Miscarriage is generally defined as the loss of a
pregnancy before viability. An estimated 23 million
miscarriages occur every year worldwide,
translating to 44
pregnancy losses each minute. The pooled
risk of
miscarriage is 15·3% (95% CI 12·5-18·7%) of all recognised
pregnancies. The
population prevalence of
women who have had one
miscarriage is 10·8% (10·3-11·4%), two
miscarriages is 1·9% (1·8-2·1%), and three or more
miscarriages is 0·7% (0·5-0·8%).
Risk factors for
miscarriage include very young or older
female age (younger than 20 years and older than 35 years), older
male age (older than 40 years), very low or very high body-mass index, Black
ethnicity, previous
miscarriages,
smoking, alcohol, stress, working night shifts,
air pollution, and exposure to
pesticides. The consequences of
miscarriage are both physical, such as
bleeding or
infection, and psychological. Psychological consequences include increases in the
risk of
anxiety,
depression,
post-traumatic stress disorder, and
suicide.
Miscarriage, and especially
recurrent miscarriage, is also a sentinel
risk marker for obstetric
complications, including
preterm birth,
fetal growth restriction,
placental abruption, and
stillbirth in
future pregnancies, and a predictor of longer-term
health problems, such as
cardiovascular disease and
venous thromboembolism. The
costs of
miscarriage affect individuals,
health-care systems, and society. The short-term national economic
cost of
miscarriage is estimated to be £471 million per year in the UK. As
recurrent miscarriage is a sentinel marker for various obstetric
risks in
future pregnancies,
women should receive care in preconception and obstetric clinics specialising in
patients at high
risk. As psychological
morbidity is common after
pregnancy loss, effective
screening instruments and
treatment options for
mental health consequences of
miscarriage need to be available. We recommend that
miscarriage data are gathered and reported to facilitate comparison of rates among countries, to accelerate
research, and to improve
patient care and
policy development. (AU)