From the Research
Investigations for recurrent miscarriages are typically recommended after two consecutive pregnancy losses, especially in women over 35 or those with specific risk factors, as suggested by the most recent and highest quality study 1. The definition of miscarriage is the loss of a pregnancy before viability, with an estimated 23 million miscarriages occurring every year worldwide, translating to 44 pregnancy losses each minute 1. Key factors to consider when deciding on the number of spontaneous miscarriages before investigations should take place include:
- 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%) 1
- Risk factors for miscarriage include very young or older female age, older male age, very low or very high body-mass index, Black ethnicity, previous miscarriages, smoking, alcohol, stress, working night shifts, air pollution, and exposure to pesticides 1
- The consequences of miscarriage are both physical, such as bleeding or infection, and psychological, including increases in the risk of anxiety, depression, post-traumatic stress disorder, and suicide 1
- 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 1 Given the potential consequences of recurrent miscarriage, early investigation is crucial, and the threshold for investigation should be lowered to two consecutive pregnancy losses, especially in women with risk factors or advanced maternal age. The investigation process should involve a comprehensive evaluation, including genetic testing of both partners, assessment of uterine anatomy, hormonal evaluations, testing for antiphospholipid syndrome, and screening for other autoimmune conditions 2. By prioritizing early investigation and comprehensive evaluation, healthcare providers can identify underlying causes of recurrent miscarriage and provide timely interventions to improve future pregnancy outcomes.