Recurrence of preeclampsia: effects of gestational age at delivery of the first pregnancy, body mass index, paternity, and interval between births

Recurrence Risk of Pregnancy Complications in Twin and Singleton Deliveries

OBJECTIVE

 This study aimed to estimate and compare the recurrence risk of preterm birth (PTB), gestational diabetes mellitus (GDM), gestational hypertension (GH), and preeclampsia and eclampsia (PE and E) in subsequent pregnancy groups (index-subsequent) of singleton-singleton (n = 49,868), twin-singleton (n = 448), and singleton-twin (n = 723) pregnancies.

STUDY DESIGN

 Birthing individuals from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Consecutive Pregnancy Study (2002-2010) with ≥ 2 singleton or twin deliveries were examined. Adjusted relative risks (aRR) and 95% confidence intervals (CI) for recurrent PTB, GDM, GH, and PE and E were estimated using Poisson regression models with robust variance estimators.

RESULTS

 The aRR of PTB and GDM ranged from 1.4 to 5.1 and 5.2 to 22.7, respectively, with the greatest recurrence relative risk for both conditions in singleton-singleton subsequent pregnancies (PTB: aRR = 5.1 [95% CI: 4.8-5.5], GDM: aRR = 22.7 [95% CI: 20.8-24.8]). The aRR of GH and PE and E ranged from 2.8 to 7.6 and 3.2 to 9.2, respectively, with the greatest recurrence relative risk for both conditions in twin-singleton subsequent pregnancies (GH: aRR = 7.6 [95% CI: 2.8-20.5], PE and E: aRR = 9.2 [95% CI: 2.9-28.6]).

CONCLUSION

 Recurrence relative risk was increased for PTB, GDM, GH, and PE and E in all subsequent pregnancy groups, which varied in magnitude based on the birth number of the index and subsequent pregnancy. This information provides insight into risk management for subsequent pregnancies including multiples.

KEY POINTS

· Recurrence risk for all conditions is persistent in all subsequent pregnancy groups.. · The magnitude of risk varies by the presence of multiples in the index or subsequent pregnancy.. · Singleton-singleton pregnancies are at the greatest risk of PTB.. · Singleton-singleton pregnancies are at the greatest risk of GDM.. · Twin-singleton pregnancies are at the greatest risk of hypertensive disorders..

Considering pregnancies as repeated versus independent events: An empirical comparison of common approaches across selected perinatal outcomes

BACKGROUND

In population-based research, pregnancy may be a repeated event. Despite published guidance on how to address repeated pregnancies to the same individual, a variety of approaches are observed in perinatal epidemiological studies. While some of these approaches are supported by the chosen research question, others are consequences of constraints inherent to a given dataset (e.g., missing parity information). These decisions determine how appropriately a given research question can be answered and overall generalizability.

OBJECTIVE

To compare common cohort selection and analytic approaches used for perinatal epidemiological research by assessing the prevalence of two perinatal outcomes and their association with a clinical and a social independent variable STUDY DESIGN: Using vital records linked to maternal hospital discharge records for singleton births, we created four cohorts: (1) all-births (2) randomly selected one birth per individual (3) first observed birth per individual (4) primiparous-births (parity 1). Sampling of births was not conditional on cluster (i.e., we did not sample all births by a given mother, but rather sampled individual births). Study outcomes were severe maternal morbidity and preeclampsia/eclampsia, and the independent variables were self-reported race/ethnicity (as a social factor) and systemic lupus erythematosus. Comparing the four cohorts, we assessed the distribution of maternal characteristics, the prevalence of outcomes, overall and stratified by parity, and risk ratios for the associations of outcomes with independent variables. Among all-births, we then compared risk ratios from three analytic strategies: with standard inference that assumes independently sampled births to the same mother in the model, with cluster-robust inference, and adjusting for parity.

RESULTS

We observed minor differences in the population characteristics between the all-birth (N=2,736,693), random-selection, and first-observed birth cohorts (both N=2,284,660), with more substantial differences between these cohorts and the primiparous-births cohort (N=1,054,684). Outcome prevalence was consistently lowest among all-births and highest among primiparous-births (e.g., severe maternal morbidity 18.9 per 1,000 births among primiparous-births vs. 16.6 per 1,000 births among all-births). When stratified by parity, outcome prevalence was always the lowest in births of parity 2 and highest among births of parity 1 for both outcomes. Risk ratios differed for study outcomes across all four cohorts, with the most pronounced differences between the primiparous-birth cohort and other cohorts. Among all-births, robust inference minimally impacted the confidence bounds of estimates, compared to the standard inference, i.e., crude estimates (e.g., lupus-severe maternal morbidity association: 4.01, 95% CI 3.54-4.55 vs. 4.01, 95% CI 3.53-4.56 for crude estimate), while adjusting for parity slightly shifted estimates, towards the null for severe maternal morbidity and away from the null for preeclampsia/eclampsia.

CONCLUSION

Researchers should consider the alignment between the methods they use, their sampling strategy, and their research question. This could include refining the research question to better match inference possible for available data, considering alternative data sources, and appropriately noting data limitations and resulting bias, as well as the generalizability of findings. If parity is an established effect modifier, stratified results should be presented.

Pre-gestational counselling for women living with CKD: starting from the bright side

Pregnancy in women living with chronic kidney disease (CKD) was often discouraged due to the risk of adverse maternal-fetal outcomes and the progression of kidney disease. This negative attitude has changed in recent years, with greater emphasis on patient empowerment than on the imperative 'non nocere'. Although risks persist, pregnancy outcomes even in advanced CKD have significantly improved, for both the mother and the newborn. Adequate counselling can help to minimize risks and support a more conscious and informed approach to those risks that are unavoidable. Pre-conception counselling enables a woman to plan the most appropriate moment for her to try to become pregnant. Counselling is context sensitive and needs to be discussed also within an ethical framework. Classically, counselling is more focused on risks than on the probability of a successful outcome. 'Positive counselling', highlighting also the chances of a favourable outcome, can help to strengthen the patient-physician relationship, which is a powerful means of optimizing adherence and compliance. Since, due to the heterogeneity of CKD, giving exact figures in single cases is difficult and may even be impossible, a scenario-based approach may help understanding and facing favourable outcomes and adverse events. Pregnancy outcomes modulate the future life of the mother and of her baby; hence the concept of 'post partum' counselling is also introduced, discussing how pregnancy results may modulate the long-term prognosis of the mother and the child and the future pregnancies.

Clinical Analysis of Risk Factors and Perinatal Outcomes in Recurrent Pre-Eclampsia with Severe Features

To analyze the differences in risk factors and pregnancy outcomes between recurrent and initial pre-eclampsia(PE) with severe features. Data from recurrent (n = 128) and initial (n = 904) PE with severe features who terminated their pregnancy or gave birth at 20 weeks of gestation or later at the tertiary teaching hospital (Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital) from January 2016 to December 2022 were collected. Risk factors for recurrent PE with severe features and differences in pregnancy outcomes between the two groups were assessed using the chi-square test, student t-test, or nonparametric test. Independent risk factors for recurrent PE with severe features were further analyzed by logistic regression. (1) Logistic regression analysis identified 3 independent risk factors for recurrent PE with severe features: history of cesarean section, rural residence and chronic hypertension. In addition, assisted reproductive technology (ART) is an independent risk factor for initial PE with severe features; (2) The incidence of oligohydramnios, chorioamnionitis, preterm birth, stillbirth, fetal growth restriction (FGR) and abnormal umbilical blood flow was higher in the recurrent PE with severe features group than in the initial PE with severe features group(P < 0.05). In contrast, the incidence of premature rupture of membrane (PROM) and postpartum hemorrhage (PPH) was higher in the group of initial PE with severe features(P < 0.05); (3) In the recurrent PE with severe features group, gestational age(GA) of birth and birth weight were lower than those in the initial PE with severe features group(P < 0.05). Also, the incidence of mild asphyxia, the rate of neonatal intensive care unit (NICU) hospitalization, length of stay in NICU, and the rate of abandoning treatment in the recurrent PE with severe features group were higher than those in the initial PE with severe features group(P < 0.05). 3 independent risk factors was identified for recurrent PE with severe features: history of cesarean section, rural residence and chronic hypertension. Women with recurrent PE with severe features are more likely to have adverse perinatal outcomes than those with initial PE with severe features.

