Can adverse maternal and perinatal outcomes be predicted when blood pressure becomes elevated? Secondary analyses from the CHIPS (Control of Hypertension In Pregnancy Study) randomized controlled trial

Even high normal blood pressure affects live birth rate in women undergoing fresh embryo transfer

STUDY QUESTION

Do differences in blood pressure within the normal range have any impacts on the live birth rate (primary outcome) or biochemical pregnancy rate (beta-hCG positivity), clinical pregnancy rate (heart beating in ultrasound), abortion rate and ectopic pregnancy rate (secondary outcomes) of fresh embryo transfer in women undergoing their IVF/ICSI treatment?

SUMMARY ANSWER

Even rather small differences in baseline blood pressure in women with normal blood pressure according to current guidelines undergoing fresh embryo transfer after IVF/ICSI affects substantially the live birth rate.

WHAT IS KNOWN ALREADY

Pre-pregnancy hypertension is a well-known risk factor for adverse pregnancy events such as preeclampsia, fetal growth restriction, placental abruption and adverse neonatal events. It is likewise well known that hypertension during pregnancy in women undergoing ART is associated with adverse pregnancy outcomes. However, whether blood pressure at the high end of the normal range has an impact on ART is unknown.

STUDY DESIGN, SIZE, DURATION

It is a prospective observational cohort study based on a single IVF center between January 2017 and December 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two thousand four hundred and eighteen women with normal blood pressure undergoing fresh embryo transfer after IVF/ICSI at the Reproductive and Genetic Hospital of CITIC-Xiangya were enrolled in this study.

MAIN RESULTS AND THE ROLE OF CHANCE

Blood pressure was measured at the first visit when women consulted the IVF center due to infertility. In women with a successful pregnancy outcome (1487 live births out of 2418 women undergoing fresh embryo transfer after IVF/ICSI), systolic blood pressure (SBP) (114.1 ± 9.48 mmHg versus 115.4 ± 9.8 mmHg, P = 0.001) and diastolic blood pressure (DBP) (74.5 ± 7.5 mmHg versus 75.3 ± 7.34 mmHg, P = 0.006) were lower than in those who did not achieve live births. Multivariate logistic regression analysis revealed that SBP (OR: 0.987, 95% CI: 0.979–0.996, P = 0.004) and DBP (OR: 0.986, 95% CI: 0.975–0.998, P = 0.016) were negatively associated with live birth. Similarly, SBP was significantly negatively related to clinical pregnancy rate (OR: 0.990, 95% CI: 0.981–0.999, P = 0.033), while for DBP the association was not statistically significant (OR: 0.994, 95% CI: 0.982–1.006, P = 0.343). However, both SBP and DBP were positively associated with miscarriage OR: 1.021 (95% CI: 1.004–1.037, P = 0.013) and OR: 1.027 (95% CI: 1.005–1.049, P = 0.014), respectively. Both SBP and DBP were unrelated to biochemical pregnancy (hCG positivity), implantation and ectopic pregnancy rate.

LIMITATIONS, REASONS FOR CAUTION

Whether lowering blood pressure before initiating ART treatment in women with SBP or DBP higher than the thresholds defined in our study will confer a benefit is unknown. Also, we cannot exclude bias due to different ethnicities. Moreover, participants in our study only received fresh embryo transfer, whether the results could apply to frozen embryo transfer is unclear.

WIDER IMPLICATIONS OF THE FINDINGS

Our study challenges the current blood pressure goals in women undergoing fresh embryo transfer after IVF/ICSI. Further studies are needed to figure out the mechanism and effective approach to increase IVF/ICSI pregnancy outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

Hunan Provincial Grant for Innovative Province Construction (2019SK4012). The authors declare that there were no conflicts of interest in this study.

TRIAL REGISTRATION NUMBER

N/A.

