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

Comparing the severity of second preeclampsia with first preeclampsia: a multicenter retrospective longitudinal cohort study

OBJECTIVE

Compare the clinical severity of second preeclampsia with the first preeclampsia.

METHODS

This retrospective longitudinal cohort study was conducted in three teaching hospitals in Guangzhou, where there were a total of 296 405 deliveries between 2010 and 2021. Two consecutive singleton deliveries complicated with preeclampsia were included. Clinical features, laboratory results within 1 week before delivery, and maternal and neonatal outcomes of both deliveries were collected. Univariate analyses were made using paired Wilcoxon tests and McNemar tests. Multivariable logistic regression and generalized linear models were performed to assess the association of adverse maternal and neonatal outcomes with second preeclampsia.

RESULTS

A total of 151 women were included in the study. The mean maternal age was 28 and 33 years for the first and second deliveries, respectively. The proportion of preventive acetylsalicylic acid use was 4.6% for the first delivery and 15.2% for the second delivery. No significant differences were observed in terms of blood pressure on admission, gestational weeks of admission and delivery, application of perinatal antihypertensive agents, rates of preterm delivery, and severe features between the two occurrences. However, the rates of heart disease, edema, and admission to the ICU were lower, and hospital stays were shorter in the second preeclampsia compared with the first preeclampsia. Sensitivity analysis conducted among women who did not use preventive acetylsalicylic acid yielded similar results. After adjusting for potential confounding variables, the occurrence of second preeclampsia was associated with significantly decreased risks of heart disease, edema, complications, and admission to the NICU, with odds ratios ranging between 0.157 and 0.336.

CONCLUSION

Contrary to expectations, the second preeclampsia did not exhibit worse manifestations or outcomes to the first occurrence. In fact, some clinical features and outcomes appeared to be better in the second preeclampsia.

Fear of childbirth prolongs interpregnancy interval: A nationwide register-based quantile logistic regression analysis

Introduction

It is not well studied how fear of childbirth (FOC) influences the interpregnancy interval (IPI). Thus, we aimed to analyze the association between FOC and the length of the IPI.

Methods

All women having their first and second pregnancies during the study period (2004-2018) were gathered from the Finnish Medical Birth Register. A logistic regression model was used to assess the association between the FOC and subsequent length of the IPI. The length of the IPI was assessed separately for women with FOC in the first pregnancy, and for women who developed the FOC in the second pregnancy. IPIs with a length in the lower quartal were considered short IPIs, and length in the upper quartal as long IPIs. Adjusted odds ratios (aOR) with 95% CIs were compared between the groups.

Results

A total of 52 709 women with short IPI (<1.05 years), 105 604 women with normal IPI, and 52 889 women with long IPI (>2.57 years) were included. A total of 3606 women had FOC in the first pregnancy, and a total of 11 473 had their first FOC diagnosis in the second pregnancy. Women with FOC in the first pregnancy had lower odds for short IPI (aOR 0.88, CI 0.81-0.95) and higher odds for long IPI (aOR 1.30, CI 1.21-1.40). Women with the first FOC diagnosis in the second pregnancy had higher odds for long IPI (aOR 1.68, CI 1.61-1.75), When only vaginal deliveries in the first pregnancy were included, women with FOC in the second pregnancy had lower odds for long IPI (aOR 0.71, CI 0.66-0.75) and higher odds for long IPI (aOR 1.52, CI 1.41-1.62), when only cesarean section was included.

Conclusion

The main finding of this study was that women with FOC had notably higher odds for long IPI. The etiologic and background factors behind FOC should be better recognized and prevented, and FOC should not only be considered as a complicating factor for pregnancy and delivery but also a factor that strongly affects the desire of women to get pregnant again.

Association of interpregnancy interval with adverse pregnancy outcomes according to the outcomes of the preceding pregnancy: a longitudinal study with 4.7 million live births from Brazil

Background

Earlier studies have proposed a link between the Interpregnancy Interval (IPI) and unfavorable birth outcomes. However, it remains unclear if the outcomes of previous births could affect this relationship. We aimed to investigate whether the occurrence of adverse outcomes-small for gestational age (SGA), preterm birth (PTB), and low birth weight (LBW)-at the immediately preceding pregnancy could alter the association between IPI and the same outcomes at the subsequent pregnancy.

Methods

We used a population-based linked cohort from Brazil (2001-2015). IPI was measured as the difference, in months, between the preceding birth and subsequent conception. Outcomes included SGA (<10th birthweight percentile for gestational age and sex), LBW (<2500 g), and PTB (gestational age <37 weeks). We calculated risk ratios (RRs), using the IPI of 18-22 months as the reference IPI category, we also stratified by the number of adverse birth outcomes at the preceding pregnancy.

