A Case of Partial Molar Pregnancy Complicated by HELLP and PRES
Authors: Core Daniel , Vervaeke Hayley , Leethy Kenna , Cooper Danielle 
Published: July 2024

Introduction: The term gestational trophoblastic disease encompasses premalignant and malignant conditions arising from trophoblastic cells. Premalignant disorders include complete or partial hydatidiform mole, whereas malignant disorders include invasive mole, choriocarcinoma, and placental-site trophoblastic tumor. Partial hydatidiform moles are triploid in nature and occur when 2 sperm fertilize a single ovum.

Preeclampsia is a syndrome complicating 2-8% of pregnancies which presents as new-onset hypertension plus proteinuria. The occurrence of hemolysis, elevated liver enzymes and low platelet count, referred to as HELLP syndrome, is a severe form of preeclampsia. A related severe manifestation is posterior reversible encephalopathy syndrome (PRES) - a clinicoradiological syndrome characterized by symptoms including headache, seizures, altered consciousness and visual disturbances. PRES is commonly associated with acute hypertension. The symptoms of PRES vary widely: i.e., the visual disturbance can vary from blurred vision and homonymous hemianopsia to cortical blindness. Seizures and status epilepticus are common.

Although preeclampsia and HELLP syndrome rarely occur before 20-weeks of gestation, reports have suggested early occurrences of these hypertensive disorders specifically in the setting of a molar pregnancy.

Case Report: The patient is a 23-year-old, female gravida 1 at 16 week 5 days who presented to an outside emergency department with a 3-day history of progressive abdominal pain which radiated to her back, arms, and shoulders. At the outside facility, the patient had multiple systolic blood pressures greater than 160 mmHg and had a witnessed 30-second seizure which resolved with an intravenous (IV) injection of 2-mg of Lorazepam and 4-gram magnesium sulfate loading dose. She was initiated on magnesium sulfate maintenance pending transfer to our institution. On admission, the patient met criteria for eclampsia and HELLP (platelets 79,000 K/uL, AST 144 U/L, ALT 96 U/L, LDH 482 U/L, Hemoglobin 8.7 g/dL). The beta human chorionic gonadotropin level (HCG) was greater than 200,000 mIU/mL. Bedside ultrasound suggested the presence of an enlarged cystic placenta and a growth restricted fetus (estimated fetal weight 124g, 2%). The patient and her family were counseled and the decision was made to proceed with misoprostol induction and termination of the pregnancy due to maternal indications. During the induction, the patient developed significant vaginal bleeding and was taken to the operating room for an uncomplicated dilation and evacuation. After the procedure, the patient developed progressive visual blurring with 4+ hyperreflexia. Magnetic resonance imaging (MRI) of the brain with and without contrast was obtained with findings significant for PRES. The MRI revealed T2 high-signal lesions within the cortex of the bilateral occipital lobes. Neurology was consulted and recommended blood pressure control and initiation of levetiracetam for seizure prophylaxis. She was initiated on long-acting nifedipine with subsequent blood pressure control. Patient’s visual symptoms and hyperreflexia resolved. Her liver function tests, platelets, and LDH also returned to normal. The patient received contraceptive counseling to prevent pregnancy during gestational neoplastic disease surveillance period. She underwent weekly beta-hCG until negative, followed by three weekly consecutive negative levels before spacing measurements to every 3 months for a period of six months per National Comprehensive Cancer Network (NCCN) guidelines.

The pathology results indicated the presence of chorionic villi composed of both large hydropic and smaller normal-appearing villi, a 69.3-gram female fetus compatible with caudal neurocutaneous defect with abnormal localization of brain tissue. The genetic profile of the villous tissue consisted of two sets of dispermic paternal alleles in addition to one set of maternal alleles consistent with a partial mole diagnosis.

Discussion: There is an association between preeclampsia and molar pregnancy. Of partial hydatidiform molar pregnancies, 41.9% will develop the symptoms of preeclampsia if left untreated. Although the pathophysiology of eclampsia spectrum disorders is incompletely understood, some evidence points to the role of increased death of trophoblasts and the maternal inflammatory response to trophoblast deportation. Additional evidence points to angiogenic factor imbalance and interestingly, molar placentas produce high levels of antiangiogenic factors. Other causative agents include placental factors that trigger maternal endothelial activation. It is known that trophoblastic debris shed from the placenta into the maternal blood is associated with this condition. It has been demonstrated that trophoblastic debris from molar pregnancies also induces endothelial cell activation through heat-shock protein 70 (HSP70) expressed on a hydatidiform molar placenta, which may be a pathogenic signal to endothelial cells. This case reiterates the association between hydatidiform moles and the hypertensive disorders of pregnancy possibly supporting the theories that such disorders may share an etiologic linkage through trophoblast debris and angiogenic factor imbalance. This case also supports screening molar pregnancies for severe preeclampsia syndrome.