Toward personalized management of chronic hypertension in pregnancy

Chronic hypertension complicates 1% to 2% of pregnancies, and it is increasingly common. Women with chronic hypertension are an easily recognized group who are in touch with a wide variety of healthcare providers before, during, and after pregnancy, mandating that chronic hypertension in pregnancy be within the scope of many practitioners. We reviewed recent data on management to inform current care and future research. This study is a narrative review of published literature. Compared with normotensive women, women with chronic hypertension are at an increased risk of maternal and perinatal complications. Women with chronic hypertension who wish to be involved in their care can do by measuring blood pressure at home. Accurate devices for home blood pressure monitoring are now readily available. The diagnostic criteria for superimposed preeclampsia remain problematic because most guidelines continue to include deteriorating blood pressure control in the definition. It has not been established how angiogenic markers may aid in confirmation of the diagnosis of superimposed preeclampsia when suspected, over and above information provided by routinely available clinical data and laboratory results. Although chronic hypertension is a strong risk factor for preeclampsia, and aspirin decreases preeclampsia risk, the effectiveness specifically among women with chronic hypertension has been questioned. It is unclear whether calcium has an independent effect in preeclampsia prevention in such women. Treating hypertension with antihypertensive therapy halves the risk of progression to severe hypertension, thrombocytopenia, and elevated liver enzymes, but a reduction in preeclampsia or serious maternal complications has not been observed; however, the lack of evidence for the latter is possibly owing to few events. In addition, treating chronic hypertension neither reduces nor increases fetal or newborn death or morbidity, regardless of the gestational age at which the antihypertensive treatment is started. Antihypertensive agents are not teratogenic, but there may be an increase in malformations associated with chronic hypertension itself. At present, blood pressure treatment targets used in clinics are the same as those used at home, although blood pressure values tend to be inconsistently lower at home among women with hypertension. Although starting all women on the same antihypertensive medication is usually effective in reducing blood pressure, it remains unclear whether there is an optimal agent for such an approach or how best to use combinations of antihypertensive medications. An alternative approach is to individualize care, using maternal characteristics and blood pressure features beyond blood pressure level (eg, variability) that are of prognostic value. Outcomes may be improved by timed birth between 38 0/7 and 39 6/7 weeks' gestation based on observational literature; of note, confirmatory trial evidence is pending. Postnatal care is facilitated by the acceptability of most antihypertensives (including angiotensin-converting enzymes inhibitors) for use in breastfeeding. The evidence base to guide the care of pregnant women with chronic hypertension is growing and aligning with international guidelines. Addressing outstanding research questions would inform personalized care of chronic hypertension in pregnancy.

Gestational systolic blood pressure trajectories and risk of adverse maternal and perinatal outcomes in Chinese women

Background

Associations between trajectories of systolic blood pressure (SBP) during pregnancy and pregnant outcomes remain unclear and disparate.

Methods

Data of 20,353 mothers without chronic hypertension and who delivered live singletons between January, 2014 and November, 2019, was extracted from Taicang register-based cohort. Based on SBP measured during 10 to 40 weeks of gestation, SBP trajectories were explored using latent class growth mixture model, and their associations with maternal and neonatal outcomes were assessed by logistic regression analyses.

Results

Six heterogeneous SBP trajectories were identified: low delayed-increasing (7.47%), low reverse-increasing (21.88%), low-stable (19.13%), medium-stable (21.64%), medium reverse-increasing (16.47%), and high stable (13.41%) trajectories. The high-stable trajectory had SBP around 125 mmHg in the 10th gestational week, and increased slightly onwards. When compared with the low-stable trajectory, the high-stable trajectory had maximally adjusted odds ratio (95% confidence interval) of 5.28 (2.76–10.10), 1.30 (1.13–1.50), 1.53 (1.12–2.08), 1.32 (1.06–1.65) and 1.64 (1.08–2.48) for gestational hypertension (GH), early-term delivery (ETD), preterm delivery (PTD), small for gestational age and low birth weight (LBW), respectively. Besides, the medium reverse-increasing trajectory showed significantly increased risk of GH and ETD, while the medium-stable trajectory had significantly elevated risk of ETD and PTD. Notably, SBP trajectories slightly but significantly improved risk discrimination of GH, ETD and LBW, over traditional risk factors.