Findings

Among 4,788,279 births from 3,804,152 mothers, absolute risks for subsequent SGA, PTB, and LBW were higher for women with more adverse outcomes in the preceding delivery. The RR of SGA and LBW for IPIs <6 months were greater for women without previous adverse outcomes (SGA: 1.44 [95% Confidence Interval (CI): 1.41-1.46]; LBW: 1.49 [1.45-1.52]) compared to those with three previous adverse outcomes (SGA: 1.20 [1.10-1.29]; LBW: 1.24 [1.15-1.33]). IPIs ≥120 months were associated with greater increases in risk for LBW and PTB among women without previous birth outcomes (LBW: 1.59; [1.53-1.65]; PTB: 2.45 [2.39-2.52]) compared to women with three adverse outcomes at the index birth (LBW: 0.92 [0.78-1.06]; PTB: 1.66 [1.44-1.88]).

Interpretation

Our study suggests that women with prior adverse outcomes may have higher risks for adverse birth outcomes in subsequent pregnancies. However, risk changes due to differences in IPI length seem to have a lesser impact compared to women without a prior event. Considering maternal obstetric history is essential in birth spacing counseling.

Funding

Wellcome Trust225925/Z/22/Z.

Development, validation, and clinical utility of a risk prediction model for recurrent preeclampsia

OBJECTIVES

We aim to establish a predictive model for recurrent preeclampsia.

METHODS

A retrospective review of medical records from three hospitals between 2010 and 2021 was conducted. The study included women who had two consecutive singleton deliveries at the same hospital, with the first delivery complicated by preeclampsia. A multivariable logistic regression model was constructed using a training cohort, and subsequently cross-validated and tested using an independent cohort. The model's performance was assessed in terms of discrimination and calibration, and its clinical utility was evaluated using decision curve analysis (DCA).

RESULTS

Among 296 405 deliveries, 694 women met the inclusion criteria, with 151 (21.8%) experiencing recurrent preeclampsia. The predictive model incorporated 10 risk factors from previous preeclampsia, including gestational weeks with elevated blood pressure, gestational diabetes mellitus (GDM), pericardial effusion, heart failure, limb edema, serum creatinine, white blood cell count, low platelet counts within one week before delivery, SBP on the first postpartum day, and postpartum antihypertensive use. Additionally, one risk factor from the index pregnancy was included, which was antihypertensive use before 20 weeks. The model demonstrated better discrimination, calibration, and a net benefit across a wide range of recurrent preeclampsia risk thresholds. Furthermore, the model has been translated into a clinical risk calculator, enabling clinicians to calculate individualized risks of recurrent preeclampsia.

CONCLUSION

Our study demonstrates that a predictive tool utilizing routine clinical and laboratory factors can accurately estimate the risk of recurrent preeclampsia. This predictive model has the potential to facilitate shared decision-making by providing personalized and risk-stratified care.

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.

Association between inter-pregnancy interval and risk of adverse birth outcomes in subsequent pregnancy: A retrospective study from Jordan

BACKGROUND

Adverse birth outcomes, such as preterm birth and low birth weight (LBW), are leading causes of neonatal morbidity and mortality. In this study, we aimed to estimate the association between inter-pregnancy interval (IPI) and the risks of adverse birth outcomes in a subsequent pregnancy.

METHODS

We conducted a retrospective analysis involving 630 mothers who delivered a singleton live infant at a leading tertiary hospital in northern Jordan from March to August 2021. Outcome variables were preterm birth (<37 weeks of gestation) and LBW (<2.5 kg). Using multivariable logistic regression, the association between IPI and these two adverse birth outcomes was investigated.

RESULTS

The rates of preterm birth and LBW were 12.4% and 16.8%, respectively. Compared with an optimal IPI (24-36 months), a short IPI (<24 months) was positively associated with preterm birth (aOR: 4.09; 95% CI: 1.48-6.55) and LBW (aOR: 3.58; 95% CI: 1.57-5.15). Infants conceived after a long IPI (≥ 60 months) had increased odds of preterm birth (aOR: 3.78; 95% CI: 1.12-5.78) and LBW (aOR: 2.65; 95% CI: 1.67-4.03). Preterm delivery was also significantly associated with the mother's age (aOR: 1.10; 95% CI: 1.04-1.17), history of multiple cesarean births (aOR: 2.67; 95% CI: 1.14-4.29), prolonged rupture of membranes (aOR: 2.46; 95% CI: 1.10-5.52), and perinatal death (aOR: 3.42; 95% CI: 1.10-5.49). A mother's history of prior LBW (aOR: 4.39; 95% CI: 1.08-6.80), hypertensive disorders (aOR: 1.95; 95% CI: 1.03-3.89), and multiple cesarean births (aOR: 4.35; 95% CI: 2.10-6.99) was associated with LBW.

CONCLUSIONS

Both short and long IPIs were related to preterm delivery and LBW. Optimal birth spacing is recommended to improve birth outcomes and must be considered when designing effective family planning programs.

