Abstract
Introduction
Spontaneous pregnancy loss (SPL) is a common health problem that affects 1:10 of childbearing women, and is linked with physical and psychological complications. As the number of nationwide studies on the incidence of SPL is few, especially from middle‐income countries, in this study we investigated the epidemiology, complications and outcomes of SPL before 22 weeks of gestation by analyzing large‐scale healthcare data from the Unified Nationwide Electronic Healthcare System (UNEHS) in Kazakhstan.
Material and methods
A population‐based study among women who experienced SPL in any healthcare setting of the Republic of Kazakhstan during the period of 2014–2019. The International Classification of Diseases (ICD) 10th edition and ICD 9th edition's procedural codes were utilized to retrieve data using relevant diagnostic and procedural codes.
Results
In total, 207 317 records of women who have experienced an SPL before 22 weeks of gestation were analyzed from all Kazakhstani regions. The estimated prevalence of SPL was 8.7%, with a 20% decline over a 6‐year period. The SPL cases ratio comprises on average 6.2 per 1000 reproductive‐age women. Incomplete miscarriage (ICD‐10 code “O03.4”) was the most common type (37.8%), followed by blighted ovum (ICD‐10 code “O02.0”; 34.1%) and missed abortion (ICD‐10 code “O02.1”; 13.5%). The most common management methods were dilation and curettage of the uterus (ICD‐9 code “69.0”; 84.7%) and aspiration curettage of the uterus (ICD‐9 code “65.0”; 15%), whereas medical management was rarely performed (2.6%).
Conclusion
The information available in UNEHS adequately identifies types of miscarriages and treatment methods. Although the prevalence of SPL before 22 weeks of gestation is decreasing, management of miscarriages requires closer attention.
Keywords: epidemiology, maternity care, miscarriage, spontaneous pregnancy loss, women's health issues
The prevalence of spontaneous pregnancy loss was high among Kazakhstani reproductive‐age women; however, it decreases with age. Appropriate management of miscarriages could help to improve the overall health indicators of reproductive‐age women.
Abbreviations
- ICD
International Classification of Diseases
- RPL
recurrent pregnancy loss
- SPL
spontaneous pregnancy loss
- UNEHS
Unified Nationwide Electronic Healthcare System
- WHO
World Health Organization
Key message.
The prevalence of spontaneous pregnancy loss was high among Kazakhstani reproductive‐age women; however, it decreases with age. Appropriate management of miscarriages could help to improve the overall health indicators of reproductive‐age women.
1. INTRODUCTION
Spontaneous pregnancy loss (SPL), also referred to as a miscarriage or spontaneous abortion, is defined as the loss of intrauterine pregnancy not caused by medical or surgical intervention aimed at termination of pregnancy. 1 , 2 , 3 , 4 Varying definitions of pregnancy loss and variations between gestational ages at SPL were reported by different regulating societies. 5 , 6 The World Health Organization (WHO) defines miscarriage as the expulsion of a fetus (embryo) weighing less than 500 g, equivalent to approximately 22 weeks of gestation, 5 while the American Society for Reproductive Medicine defines SPL as the loss of an embryo before 20 weeks of gestational age. 7 Furthermore, the European Society of Human Reproduction and Embryology characterizes spontaneous miscarriage as the pregnancy loss at <24 weeks of gestation age. 4
SPL is generally categorized into threatened, inevitable, incomplete, complete, missed, recurrent and septic abortions. 3 , 5 , 8 Based on the gestational age at termination of pregnancy, SPL can be divided into early (<12 weeks), and late (13 to 22–24 weeks). 6 , 8 A subset of SPL is recurrent pregnancy loss (RPL), defined by at least two (or three) consequent miscarriages 9 depending on the guideline followed. 4 , 7 , 10