Association of interpregnancy interval and risk of adverse pregnancy outcomes in woman by different previous gestational ages

BACKGROUND

With an increasing proportion of multiparas, proper interpregnancy intervals (IPIs) are urgently needed. However, the association between IPIs and adverse perinatal outcomes has always been debated. This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages.

METHODS

We used individual data from China's National Maternal Near Miss Surveillance System between 2014 and 2019. Multivariable Poisson models with restricted cubic splines were used. Each adverse outcome was analyzed separately in the overall model and stratified models. The stratified models included different categories of fertility policy periods (2014-2015, 2016-2017, and 2018-2019) and infant gestational age in previous pregnancy (<28 weeks, 28-36 weeks, and ≥37 weeks).

RESULTS

There were 781,731 pregnancies enrolled in this study. A short IPI (≤6 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.63 [1.55, 1.71] for vaginal delivery [VD] and 1.10 [1.03, 1.19] for cesarean section [CS]), low Apgar scores and small for gestational age (SGA), and a decreased risk of diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. A long IPI (≥60 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.18 [1.11, 1.26] for VD and 1.39 [1.32, 1.47] for CS), placenta previa, postpartum hemorrhage, diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes. The estimated risk of preterm birth, low Apgar scores, SGA, diabetes mellitus in pregnancy, and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss.

CONCLUSION

For pregnant women with shorter or longer IPIs, more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.

Birth spacing and risk of adverse pregnancy and birth outcomes: A systematic review and dose-response meta-analysis

INTRODUCTION

The association between extreme birth spacing and adverse outcomes is controversial, and available evidence is fragmented into different classifications of birth spacing.

MATERIAL AND METHODS

We conducted a systematic review of observational studies to evaluate the association between birth spacing (i.e., interpregnancy interval and interoutcome interval) and adverse outcomes (i.e., pregnancy complications, adverse birth outcomes). Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated using a random-effects model, and the dose-response relationships were evaluated using generalized least squares trend estimation.

RESULTS

A total of 129 studies involving 46 874 843 pregnancies were included. In the general population, compared with an interpregnancy interval of 18-23 months, extreme intervals (<6 months and ≥ 60 months) were associated with an increased risk of adverse outcomes, including preterm birth, small for gestational age, low birthweight, fetal death, birth defects, early neonatal death, and premature rupture of fetal membranes (pooled OR range: 1.08-1.56; p < 0.05). The dose-response analyses further confirmed these J-shaped relationships (pnon-linear  < 0.001-0.009). Long interpregnancy interval was only associated with an increased risk of preeclampsia and gestational diabetes (pnon-linear  < 0.005 and pnon-linear  < 0.001, respectively). Similar associations were observed between interoutcome interval and risk of low birthweight and preterm birth (pnon-linear  < 0.001). Moreover, interoutcome interval of ≥60 months was associated with an increased risk of cesarean delivery (pooled OR 1.72, 95% CI 1.04-2.83). For pregnancies following preterm births, an interpregnancy interval of 9 months was not associated with an increased risk of preterm birth, according to dose-response analyses (pnon-linear  = 0.008). Based on limited evidence, we did not observe significant associations between interpregnancy interval or interoutcome interval after pregnancy losses and risk of small for gestational age, fetal death, miscarriage, or preeclampsia (pooled OR range: 0.76-1.21; p > 0.05).

CONCLUSIONS

Extreme birth spacing has extensive adverse effects on maternal and infant health. In the general population, interpregnancy interval of 18-23 months may be associated with potential benefits for both mothers and infants. For women with previous preterm birth, the optimal birth spacing may be 9 months.

Pre-eclampsia in a first pregnancy and subsequent pregnancy outcomes: a nationwide cohort study

BACKGROUND

For women whose first pregnancy was complicated by pre-eclampsia (PE), particularly if severe and requiring early birth, the risk of recurrence and maternal and neonatal outcomes at subsequent birth are important considerations.

METHODS

In this observational cohort study, all primiparous women who gave birth in Denmark between 1997 and 2016 were identified using nationwide registries. Women were stratified by whether they developed PE and followed from date of birth until subsequent birth, emigration, death or end of study (December 2016). The cumulative incidences of subsequent birth among women with versus without PE were assessed using the Aalen-Johansen estimator. Subsequent outcomes including PE recurrence and maternal and neonatal morbidity and mortality were also examined. Factors associated with subsequent birth and recurrent PE were examined using multivariable Cox regression models.

RESULTS

Among 510 615 primiparous women with singleton pregnancies, 21 683 (4.2%) developed PE, with 1819 (0.4%) being early-onset PE (birth <34 weeks). Women with PE had a lower subsequent birth rate (57.4%) compared with women without PE (61.2%), and it was considerably lower among women with early-onset PE (49.4%). Among women with PE who had a subsequent birth, the overall recurrence rate of PE was 15.8% and higher among those with early-onset PE (31.5%). The gestational age increased with a median of 3 days (IQR -5 to 14) overall and 50 days (IQR 35-67) among those with early-onset PE. Moreover, neonatal and maternal morbidity and mortality were substantially improved in a subsequent pregnancy.

CONCLUSIONS

Primiparous women with PE have a significantly lower rate of a subsequent birth than women without PE, yet the absolute difference was modest. Although the overall risk of recurrent PE is 1 in 6, maternal and neonatal morbidity and mortality at subsequent birth are substantially improved.

Hypertensive Disorders of Pregnancy: Common Clinical Conundrums

Importance

Hypertensive complications of pregnancy comprise 16% of maternal deaths in developed countries and 7.4% of deaths in the United States. Rates of preeclampsia increased 25% from 1987 to 2004, and rates of severe preeclampsia have increased 6.7-fold between 1980 and 2003.

Objective

The aim of this study was to review current and available evidence for common clinical questions regarding the management of hypertensive disorders of pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines on hypertension in pregnancy were reviewed.

Results

Severe gestational hypertension should be managed as preeclampsia with severe features. Serum uric acid levels can be useful in predicting development of superimposed preeclampsia for women with chronic hypertension. When presenting with preeclampsia with severe features before 34 weeks, expectant management should be considered only when both maternal and fetal conditions are stable. In the setting of hypertensive disorders of pregnancy, oral antihypertensive medications should be initiated when systolic blood pressure is greater than 160 mm Hg or when diastolic blood pressure is greater than 110 mm Hg, with the most ideal agents being labetalol or nifedipine. Furthermore, although risk of preeclampsia recurrence in future pregnancy is low, women with a history of preeclampsia should be managed with 81 mg aspirin daily for preeclampsia prevention.

Conclusions and Relevance

Despite the frequency with which hypertensive disorders of pregnancy are encountered clinically, situations arise frequently with limited evidence to guide providers in their management. An urgent need exists to better understand this disease to optimize outcomes for impacted patients.

Integrating Combined First Trimester Screening for Preeclampsia into Routine Ultrasound Examination

Introduction The Fetal Medicine Foundation (FMF) London has developed a first trimester screening algorithm for preeclampsia (PE), based on maternal characteristics and past risk factors, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), and placental growth factor (PlGF). The aim of this study was to determine the feasibility of integrating PE screening into routine practice.

