Hypertensive Disorders in Twin Pregnancies

Twin gestations carry a two to three-fold increased risk of hypertensive disorders compared with singleton pregnancies. These conditions include chronic hypertension, gestational hypertension and preeclampsia, each defined by timing of onset and severity of organ involvement. The dual placental mass of twin pregnancies imposes heightened haemodynamic stress, provoking endothelial dysfunction, altered angiogenic signalling and oxidative stress. Chorionicity determines whether twins share a placenta or have separate placentas, affecting the distribution of blood flow and risk of selective intrauterine growth restriction. Intertwin weight discordance further complicates clinical management, as discordant growth has been linked to more severe maternal blood pressure elevations. Diagnosis often relies on serial blood pressure monitoring and laboratory assessment of liver and renal function, but standard thresholds may be less predictive in multifetal gestations. Globally, hypertensive complications in twin pregnancies contribute substantially to preterm birth, fetal growth restriction and maternal morbidity and mortality. Improved understanding of angiogenic biomarkers and personalised risk profiling promises better prevention and management strategies, particularly in resource-limited settings.

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Hypertensive Disorders in Twin Pregnancies publication trend

The graph below shows the total number of articles in hypertensive disorders in twin pregnancies across all publications each year (not limited to Nature Index journals).

Technical terms

Preeclampsia: A pregnancy-specific syndrome characterised by new-onset hypertension and multi-organ involvement, typically after 20 weeks’ gestation.

Chorionicity: The number of placental chorions in a twin gestation, distinguishing monochorionic from dichorionic twin pregnancies.

sFlt-1/PlGF ratio: The proportion of anti-angiogenic (sFlt-1) to pro-angiogenic (PlGF) factors in maternal blood, used to assess placental function.

Selective intrauterine growth restriction (sIUGR): Disparate growth of one twin due to unequal placental sharing, leading to compromised blood flow in the smaller twin.

Intertwin weight discordance: The percentage difference in birth weight between twins, calculated to assess relative growth disparity within a twin pair.

References

1. sFlt-1 Levels as a Predicting Tool in Placental Dysfunction Complications in Multiple Pregnancies. Biomedicines (2023).
2. Are Twin Pregnancies Complicated by Weight Discordance or Fetal Growth Restriction at Higher Risk of Preeclampsia?. Journal of Clinical Medicine (2020).
3. Preeclampsia in twin pregnancies: association with selective intrauterine growth restriction. The Journal of Maternal-Fetal & Neonatal Medicine (2015).
4. Maternal cardiovascular adaptation to twin pregnancy: a population-based prospective cohort study. BMC Pregnancy and Childbirth (2020).
5. sFlt-1/PlGF ratio as a predictor of pregnancy outcomes in twin pregnancies: a systematic review. The Journal of Maternal-Fetal & Neonatal Medicine (2023).
6. Hypertensive disorders of pregnancy and neonatal outcomes in twin vs. singleton pregnancies after assisted reproductive technology. Frontiers in Pediatrics (2022).