The influence of birth outcomes and pregnancy complications on interpregnancy interval: a quantile regression analysis

PURPOSE

To ascertain whether adverse pregnancy outcomes at first pregnancy influence subsequent interpregnancy intervals (IPIs) and whether the size of this effect varies with IPI distribution METHODS: We included 251,892 mothers who gave birth to their first two singletons in Western Australia, from 1980 to 2015. Using quantile regression, we investigated whether gestational diabetes, hypertension, or preeclampsia in the first pregnancy influenced IPI to subsequent pregnancy and whether effects were consistent across the IPI distribution. We considered intervals at the 25th centile of the distribution as 'short' and the 75th centile as 'long'.

RESULTS

The average IPI was 26.6 mo. It was 0.56 mo (95% CI: 0.25-0.88 mo) and 1.12 mo (95% CI: 0.56 - 1.68 mo) longer after preeclampsia, and gestational hypertension respectively. There was insufficient evidence to suggest that the association between previous pregnancy complications and IPI differed by the extent of the interval. However, associations with marital status, race/ethnicity and stillbirth contributed to either shortening or prolonging IPIs differently across the distribution of IPI.

CONCLUSION

Mothers with preeclampsia and gestational hypertension had slightly longer subsequent IPIs than mothers whose pregnancies were not complicated by these conditions. However, the extent of the delay was small (<2 mo).

Hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy (HDP) are one of the most commonly occurring complications of pregnancy and include chronic hypertension, gestational hypertension, and pre-eclampsia. New developments in early pregnancy screening to identify women at high risk for pre-eclampsia combined with targeted aspirin prophylaxis could greatly reduce the number of affected pregnancies. Furthermore, recent advances in the diagnosis of pre-eclampsia, such as placental growth factor based testing, have been shown to improve the identification of those pregnancies at highest risk of severe complications. Evidence from trials has refined the target blood pressure and timing of delivery to manage chronic hypertension and pre-eclampsia with non-severe features, respectively. Importantly, a wealth of epidemiological data now links HDP to future cardiovascular disease and diabetes decades after an affected pregnancy. This review discusses the current guidelines and research data on the prevention, diagnosis, management, and postnatal follow-up of HDP. It also discusses the gap in knowledge regarding the long term risks for cardiovascular disease following HDP and illustrates the importance of improving adherence to postnatal guidelines to monitor hypertension and the need for more research focused on primary prevention of future cardiovascular disease in women identified as being at high risk because of HDP.

A Prospective Study to Determine the Predictive Ability of HDP-Gestosis Score for the Development of Pre-eclampsia

Background

HDP-gestosis score is a risk scoring system (score 1-3) for the development of pre-eclampsia. When a pregnant woman's total score is equal to or greater than 3, she is labelled as "at risk for pre-eclampsia" and is managed accordingly.

Objectives

To determine the sensitivity, specificity, Positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of HDP-gestosis score for predicting pre-eclampsia.

Methods

This prospective study included 473 pregnant women who presented at the department of Obstetrics and Gynaecology, from June 2020 to December 2021. After 20 weeks of pregnancy, the patients were assessed for the development of pre-eclampsia. Details of age, gravida, obstetric history, menstrual cycle regularity, polycystic ovarian disease history, duration of marriage, parity, past medical and surgical intervention, previous/present medication, and family history were taken. Gestosis score was calculated and classified into mild (score of 1), moderate (score of 2) and high risk (score of ≥ 3) for the development of Pre-eclampsia (PE). Sensitivity, Specificity, PPV, NPV and diagnostic accuracy of HDP-gestosis score for predicting the development of PE were determined.

Results

The mean age, gestational age, and BMI of the women were 28.4 ± 6.8 years, 11.5 ± 2.04 weeks, and 24.5 ± 3.7 kg/m^2, respectively. The gestosis score was 2 in 43.13% of the participants, 1 in 42.28%, and ≥ 3 in 14.59% of the women. PE developed in 15.01% (n = 71) participants. The Sensitivity, Specificity, PPV, NPV, and Diagnostic accuracy of HDP-gestosis score for predicting PE were 83.1%, 97.51%, 85.51%, 97.03% and 95.35%, respectively.

Conclusion

Gestosis score is a novel early marker for prediction of the development of PE allowing for a prompt management for the patients, thereby curbing the adverse consequences.

Interpregnancy interval and maternal and neonatal morbidity: a nationwide cohort study

This study aimed to assess the association between interpregnancy interval (IPI)-the time from childbirth to conception of the next pregnancy-and maternal and neonatal morbidity. The World Health Organization (WHO) currently recommends an IPI of at least 24 months after a live birth to reduce adverse birth outcomes. However, assessing the relationship between IPI and perinatal outcome is complicated by confounding factors. We conducted a nationwide population-based cohort study using Swedish registry data, allowing for adjustment of maternal characteristics and health at first birth. The study population consisted of all women with a singleton, live, and vaginal first birth with a second singleton birth within five years during 1997-2017, covering 327,912 women and 655,824 neonates. IPI was grouped into six-month intervals with 24-29 months as the reference. The association between IPI and morbidity was examined using multivariate logistic regression. For women having a vaginal delivery at their first birth, intervals < 24-29 months were associated with decreased maternal morbidity and unaffected neonatal morbidity. Intervals > 24-29 months were associated with increased maternal and neonatal morbidity. Our findings question the relevance of WHO's recommendation of an IPI of at least 24 months in a high-income country.