Material and Methods All pregnancies with a fetal crown-rump length of 45 – 84 mm presenting to our ultrasound department between January 2014 and September 2020 were included in this analysis. Screening for PE was offered to singleton pregnancies only. The number of screening tests performed in the eligible population was assessed and the reasons for missed screenings identified with the help of the electronic clinical database. SPSS Statistics 25 and GraphPad version 8.0 for Windows were used for statistical analysis.

Results 6535 pregnancies were included, 4510 (69.0%) of which were screened for PE. The percentage of patients being offered PE screening increased over the years from 63.1 to 96.7% (r _s  = 0.96; p = 0.003), while the rate of screenings performed in eligible patients remained stable at a median [range] of 86.2% [78.0 – 91.8%] (p = ns). 2025 (31.0%) pregnancies were not screened for PE, 1306 (64.5%) because they were not eligible for screening. 145 (2.2%) women explicitly declined PE screening; their background risk was lower than that of women who accepted screening.

Conclusion Our study shows that integration of PE screening into the routine first trimester ultrasound scan is feasible and widely accepted by pregnant women and health care providers.

Manipulating CD4+ T Cell Pathways to Prevent Preeclampsia

Preeclampsia (PreE) is a placental disorder characterized by hypertension (HTN), proteinuria, and oxidative stress. Individuals with PreE and their children are at an increased risk of serious short- and long-term complications, such as cardiovascular disease, end-organ failure, HTN, neurodevelopmental disorders, and more. Currently, delivery is the only cure for PreE, which remains a leading cause of morbidity and mortality among pregnant individuals and neonates. There is evidence that an imbalance favoring a pro-inflammatory CD4+ T cell milieu is associated with the inadequate spiral artery remodeling and subsequent oxidative stress that prime PreE’s clinical symptoms. Immunomodulatory therapies targeting CD4+ T cell mechanisms have been investigated for other immune-mediated inflammatory diseases, and the application of these prevention tactics to PreE is promising, as we review here. These immunomodulatory therapies may, among other things, decrease tumor necrosis factor alpha (TNF-α), cytolytic natural killer cells, reduce pro-inflammatory cytokine production [e.g. interleukin (IL)-17 and IL-6], stimulate regulatory T cells (Tregs), inhibit type 1 and 17 T helper cells, prevent inappropriate dendritic cell maturation, and induce anti-inflammatory cytokine action [e.g. IL-10, Interferon gamma (IFN-γ)]. We review therapies including neutralizing monoclonal antibodies against TNF-α, IL-17, IL-6, and CD28; statins; 17-hydroxyprogesterone caproate, a synthetic hormone; adoptive exogenous Treg therapy; and endothelin-1 pathway inhibitors. Rebalancing the maternal inflammatory milieu may allow for proper spiral artery invasion, placentation, and maternal tolerance of foreign fetal/paternal antigens, thereby combatting early PreE pathogenesis.

No association between perinatal mood disorders and hypertensive pregnancies

Mental health disorders such as anxiety and/or depression are the most common mental health disorders seen among reproductive aged women and can increase during pregnancy. Many sociodemographic risk factors have been associated with anxiety and/or depression in pregnancy, which can lead to adverse maternal and infant outcomes including the risk of a hypertensive pregnancy. The current study prospectively examined self-reported anxiety, depression and stress in pregnant women without a history of fetal loss or mood disorders beginning at 20-26 weeks. At each study visit, circulating immune factors associated with perinatal mood disorders were measured in blood samples that were collected. A total of 65 women were eligible for data analysis, 26 of which had hypertensive pregnancies. There was not a significant difference in self-reported depression, anxiety or stress between hypertensive disorders of pregnancy and normotensive women. Black women were more likely to have a hypertensive pregnancy and develop a perinatal mood disorder compared to non-black women. Both the inflammatory cytokines interleukin-17 and tumor necrosis factor-alpha were increased in patients with perinatal mood disorders. However, additional research is needed in a larger sample to truly understand the relationship between these factors along with the underlying etiologies and the associated outcomes.

Association between interpregnancy interval and pregnancy complications by history of complications: a population-based cohort study

OBJECTIVE

To examine if the association between interpregnancy interval (IPI) and pregnancy complications varies by the presence or absence of previous complications.

DESIGN AND SETTING

Population-based longitudinally linked cohort study in Western Australia (WA).

PARTICIPANTS

Mothers who had their first two (n=252 368) and three (n=96 315) consecutive singleton births in WA between 1980 and 2015.

OUTCOME MEASURES

We estimated absolute risks (AR) of preeclampsia (PE) and gestational diabetes (GDM) for 3-60 months of IPI according to history of each outcome. We modelled IPI using restricted cubic splines and reported adjusted relative risk (RRs) with 95% CI at 3, 6, 12, 24, 36, 48 and 60 months, with 18 months as reference.

RESULTS

Risks of PE and GDM were 9.5%, 2.6% in first pregnancies, with recurrence rates of 19.3% and 41.5% in second pregnancy for PE and GDM, respectively. The AR of GDM ranged from 30% to 43% across the IPI range for mothers with previous GDM compared with 2%-8% for mothers without previous GDM. For mothers with no previous PE, greater risks were observed for IPIs at 3 months (RR 1.24, 95% CI 1.07 to 1.43) and 60 months (RR 1.40, 95% CI 1.29 to 1.53) compared with 18 months. There was insufficient evidence for increased risk of PE at shorter IPIs of <18 months for mothers with previous PE. Shorter IPIs of <18 months were associated with lower risk than at IPIs of 18 months for mothers with no previous GDM.

CONCLUSIONS

The associations between IPIs and risk of PE or GDM on subsequent pregnancies are modified by previous experience with these conditions. Mothers with previous complications had higher absolute, but lower RRs than mothers with no previous complications. However, IPI remains a potentially modifiable risk factor for mothers with previous complicated pregnancies.

Preeclampsia Across Pregnancies and Associated Risk Factors: Findings From a High-Risk US Birth Cohort

Background

Preeclampsia increases women's risks for maternal morbidity and future cardiovascular disease. The aim of this study was to identify opportunities for prevention by examining the association between cardiometabolic risk factors and preeclampsia across 2 pregnancies among women in a high‐risk US birth cohort.

Methods and Results

Our sample included 618 women in the Boston Birth Cohort with index and subsequent pregnancy data collected using standard protocols. We conducted log‐binomial univariate regression models to examine the association between preeclampsia in the subsequent pregnancy (defined as incident or recurrent preeclampsia) and cardiometabolic risk factors (ie, obesity, hypertension, diabetes mellitus, preterm birth, low birth weight, and gestational diabetes mellitus) diagnosed before and during the index pregnancy, and between index and subsequent pregnancies. At the subsequent pregnancy, 7% (36/540) had incident preeclampsia and 42% (33/78) had recurrent preeclampsia. Compared with women without obesity, women with obesity had greater risk of incident preeclampsia (unadjusted risk ratio [RR], 2.2 [95% CI, 1.1–4.5]) and recurrent preeclampsia (unadjusted RR, 3.1 [95% CI, 1.5–6.7]). Preindex pregnancy chronic hypertension and diabetes mellitus were associated with incident, but not recurrent, preeclampsia (hypertension unadjusted RR, 7.9 [95% CI, 4.1–15.3]; diabetes mellitus unadjusted RR, 5.2 [95% CI, 2.5–11.1]. Women with new interpregnancy hypertension versus those without had a higher risk of incident and recurrent preeclampsia (incident preeclampsia unadjusted RR, 6.1 [95% CI, 2.9–13]); recurrent preeclampsia unadjusted RR, 2.4 [95% CI, 1.5–3.9]).

Conclusions

In this diverse sample of high‐risk US women, we identified modifiable and treatable risk factors, including obesity and hypertension for the prevention of preeclampsia.