Conclusion

Women with different SBP trajectories were at varied risk of adverse maternal and fetal outcomes. Meanwhile, our study suggested that BP monitoring during pregnancy is necessary, especially for women with high SBP in early pregnancy or upward trajectory.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03599-7.

Postpartum blood pressure patterns in severe preeclampsia and normotensive pregnant women following abdominal deliveries: a cohort study

Objective: To determine blood pressure (BP) patterns in the immediate postpartum period in preeclampsia with severe features (sPE) and normotensive pregnant women who had cesarean deliveries (CD).Study design: The BP levels of two groups comprising 50 sPE and 90 normotensive pregnant women who had CD were measured before delivery and on days 0-3 postpartum at four time points (05:00, 08:00, 14:00, and 22:00). Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PIGF) were measured in the maternal serum ≤48 h before delivery.Results: Antihypertensive therapy was administered to 98, 96, 82, 78, and 56% of sPE antepartum and on postpartum days 0-3, respectively. De novo postpartum hypertension (BP ≥ 140/90 mmHg) occurred in 24.4% (22/90) of the normotensive group but only one required antihypertensive therapy. The occurrence of de novo postpartum hypertension was associated with maternal weight before delivery ≥ 84.5 kg (relative risks (RR) 2.6, CI 95% 1.2-5.8, p = .017), and body mass index before delivery ≥ 33.3 kg/m2 (RR 2.9, CI 95% 1.3-6.4, p = .008). In sPE, the BP decreased between predelivery period and postpartum day 0. From days 1 to 3 postpartum, there was a continuous increase in the daily mean BPs in both groups, with average daily increments (systolic/diastolic) being 5.6/4.6 mmHg and 0.6/1.3 mmHg in the sPE and normotensive women, respectively. Patient's group and time had a significant effect on BP, p < .001. Overall, daily mean BPs were higher in the sPE than the normotensive group (p < .001). Perceived stress (p = .022), low birth weight (p = .002), 5 min Apgar score ≤ 6 (p < .001) were significantly higher in the sPE group. sFlt-1/PIGF ratio was high in the hypertensive groups: sPE versus normotensive group, p < .001; de novo postpartum hypertension versus normotensives group that remained normotensive, p = .102.Conclusion: Postpartum BP and antihypertensive requirements are important considerations in managing sPE and normotensive pregnancies. sPE is associated with increased maternal stress and poor perinatal outcomes.

The value of fetal Doppler indices as predictors of perinatal outcome in women with preeclampsia with severe features

Objective: To evaluate the diagnostic performance of Doppler sonography of umbilical artery (UA), fetal middle cerebral artery (MCA), ductus venosus (DV) & umbilical vein (UV) for prediction of adverse perinatal outcome.Material and Methods: A prospective cohort study conducted on 60 women diagnosed  with preeclampsia with severe features divided into two groups based on adverse perinatal outcome.Results: Statistically Significant differences were demonstrated UA PI (1.28 ± 0.23 vs. 0.96 ± 0.21, P <0.001), UA RI (0.78 ± 0.09 vs. 0.62 ± 0.09, P <0.001), MCA PI (1.27 ± 0.28 vs. 1.45±0.20, P 0.005), MCA RI (0.67 ± 0.10 vs. 0.76 ± 0.08, P<0.001), Cerebroplacental ratio (1.01 ± 0.36 vs. 1.57 ± 0.35, P <0.001), DV PVIV (0.67 ± 0.20 vs. 0.51 ± 0.14, P= 0.004), DV PSV (54.74 ± 17.11 vs. 42.15 ± 9.42, P= 0.004)  and abnormal DV a wave (23.8 vs. 0%, P = 0.004) in women with adverse and normal perinatal outcome respectively. UA PI and CPR had the highest specificity while UA RI had the highest sensitivity for detection of adverse perinatal outcome.Conclusion: CPR < 1 can be used to identify fetuses at risk of morbidity and mortality among such cases.

