From the Guidelines
Approximately 12%–24% of pregnancies result in miscarriage. This estimate is based on the most recent and highest quality study available, which was published in the Journal of Thrombosis and Haemostasis in 2022 1. The study highlights that the majority of miscarriages, about 85%, occur during the first trimester, which may happen before the first appointment with maternity services. It's essential to note that the actual rate of miscarriage might be higher due to miscarriages occurring before a woman knows she's pregnant. The risk factors associated with miscarriage include chromosomal abnormalities, certain medical conditions, structural problems in the uterus, lifestyle factors such as smoking and excessive alcohol consumption, and being significantly underweight or overweight. However, the study does not provide a detailed analysis of these factors.
Key points to consider:
- The risk of miscarriage is highest during the first trimester, with about 85% of miscarriages happening during this period 1.
- The actual rate of miscarriage might be higher due to miscarriages occurring before a woman knows she's pregnant.
- Age is not explicitly mentioned as a risk factor in the study, but it is a known factor in other research.
- Most miscarriages result from chromosomal abnormalities in the developing embryo, which are typically random events not caused by anything the parents did or didn't do.
- Other factors that can increase miscarriage risk include certain medical conditions, structural problems in the uterus, smoking, excessive alcohol consumption, and being significantly underweight or overweight.
It's crucial to prioritize the most recent and highest quality study available when determining the percentage of pregnancies that miscarry, which is why the estimate of 12%–24% is based on the 2022 study published in the Journal of Thrombosis and Haemostasis 1.
From the Research
Miscarriage Statistics
- An estimated 15% of pregnancies end in miscarriage 2
- Approximately 25% of women experience a miscarriage in their lifetime 2
- The pooled risk of miscarriage is 15·3% (95% CI 12·5-18·7%) of all recognised pregnancies 3
- 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%) 3
Risk Factors for Miscarriage
- Very young or older female age (younger than 20 years and older than 35 years) 3
- Older male age (older than 40 years) 3
- Very low or very high body-mass index 3
- Black ethnicity 3
- Previous miscarriages 3
- Smoking, alcohol, stress, working night shifts, air pollution, and exposure to pesticides 3
Management of Miscarriage
- Expectant management, medical management with mifepristone and misoprostol, and surgical management with manual vacuum aspiration are common methods of managing miscarriage 2, 4
- Vaginal micronised progesterone can be recommended to women with early pregnancy bleeding and a history of previous miscarriage to improve the prospects of livebirth 4