The incidence of SPL is difficult to estimate because some early pregnancy losses may occur before the patient knows she is pregnant. 6 Moreover, the incidence is different among various age groups. Nearly 10%–15% of clinical pregnancies and an estimated 30% of all pregnancies terminate with spontaneous pregnancy losses, making it the most frequent pregnancy complication. 3 , 5 , 6 , 11 , 12 Furthermore, the risk of pregnancy loss is significantly affected by a woman's age as well as the number of previous miscarriages. Thus, the overall incidence in women of all ages is reported at 12%–20%; in women between aged between 25 and 29 years it reaches up to 27% and in women aged over 45 years up to 75%. 5 , 13 At the same time, the lowest risk of SPL is for women without a history of pregnancy losses, and the risk rises by roughly 10% with each subsequent pregnancy loss and is the highest in women who experienced three or more spontaneous pregnancy losses (42%). 5 In the case of RPL, due to variance in the definitions, it is quite difficult to determine the prevalence, which varies between 1% and 5%. 4 , 14 , 15
Multiple etiologic factors are associated with a heightened risk of pregnancy loss, which includes single autosomal trisomy 15, 16, 21 or 22 and aneuploidy (>80%), advanced maternal age (9%–75%), uterine morphologic pathologies (10%–15%), endocrine diseases (17%–20%), thrombophilia, infectious agents (0.5%–5%) and autoimmune disorders (20%). 5 , 6 , 8 , 16 , 17 , 18 Other risk factors for SPL include cigarette smoking, alcohol use, black ethnicity, the outcome of earlier pregnancies and environmental factors. 2 , 5 , 6 , 19 Despite the identification of these and related factors, the exact cause is unexplained (idiopathic) and not clearly identified in >50% of the cases. 15 , 20
The Republic of Kazakhstan is a middle‐income Central Asian country with a population of 19 million; 21 , 22 females account for 52%, of whom 51% are of reproductive age. 22 , 23 , 24 The annual number of deliveries is approximately 400 000. The Kazakhstani government prioritizes support for maternity and childcare 22 , 25 , 26 and has approved a US$7.5 billion State Program for the Development of Healthcare 2020–2025, 26 which targets the reduction of maternal mortality to 14.5 per 100 000 live births and a reduction of infant mortality to 8.3 per 1000 live births. The national guidelines in Kazakhstan define SPL according to the WHO criteria. 5 , 27 However, the incidence of spontaneous pregnancy losses is not documented or included in the annual health reports of the Ministry of Healthcare. 28 Therefore, the aim of this study was to investigate the epidemiology, complications and outcomes of SPL before 22 weeks of gestation by analyzing large‐scale Kazakhstani healthcare data from the Unified Nationwide Electronic Healthcare System (UNEHS). The hypothesis was that there is a high prevalence of miscarriages among reproductive‐age women in Kazakhstan.
2. MATERIAL AND METHODS
2.1. Study design and population
The study population consisted of patients who were hospitalized with SPL at ≤21+6 weeks of gestation in any Kazakhstani clinical setting during 2014–2019. The data were retrieved from UNEHS, which was introduced at the end of 2013 to unify healthcare data storage through the country's healthcare system. 29 Admissions to hospitals within 42 days and related to the initial one were also analyzed. Identification of these women in UNEHS and hospital records was based on the personal identification number assigned to every Kazakhstani citizen. The following variables were available from the system: patient demographic data (age, sex, ethnicity, location of residency), dates of hospital admission, discharge and outcomes, surgical procedures, diagnoses and admission type. The International Classification of Diseases (ICD), 9th and 10th editions were used for coding surgeries and diagnoses (primary and complication), respectively.