The performance of pre-delivery serum concentrations of angiogenic factors in predicting postpartum antihypertensive drug therapy following abdominal delivery in severe preeclampsia and normotensive pregnancy

Background

The imbalance between circulating concentrations of anti- and pro-angiogenic factors is usually intense in preeclampsia with severe features (sPE). It is possible that pre-delivery circulating levels of angiogenic factors in sPE may be associated with postpartum antihypertensive drug requirements.

Objective

To determine the predictive association between maternal pre-delivery serum concentrations of angiogenic factors and the use of ≥3 slow- and/or a rapid-acting antihypertensive drug therapy in sPE on postpartum days zero to three following caesarean delivery.

Study design

Women with sPE (n = 50) and normotensive pregnancies (n = 90) were recruited prior to childbirth. Serum samples were obtained from each participant < 48 hours before delivery to assess the concentrations of placental growth factor (PIGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) using the Roche Elecsys platform. Each participant was followed up on postpartum days zero, one, two and three to monitor BP and confirm antihypertensive treatment. The optimal cut-off thresholds of sFlt-1/PIGF ratio from receiver operating characteristic curve predictive of the antihypertensive therapy were subjected to diagnostic accuracy assessment.

Results

The majority 58% (29/50) of sPE had multiple severe features of preeclampsia in the antenatal period with the commonest presentation being severe hypertension in 88% (44/50) of this group, followed by features of impending eclampsia which occurred in 42% (21/50). The median gestational age at delivery was 38 (Interquartile range, IQR 1) vs 36 (IQR 6) weeks, p < 0.001 in normotensive and sPE groups respectively. Notably, the median sFlt-1/PIGF ratio in normotensive and sPE groups were 7.3 (IQR 17.9) and 179.1 (IQR 271.2) respectively, p < 0.001. Of the 50 sPE participants, 34% (17/50) had early-onset preeclampsia. The median (IQR) of sFlt-1/PIGF in the early- and late-onset preeclampsia groups were 313.52 (502.25), and 166.59(195.37) respectively, p = 0.006. From postpartum days zero to three, 48% (24/50) of sPE received ≥ 3 slow- and/or a rapid-acting antihypertensive drug. However, the daily administration of ≥ 3 slow- and/or a rapid-acting antihypertensive drug in sPE were pre-delivery 26% (13/50), postpartum day zero 18% (9/50), postpartum day one 34% (17/50), postpartum day two 24% (12/50) and postpartum day three 20% (10/50). In sPE, the pre-delivery sFlt-1/PIGF ratio was predictive of administration of ≥3 slow- and/or a rapid-acting antihypertensive drug on postpartum days zero, one and two with the optimal cut-off ratio being ≥315.0, ≥181.5 and ≥ 267.8 respectively (sensitivity 72.7–75.0%, specificity 64.7–78.6%, positive predictive value 40.0–50.0% and negative predictive value 84.6% - 94.3%). The predictive performance of sFlt-1/PIG ratio on postpartum day 3 among the sPE was not statistically significant (area under receiver operating characteristic curve, 0.6; 95% CI, 0.3–0.8).

Conclusion

A pre-delivery sFlt-1/PIGF ratio (< 181.5) is a promising predictor for excluding the need for ≥3 slow- and/or a rapid-acting antihypertensive drug therapy in the immediate postpartum period in sPE.

Current and emerging pharmacotherapy for emergency management of preeclampsia

INTRODUCTION

Preeclampsia is a disease specific to pregnancy characterised by new onset hypertension with maternal organ dysfunction and/or fetal growth restriction. It remains a major cause of maternal and perinatal morbidity and mortality. For fifty years, antihypertensives have been the mainstay of treating preeclampsia, reducing maternal morbidity and mortality. With increased knowledge of the mechanisms underlying the disease has come opportunities for novel therapies that complement antihypertensives by protecting the maternal vasculature. Areas covered: In this review, the authors consider, in detail, the antihypertensives commonly used today in the emergency care of women with severe preeclampsia. They also review less common anti-hypertensive agents and discuss the role of magnesium sulphate in the management of preeclampsia and the prevention of eclampsia. Finally, they explore novel therapeutics for the acute management of preeclampsia. Expert opinion: The rapid control of maternal hypertension will, and must, remain the mainstay of emergency treatment for women with severe preeclampsia. The role of magnesium sulphate as a primary prevention for eclampsia is context dependant and should not displace a focus on correcting blood pressure safely. The exploration of novel adjuvant therapies will likely allow us to prolong pregnancy longer and improve perinatal outcomes safely for the mother.

