Early and late onset pre-eclampsia and small for gestational age risk in subsequent pregnancies

Derivation and Validation of Prediction of Preterm Preeclampsia Using Machine Learning Algorithms

OBJECTIVE

 This study aimed to develop machine learning (ML) models for predicting preterm preeclampsia using the information available before 23 weeks gestation.

STUDY DESIGN

 This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) cohort. We considered 131 features available before 23 weeks including maternal demographics, obstetrics and family history, social determinants of health, physical activity, nutrition, and early second-trimester ultrasound. Our primary outcome was preterm preeclampsia before 37 weeks. The dataset was randomly split into a training set (70%) and a validation set (30%). ML models using glmnet, multilayer perceptron, random forest, XGBoost (extreme gradient boosting), and LightGBM models were developed. Using the ML approach that achieved the best area under the curve (AUC), we developed the final model. Further feature selection was conducted from the top 25 important features based on SHapley Additive exPlanations (SHAP) values. The performance of the final model was assessed using the validation dataset.

RESULTS

 Of 9,467 individuals, 219 (2.3%) had preterm preeclampsia. The AUC of the XGBoost model was the highest (AUC = 0.749 [95% confidence interval (95% CI), 0.736-0.762]) compared with other models. Therefore, XGBoost was used to develop models using fewer variables. The XGBoost model with the eight features (in order of importance: mean uterine artery pulsatility index in the early second trimester, chronic hypertension, pregestational diabetes, uterine artery notch, systolic and diastolic blood pressure in the first trimester, body mass index, and maternal age) was chosen as the final model as it had an AUC of 0.741 (95% CI, 0.730-0.752) which was not inferior to the original model (p = 0.58). The final model in the validation dataset had an AUC of 0.779 (95% CI, 0.722-0.831). An online application of the final model was developed ( https://kawakita.shinyapps.io/Preterm_preeclampsia/ ).

CONCLUSION

 ML algorithms using information available before 23 weeks can accurately predict preterm preeclampsia before 37 weeks.

KEY POINTS

· Prediction models using uterine artery Doppler have not been adopted in the US.. · We developed a model using an ML algorithm.. · An online application of the final model was developed.. · ML algorithms using information available before 23 weeks can accurately predict preterm preeclampsia before 37 weeks..

Effects of ambient air pollution on the risk of small- and large-for-gestational-age births: an analysis using national birth data in Japan

OBJECTIVES

Small-for-gestational-age (SGA) and large-for-gestational-age (LGA) births are major adverse birth outcomes related to newborn health. In contrast, the association between ambient air pollution levels and SGA or LGA births has not been investigated in Japan; hence, the purpose of our study is to investigate this association.

METHODS

We used birth data from Vital Statistics in Japan from 2017 to 2021 and municipality-level data on air pollutants, including nitrogen dioxide (NO2), sulfur dioxide (SO2), photochemical oxidants, and particulate matter 2.5 (PM2.5). Ambient air pollution levels throughout the first, second, and third trimesters, as well as the whole pregnancy, were calculated for each birth. The association between SGA/LGA and ambient levels of the air pollutants was investigated using crude and adjusted log-binomial regression models. In addition, a regression model with spline functions was also used to detect the non-linear association.

RESULTS

We analyzed data from 2,434,217 births. Adjusted regression analyses revealed statistically significant and positive associations between SGA birth and SO2 level, regardless of the exposure period. Specifically, the risk ratio for average SO2 values throughout the whole pregnancy was 1.014 (95% confidence interval [CI] 1.009, 1.019) per 1 ppb increase. In addition, regression analysis with spline functions indicated that an increase in risk ratio for SGA birth depending on SO2 level was linear. Furthermore, statistically significant and negative associations were observed between LGA birth and SO2 except for the third trimester.

CONCLUSIONS

It was suggested that ambient level of SO2 during the pregnancy term is a risk factor for SGA birth in Japan.

BMI modifies the effect of pregnancy complications on risk of small- or large-for-gestational-age newborns

BACKGROUND

Maternal physical condition (reflected by maternal body mass index (BMI) at delivery) and pregnancy complications influence neonatal health outcomes. High BMI during pregnancy increases various health problems' risks, but studies about the synthesized effect of these factors on fetal growth, are scarce.

METHODS

The retrospective cohort study was conducted in Zhejiang Province, China from 1 January 2019 to 31 December 2021. The associations between complications and small-for-gestational-age (SGA) and large-for-gestational-age (LGA) were measured by the Fine-Gray model and subgroup analysis. Effect modification and interaction analyses were conducted to explore BMI's modification effect and complications' interaction.