Weight gain during pregnancy: A narrative review on the recent evidences

Gestational weight gain is necessary for the normal fetus development, in fact a series of studies have evidenced that both low and excessive gestational weight gain is associated with negative fetal-neonatal outcomes. So, evidences on the optimal gestational weight gain across the ranges of the pre-pregnancy maternal body mass index are necessary. In this context, while for normal weight and underweight the recommendations of IOM are clearly stated and supported by well designed and conducted clinical studies, those for the obese pregnant women are even today debated. Pre-pregnancy obesity is associated with high risk to develop hypertension, gestational diabetes, cesarean section and high birth weight. The Institute of Medicine guidelines, in 2009, recommended that women with obesity gain 11-20 lb at a rate of 0.5 lb/week during the second and third trimesters of pregnancy. Successively, taking into account a series of meta-analysis, the American College of Obstetricians and Gynecologists emphasized that the IOM weight gain targets for obese pregnant women are too high. However the high risk to have babies small for gestational age, related to a low weight gain or a losing of weight during pregnancy, has also been demonstrated. More recent studies have taken into consideration the maternal and fetal outcomes of obese pregnant women with different obesity class (I,II,III) and different weight gain during pregnancy. The analysis of these studies, discussed in this narrative review, show that the appropriate gestational weight gain should be personalized considering the three obesity class; furthermore both an upper and lower limit of gestational weight gain should be reconsidered in order to prevent the negative maternal and fetal outcomes in these women.

Hypertension in Pregnancy: Diagnosis, Blood Pressure Goals, and Pharmacotherapy: A Scientific Statement From the American Heart Association

Hypertensive disorders of pregnancy (HDP) remain one of the major causes of pregnancy-related maternal and fetal morbidity and mortality worldwide. Affected women are also at increased risk for cardiovascular disease later in life, independently of traditional cardiovascular disease risks. Despite the immediate and long-term cardiovascular disease risks, recommendations for diagnosis and treatment of HDP in the United States have changed little, if at all, over past decades, unlike hypertension guidelines for the general population. The reasons for this approach include the question of benefit from normalization of blood pressure treatment for pregnant women, coupled with theoretical concerns for fetal well-being from a reduction in utero-placental perfusion and in utero exposure to antihypertensive medication. This report is based on a review of current literature and includes normal physiological changes in pregnancy that may affect clinical presentation of HDP; HDP epidemiology and the immediate and long-term sequelae of HDP; the pathophysiology of preeclampsia, an HDP commonly associated with proteinuria and increasingly recognized as a heterogeneous disease with different clinical phenotypes and likely distinct pathological mechanisms; a critical overview of current national and international HDP guidelines; emerging evidence that reducing blood pressure treatment goals in pregnancy may reduce maternal severe hypertension without increasing the risk of pregnancy loss, high-level neonatal care, or overall maternal complications; and the increasingly recognized morbidity associated with postpartum hypertension/preeclampsia. Finally, we discuss the future of research in the field and the pressing need to study socioeconomic and biological factors that may contribute to racial and ethnic maternal health care disparities.

Annual body mass index gain and risk of hypertensive disorders of pregnancy in a subsequent pregnancy

Weight gain during interpregnancy period is related to hypertensive disorders of pregnancy (HDP). However, in interpregnancy care/counseling, the unpredictability of the timing of the next conception and the difficulties in preventing age-related body weight gain must be considered while setting weight management goals. Therefore, we suggest considering the annual change in the body mass index (BMI). This study aimed to clarify the association between annual BMI changes during the interpregnancy period and HDP risk in subsequent pregnancies. A multicenter retrospective study of data from 2009 to 2019 examined the adjusted odds ratio (aOR) of HDP in subsequent pregnancies. The aORs in several annual BMI change categories were also calculated in the subgroups classified by HDP occurrence in the index pregnancy. This study included 1,746 pregnant women. A history of HDP (aOR, 16.76; 95% confidence interval [CI], 9.62 − 29.22), and annual BMI gain (aOR, 2.30; 95% CI, 1.76 − 3.01) were independent risk factors for HDP in subsequent pregnancies. An annual BMI increase of ≥ 1.0 kg/m²/year was related to HDP development in subsequent pregnancies for women without a history of HDP. This study provides data as a basis for interpregnancy care/counseling, but further research is necessary to validate our findings and confirm this relationship.

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.

The interval between births and the risk of recurrent preeclampsia among predominantly high risk women in urban tertiary care center

INTRODUCTION

Women with a history of preeclampsia have a higher risk of recurrent preeclampsia. This study sought to ascertain the relationship between the interbirth interval and the risk of recurrent preeclampsia and difference in angiogenic markers between the two groups.