For this study, SPL was defined according to the Kazakhstani national guideline on pregnancy loss management as a nonviable intrauterine pregnancy loss at up to the 22nd week of pregnancy, or the birth of a fetus weighing <500 g. 27
2.2. Patient identification and definitions
The initial cohort consists of 30 168 604 medical records of women registered for pregnancy, childbirth and puerperium follow‐up. A total of 211 381 records of SPL cases were identified using specific ICD‐10 codes (https://www.icd10data.com/) as selection criteria for this study (Table S1). In addition, specific ICD‐9 procedural codes (https://www.icd10data.com/) were applied to retrieve information on the surgical management of miscarriage cases (Table S1). Rare surgeries linked to the ICD‐10 “O.02”–“O.03” codes were retrieved as well. After removing duplicates and data cleaning, a dataset for 207 317 SPL cases was extracted, which corresponds to 189 997 unique patients, as some patients had repetitive spontaneous loss of pregnancy. The detailed patient selection process is depicted in Figure 1.
FIGURE 1.
Data identification flow chart.
2.3. Statistical analysis
STATA 16 MP2 software was used for data processing and statistical analysis. 30 The demographic characteristics of study participants were presented as frequencies and percentages. Since age distribution did not follow a normal (Gaussian) distribution, differences in median values and interquartile range were tested by the non‐parametric Kruskal–Wallis test. In bivariate analyses, Kruskal–Wallis and Pearson's chi‐square tests were used in assessing the significance of the cross‐tabulation between demographic characteristics and the main diagnosis; two‐sided P‐values <0.05 were considered significant.
2.4. Ethics statement
The study was conducted in compliance with the Declaration of Helsinki and approved by the Nazarbayev University Institutional Review Ethics Committee (protocol reference NU‐IREC 490/18112021 and 599/05092022, approved on September 29, 2022). Exemption from informed consent has been granted to this study due to the retrospective nature of the study, in which only anonymous data were analyzed.
3. RESULTS
3.1. Study population description
For the period of 6 years (2014–2019), 2 374 530 pregnancies were registered in the country. In total, 207 317 records of women who have experienced an SPL before 22 weeks of gestation were identified and analyzed in the national electronic database from all Kazakhstani regions (Figure 1). Figure 2 shows the dynamics of SPL prevalence before 22 weeks of gestation. Over the period of 6 years (2014–2019), there was a 20% decline in rates of pregnancy loss from 38 897 to 30 998 cases. Based on these data, the overall estimated prevalence of SPL was calculated at the level of 8.7%. The detailed yearly prevalence is shown in Figure 2, with the highest reported in 2014 (10%) and the lowest in 2019 (7.5%).
FIGURE 2.
Prevalence of spontaneous pregnancy loss (2014–2019).
A summary of the social and demographic characteristics of the study participants is provided in Table 1. Maternal age ranged from 18 to 55 years, and the median age of the participants was 29 years (interquartile range 24–35). The majority of women with SPL were at an early reproductive age, between 20 and 34 years (69.8%); 25.6% of participants were between 35 and 44 years old. Notably, 8202 patients (4%) were 15–19 years old. The SPL ratio per 1000 women of corresponding age was high among women in the 20–24, 25–29 and 30–34 age groups; 10.8, 11.0 and 10.6, respectively.
TABLE 1.
Study participants characteristics and spontaneous pregnancy loss facts (2014–2019).
