The Impact of  Placentas with ‘at risk’ Pathologies on Pregnancy Outcomes.

 

Four large maternity units in east London:

 

The Royal London, Whipps Cross and Newham University Hospitals (Barts Health NHS Trust) and Homerton University Hospital NHS Trust serve Tower Hamlets, Waltham Forest, Newham and Hackney which are some of the most ethnically diverse communities in the country.

 

Diversity data for Barts Health patients indicates 41% are White, 33% Asian, 14% Black and 12% other.

 

There were 19, 607 deliveries in 2023:

 

Of these, 2022 placentas (10.3%) were referred for histopathology and 656 (32.4%) had ‘at risk’ pathologies - this equates to 3.3% of all deliveries.

‘At risk’ placenta pathologies:

are defined as those with a significant risk of recurrence in future pregnancies. They can be associated with maternal disease and/or modifiable risk factors. They may be divided into:

Developmental pathologies:

Maternal vascular malperfusion (MVM)

Delayed villous maturation (DVM)

placental hypoplasia (<10th centile for gestation)

Idiopathic chronic inflammatory lesions:

High grade villitis of unknown aetiology (HG VUE)

Chronic histiocytic intervillositis (CHI)

Massive perivillous fibrin deposition (MPFD)

Acquired pathologies:

Foetal vascular malperfusion (FVM)

 

Pregnancy outcomes in ‘at risk’ placentas:

 

605 (92.2%) live births

 

45 (6.8%) stillbirths

 

2 x TOP >24/40

 

4 x miscarriages

 

60% live births required EmCS

 

50.6% live births were preterm

 

Maternal demographics in ‘at risk’ placentas

 

Age: mean 31.5 years (range 16-48 years)

 

Gestation: mean 35/40 (range 20-42/40)

 

BMI: 3% <18.5; 36% 18.5-24.9; 60% >25

 

Non-smokers 87%, ex-smoker 7%, smoker 5%

 

Conclusion: ‘at risk’ pathologies are present in one third of placentas sent for histopathology (and 3% of pregnancies). They are  associated with a high risk of emergency C/S and prematurity, and may occur at any gestation (with the exception of DVM - usually diagnosed after 34/40). Our findings suggest there may be a higher prevalence of ‘at risk’ placentas in mothers of Asian ethnicity.

 

A specialist multidisciplinary team in east London provides post-natal follow-up after an affected pregnancy. This includes discussion of complex cases, and individualised counselling with a plan for future pregnancy management.  We hope that this approach facilitates informed decision making about future pregnancies and has the potential to improve their outcomes.