RESULTS

Several complications increased the risk for SGA and LGA, some significance varied in different subgroups. There was a positive effect modification of gestational diabetes mellitus (GDM) across BMI strata on LGA (relative excess risk due to interaction (RERI) [95% CI] = 0.57 [0.09,1.04]). Several pairwise complications' interactions were synergistic (e.g., pregestational diabetes and intraamniotic infection for SGA (ratio of ORs [95% CI] = 8.50 [1.74,41.37]), pregestational diabetes and assisted reproductive technology (ART) for LGA (ratio of ORs [95% CI] = 2.71 [1.11,6.62])), one was antagonistic (placental problems and ART for LGA (ratio of ORs [95% CI] = 0.58 [0.35,0.96])).

CONCLUSIONS

High-BMI positively modified the risk of GDM on LGA. Many interactions existed when two specific pregnancy complications occurred simultaneously.

IMPACT

This is the largest retrospective study covering more than 10 pregnancy complications to date in this aspect. High-BMI (BMI > 28 kg/m2) positively modifies the risk of GDM on LGA. Many pregnancy complications influence the risk of SGA and LGA, with several interactions that may create a "syndrome" effect. Pregnant women with different BMIs should consider the additional risks caused by pregnancy complications for their heterogeneous effects on abnormal fetal growth. Measures should be taken to prevent the occurrence of other exposure factors in the "syndrome". This study may aid in developing a new strategy for improving neonatal outcomes.

Association between maternal hypertension and infant neurodevelopment in extremely preterm infants

OBJECTIVE

To examine the association between maternal hypertension during pregnancy and neurodevelopmental impairment (NDI) at 24 months post-menstrual age in extremely preterm infants.

STUDY DESIGN

Using data from two tertiary neonatal units (2011-2017) for infants born at 23 + 0 to 28 + 6 weeks, we investigated outcomes of NDI related to maternal hypertension and small-for-gestational-age (SGA) status.

RESULTS

Of 1019 pre-term infants, 647 had complete data and were included in the analysis. Ninety-six (15%) had maternal hypertension exposure; 25 (4%) were also SGA. Infants with maternal hypertension showed a higher odds of any NDI (aOR: 2.29, 95% CI = 1.36-3.87) and significant NDI (aOR: 2.01, 95% CI = 1.02-3.95). The combination of hypertension and SGA further elevated this risk (aOR for any NDI: 4.88, 95% CI = 1.80-13.22; significant NDI: 6.91, 95% CI = 2.50-19.12).

CONCLUSION

Maternal hypertension during pregnancy elevates the risk of NDI in extremely preterm infants, more so when combined with SGA.

Challenges in Conducting Clinical Trials for Preeclampsia

PURPOSE OF REVIEW

To review recent data describing the challenges and innovations in therapeutic research focused on the prevention and treatment of preeclampsia.

RECENT FINDINGS

Pregnant individuals have traditionally been excluded from therapeutic research, resulting in a paucity of innovation in therapeutics for pregnancy-specific medical conditions, especially preeclampsia. With the increased awareness of maternal morbidity and mortality, there is significant interest among researchers to expand therapeutic research in pregnancy. Several medications, including aspirin, pravastatin, metformin, and esomeprazole, which are commonly used in non-pregnant populations, are now being investigated for preeclampsia prevention. However, given the historic precedent of exclusion, along with the regulatory, ethical, and feasibility concerns that accompany this population, the study of these and novel medications has been complicated by numerous challenges. While complex, and laden with challenges, there is great ongoing need for therapeutic research to address preeclampsia. Aspirin, pravastatin, metformin, and esomeprazole have all shown promise as potential therapeutic agents; however, their use remains to be optimized, and innovative therapeutics need to be developed.

Who Needs a Second Dose of Exogenous Surfactant?

OBJECTIVE

To identify prenatal and postnatal risk factors associated with surfactant redosing.

STUDY DESIGN

Retrospective, single-regional center study including all infants born from 24 + 0 to 31 + 6 weeks of gestation in the Marche Region, Italy, and admitted to a single level III regional NICU from January 1, 2004, to February 28, 2021. Clinical factors associated with surfactant redosing were identified through logistic regression analysis.

RESULTS

Of 1615 consecutive admissions, 662 infants were treated with exogenous surfactant: 462 (70%) received a single dose and 200 (30%) received more than 1 dose (25.5% two doses and 4.5% three doses). Risk of redosing was higher for infants born to mothers with hypertension in pregnancy (OR 3.95, P < .001), for small for gestational age (SGA) infants (OR 3.93, P < .001) and when the first surfactant dose was 100 mg/kg instead of 200 mg/kg (OR 4.56/4.61, P < .001). Infants with greater GA, delayed first surfactant administration, and milder respiratory distress syndrome had reduced risk of redosing. Infants who required multiple surfactant doses had a higher rate of bronchopulmonary dysplasia and mortality, as well as longer duration of respiratory support than patients that received 1 dose.