| Variables | Median (IQR) or n (%) | Per 1000 women of corresponding age | Diagnosis, n (%) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N96 | O02.0 | O02.1 | O03.0 | O03.1 | O03.2 | O03.3 | O03.4 | O03.7 | O03.8 | O03.9 | p‐Value | |||
| Age, median (IQR) | 29 (24; 35) | ‐ | 31.0 (26.0, 36.0) | 30.0 (25.0, 35.0) | 30.0 (25.0, 36.0) | 28.0 (24.0, 34.0) | 29.0 (24.0, 34.0) | 29.0 (25.0, 33.0) | 30.0 (24.0, 34.0) | 29.0 (24.0, 34.0) | 34.0 (30.0, 35.0) | 28.0 (24.0, 33.0) | 29.0 (24.0, 34.0) | <0.001 |
| Age groups | ||||||||||||||
| 15–19 | 8202 (4%) | 2.5 | 3 (2.2%) | 2261 (3.5%) | 817 (2.9%) | 296 (4.0%) | 1010 (4.3%) | 4 (5.7%) | 14 (4.8%) | 3587 (4.6%) | 0 (0.0%) | 37 (6.1%) | 173 (4.3%) | <0.001 |
| 20–24 | 43 167 (20.8%) | 10.8 | 21 (15.7%) | 12 773 (19.6%) | 5170 (18.5%) | 1735 (23.5%) | 4945 (21.1%) | 12 (17.1%) | 69 (23.5%) | 17 433 (22.3%) | 1 (20.0%) | 123 (20.9%) | 885 (22.1%) | |
| 25–29 | 54 429 (26.3%) | 11.0 | 30 (22.4%) | 16 623 (25.5%) | 7214 (25.8%) | 2114 (28.6%) | 6289 (26.8%) | 20 (28.6%) | 60 (20.4%) | 20 862 (26.7%) | 0 (0.0%) | 167 (28.4%) | 1050 (26.2%) | |
| 30–34 | 47 000 (22.7%) | 10.6 | 37 (27.6%) | 15 086 (23.2%) | 6504 (23.3%) | 1647 (22.3%) | 5388 (22.9%) | 18 (25.7%) | 84 (28.6%) | 17 164 (21.9%) | 2 (40.0%) | 134 (22.8%) | 936 (23.4%) | |
| 35–39 | 36 213 (17.5%) | 9.6 | 29 (21.6%) | 12 173 (18.7%) | 5367 (19.2%) | 1103 (14.9%) | 3855 (16.4%) | 9 (12.9%) | 42 (14.3%) | 12 863 (16.4%) | 1 (20.0%) | 91 (15.5%) | 680 (17.0%) | |
| 40–44 | 16 879 (8.1%) | 4.7 | 12 (9.0%) | 5839 (9.0%) | 2641 (9.5%) | 449 (6.1%) | 1805 (7.7%) | 7 (10.0%) | 21 (7.1%) | 5808 (7.4%) | 1 (20.0%) | 32 (5.4%) | 264 (6.6%) | |
| 45–49 | 1396 (0.7%) | 0.4 | 2 (1.5%) | 378 (0.6%) | 213 (0.8%) | 36 (0.5%) | 187 (0.8%) | 0 (0.0%) | 4 (1.4%) | 552 (0.7%) | 0 (0.0%) | 4 (0.7%) | 20 (0.5%) | |
| 50+ | 31 (<1%) | 0.01 | 0 (0.0%) | 10 (<1%) | 3 (<1%) | 2 (<1%) | 5 (<1%) | 0 (0.0%) | 0 (0.0%) | 11 (<1%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | |
| Ethnicity | ||||||||||||||
| Kazakh | 156 519 (75.5%) | 6.6 | 77 (57.5%) | 50 035 (76.8%) | 22 034 (78.9%) | 5893 (79.8%) | 15 624 (66.5%) | 64 (91.4%) | 209 (71.1%) | 59 158 (75.6%) | 3 (60.0%) | 507 (86.2%) | 2915 (72.7%) | <0.001 |
| Russian | 26 745 (12.9%) | 6.8 | 26 (19.4%) | 6823 (10.5%) | 3496 (12.5%) | 661 (9.0%) | 5005 (21.3%) | 2 (2.9%) | 39 (13.3%) | 10 024 (12.8%) | 1 (20.0%) | 43 (7.3%) | 625 (15.6%) | |
| Other | 22 978 (11.1%) | 6.8 | 31 (23.1%) | 7966 (12.2%) | 2249 (8.1%) | 775 (10.5%) | 2728 (11.6%) | 4 (5.7%) | 46 (15.6%) | 8684 (11.1%) | 1 (20.0%) | 37 (6.3%) | 457 (11.4%) | |
| Missing data | 1075 (0.5%) | ‐ | 0 (0.0%) | 319 (0.5%) | 150 (0.5%) | 53 (0.7%) | 127 (0.5%) | 0 (0.0%) | 0 (0.0%) | 414 (0.5%) | 0 (0.0%) | 1 (0.2%) | 11 (0.3%) | |
| Location | ||||||||||||||
