European Journal of Cardiovascular Medicine

Hypertensive disorders during pregnancy (HDP) are major contributors to maternal and perinatal morbidity and mortality worldwide, affecting 5-10% of all pregnancies. In India, the incidence of HDP is approximately 10.08%, as reported by the National Eclampsia Registry (NEP).

HDP can result in significant adverse outcomes for both the mother and the baby, including maternal death, eclampsia, HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelet count), placental abruption, preterm delivery, and the need for cesarean delivery.In newborns,  can cause perinatal death, stillbirth, neonatal death, low birth weight, NICU admission, and serious neonatal morbidity. Intrauterine growth restriction (IUGR) is a key consequence of placental insufficiency, commonly associated with hypertensive disorders during pregnancy. Oligohydramnios, another condition linked to placental insufficiency, can also significantly affect pregnancy outcomes.

Placental insufficiency, which encompasses HDP, fetal growth restriction (FGR), and oligohydramnios, is a primary factor contributing to adverse perinatal outcomes. The interplay between these conditions complicates the management of affected pregnancies, necessitating close monitoring and tailored interventions

Aims and objectives

To compare Maternal and  perinatal outcome of oligohydramnios or fetal growth restrictions(FGR) or both  with normal amniotic fluid index(AFI) and fetal growth in hypertensive disorders in pregnancy(HDP)

• STUDY DESIGN: Retrospective Comparative study
• STUDY AREA: Sapthagiri institute of medical science and research centre
• SAMPLE SIZE :234
• INCLUSION CRITERIA: Parturient mother diagnosed to have Hypertensive disorders in pregnancy
• EXCLUSION CRITERIA: Parturients having irregular antenatal checkups, uterine malformation, uterine infections , history of cardiac disease , kidney disease or liver dysfunction previously ,any drug intake of non steroid anti- inflammatory drugs , smoking and tobacco use ,PROM/PPROM,congenital anomal(renal agensis)

MATERNAL FEATURES AND FETAL OUTCOME

NEONATAL OUTCOME

SUB GROUP ANALYSIS

MATERNAL FEATURES AND OUTCOME         

NEONATAL OUTCOME

Maternal Demographic Features and Outcomes:

The study found no statistically significant differences between the two groups in terms of age, parity, gestational age, HELLP syndrome, hypertensive retinopathy, pulmonary edema, peripartum cardiomyopathy, PRES syndrome, or ICU admission.

However, the HDP group with oligohydramnios or FGR demonstrated significantly higher rates of impaired Doppler findings compared to the normal AFI and fetal growth group (p = 0.004). Cesarean section rates were also higher in the HDP group with oligohydramnios or FGR.

Neonatal Outcomes:A statistically significant difference in neonatal birth weight was observed (p = 0.001). However, there were no significant differences in APGAR scores at 1 and 5 minutes, NICU admissions, respiratory distress syndrome (RDS), or neonatal death rates.

Subgroup Analysis:Comparative analysis between the subgroups (only oligohydramnios, only FGR, and oligohydramnios with FGR) showed no significant differences in maternal demographic factors or other complications such as abruptio placenta, acute fetal distress, HELLP syndrome, or eclampsia.

However, cesarean sections were more common in the FGR and oligohydramnios group compared to the other two groups. NICU admissions and acute fetal distress were significantly higher in the combined FGR and oligohydramnios group (p = 0.05).

The maternal demographic features and outcomes in the study groups revealed no significant differences in terms of age, parity, gestational age, or other serious maternal conditions such as HELLP syndrome, hypertensive retinopathy, or pulmonary edema between the oligohydramnios or fetal growth restriction (FGR) hypertensive disorder of pregnancy (HDP) group and the HDP with normal amniotic fluid index and fetal growth group. However, the oligohydramnios or FGR HDP group exhibited significantly higher rates of impaired Doppler findings and a higher cesarean section rate compared to the other group, indicating more severe complications in these pregnancies.

Regarding neonatal outcomes, a significant difference in neonatal birth weight was observed between the groups, with the oligohydramnios or FGR HDP group having lower birth weights. This suggests that pregnancies complicated by these conditions may lead to more severe fetal growth restriction. However, no significant differences were noted in APGAR scores, NICU requirements, respiratory distress syndrome (RDS), or neonatal death rates, indicating that while birth weight is impacted, other immediate neonatal outcomes may not be as profoundly affected.