CONCLUSIONS

Hypertension in pregnancy and SGA status were found to be statistically and clinically significant predictors of surfactant redosing. Understanding the pathophysiology of these conditions requires further investigation.

Biopsychosocial contexts of timely and adequate prenatal care utilization among women with criminal legal involvement and opioid use disorder

OBJECTIVE

Pregnant women with criminal legal involvement and opioid use disorder (CL-OUD) living in non-urban regions may be at risk for complex biomedical, psychological, and social barriers to prenatal care and healthy pregnancy. Yet, limited research has explored prenatal care utilization patterns among this subpopulation. This study describes the biopsychosocial factors of pregnant women with a history of criminal legal involvement and opioid use disorder (CL-OUD) associated with timely prenatal care initiation and adequate prenatal care utilization (APNCU).

METHODS

Analyses were conducted on a subsample of medical record data from an observational comparative effectiveness study of medication treatment models for pregnant women with diagnosed opioid use disorder (OUD) who received prenatal care in Northern New England between 2015 and 2022. The subsample included women aged ≥ 16 years with documented criminal legal involvement. Analyses included χ2, Fisher exact tests, and multiple logistic regression to assess differences in timely prenatal care and APNCU associated with biopsychosocial factors selected by backwards stepwise regression.

RESULTS

Among 317 women with CL-OUD, 203 (64.0%) received timely prenatal care and 174 (54.9%) received adequate care. Timely prenatal care was associated with having two or three prior pregnancies (aOR 2.37, 95% CI 1.07-5.20), receiving buprenorphine at care initiation (aOR 1.85, 95% CI 1.01-3.41), having stable housing (aOR 2.49, 95% CI 1.41-4.41), and being mandated to court diversion (aOR 4.06, 95% CI 1.54-10.7) or community supervision (aOR 2.05, 95% CI 1.16-3.63). APNCU was associated with having a pregnancy-related medical condition (aOR 2.17, 95% CI 1.27-3.71), receiving MOUD throughout the entire prenatal care period (aOR 3.40, 95% CI 1.45-7.94), having a higher number of psychiatric diagnoses (aOR 1.35, 95% CI 1.07-1.70), attending a rurally-located prenatal care practice (aOR 2.14, 95% CI 1.22-3.76), having stable housing (aOR 1.94, 95% CI 1.06-3.54), and being mandated to court diversion (aOR 3.11, 95% CI 1.19-8.15).

CONCLUSION

While not causal, results suggest that timely and adequate prenatal care among women with CL-OUD may be supported by OUD treatment, comorbid indications for care, stable access to social resources, and maintained residence in the community (i.e., community-based alternatives to incarceration).

A Retrospective Assessment of Thrombophilia in Pregnant Women with First and Second Trimester Pregnancy Loss

Recurrent Pregnancy Loss (RPL) affects between 1% to 5% of women of reproductive age. It is widely believed that RPL is a complex disorder that is influenced by chromosomal abnormalities, genetic mutations, uterine anatomic deformity, endocrine dysfunction, immunologic factors, infections, and the environment. Thrombotic disorders are a frequent cause of RPL, accounting for almost half of all cases; however, in the rest of the cases, the cause of RPL remains unclear. Therefore, in this study, it was planned to determine the genetic mutations involved in RPL during the first and second trimester of pregnancy. An observational retrospective cohort study was conducted in 2021, collecting data from 157 first trimester miscarriages and 54 s trimester pregnancies. All patients with a panel of laboratory and genetic analysis for thrombophilia were included for data analysis. It was observed that four factors were significantly more prevalent in one of the groups. Factor V Leiden (FVL) homozygosity and antiphospholipid syndrome (APS) antibodies were statistically significantly more common in pregnant women who suffered first trimester pregnancy losses. On the other hand, Protein C deficiency and Glycoprotein Ia polymorphism were statistically significantly more frequent in the second trimester group. The strongest independent risk factors for first trimester pregnancy loss were FVL and prothrombin (PT) compound mutations (OR = 3.11), followed by FVL homozygous mutation (OR = 3.66), and APS antibodies (OR = 4.47). Regarding second trimester pregnancy loss risk factors, the strongest were FVL and PT compound (OR = 3.24), followed by Glycoprotein Ia polymorphism (OR = 3.61), and respectively, APS antibodies (OR = 3.85). Numerous thrombophilic risk factors for early and late pregnancy loss have been found, including several mutations that seem to occur more often either during the first or the second trimester. Even though we are aware of risk-free and efficient diagnostics for thrombophilia abnormalities, no intervention has been proved to be clearly successful after the detection of these variables.

