 0.95 to 1.07, I(2) 0 %] with intervals of less than 2 years and 1.10 [95 % CI 1.02 to 1.19, I(2) 0 %] with intervals longer than 4 years.

CONCLUSION

Compared to inter-pregnancy intervals of 2 to 4 years, shorter intervals are not associated with an increased risk of recurrent pre-eclampsia but longer intervals appear to increase the risk. The results of this review should be interpreted with caution as included studies are observational and thus subject to possible confounding factors.