Interpregnancy interval and hypertensive disorders of pregnancy: A population-based cohort study

BACKGROUND

Despite extensive research on risk factors and mechanisms, the extent to which interpregnancy interval (IPI) affects hypertensive disorders of pregnancy in high-income countries remains unclear.

OBJECTIVES

To examine the association between IPI and hypertensive disorders of pregnancy in a high-income country setting using both within-mother and between-mother comparisons.

METHODS

A retrospective population-based cohort study was conducted among 103 909 women who delivered three or more consecutive singleton births (n = 358 046) between 1980 and 2015 in Western Australia. We used conditional Poisson regression with robust variance, matching intervals of the same mother and adjusted for factors that vary within-mother across pregnancies, to investigate the association between IPI categories (reference 18-23 months), and the risk of hypertensive disorders of pregnancy. For comparison with previous studies, we also applied unmatched Poisson regression (between-mother analysis).

RESULTS

The incidence of preeclampsia and gestational hypertension during the study period was 4%, and 2%, respectively. For the between-mother comparison, mothers with intervals of 6-11 months had lower risk of preeclampsia with adjusted relative risk (RR) 0.92 (95% confidence interval [CI] 0.85, 0.98) compared to reference category of 18-23 months. With the within-mother matched design, we estimated a larger effect of long IPI on risk of preeclampsia (RR 1.29, 95% CI 1.18, 1.42 for 60-119 months; and RR 1.30, 95% CI 1.10, 1.53 for intervals ≥120 months) compared to 18-23 months. Short IPIs were not associated with hypertensive disorders of pregnancy.

CONCLUSIONS

In our cohort, longer IPIs were associated with increased risk of preeclampsia. However, there was insufficient evidence to suggest that short IPIs (<6 months) increase the risks of hypertensive disorders of pregnancy.

Prevalence of hypertensive disorders during pregnancy in France (2010-2018): The Nationwide CONCEPTION Study

Hypertensive disorders of pregnancy (HDP) are one of the leading causes of maternal and fetal morbidity and mortality. We aimed to estimate the prevalence of each HDP in France and to study their associations. All pregnant women who delivered in France between 2010 and 2018 were included in a cohort and followed during their pregnancy and 6 weeks of postpartum. Each HDP occurring during the follow-up was identified. Prevalence of each HDP and cumulative incidence by gestational age were estimated. Incidence rate ratio (IRR) and 95% confidence interval (CI) for preeclampsia among women with preexisting or gestational hypertension (GH) were estimated using Poisson regression and adjusted for age were estimated. Between 2010 and 2018, 6 302 810 deliveries were included. HDP complicated 7.4% of pregnancies. Preeclampsia and GH complicated 2.0% and 4.2% of pregnancies, respectively. Most of preeclampsia cases occurred without a prior HDP. HELLP syndrome represented 10.4% of preeclampsia cases. Compared to nulliparous pregnancies without HDP prior preeclampsia, the age-adjusted IRR of preeclampsia was 6.2 [95% CI: 6.1-6.4] in nulliparous pregnancies with preexisting hypertension and 2.9 [95% CI: 2.8-3.0] in nulliparous pregnancies with GH. In France, HDP occurred in 7.4% of all pregnancies. Women with preexisting chronic hypertension are at high risk to present preeclampsia during pregnancy. Preeclampsia complicated 2.0% of pregnancies in France. Tailoring management of women according to the HDP is a major challenge to avoid complications related to these disorders.

Preeclampsia before 26 weeks of gestation: Obstetrical prognosis for the subsequent pregnancy

INTRODUCTION

Gestational age at delivery seems to be a risk factor of recurrence of preeclampsia. The objective of this study was to analyze adverse pregnancy outcomes and recurrence of preeclampsia during the subsequent pregnancy in women with a history of pre-eclampsia delivered before 26 weeks of gestation.

MATERIAL AND METHOD

We performed a retrospective study in two French tertiary care hospitals between 2000 and 2018. Patients with a history of pre-eclampsia delivered before 26 weeks of gestation were analyzed. Information on the immediate subsequent pregnancy was collected. Adverse composite outcome was defined as recurrent preeclampsia, HELLP syndrome, placental abruption, fetal growth restriction <3rd percentile or <10^e percentile with Doppler abnormalities, maternal death and fetal death.

RESULTS

Among the 107 patients who met the criteria, 48 were analyzed for a subsequent pregnancy. Seventeen women (35.4 %) developed an adverse composite outcome, occurring for 15 women (31.2 %) before 34 weeks. Ten women (20.8 %) developed a recurrent preeclampsia occurring for 5 women (10.4 %) before 34 weeks. We related 3 HELLP syndromes, 1 placental abruption, 9 fetal growth restrictions, 3 fetal deaths and no maternal death. Compared to baseline normotensive women, chronic hypertension was significantly associated with an increased risk of adverse composite outcome (19.3 vs 58.8 %, p-value 0.014).

CONCLUSION

In our population, preeclampsia with delivery before 26 weeks is associated with 35.4 % of adverse composite outcomes and 20.8 % of recurrent preeclampsia during the immediate subsequent pregnancy. These results justify the importance of an ongoing monitoring of these patients during subsequent pregnancy.

Determinants of pre-eclampsia among pregnant women attending perinatal care in hospitals of the Omo district, Southern Ethiopia

Pre‐eclampsia is estimated to cause 70 000 maternal death globally every year, with the majority of deaths in low‐ and middle‐income countries. In Ethiopia, pre‐eclampsia causes 16% of direct maternal deaths. Despite the high burden of disease, pre‐eclampsia remains poorly studied in low and middle‐income countries. In this study, we aimed to identify risk factors for pre‐eclampsia in pregnant women attending hospitals in the Omo district of Southern Ethiopia. Data were collected via face‐to‐face interviews. Logistic regression analysis was computed to examine the relationship between the independent variable and pre‐eclampsia. An adjusted odds ratio (AOR) with the corresponding 95% confidence interval (CI) excluding 1 in the multivariable analysis was considered to identify factors associated with pre‐eclampsia at a p‐value of <0.05. A total of 167 cases and 352 controls were included. Factors that were found to have a statistically significant association with pre‐eclampsia were primary relatives who had a history of chronic hypertension (AOR 2.1, 95% CI: 1.06‐4.21), family history of diabetes mellitus (AOR 2.35; 95% CI: 1.07‐5.20), preterm gestation (AOR = 1.56, 95% CI: 1.05‐2.32), and pre‐conception smoking exposure (AOR = 4.16, 95% CI: 1.1‐15.4). The study identified that a family history of chronic illnesses and diabetes mellitus, preterm gestation, and smoking exposure before conception were the risk factors for pre‐eclampsia. Presumably, addressing the identified risk factors may give further insight into where interventions and resources should be focused, as well as having an understanding of the burden of disease.

Management of hypertension in pregnancy

Hypertensive diseases of pregnancy remain a leading cause of maternal and neonatal morbidity and mortality. Therefore, we sought to review the management of these conditions in pregnancy. In this review we discuss the most updated definitions, different antihypertensives, delivery recommendations and overall goals of management, including their effects on uteroplacental perfusion. We also highlight different medical situations where one antihypertensive may be preferable over others.

Family history of chronic illness, preterm gestational age and smoking exposure before pregnancy increases the probability of preeclampsia in Omo district in southern Ethiopia: a case-control study

BACKGROUND

Preeclampsia is a complex syndrome that is considered a disorder specific to pregnancy. However, research indicates that diffuse maternal endothelial damage may persist after childbirth. On the other hand, women who had a history of pre-eclampsia are at an increased risk of vascular disease. Considering that the multifactorial nature of pre-eclampsia in a remote health setting, knowledge of risk factors of preeclampsia gives epidemiological significance specific to the study area. Therefore, this study aimed to identify the determinants of preeclampsia among pregnant women attending perinatal service in Omo district Hospitals in southern Ethiopia.