METHODS

Data was collected from an ongoing cohort study of women with hypertensive disorders of pregnancy (HDP) enrolled at the admission to the labor and delivery floor. From this dataset, multigravida women with a prior diagnosis of preeclampsia were identified and compared to women with no prior history of preeclampsia.

RESULTS

Of the 375 women with HDP who were predominantly African American, 245 were multigravida and 44 (18.0%) had a prior history of preeclampsia. Women with prior preeclampsia had an earlier gestational age of delivery, higher rates of preterm delivery and a higher incidence of preeclampsia with severe features (56.8% vs 29.8%) in the index pregnancy (p-values ≤ 0.001) than those without. The median number of years between history of preeclampsia in previous pregnancy and current pregnancy was 6 years (IQR 3, 8). Among patients with a prior history of preeclampsia, the interbirth interval was not associated with severe preeclampsia (p = 0.60) and there was no difference in angiogenic factors between patients with a prior history of preeclampsia compared to those without.

CONCLUSIONS

In this study, the duration of the interbirth interval was not identified as a risk factor of developing severe preeclampsia in a subsequent pregnancy and angiogenic factors are not a reflection of maternal predisposition to recurrent preeclampsia.

Individual and Obstetric Risk Factors of Preeclampsia among Singleton Pregnancy in Hospitals of Southern Ethiopia

Background

Preeclampsia is the second most common problem that causes maternal morbidity and complication in low-income countries. In contrast to death due to other direct causes, preeclampsia-related death is appeared to be connected with multiple factors; yet, factors have paucity and are limited. Considering the clinical significance, this study aimed to identify that individual and obstetric factors of preeclampsia can be an input for disease identification involving clinicians in southern Ethiopia.

Methods

A case-control study was conducted among mothers with a singleton pregnancy who attended perinatal care in all six public hospitals in the provinces around the Omo stream. A sample size of 487 women with a singleton pregnancy (163 cases and 326 controls) was involved in the study. All cases were enrolled, while controls were selected consecutively using a random sampling technique. Data were gathered using a structured questionnaire and data extraction sheet. Descriptive data were presented using percentages and numbers. Multivariable logistic regression analysis was carried out to identify factors at a p value of less than 0.05.

Results

There was a statistically significant association between the family history of hypertension (AOR = 2.42, 95% CI: 1.16–5.05), no pregnancy interval (AOR = 1.62; 95% CI: 1.03–2.55), and normal body mass index (AOR = 0.42, 95% CI: 0.21–0.87) and the occurrence of preeclampsia.

Conclusion

Primary relatives with a history of chronic hypertension and no pregnancy interval were identified as risk factors of preeclampsia, while having a normal body mass index was found to be a protective factor of preeclampsia occurrence. To improve early detection and timely management of preeclampsia, the clinician should give attention to women who have no previous childbirth and whose close relatives had a history of chronic hypertension, as well as working on the protective factor is recommended.

Factors associated with hypertensive disorders of pregnancy in sub-Saharan Africa: A systematic and meta-analysis

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are common complications of pregnancy globally, including sub-Saharan African (SSA) countries. Although it has a high burden of maternal and neonatal mortality and morbidity, evidence on the risk of the problem is limited. Therefore, the aim of this review was to systematically examine factors associated with HDP among women in SSA countries.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed. Articles conducted in SSA and published in English from January 2000 to May 2020 from electronic databases including MEDLINE, EMBASE, PubMed, and CINAHL were included. Articles, which focused on HDP and found to be relevant through the reference check, were included. Additional articles found through a hand search of reference lists were also included. The quality of papers was appraised using the Critical Appraisal Skills Programme (CASP) scale. Two reviewers independently screened, extracted, and assessed the quality of the articles. STATA 16 software was used to compute the pooled estimated odds ratios for each of the identified associated factor. Both random and fixed effect models were used for analysis. Heterogeneity of the studies and small study bias were checked by I2 and asymmetric test, respectively.

RESULTS

Twenty-seven studies met the inclusion criteria and included in the systematic review and meta-analysis. Significant associations with HDP were identified through meta-analysis for the following variables: being primiparous (OR: 1.78; 95% CI: 1.11, 2.44), having previous HDP (OR: 3.75; 95% CI: 2.05, 5.45), family history of HDP (OR: 2.73; 95% CI: 1.85, 3.6), and lower maternal educational level (OR: 1.65; 95% CI: 1.17, 2.13). Due to the limited number of studies found specific to each variable, there was inconclusive evidence for a relationship with a number of factors, such as maternal nutrition, antenatal care visits, birth spacing, multiple birth, physical activity during pregnancy, use of contraceptives, place of residency, family size, and other related associated factors.

CONCLUSIONS

The risk of developing HDP is worse among women who have a history of HDP (either themselves or their family), are primiparous, or have a lower maternal educational level. Therefore, investment in women's health needs considered to reduce the problem, and health service providers need to give due attention to women with at increased risk to HDP. Additionally, interventions need to focus on increasing women's access to education and their awareness of potential associated factors for HDP.