In the subgroup analysis, which examined oligohydramnios only, FGR only, and oligohydramnios with FGR, no significant differences were found regarding maternal demographic factors or other complications like abruptio placenta, acute fetal distress, or eclampsia. However, cesarean sections were more common in the FGR and oligohydramnios group compared to the other subgroups. For neonatal outcomes, NICU admissions and acute fetal distress were significantly higher in the FGR and oligohydramnios group, emphasizing the increased risk associated with the combined condition of both oligohydramnios and FGR.

These findings underscore the complexity of pregnancies complicated by oligohydramnios and fetal growth restriction. The presence of both conditions is associated with more severe maternal and neonatal outcomes, suggesting that these pregnancies are at a higher risk of adverse events. Further research is warranted to explore the underlying mechanisms that contribute to these outcomes and to develop more effective management strategies for these high-risk pregnancies.

Although the exact etiology of HDP remains unclear, current theories focus on abnormalities in placental function, particularly during early pregnancy. One key mechanism frequently implicated is the impaired remodeling of the spiral arteries, which normally occurs around the time of implantation. This process is crucial for establishing optimal placental circulation, and when it is disrupted, placental perfusion is compromised. This leads to the characteristic features of HDP, such as maternal hypertension and endothelial dysfunction, which have been extensively documented in the literature (4).

Amniotic fluid volume has become an important marker of fetal well-being. Initially, oligohydramnios was thought to result solely from utero-placental insufficiency, where altered blood flow redirects to essential organs, thereby reducing renal perfusion and fetal urine output, which subsequently decreases amniotic fluid levels. However, recent research suggests that a reduction in amniotic fluid index (AFI) may not be exclusively a response to fetal hypoxia. Instead, placental vascular abnormalities in both maternal and fetal circulations are now considered significant contributors to complications such as FGR, HDP, and oligohydramnios (5, 6). This evolving understanding highlights the intricate relationship between placental dysfunction and fetal health, which may have broader implications for managing these high-risk pregnancies.

Oligohydramnios is recognized as an independent risk factor for early neonatal morbidity, particularly in pregnancies complicated by preterm HDP. Clinical guidelines suggest that an AFI <5 cm can be used as a marker to guide delivery decisions in these high-risk cases. This threshold offers a timely intervention that can reduce neonatal complications, including preterm birth and the associated morbidities (7,15).

Fetal growth restriction (FGR), defined as an estimated fetal weight (EFW) below the 10th percentile, is a significant concern in obstetrics. In the United States, FGR is primarily diagnosed using EFW (17), while in Europe, additional criteria, such as abdominal circumference (AC) <10th percentile and abnormal uterine artery Doppler pulsatility index (PI), are also employed (8). The Royal College of Obstetricians and Gynaecologists (RCOG) underscores that EFW or AC <10th percentile can serve as reliable clinical markers for FGR, although serial measurements assessing growth velocity provide valuable additional insights (9,18). Postnatal criteria, including abnormal Doppler waveforms or a birth weight below the 3rd percentile, further help in identifying and managing FGR cases (10).

Placental pathology in pregnancies affected by FGR often reveals severe abnormalities, including decidual vasculopathy, placental infarction, and fetal thrombotic vasculopathy. These conditions contribute to poor fetal growth and are detectable through abnormal umbilical artery (UA) Doppler findings, which are commonly used to monitor placental function (11, 12). Additionally, emerging biomarkers, such as the sFlt-1:PlGF ratio, have shown promise as supplementary tools in detecting placental insufficiency, offering additional diagnostic value alongside traditional measurements of fetal weight and Doppler parameters (13).

Maternal conditions such as HDP, gestational hypertension, and FGR often share common pathological mechanisms involving impaired placental development and vascular dysfunction. The interplay between these factors underscores the critical need for early detection and monitoring to prevent adverse maternal and fetal outcomes. As our understanding of these complex relationships evolves, clinical management strategies must adapt to minimize complications and improve outcomes for both mothers and their babies (14,19).

In conclusion, while the precise causes of HDP, oligohydramnios, and FGR remain multifactorial, recent advances in our understanding of placental biology, Doppler imaging, and the use of biomarkers provide new insights into the pathophysiology of these conditions. These developments are poised to improve how we diagnose, manage, and treat high-risk pregnancies, ultimately leading to better maternal and fetal outcomes

 This study highlights the relationship between hypertensive disorders during pregnancy and adverse maternal and neonatal outcomes when complicated by oligohydramnios or FGR. The findings suggest that pregnancies involving only oligohydramnios have more favorable outcomes than those involving only FGR or the coexistence of both conditions.Close monitoring and early intervention for patients with FGR or combined oligohydramnios and FGR are recommended to improve pregnancy outcomes. Future research focusing on improved diagnostic tools and monitoring protocols may further enhance the management of these high-risk pregnancies.

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