METHODS

An institution-based unmatched case-control study design was conducted among women visiting for perinatal service in Omo District public hospitals between February to August 2018. A total of 167 cases and 352 controls were included. Data were collected via face-to-face interviews. Bivariable and multivariable logistic regression analysis were computed to examine the effect of the independent variable on preeclampsia using Statistical Package for Social Sciences version 26 window compatible software. Variables with a p-value of less than 0.05 were considered statistically significant.

RESULTS

Factors that were found to have a statistically significant association with pre-eclampsia were primary relatives who had history of chronic hypertension (AOR 2.1, 95% CI: 1.06-4.21), family history of diabetes mellitus (AOR 2.35; 95% CI: 1.07-5.20), preterm gestation(AOR = 1.56, 95%CI, 1.05-2.32), and pre-conception smoking exposure (AOR = 4.16, 95%CI, 1.1-15.4).

CONCLUSIONS

The study identified the risk factors for pre-eclampsia. Early detection and timely intervention to manage pre-eclampsia, and obstetric care providers need to emphasize women at preterm gestation and a history of smoking before pregnancy.

Probability and outcomes of second pregnancy after HELLP syndrome in the first: A population-based registry study

INTRODUCTION

Some studies have suggested that women may avoid further pregnancies after experiencing a pregnancy affected by a hypertensive disorder. Large population-based studies are needed to better understand the outcomes of later pregnancies among women who have a history of hypertensive disorders of pregnancy. The aims of the study were to assess outcomes of the second pregnancy and second delivery rate among women experiencing Hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome in their first pregnancy.

MATERIAL AND METHODS

This population-based registry study included all women with a first delivery registered in the Medical Birth Registry of Norway from 1999 to 2014 (n = 418 897). Logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for adverse outcomes of the second delivery and the probability of no second delivery among women with HELLP syndrome in first pregnancy compared with women without HELLP syndrome. We also compared outcomes in the first and second pregnancies among women with HELLP syndrome in first.

RESULTS

HELLP syndrome occurred in 0.24% of first pregnancies (n = 1006). Among women with HELLP syndrome in their first pregnancy, adverse outcomes were substantially less frequent in the second pregnancy: preterm deliveries declined from 56.0% to 14.2%, and small for gestational age from 6.6% to 2.8%. More than 75% had no hypertensive disorder in their second pregnancy. Still, compared with women without a history of HELLP syndrome, ORs for adverse outcomes in second pregnancies were increased: preterm birth (OR 3.7, 95% CI 2.8-4.8), small for gestational age (OR 2.7, 95% CI 1.6-4.8), perinatal death (OR 3.1, 95% CI 1.4-7.0), placental abruption (OR 4.2, 95% CI 1.8-9.4) and hypertensive complication (OR 8.3, 95% CI 6.7-10.3). HELLP syndrome did not influence the probability of a second delivery.

CONCLUSIONS

Among women with HELLP syndrome in their first pregnancy, the occurrence of adverse pregnancy outcomes was substantially reduced in the second pregnancy. However, compared with unaffected women, they were still at greater risk of pregnancy complications.

Low antithrombin activity before delivery predicts subsequent hypertensive disorders in pregnancy

OBJECTIVE

To examine whether laboratory parameters can predict the onset of recurrent hypertensive disorders of pregnancy (HDP).

METHODS

A retrospective study of 257 women with consecutive deliveries at a hospital in Sapporo, Japan, between 2009 and 2017. Women were divided into four groups according to whether or not they had HDP in the first and second peripartum periods (HDP-HPD, HDP-Non, Non-HDP, Non-Non). HDP was defined as gestational hypertension and/or proteinuria. Laboratory parameters measured on the day of or 1 day before delivery were compared between peripartum-1 and peripartum-2.

RESULTS

Frequency of HDP in peripartum-2 was higher among the 24 (9.3%) women with HPD in peripartum-1 (6/24, 25.0%) than among the 233 (90.7%) women without (3/233, 1.3%) (P<0.001). In peripartum-1, women with HDP had lower median antithrombin activity than those without (74% vs 89%, P=0.021). Antithrombin activity in peripartum-1 was also lower in the HDP-HDP (67%) than in the HDP-Non (79%) group (P=0.021). Antithrombin activities of 77% or less at the first delivery predicted HDP in peripartum-1 (P<0.001) and 70% or less predicted HDP in peripartum-2 (P=0.018).

CONCLUSION

Women with HDP in peripartum-1 had a higher incidence of HDP recurrence. Low antithrombin before a first delivery might predict recurrent HDP in a second pregnancy.

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.

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.

Preterm and term preeclampsia: differences in biochemical parameter and pregnancy outcomes

OBJECTIVE

To analyze the similarities and differences in the clinical parameters, laboratory biomarkers, and pregnancy outcomes between preterm and term preeclampsia (PE).

METHODS

Data on 185 women diagnosed with PE were collected from a Jiangsu Province Hospital from January 2017 to December 2017 and analyzed. 74 (40%) patients were diagnosed with preterm PE, of which 70 (94.6%) patients with PE with severe features (PEs) and the rest with PE. 111 (60%) patients were diagnosed with term PE, of which 54 (48.6%) patients with PEs and the rest with PE.

RESULTS

Preterm PE group had significantly higher blood pressure than that of term PE, with mean delivery at gestational age of 34.3[Formula: see text]2.1 weeks for preterm PE and 39[Formula: see text]1.2 weeks for term PE. Preterm PE group was associated with previous cesarean section and PE history, fetal growth restriction (FGR), non-reassuring fetal status (NRFS), and fetal umbilical artery (UA) systolic velocity/diastolic velocity ratio (S/D R) abnormality, neonatal lower birth weight, lower APGAR score, and higher NICU transfer rate. 74.3% of pregnant women from preterm PE group had proteinuria of +2 to +4, whilst only 37.8% pregnant women from term PE group developed that condition. Liver and renal function, also serum Ca and K were significantly higher in preterm PE.

CONCLUSION

Our study found that preterm PE significantly correlated with higher incidence of PEs, neonatal morbidities, also higher liver and kidney function compared to term PE. These results may be helpful for obstetricians to make accurate quantification of risk regarding every result of antenatal check-up, and perform close follow up if any abnormalities were found on blood pressure, ultrasound, or blood tests.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Subsequent pregnancy outcome after mid-trimester termination of pregnancy for preeclampsia

BACKGROUND

In this study we determined the outcome of subsequent pregnancies after termination of pregnancy for preeclampsia, with the purpose of presenting data useful for counselling these women on future pregnancies.

STUDY DESIGN

The cohort consisted of 131 women with a history of termination of pregnancy for preeclampsia.

RESULTS

Data of 79 pregnancies were available for analysis, including 13 women with chronic hypertension and 16 women with thrombophilia. There were seven miscarriages (8.8%) and 72 ongoing pregnancies. Low-dose aspirin was prescribed for 64 women (89%). The mean gestational age at delivery was 356/7 ± 4 weeks with a mean birth weight of 2571 ± 938 g. Overall recurrence rate for preeclampsia was 29% at a mean gestational age of 32 weeks. Thirty-eight women had an uncomplicated pregnancy (53%). The women with chronic hypertension had the highest recurrence rate of 38%. Neonatal mortality was 4%.

CONCLUSION

The course of subsequent pregnancies after mid-trimester termination for preeclampsia is uncomplicated in 53% with a recurrence rate for preeclampsia of 29%. The mean gestational age at delivery was 11 weeks later and birth weight 2000 g higher than in the index pregnancy.