Pathogenesis of Preeclampsia and Therapeutic Approaches Targeting the Placenta

Preeclampsia (PE) is a serious pregnancy complication, affecting about 5–7% of pregnancies worldwide and is characterized by hypertension and damage to multiple maternal organs, primarily the liver and kidneys. PE usually begins after 20 weeks’ gestation and, if left untreated, can lead to serious complications and lifelong disabilities—even death—in both the mother and the infant. As delivery is the only cure for the disease, treatment is primarily focused on the management of blood pressure and other clinical symptoms. The pathogenesis of PE is still not clear. Abnormal spiral artery remodeling, placental ischemia and a resulting increase in the circulating levels of vascular endothelial growth factor receptor-1 (VEGFR-1), also called soluble fms-like tyrosine kinase-1 (sFlt-1), are believed to be among the primary pathologies associated with PE. sFlt-1 is produced mainly in the placenta during pregnancy and acts as a decoy receptor, binding to free VEGF (VEGF-A) and placental growth factor (PlGF), resulting in the decreased bioavailability of each to target cells. Despite the pathogenic effects of increased sFlt-1 on the maternal vasculature, recent studies from our laboratory and others have strongly indicated that the increase in sFlt-1 in PE may fulfill critical protective functions in preeclamptic pregnancies. Thus, further studies on the roles of sFlt-1 in normal and preeclamptic pregnancies are warranted for the development of therapeutic strategies targeting VEGF signaling for the treatment of PE. Another impediment to the treatment of PE is the lack of suitable methods for delivery of cargo to placental cells, as PE is believed to be of placental origin and most available therapies for PE adversely impact both the mother and the fetus. The present review discusses the pathogenesis of PE, the complex role of sFlt-1 in maternal disease and fetal protection, and the recently developed placenta-targeted drug delivery system for the potential treatment of PE with candidate therapeutic agents.

Factors associated with short birth interval in low- and middle-income countries: a systematic review

Background

There is ample evidence of associations between short birth interval and adverse maternal and child health outcomes, including infant and maternal mortality. Short birth interval is more common among women in low- and middle-income countries. Identifying actionable aspects of short birth interval is necessary to address the problem. To our knowledge, this is the first systematic review to systematize evidence on risk factors for short birth interval in low- and middle-income countries.

Methods

A systematic mixed studies review searched PubMed, Embase, LILACS, and Popline databases for empirical studies on the topic. We included documents in English, Spanish, French, Italian, and Portuguese, without date restriction. Two independent reviewers screened the articles and extracted the data. We used the Mixed Methods Appraisal Tool to conduct a quality appraisal of the included studies. To accommodate variable definition of factors and outcomes, we present only a narrative synthesis of the findings.

Results

Forty-three of an initial 2802 documents met inclusion criteria, 30 of them observational studies and 14 published after 2010. Twenty-one studies came from Africa, 18 from Asia, and four from Latin America. Thirty-two reported quantitative studies (16 studies reported odds ratio or relative risk, 16 studies reported hazard ratio), 10 qualitative studies, and one a mixed-methods study. Studies most commonly explored education and age of the mother, previous pregnancy outcome, breastfeeding, contraception, socioeconomic level, parity, and sex of the preceding child. For most factors, studies reported both positive and negative associations with short birth interval. Shorter breastfeeding and female sex of the previous child were the only factors consistently associated with short birth interval. The quantitative and qualitative studies reported largely non-overlapping results.

Conclusions

Promotion of breastfeeding could help to reduce short birth interval and has many other benefits. Addressing the preference for a male child is complex and a longer-term challenge. Future quantitative research could examine associations between birth interval and factors reported in qualitative studies, use longitudinal and experimental designs, ensure consistency in outcome and exposure definitions, and include Latin American countries.

Trial registration

Prospectively registered on PROSPERO (International Prospective Register for Systematic Reviews) under registration number CRD42018117654.

Life Course Trajectories of Cardiovascular Risk Factors in Women With and Without Hypertensive Disorders in First Pregnancy: The HUNT Study in Norway

Background

Women with hypertensive pregnancy disorders have adverse levels of cardiovascular risk factors. It is unclear how this adverse risk factor profile evolves during adult life. We compared life course trajectories of cardiovascular risk factors in women with preeclampsia or gestational hypertension in their first pregnancy to normotensive women.

Methods and Results

We linked information on cardiovascular risk factors from the population‐based HUNT (Nord‐Trøndelag Health Study) surveys with pregnancy information from the Medical Birth Registry of Norway. Trajectories of cardiovascular risk factors were constructed for 22 308 women with a normotensive first pregnancy; 1092 with preeclampsia, and 478 with gestational hypertension in first pregnancy. Already before first pregnancy, women with preeclampsia in their first pregnancy had higher measures of adiposity, blood pressure, heart rate, and serum lipids and glucose compared with women with a normotensive first pregnancy. After first pregnancy, there was a parallel development in cardiovascular risk factor levels, but women with a normotensive first pregnancy had a time lag of >10 years compared with the preeclampsia group. There were no clear differences in risk factor trajectories between women with gestational hypertension and women with preeclampsia.