Ophthalmic artery Doppler at 19-23 weeks' gestation in pregnancies that deliver small-for-gestational-age neonates

OBJECTIVES

First, to explore hemodynamic differences between pregnancies delivering a small-for-gestational-age (SGA) neonate in the absence of hypertensive disorders and those that develop pre-eclampsia (PE) or gestational hypertension (GH), by comparing the ophthalmic artery peak systolic velocity (PSV) ratio and first (PSV1) and second (PSV2) PSV at 19-23 weeks' gestation, and second, to compare these pregnancies for markers of placental perfusion and function.

METHODS

This was a prospective observational study in women attending for a routine hospital visit at 19 + 1 to 23 + 3 weeks' gestation. This visit included recording of maternal demographic characteristics and medical history, ultrasound examination for assessment of fetal anatomy and growth, and measurement of maternal ophthalmic artery PSV ratio, PSV1, PSV2, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF). The values of PSV ratio, PSV1, PSV2, MAP, UtA-PI and PlGF were converted to multiples of the median (MoM) or deltas. Mean MoMs or deltas of these biomarkers in the SGA, PE and GH groups were compared with those in the unaffected group. The definition of SGA was birth weight below the 10^th percentile in the absence of PE or GH.

RESULTS

The study population of 5214 pregnancies contained 4375 (83.9%) that were unaffected by SGA, PE or GH, 563 (10.8%) complicated by SGA, 157 (3.0%) with PE and 119 (2.3%) with GH. There were three main findings of the study. First, in the SGA, PE and GH groups, compared with unaffected pregnancies, the PSV ratio delta, PSV2 MoM, MAP MoM and UtA-PI MoM were increased and PlGF MoM was decreased; however, the magnitude of most changes was smaller in the SGA group than in PE and GH groups. Second, in the PE and GH groups, but not in the SGA group, PSV1 MoM was increased. Third, in general, in the pathological pregnancies, the magnitude of deviation of biomarkers from unaffected pregnancies was greater for those delivering at < 37 than at ≥ 37 weeks' gestation.

CONCLUSION

In mid-gestation, pregnancies that subsequently develop hypertensive disorders and those delivering a SGA neonate, compared with unaffected pregnancies, have abnormal uteroplacental measurements and increased maternal ophthalmic artery PSV ratio. These data suggest similar pathophysiology in the two conditions, with evidence of placental dysfunction and increased peripheral vascular resistance, but the magnitude of abnormalities is greater in hypertensive disorders. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Placental Findings in Preterm and Term Preeclampsia: An Integrative Review of the Literature

INTRODUCTION

 Preeclampsia (PE) is a pregnancy complication associated with increased maternal and perinatal morbidity and mortality. The disease presents with recent onset hypertension (after 20 weeks of gestation) and proteinuria, and can progress to multiple organ dysfunction, with worse outcomes among early onset preeclampsia (EOP) cases (< 34 weeks). The placenta is considered the root cause of PE; it represents the interface between the mother and the fetus, and acts as a macromembrane between the two circulations, due to its villous and vascular structures. Therefore, in pathological conditions, macroscopic and microscopic evaluation can provide clinically useful information that can confirm diagnosis and enlighten about outcomes and future therapeutic benefit.

OBJECTIVE

 To perform an integrative review of the literature on pathological placental findings associated to preeclampsia (comparing EOP and late onset preeclampsia [LOP]) and its impacts on clinical manifestations.

RESULTS

 Cases of EOP presented worse maternal and perinatal outcomes, and pathophysiological and anatomopathological findings were different between EOP and LOP placentas, with less placental perfusion, greater placental pathological changes with less villous volume (villous hypoplasia), greater amount of trophoblastic debris, syncytial nodules, microcalcification, villous infarcts, decidual arteriolopathy in EOP placentas when compared with LOP placentas. Clinically, the use of low doses of aspirin has been shown to be effective in preventing PE, as well as magnesium sulfate in preventing seizures in cases of severe features.

CONCLUSION

 The anatomopathological characteristics between EOP and LOP are significantly different, with large morphological changes in cases of EOP, such as hypoxia, villous infarctions, and hypoplasia, among others, most likely as an attempt to ascertain adequate blood flow to the fetus. Therefore, a better understanding of the basic macroscopic examination and histological patterns of the injury is important to help justify outcomes and to determine cases more prone to recurrence and long-term consequences.