Confounding, causality, and confusion: the role of intermediate variables in interpreting observational studies in obstetrics

Prospective and retrospective cohorts and case-control studies are some of the most important study designs in epidemiology because, under certain assumptions, they can mimic a randomized trial when done well. These assumptions include, but are not limited to, properly accounting for 2 important sources of bias: confounding and selection bias. While not adjusting the causal association for an intermediate variable will yield an unbiased estimate of the exposure-outcome's total causal effect, it is often that obstetricians will want to adjust for an intermediate variable to assess if the intermediate is the underlying driver of the association. Such a practice must be weighed in light of the underlying research question and whether such an adjustment is necessary should be carefully considered. Gestational age is, by far, the most commonly encountered variable in obstetrics that is often mislabeled as a confounder when, in fact, it may be an intermediate. If, indeed, gestational age is an intermediate but if mistakenly labeled as a confounding variable and consequently adjusted in an analysis, the conclusions can be unexpected. The implications of this overadjustment of an intermediate as though it were a confounder can render an otherwise persuasive study downright meaningless. This commentary provides an exposition of confounding bias, collider stratification, and selection biases, with applications in obstetrics and perinatal epidemiology.

Cluster analysis to estimate the risk of preeclampsia in the high-risk Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) study

OBJECTIVES

Preeclampsia is divided into early-onset (delivery before 34 weeks of gestation) and late-onset (delivery at or after 34 weeks) subtypes, which may rise from different etiopathogenic backgrounds. Early-onset disease is associated with placental dysfunction. Late-onset disease develops predominantly due to metabolic disturbances, obesity, diabetes, lipid dysfunction, and inflammation, which affect endothelial function. Our aim was to use cluster analysis to investigate clinical factors predicting the onset and severity of preeclampsia in a cohort of women with known clinical risk factors.

METHODS

We recruited 903 pregnant women with risk factors for preeclampsia at gestational weeks 12+0-13+6. Each individual outcome diagnosis was independently verified from medical records. We applied a Bayesian clustering algorithm to classify the study participants to clusters based on their particular risk factor combination. For each cluster, we computed the risk ratio of each disease outcome, relative to the risk in the general population.

RESULTS

The risk of preeclampsia increased exponentially with respect to the number of risk factors. Our analysis revealed 25 number of clusters. Preeclampsia in a previous pregnancy (n = 138) increased the risk of preeclampsia 8.1 fold (95% confidence interval (CI) 5.7-11.2) compared to a general population of pregnant women. Having a small for gestational age infant (n = 57) in a previous pregnancy increased the risk of early-onset preeclampsia 17.5 fold (95%CI 2.1-60.5). Cluster of those two risk factors together (n = 21) increased the risk of severe preeclampsia to 23.8-fold (95%CI 5.1-60.6), intermediate onset (delivery between 34+0-36+6 weeks of gestation) to 25.1-fold (95%CI 3.1-79.9) and preterm preeclampsia (delivery before 37+0 weeks of gestation) to 16.4-fold (95%CI 2.0-52.4). Body mass index over 30 kg/m2 (n = 228) as a sole risk factor increased the risk of preeclampsia to 2.1-fold (95%CI 1.1-3.6). Together with preeclampsia in an earlier pregnancy the risk increased to 11.4 (95%CI 4.5-20.9). Chronic hypertension (n = 60) increased the risk of preeclampsia 5.3-fold (95%CI 2.4-9.8), of severe preeclampsia 22.2-fold (95%CI 9.9-41.0), and risk of early-onset preeclampsia 16.7-fold (95%CI 2.0-57.6). If a woman had chronic hypertension combined with obesity, gestational diabetes and earlier preeclampsia, the risk of term preeclampsia increased 4.8-fold (95%CI 0.1-21.7). Women with type 1 diabetes mellitus had a high risk of all subgroups of preeclampsia.

CONCLUSION

The risk of preeclampsia increases exponentially with respect to the number of risk factors. Early-onset preeclampsia and severe preeclampsia have different risk profile from term preeclampsia.

The Impact of Small for Gestational Age Births in Early and Late Preeclamptic Pregnancies for Preeclampsia Recurrence: a Cohort Study of Successive Pregnancies in Sweden

BACKGROUND

Results from uterine artery Doppler investigations suggest that the aetiology of late preeclampsia with fetal growth restriction may be more similar to the aetiology of early preeclampsia than with late preeclampsia without fetal growth restriction. We hypothesised that a small-for-gestational-age (SGA) birth in a late preeclamptic pregnancy may be associated with increased subsequent risk of early preeclampsia. We also studied effects of maternal factors on risks of preeclampsia recurrence.

METHODS

In a nation-wide Swedish cohort study of first and second consecutive single births between 1992 and 2012, we identified 22 473 mothers with preeclampsia in their first pregnancy. We calculated relative risks (RR), and 95% confidence intervals (CI), to investigate associations between subtypes of preeclampsia in the first pregnancy and risks of early (<34 weeks) and late (≥34 weeks) preeclampsia in the second pregnancy.

RESULTS

In women with a previous late preeclampsia, a co-occurring SGA birth was associated with an increased risk of subsequent early preeclampsia (adjusted RR 2.85, 95% CI 1.93, 4.20), but not of subsequent late preeclampsia. Among women with a previous early preeclampsia, a co-occurring SGA birth was not associated with increased subsequent risks of early or late preeclampsia. Interpregnancy weight gain was associated with increased risks of early and late preeclampsia in the second pregnancy.

CONCLUSIONS

Late preeclampsia combined with fetal growth restriction may be regarded as an ischaemic placental disease. Given the high absolute risk of preeclampsia recurrence, preventing weight gain may be especially important in women with previous preeclampsia.

The role of placental histopathological lesions in predicting recurrence of preeclampsia

OBJECTIVE

We aimed to study the role of placental pathology in the prediction of preeclampsia (PE) recurrence.

METHODS

The medical records and pathological placental reports of all women diagnosed with PE, during 2008-2015, were reviewed. The study population was divided according to the outcome of their subsequent pregnancy: those who did (recurrence group) or did not (no-recurrence group) develop recurrent PE. Data regarding maternal characteristics and placental maternal/fetal vascular malperfusion lesions, of the initial pregnancies, were compared. Two prediction models were generated for PE recurrence.

RESULTS

Compared to the no-recurrence group (n = 130), the recurrence group (n = 96) was characterized by lower gestational age (p < 0.001), longer inter-pregnancy interval (p = 0.012), and higher rate of severe features (p < 0.001). By logistic regression analysis composite maternal (aOR = 3.05, 95%CI 1.39-6.71, p = 0.005), fetal (aOR = 9.31, 95%CI 3.9-22.1, p < 0.001), and concurrent maternal + fetal (aOR = 13.94, 95%CI 5.08-38.21, p < 0.001), vascular malperfusion lesions were found to be independently associated with recurrence. A clinical prediction model accounted for 20.8% of PE recurrence (R²  = 0.208, AUC = 0.732), while a clinical-pathological model accounted for 34.2% of recurrence (R²  = 0.342, AUC = 0.80).

CONCLUSION

Placental maternal and fetal vascular malperfusion lesions are independently associated with increased risk for PE recurrence. A clinical-pathological prediction model for recurrence of PE is superior to a prediction model based merely on clinical factors. © 2016 John Wiley & Sons, Ltd.

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.

LMWH in the prevention of preeclampsia and fetal growth restriction in women without thrombophilia. A systematic review and meta-analysis

Placental mediated pregnancy complications such as preeclampsia and fetal growth restriction (FGR) are common, serious, and associated with increased morbidity and mortality. We conducted a systematic review and meta-analysis to determine the effect of treatment with low-molecular-weight heparins (LMWHs) for secondary prevention of these complications in non thrombophilic women. We searched the electronic databases PubMed, Scopus, and Cochrane Library for randomised controlled trials addressing this question. Five studies including 403 patients met the inclusion criteria, 68 developed preeclampsia and 118 FGR. The studies were very heterogeneous in terms of inclusion criteria, LMWH preparation, and dosage. Meta-analyses were performed using random-effect models. The overall use of LMWHs was associated with a risk reduction for preeclampsia (Relative risk (RR) 0.366; 95 % confidence interval (CI), 0.219-0.614) and FGR (RR 0.409; 95 % CI, 0.195-0.932) vs. no treatment. From the data available for analysis it appears that the use of Dalteparin is associated with a risk reduction for preeclampsia (p=0.002) and FGR (p<0.001); while Enoxaparin is associated with risk reduction for preeclampsia (p=0.013) but not for FGR (p=0.3). In spite of the small number of studies addressing the research question, and the high variability among them, our meta-analysis found a modest beneficial effect of LMWH for secondary prevention of preeclampsia and FGR. Further studies are needed to address these questions before a definite conclusion can be reached.