Conclusions

Women with hypertensive pregnancy disorders in their first pregnancy had an adverse cardiovascular risk factor profile before pregnancy compared with normotensive women, and the differences persisted beyond 50 years of age. Hypertensive disorders in pregnancy signal long‐term increases in modifiable cardiovascular risk factors, and may be used to identify women who would benefit from early prevention strategies.

Prediction of pre-eclampsia: review of reviews

OBJECTIVE

Primary studies and systematic reviews provide estimates of varying accuracy for different factors in the prediction of pre-eclampsia. The aim of this study was to review published systematic reviews to collate evidence on the ability of available tests to predict pre-eclampsia, to identify high-value avenues for future research and to minimize future research waste in this field.

METHODS

MEDLINE, EMBASE and The Cochrane Library including DARE (Database of Abstracts of Reviews of Effects) databases, from database inception to March 2017, and bibliographies of relevant articles were searched, without language restrictions, for systematic reviews and meta-analyses on the prediction of pre-eclampsia. The quality of the included reviews was assessed using the AMSTAR tool and a modified version of the QUIPS tool. We evaluated the comprehensiveness of search, sample size, tests and outcomes evaluated, data synthesis methods, predictive ability estimates, risk of bias related to the population studied, measurement of predictors and outcomes, study attrition and adjustment for confounding.

RESULTS

From 2444 citations identified, 126 reviews were included, reporting on over 90 predictors and 52 prediction models for pre-eclampsia. Around a third (n = 37 (29.4%)) of all reviews investigated solely biochemical markers for predicting pre-eclampsia, 31 (24.6%) investigated genetic associations with pre-eclampsia, 46 (36.5%) reported on clinical characteristics, four (3.2%) evaluated only ultrasound markers and six (4.8%) studied a combination of tests; two (1.6%) additional reviews evaluated primary studies investigating any screening test for pre-eclampsia. Reviews included between two and 265 primary studies, including up to 25 356 688 women in the largest review. Only approximately half (n = 67 (53.2%)) of the reviews assessed the quality of the included studies. There was a high risk of bias in many of the included reviews, particularly in relation to population representativeness and study attrition. Over 80% (n = 106 (84.1%)) summarized the findings using meta-analysis. Thirty-two (25.4%) studies lacked a formal statement on funding. The predictors with the best test performance were body mass index (BMI) > 35 kg/m² , with a specificity of 92% (95% CI, 89-95%) and a sensitivity of 21% (95% CI, 12-31%); BMI > 25 kg/m² , with a specificity of 73% (95% CI, 64-83%) and a sensitivity of 47% (95% CI, 33-61%); first-trimester uterine artery pulsatility index or resistance index > 90^th centile (specificity 93% (95% CI, 90-96%) and sensitivity 26% (95% CI, 23-31%)); placental growth factor (specificity 89% (95% CI, 89-89%) and sensitivity 65% (95% CI, 63-67%)); and placental protein 13 (specificity 88% (95% CI, 87-89%) and sensitivity 37% (95% CI, 33-41%)). No single marker had a test performance suitable for routine clinical use. Models combining markers showed promise, but none had undergone external validation.

CONCLUSIONS

This review of reviews calls into question the need for further aggregate meta-analysis in this area given the large number of published reviews subject to the common limitations of primary predictive studies. Prospective, well-designed studies of predictive markers, preferably randomized intervention studies, and combined through individual-patient data meta-analysis are needed to develop and validate new prediction models to facilitate the prediction of pre-eclampsia and minimize further research waste in this field. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Developing evidence-based recommendations for optimal interpregnancy intervals in high-income countries: protocol for an international cohort study

INTRODUCTION

Short interpregnancy interval (IPI) has been linked to adverse pregnancy outcomes. WHO recommends waiting at least 2 years after a live birth and 6 months after miscarriage or induced termination before conception of another pregnancy. The evidence underpinning these recommendations largely relies on data from low/middle-income countries. Furthermore, recent epidemiological investigations have suggested that these studies may overestimate the effects of IPI due to residual confounding. Future investigations of IPI effects in high-income countries drawing from large, population-based data sources are needed to inform IPI recommendations. We aim to assess the impact of IPIs on maternal and child health outcomes in high-income countries.

METHODS AND ANALYSIS

This international longitudinal retrospective cohort study will include more than 18 million pregnancies, making it the largest study to investigate IPI in high-income countries. Population-based data from Australia, Finland, Norway and USA will be used. Birth records in each country will be used to identify consecutive pregnancies. Exact dates of birth and clinical best estimates of gestational length will be used to estimate IPI. Administrative birth and health data sources with >99% coverage in each country will be used to identify maternal sociodemographics, pregnancy complications, details of labour and delivery, birth and child health information. We will use matched and unmatched regression models to investigate the impact of IPI on maternal and infant outcomes, and conduct meta-analysis to pool results across countries.

