Perinatal Outcomes among Thalassaemia Carriers in Hong Kong

Abstract

Objective: To compare adverse pregnancy outcomes, namely low birth weight, low Apgar scores at 1 and 5 minutes, extremely low Apgar scores at 1 and 5 minutes, and preterm delivery between thalassaemia carriers and healthy controls.

Methods: A retrospective review of all pregnancies delivered in a public hospital in Hong Kong in which routine thalassaemia screening was performed at the booking visit was conducted. The obstetric database and medical records from 1 July 2010 to 31 December 2011 were reviewed. Adverse obstetric outcomes between pregnant women who were thalassaemia carriers and healthy controls were compared. Outcomes of interest included low birth weight, low Apgar score at birth, and preterm delivery. Independent paired t test was used to analyse parametric data and Chi-square or Fisher’s exact tests were used to analyse non-parametric data.

Results: A total of 7661 deliveries with valid data were identified during the study period, of which 287 (3.7%) occurred in thalassaemia carriers. Among the 287 thalassaemia carriers, 159 (55.4%), 107 (37.3%), and 21 (7.3%) were found to have α, β, and other haemoglobinopathy, respectively. Anaemia occurred in 6.2% (472/7620) of deliveries for which anaemia data were available. No significant differences in low birth weight (p=0.74), low Apgar scores at 1 minute (p=0.66) and 5 minutes (p=0.72), or preterm delivery (p=0.83) were noted between thalassaemia carriers and healthy controls. However, anaemia in pregnancy was significantly associated with adverse perinatal outcome, including low birth weight (p=0.03), low Apgar scores at 1 minute (p=0.02) and 5 minutes (p=0.04), and preterm delivery (p=0.02).

Conclusion: In general, the course of pregnancy of thalassaemia carriers was favourable without significant adverse perinatal outcomes. However, adverse outcomes were associated with anaemia. We recommend vigilant investigation, treatment, and prevention of anaemia to improve pregnancy outcomes.