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.

Preeclampsia: Short-term and Long-term Implications

Preeclampsia is a hypertensive disorder that affects 4% of pregnancies and has a high risk of maternal, fetal, and neonatal morbidity and mortality, as well as long-term cardiovascular risk. Recent updates in the definition, diagnosis, and management guidelines for preeclampsia warrant review by general obstetrician-gynecologists. Screening and prevention algorithms for preeclampsia are available, but ultimately the cure remains delivery of the fetus and placenta. Close monitoring for the development and worsening of preeclampsia during pregnancy is essential to optimize both maternal and fetal/neonatal outcomes.

Persistent Maternal Cardiac Dysfunction After Preeclampsia Identifies Patients at Risk for Recurrent Preeclampsia

The purpose of our study was to assess cardiac function in nonpregnant women with previous early preeclampsia before a second pregnancy to highlight the cardiovascular pattern, which may take a risk for recurrent preeclampsia. Seventy-five normotensive patients with previous preeclampsia and 147 controls with a previous uneventful pregnancy were enrolled in a case-control study and submitted to echocardiographic examination in the nonpregnant state 12 to 18 months after the first delivery. All patients included in the study had pregnancy within 24 months from the echocardiographic examination and were followed until term. Twenty-two (29%) of the 75 patients developed recurrent preeclampsia. In the nonpregnant state, patients with recurrent preeclampsia compared with controls and nonrecurrent preeclampsia had lower stroke volume (63 ± 14 mL versus 73 ± 12 mL and 70 ± 11 mL, P<0.05), cardiac output (4.6 ± 1.2 L versus 5.3 ± 0.9 L and 5.2 ± 1.0 L, P<0.05), higher E/E' ratio (11.02 ± 3.43 versus 7.34 ± 2.11 versus 9.03 ± 3.43, P<0.05), and higher total vascular resistance (1638 ± 261 dyne · s(-1) · cm(-5) versus 1341 ± 270 dyne · s(-1) · cm(-5) and 1383 ± 261 dyne · s(-1) · cm(-5), P<0.05). Left ventricular mass index was higher in both recurrent and nonrecurrent preeclampsia compared with controls (30.0 ± 6.3 g/m(2.7) and 30.4 ± 6.8 g/m(2.7) versus 24.8 ± 5.0 g/m(2.7), P<0.05). Signs of diastolic dysfunction and different left ventricular characteristics are present in the nonpregnant state before a second pregnancy with recurrent preeclampsia. Previous preeclamptic patients with nonrecurrent preeclampsia show left ventricular structural and functional features intermediate with respect to controls and recurrent preeclampsia.

Diagnosis and Treatment of Hypertensive Pregnancy Disorders. Guideline of DGGG (S1-Level, AWMF Registry No. 015/018, December 2013)

Purpose: Official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). Hypertensive pregnancy disorders contribute significantly to perinatal as well as maternal morbidity and mortality worldwide. Also in Germany these diseases are a major course for hospitalization during pregnancy, iatrogenic preterm birth and long-term cardiovascular morbidity. Methods: This S1-guideline is the work of an interdisciplinary group of experts from a range of different professions who were commissioned by DGGG to carry out a systematic literature search of positioning injuries. Members of the participating scientific societies develop a consensus in an informal procedure. Afterwards the directorate of the scientific society approves the consensus. Recommendations: This guideline summarizes the state-of-art for classification, risk stratification, diagnostic, treatment of hypertensive pregnancy disorders.

Delivery Blood Pressure and Other First Pregnancy Risk Factors in Relation to Hypertensive Disorders in Second Pregnancies

BACKGROUND

First pregnancy characteristics and blood pressure (BP) measures may be associated with second pregnancy hypertensive disorder risk. We examined the association between first pregnancy risk factors and second pregnancy hypertensive disorders.

METHODS

Electronic medical records of nulliparas (n = 26,787) delivering at least twice in Utah (2002-2010) were used. Polychotomous logistic regression models estimated the association of first pregnancy risk factors with second pregnancy hypertensive disorders (gestational hypertension, preeclampsia, or chronic hypertension) stratified by first pregnancy hypertensive status and adjusted for second characteristics.

RESULTS

Among normotensive women in their first pregnancy, preterm birth (<34 weeks) and elevated BP at delivery admission in the first pregnancy increased odds of all incident hypertensive disorders in the second. Even borderline admission BP (either systolic or diastolic BP: 130-139 or 85-89 mm Hg, respectively) was associated with a doubling of hypertensive disorder risk in a subsequent pregnancy. First pregnancy BP was also associated with recurrence risks for hypertensive disorders, but the relation was stronger for women with gestational hypertension in their first pregnancy with more than 2-fold elevated risk across all BP categories (odds ratios range: 2.32-12.6). However, the majority of women (75%) with a hypertensive disorder in the first pregnancy do not repeat this outcome in the second pregnancy.

CONCLUSION

Delivery admission BP of a first pregnancy was strongly related to hypertensive disorder incidence and recurrence in the subsequent pregnancy. Although crude, these measures may prove useful as a predictor of long-term maternal health and future pregnancy risk.

Placental abruption and subsequent risk of pre-eclampsia: a population-based case-control study

BACKGROUND

Pre-eclampsia and placental abruption may share a common pathophysiologic mechanism, namely, uteroplacental ischaemia. The aim of this study was to investigate the association between placental abruption and risk of pre-eclampsia in a subsequent pregnancy, and to determine whether the association differs by the gestational age at the time of abruption.

METHODS

A nested case-control study among multiparous women in the Medical Birth Register of Finland from 1996-2010 was conducted. Cases of pre-eclampsia (n = 6487) and frequency matched controls (n = 25,948) were linked to the Hospital Discharge Registry to ascertain data on prior abruption. Abruption was categorised as preterm (<37 weeks) or term (≥37 weeks) based on the gestational age at delivery. We fit logistic regression models to evaluate the associations between abruption and the odds of pre-eclampsia in the subsequent pregnancy before and after adjusting for potential confounders.

RESULTS

Preterm abruption was associated with over a twofold increase in risk of pre-eclampsia [odds ratio (OR) 2.2, 95% confidence interval (CI) 1.5, 3.3] in a subsequent pregnancy. In contrast, term abruption was not associated with pre-eclampsia (OR 1.1, 95% CI 0.7, 1.7). The association between preterm abruption and pre-eclampsia was further elevated among women with a history of pre-eclampsia. Associations with preterm abruption were also strengthened when the outcome was pre-eclampsia with early delivery (<34 weeks).

CONCLUSIONS

These findings suggest that placental abruption in a prior pregnancy is associated with a different risk profile of pre-eclampsia based on the gestational age of the abruption-affected pregnancy.

Prior cesarean section is associated with increased preeclampsia risk in a subsequent pregnancy

Background

To evaluate the impact of a prior cesarean section on preeclampsia risk in a subsequent pregnancy.