ETHICS AND DISSEMINATION

Ethics boards at participating sites approved this research (approval was not required in Finland). Findings will be published in peer-reviewed journals and presented at international conferences, and will inform recommendations for optimal IPI in high-income countries. Findings will provide important information for women and families planning future pregnancies and for clinicians providing prenatal care and giving guidance on family planning.

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.

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.

HELLP syndrome, risk factors in first and second pregnancy: a population-based cohort study

INTRODUCTION

HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) may have specific risk factors and risk factors varying from first to second pregnancy. The aims of the study were to estimate the risk of HELLP syndrome by potential risk factors in first and second pregnancy, respectively.

MATERIAL AND METHODS

A population-based cohort study including all women in Norway having their first baby (≥22 gestational weeks) during 1999 to 2014, registered in the Medical Birth Registry (n = 418 897). A subset of women with at least two births (n = 249 070) was used for estimates in second pregnancy. Relative risks with 95% CIs for HELLP syndrome were estimated using logistic regression and adjusted for maternal age and year of childbirth.

RESULTS

Body mass index ≥30 kg/m² and diabetes were associated with HELLP syndrome in first, but not in second pregnancy. Chronic hypertension and multiple pregnancy were associated with HELLP syndrome both in first and second pregnancy. In second pregnancy the strongest risk factors were a history of HELLP syndrome or preterm preeclampsia in the first. The risk was inversely correlated with gestational age at first delivery. The overall relative risk for recurrence of HELLP syndrome was 54.4 (95% CI 34.3-86.2) and 129.5 (95% CI 45.7-367.2) after HELLP syndrome before 29 weeks of gestation in first pregnancy.

CONCLUSIONS

Important risk factors for HELLP syndrome differ from first to second pregnancy. HELLP syndrome in second pregnancy is rare, but the relative risk is very high in women with HELLP syndrome or preterm preeclampsia in their first pregnancy.

Defective decidualization during and after severe preeclampsia reveals a possible maternal contribution to the etiology

In preeclampsia (PE), cytotrophoblast (CTB) invasion of the uterus and spiral arteries is often shallow. Thus, the placenta's role has been a focus. In this study, we tested the hypothesis that decidual defects are an important determinant of the placental phenotype. We isolated human endometrial stromal cells from nonpregnant donors with a previous pregnancy that was complicated by severe PE (sPE). Compared with control cells, they failed to decidualize in vitro as demonstrated by morphological criteria and the analysis of stage-specific antigens (i.e., IGFBP1, PRL). These results were bolstered by global transcriptional profiling data that showed they were transcriptionally inert. Additionally, we used laser microdissection to isolate the decidua from tissue sections of the maternal-fetal interface in sPE. Global transcriptional profiling revealed defects in gene expression. Also, decidual cells from patients with sPE, which dedifferentiated in vitro, failed to redecidualize in culture. Conditioned medium from these cells failed to support CTB invasion. To mimic aspects of the uterine environment in normal pregnancy, we added PRL and IGFBP1, which enhanced invasion. These data suggested that failed decidualization is an important contributor to down-regulated CTB invasion in sPE. Future studies will be aimed at determining whether this discovery has translational potential with regard to assessing a woman's risk of developing this pregnancy complication.

Seasonal variation in geographical access to maternal health services in regions of southern Mozambique

BACKGROUND

Geographic proximity to health facilities is a known determinant of access to maternal care. Methods of quantifying geographical access to care have largely ignored the impact of precipitation and flooding. Further, travel has largely been imagined as unimodal where one transport mode is used for entire journeys to seek care. This study proposes a new approach for modeling potential spatio-temporal access by evaluating the impact of precipitation and floods on access to maternal health services using multiple transport modes, in southern Mozambique.

METHODS

A facility assessment was used to classify 56 health centres. GPS coordinates of the health facilities were acquired from the Ministry of Health while roads were digitized and classified from high-resolution satellite images. Data on the geographic distribution of populations of women of reproductive age, pregnancies and births within the preceding 12 months, and transport options available to pregnant women were collected from a household census. Daily precipitation and flood data were used to model the impact of severe weather on access for a 17-month timeline. Travel times to the nearest health facilities were calculated using the closest facility tool in ArcGIS software.

RESULTS

Forty-six and 87 percent of pregnant women lived within a 1-h of the nearest primary care centre using walking or public transport modes respectively. The populations within these catchments dropped by 9 and 5% respectively at the peak of the wet season. For journeys that would have commenced with walking to primary facilities, 64% of women lived within 2 h of life-saving care, while for those that began journeys with public transport, the same 2-hour catchment would have contained 95% of the women population. The population of women within two hours of life-saving care dropped by 9% for secondary facilities and 18% for tertiary facilities during the wet season.

CONCLUSIONS

Seasonal variation in access to maternal care should not be imagined through a dichotomous and static lens of wet and dry seasons, as access continually fluctuates in both. This new approach for modelling spatio-temporal access allows for the GIS output to be utilized not only for health services planning, but also to aid near real time community-level delivery of maternal health services.