The CHIPS Randomized Controlled Trial (Control of Hypertension in Pregnancy Study): Is Severe Hypertension Just an Elevated Blood Pressure?

Supplemental Digital Content is available in the text.

To determine whether clinical outcomes differed by occurrence of severe hypertension in the international CHIPS trial (Control of Hypertension in Pregnancy Study), adjusting for the interventions of “less tight” (target diastolic blood pressure [dBP] 100 mm Hg) versus “tight” control (target dBP 85 mm Hg). In this post-hoc analysis of CHIPS data from 987 women with nonsevere nonproteinuric preexisting or gestational hypertension, mixed effects logistic regression was used to compare the following outcomes according to occurrence of severe hypertension, adjusting for allocated group and the influence of baseline factors: CHIPS primary (perinatal loss or high-level neonatal care for >48 hours) and secondary outcomes (serious maternal complications), birth weight <10th percentile, preeclampsia, delivery at <34 or <37 weeks, platelets <100×10⁹/L, elevated liver enzymes with symptoms, maternal length of stay ≥10 days, and maternal readmission before 6 weeks postpartum. Three hundred and thirty-four (34.1%) women in CHIPS developed severe hypertension that was associated with all outcomes examined except for maternal readmission (P=0.20): CHIPS primary outcome, birth weight <10th percentile, preeclampsia, preterm delivery, elevated liver enzymes (all P<0.001), platelets <100×10⁹/L (P=0.006), and prolonged hospital stay (P=0.03). The association between severe hypertension and serious maternal complications was seen only in less tight control (P=0.02). Adjustment for preeclampsia (464, 47.3%) did not negate the relationship between severe hypertension and the CHIPS primary outcome (P<0.001), birth weight <10th percentile (P=0.005), delivery at <37 (P<0.001) or <34 weeks (P<0.001), or elevated liver enzymes with symptoms (P=0.02). Severe hypertension is a risk marker for adverse maternal and perinatal outcomes, independent of BP control or preeclampsia co-occurrence.

Can adverse maternal and perinatal outcomes be predicted when blood pressure becomes elevated? Secondary analyses from the CHIPS (Control of Hypertension In Pregnancy Study) randomized controlled trial

Introduction

For women with chronic or gestational hypertension in CHIPS (Control of Hypertension In Pregnancy Study, NCT01192412), we aimed to examine whether clinical predictors collected at randomization could predict adverse outcomes.

Material and methods

This was a planned, secondary analysis of data from the 987 women in the CHIPS Trial. Logistic regression was used to examine the impact of 19 candidate predictors on the probability of adverse perinatal (pregnancy loss or high level neonatal care for >48 h, or birthweight <10th percentile) or maternal outcomes (severe hypertension, preeclampsia, or delivery at <34 or <37 weeks). A model containing all candidate predictors was used to start the stepwise regression process based on goodness of fit as measured by the Akaike information criterion. For face validity, these variables were forced into the model: treatment group (“less tight” or “tight” control), antihypertensive type at randomization, and blood pressure within 1 week before randomization. Continuous variables were represented continuously or dichotomized based on the smaller p‐value in univariate analyses. An area‐under‐the‐receiver‐operating‐curve (AUC ROC) of ≥0.70 was taken to reflect a potentially useful model.

Results

Point estimates for AUC ROC were <0.70 for all but severe hypertension (0.70, 95% CI 0.67–0.74) and delivery at <34 weeks (0.71, 95% CI 0.66–0.75). Therefore, no model warranted further assessment of performance.

Conclusions

CHIPS data suggest that when women with chronic hypertension develop an elevated blood pressure in pregnancy, or formerly normotensive women develop new gestational hypertension, maternal and current pregnancy clinical characteristics cannot predict adverse outcomes in the index pregnancy.