Methods

Study data were collected from the Korea National Health Insurance Claims Database of the Health Insurance Review and Assessment Service for 2006–2010. Patients who had their first delivery in 2006 and subsequent delivery between 2007 and 2010 in Korea were enrolled. The overall incidence of preeclampsia during the second pregnancy was estimated and to evaluate the risk of preeclampsia in the second pregnancy, a model of multivariate logistic regression analysis was performed with preeclampsia as the final outcome

Results

The risk of preeclampsia in any pregnancy was 2.17%; the risk in the first pregnancy was 2.76%, and that in the second pregnancy was 1.15%. During the second pregnancy, the risk of preeclampsia was 13.30% for women who had developed preeclampsia in their first pregnancy and 0.85% for those who had not. In the entire population, prior cesarean section was associated with preeclampsia risk in their subsequent pregnancy (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.13–1.41). Among women with and without preeclampsia in their first pregnancy, a prior cesarean section was associated with preeclampsia risk in their second pregnancy (OR, 1.35; 95% CI, 1.09–1.67; OR, 1.23; 95% CI, 1.08–1.40, respectively).

Conclusions

Our study showed that cesarean section in a first pregnancy was associated with increased preeclampsia risk in the second pregnancy. These results provide physicians with a preeclampsia risk evaluation method for a second pregnancy that they may aid counseling in patients.

A KIR B centromeric region present in Africans but not Europeans protects pregnant women from pre-eclampsia

In sub-Saharan Africans, maternal mortality is unacceptably high, with >400 deaths per 100,000 births compared with <10 deaths per 100,000 births in Europeans. One-third of the deaths are caused by pre-eclampsia, a syndrome arising from defective placentation. Controlling placentation are maternal natural killer (NK) cells that use killer-cell immunoglobulin-like receptor (KIR) to recognize the fetal HLA-C molecules on invading trophoblast. We analyzed genetic polymorphisms of maternal KIR and fetal HLA-C in 484 normal and 254 pre-eclamptic pregnancies at Mulago Hospital, Kampala, Uganda. The combination of maternal KIR AA genotypes and fetal HLA-C alleles encoding the C2 epitope associates with pre-eclampsia [P = 0.0318, odds ratio (OR) = 1.49]. The KIR genes associated with protection are located in centromeric KIR B regions that are unique to sub-Saharan African populations and contain the KIR2DS5 and KIR2DL1 genes (P = 0.0095, OR = 0.59). By contrast, telomeric KIR B genes protect Europeans against pre-eclampsia. Thus, different KIR B regions protect sub-Saharan Africans and Europeans from pre-eclampsia, whereas in both populations, the KIR AA genotype is a risk factor for the syndrome. These results emphasize the importance of undertaking genetic studies of pregnancy disorders in African populations with the potential to provide biological insights not available from studies restricted to European populations.

Risk factors differ between recurrent and incident preeclampsia: a hospital-based cohort study

PURPOSE

To examine whether risk factors, including prepregnancy body mass index (BMI), differ between recurrent and incident preeclampsia.

METHODS

Data included electronic medical records of nulliparas (n = 26,613) delivering 2 times or more in Utah (2002-2010). Modified Poisson regression models were used to examine (1) adjusted relative risks (RR) of preeclampsia and 95% confidence intervals (CI) associated with prepregnancy BMI; (2) maternal risk factor differences between incident and recurrent preeclampsia among primiparous women.

RESULTS

In the first pregnancy, compared with normal weight women (BMI: 18.5-24.9), preeclampsia risks for overweight (BMI: 25-29.9), obese class I (BMI: 30-34.9), and obese class II/III (BMI: ≥ 35) women were 1.82 (95% CI = 1.60-2.06), 2.10 (95% CI = 1.76-2.50), and 2.84 (95% CI = 2.32-3.47), respectively, whereas second pregnancy-incident preeclampsia risks were 1.66 (95% CI = 1.27-2.16), 2.31 (95% CI = 1.67-3.20), and 4.29 (95% CI = 3.16-5.82), respectively. Recurrent preeclampsia risks associated with BMI were highest among obese class I women (RR = 1.60; 95% CI = 1.06-2.42) without increasing in a dose-response manner. Nonwhite women had higher recurrence risk than white women (RR = 1.70; 95% CI = 1.16-2.50), whereas second pregnancy-incident preeclampsia risk did not differ by race.

CONCLUSION

Prepregnancy BMI appeared to have stronger associations with risk of incident preeclampsia either in the first or second pregnancy, than with recurrence risk. Nonwhite women had higher recurrence risk.

Pregnancy, parturition and preeclampsia in women of African ancestry

Maternal and associated neonatal mortality rates in sub-Saharan Africa remain unacceptably high. In Mulago Hospital (Kampala, Uganda), 2 major causes of maternal death are preeclampsia and obstructed labor and their complications, conditions occurring at the extremes of the birthweight spectrum, a situation encapsulated as the obstetric dilemma. We have questioned whether the prevalence of these disorders occurs more frequently in indigenous African women and those with African ancestry elsewhere in the world by reviewing available literature. We conclude that these women are at greater risk of preeclampsia than other racial groups. At least part of this susceptibility seems independent of socioeconomic status and likely is due to biological or genetic factors. Evidence for a genetic contribution to preeclampsia is discussed. We go on to propose that the obstetric dilemma in humans is responsible for this situation and discuss how parturition and birthweight are subject to stabilizing selection. Other data we present also suggest that there are particularly strong evolutionary selective pressures operating during pregnancy and delivery in Africans. There is much greater genetic diversity and less linkage disequilibrium in Africa, and the genes responsible for regulating birthweight and placentation may therefore be easier to define than in non-African cohorts. Inclusion of African women into research on preeclampsia is an essential component in tackling this major disparity of maternal health.

Prediction of recurrence of hypertensive disorders of pregnancy in the term period, a retrospective cohort study

OBJECTIVES

To assess the recurrence risk of term hypertensive disease of pregnancy and to determine which potential risk factors are predictive of recurrence.

STUDY DESIGN

We performed a retrospective cohort study in two secondary and one tertiary care hospitals in the Netherlands. We identified women with a hypertensive disorder in the index pregnancy and delivery after 37weeks of gestation between January 2000 and December 2002. Data were extracted from medical files and women were approached for additional information on subsequent pregnancies. Adverse outcome was defined as recurrence of a hypertensive disorder in the next subsequent pregnancy.

MAIN OUTCOME MEASURES

The absolute risk of recurrence and a prediction model containing demographic and clinical factors predictive of recurrence.

RESULTS

We identified 638 women for potential inclusion, of whom 503 could be contacted. Of these women, 312 (62%) had a subsequent pregnancy. Hypertensive disorders recurred in 120 (38%, 95% CI 33-44) women, of whom 15 (5%, 95% CI 3-7) delivered preterm. Women undergoing recurrence were more at risk to develop chronic hypertension after pregnancy (35% versus 16%, OR 2.8, 95% CI 1.5-5.3). Body mass index, non-White European origin, chronic hypertension, maximum diastolic blood pressure, no use of anticonvulsive medication and interpregnancy interval were predictors for recurrence.

CONCLUSIONS

Women with hypertensive disorders and term delivery have a substantial chance of recurrence, but a small risk of preterm delivery. A number of predictors for recurrence could be identified and women with a recurrence more often developed chronic hypertension.

Epidemiology of ischemic placental disease: a focus on preterm gestations

Preeclampsia, placental abruption, and intrauterine growth restriction (IUGR) have collectively been termed ischemic placental disease (IPD) due to a suspected common biological pathway involving poor placentation in early pregnancy and subsequent placental insufficiency. Despite decades of research, the etiologies of these conditions remain largely unknown and preventive and therapeutic strategies are lacking. It has been suggested that the underpinnings of IPD lie primarily in preterm gestations and that classification of these conditions based on the gestational age at onset will facilitate etiologic research. The purpose of this review is to describe our current knowledge regarding the risk factors, co-occurrence, and recurrence of the conditions of IPD with a specific focus on the preterm gestational window.