Background:
Triploidy is a rare chromosomal disorder where a fetus has 69 chromosomes instead of 46, usually resulting in early miscarriage(1). HELLP syndrome is a severe form of pre-eclampsia defined by haemolysis, elevated liver enzymes and low platelets(2). Mirror syndrome occurs where there is fetal hydrops, maternal oedema and pre-eclampsia(2,3).
Aim: To highlight a management strategy for this complex condition.
Method: Evaluation of the clinical course and scoping literature review.
Clinical Course:
A 32-year-old woman presented at 16+6 weeks with vomiting and epigastric pain radiating to the back. She was hypertensive, thyrotoxic with TSH <0.01mIU/L (Reference Range (RR) 0.5 – 4.0 mIU/L), Free T4 36.9 pmol/L (RR 10-23 pmol/L) and negative TSH receptor antibody, anaemic with Hb 78g/L (RR 115-165g/L) and had a mild troponin rise of 133ng/L (RR <11 ng/L) with minimal ECG changes. Echocardiogram demonstrated bilateral pleural effusions, raising suspicion for mirror syndrome.
A 12+2 week ultrasound showed increased nuchal translucency (3.1 mm), and non-invasive prenatal testing (NIPT) was low risk for trisomies 13, 18 and 21.
At 17+3/40 ultrasound revealed fetal hydrops, ascites and pleural effusions, leading to a decision for termination. Delivery of fetus and placenta was expedited due to evolving HELLP syndrome with thrombocytopenia (platelets 86 x10^9/L (RR 150-400 x10^9/L)) and increased peripheral oedema. Placental karyotyping confirmed triploidy (69,XXX).
Conclusion:
Progression to HELLP syndrome is a known complication of triploid pregnancies progressing into the second trimester (2,4) which is consistent with this case. Timely delivery of fetus and placenta is necessary to optimise maternal outcomes(2).