By: Christi Eudy
Editor’s Note: To continue commemoration of Pregnancy & Infant Loss Awareness Month, we are featuring a research summary by former FACTS elective student Christi Eudy of a 2021 article, titled “Miscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss.” [1] Eudy highlights the role of FABMs and charting the female cycle to identify pregnancy earlier in its course and moderate some of the risks involved. This provides women at higher risk for miscarriage and their physicians an opportunity to use both the charts and lab testing to assess factors that could increase the risk of another miscarriage, including hormonal imbalance. Progesterone supplementation can be used in these patients, along with other interventions, to support a pregnancy.
Introduction
Miscarriage is a common occurrence with an estimated 23 million miscarriages every year worldwide, or 44 pregnancy losses each minute. Despite the frequency of miscarriages, many women, couples, and healthcare professionals may not fully understand miscarriages, which causes misconceptions and may contribute to increased psychological issues. Most affected women and families want to know why they had a miscarriage, if it will happen again, how they may prevent another one, and how to cope with their loss. The research by Quenby et al. does not claim to answer all these questions, but it does demonstrate the prevalence of miscarriage and discusses unmodifiable and modifiable risk factors, complications, and economic costs. [1]
“Most affected women and families want to know why they had a miscarriage, if it will happen again, how they may prevent another one, and how to cope with their loss.”
Methodology
The researchers performed a comprehensive literature search on MEDLINE to identify systematic reviews published before May 14, 2020. Miscarriage risk factors that were studied included demographic, lifestyle, clinical, and environmental factors. An additional search was conducted for observational studies of obstetric, perinatal, and long-term health risks associated with miscarriage. Search terms and medical terms for miscarriage were combined with each risk factor, pregnancy consequences, and perinatal and long-term health outcomes. Key findings were extracted from nine studies across Europe and North America, with a total of 4,638,974 pregnancies.
Results
The overall miscarriage risk was 15.3% (95% CI 12·5–18·7%) of all recognized pregnancies. Women with no history of miscarriage had an 11% risk of miscarriage, with the risk increasing by about 10% for each additional miscarriage, and up to 42% in women with three or more previous miscarriages. 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%).
Unmodifiable risk factors included age and ethnicity. Women 20 to 29 years old had the lowest risk of miscarriage at 12%, increasing to 65% in women aged 45 years and older. Men older than 40, also had higher risk of miscarriage even after adjusting for the age of his female partner. One plausible cause for the increased risk of miscarriage with age is the parallel increase of pregnancies with chromosomal abnormalities. Additionally, black ethnicity was also associated with an increased risk of miscarriage.
Modifiable risk factors for miscarriage included high female body mass index (BMI), smoking, alcohol, persistent stress, working night shift, exposure to air pollution, and pesticides. The BMI associated with the lowest risk of miscarriage was 18.5 to 24.9 kg/m².
“Modifiable risk factors for miscarriage included high female body mass index (BMI), smoking, alcohol, persistent stress, working night shift, exposure to air pollution, and pesticides.”
Risks of miscarriage include future obstetric complications, increasing the risk of fetal growth restriction, placental abruption, preterm birth, and stillbirth in future pregnancies. The risk of preterm birth increases with each previous miscarriage; women with three or more previous miscarriages are at the highest risk. Effects of miscarriage include both physical consequences (bleeding and infection) and psychological consequences (increased risk of anxiety, depression, post-traumatic stress disorder, and suicide). A history of recurrent miscarriage is also a predictor of longer-term health problems, including cardiovascular disease, venous thromboembolism, and mental health issues.
The economic costs of miscarriage impact individuals, healthcare systems, and society at large. The UK estimates the national economic cost of miscarriage to be £471 million per year, but more research is needed to understand the costs. Furthermore, without a standardized method of data collection and measurement, it is challenging to compare miscarriage rates across countries.
Discussion
Education remains one of the best ways to counter the misconceptions and grief surrounding miscarriage. Unmodifiable risk factors, such as age, ethnicity, and previous miscarriage, play a substantial role in miscarriage rates. Women should be adequately counseled on the risks, ideally earlier in life and prior to conception. Modifiable risk factors, such as high BMI, smoking, alcohol, persistent stress, working night shift, exposure to air pollution, and pesticides, should be explored as potential causes for miscarriage. Once these factors have been discussed and optimized, women should be educated on the fact that over half of miscarriages occur due to chromosomal abnormalities and not due to a preventable factor. Women should be informed of any additional reasons for miscarriage, and effective screening instruments and treatment options for mental health consequences of miscarriage need to be made available.
“Once these modifiable risk factors have been discussed and optimized, women should be educated on the fact that over half of miscarriages occur due to chromosomal abnormalities and not due to a preventable factor.”
If miscarriage does occur, women should receive additional preconception counseling, as previous miscarriage remains a significant risk factor for recurrent miscarriage. Providing additional educational materials and grief counseling tailored to the woman or family may help them cope with the loss.
More research needs to be conducted on the causes and effects of miscarriage, but certain limitations in the data collection process need to addressed. Definitions for miscarriage and recurrent miscarriage vary across countries and medical communities, making accurate collection and comparison of data difficult. Additionally, because many early miscarriages are managed at home, much of the data available is self-reported and may be underreported. Some women may not even realize they experienced a miscarriage, artificially decreasing the number of miscarriages reported. Women who use fertility awareness-based methods (FABMs) and chart their cycles are often able to identify pregnancy earlier in its course, possibly leading to an increase in the number of miscarriages reported, which may more accurately capture the extent of the problem. Addressing some of these limitations will lead to a more accurate comparison of global miscarriage rates, accelerating research, improving patient care, and advancing policy development.
References
[1] Quenby S, Gallos ID, Dhillon-Smith RK, et al. Miscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss. Lancet. 2021;397(10285):1658-1667. doi:10.1016/S0140-6736(21)00682-6
ABOUT THE AUTHOR
Christi Eudy
Christi Eudy is a preliminary general surgery resident at Creighton University in Phoenix, AZ. She has a passion for women’s health and advocacy. She desires to work with the medically underserved both nationally and internationally. Her hobbies outside of medicine include being outdoors, painting, knitting, and drinking lots (and lots) of coffee.
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