| Almaty city | 24 742 (11.9%) | 6.8 | 68 (50.7%) | 5164 (7.9%) | 9209 (33%) | 1342 (18.2%) | 187 (0.8%) | 2 (2.9%) | 32 (10.9%) | 8615 (11.0%) | 1 (20.0%) | 1 (0.2%) | 121 (3.0%) | <0.001 |
| Astana city (capital) | 12 010 (5.8%) | 6.7 | 6 (4.5%) | 6586 (10.1%) | 637 (2.3%) | 2420 (32.8%) | 521 (2.2%) | 1 (1.4%) | 2 (0.7%) | 1747 (2.2%) | 0 (0.0%) | 2 (0.3%) | 88 (2.2%) | |
| Rural | 79 335 (38.3%) | 6.8 | 25 (18.7%) | 24 789 (38.1%) | 6612 (23.7%) | 1495 (20.3%) | 8927 (38.0%) | 54 (77.1%) | 167 (56.8%) | 34 483 (44.1%) | 3 (60.0%) | 263 (44.7%) | 2517 (62.8%) | |
| Urban | 127 982 (61.7%) | 6.7 | 109 (81.3%) | 40 354 (61.9%) | 21 317 (76.3%) | 5887 (79.7%) | 14 557 (62.0%) | 16 (22.9%) | 127 (43.2%) | 43 797 (55.9%) | 2 (40.0%) | 325 (55.3%) | 1491 (37.2%) | |
| Total | 207 317 (100%) | 6.8 | 134 (0.06%) | 65 143 (31.4%) | 27 929 (13.5%) | 7382 (3.5%) | 23 484 (11.3%) | 70 (<0.1%) | 294 (0.1%) | 78 280 (37.8%) | 5 (<0.1%) | 588 (0.3%) | 4008 (1.9%) | |
Note: ICD‐10 codes: N96 – habitual abortion; O02.0 – blighted ovum and non‐hydatidiform mole; O02.1 – missed abortion; O03.0 – spontaneous abortion, incomplete, complicated by genital tract and pelvic infection; O03.1 – spontaneous abortion, incomplete, complicated by delayed or excessive hemorrhage; O03.2 – spontaneous abortion, incomplete, complicated by embolism; O03.3 – spontaneous abortion, incomplete, with other and unspecified complications; O03.4 – spontaneous abortion, incomplete, without complication; O03.7 – spontaneous abortion, complete or unspecified, complicated by embolism; O03.8 – spontaneous abortion, complete or unspecified, with other and unspecified complications; O03.9 – spontaneous abortion, complete or unspecified, without complication.
The ethnic distribution of the investigated population included 75.5% of Kazakh ethnicity, 12.9% of Russian ethnicity and 11.1% of other ethnic groups. The distribution of cases analyzed from the country regions was diverse/unequal. The largest number of SPL was reported from Almaty city (11.9%, 6.8 per 1000 reproductive‐age women) (Table 1). High numbers were also found in the Almaty (10.7%) and Turkestan regions (10.3%) (Table S2). The number of urban residents among patients with spontaneous pregnancy losses was higher than the rural ones; respectively 61.7% and 38.3% (Table 1).
3.2. Spontaneous pregnancy loss rates
SPL was assessed based on the ICD‐10 code classification. As shown in Table 1 and Figure 3, incomplete spontaneous pregnancy losses, without complications (ICD‐10 code “O03.4”) was reported as the most common type of pregnancy loss (37.8%). The second most frequent condition was a blighted ovum and non‐hydatidiform mole (ICD‐10 code “O02.0”), which was registered in 34.1% of all SPL cases. Missed abortion (ICD‐10 code “O02.1”) was reported in 13.5% of patients, and RPL (ICD‐10 code “N96”) in only 0.06% of patients. Incomplete, spontaneous abortion complicated by excessive bleeding (ICD‐10 code “O03.1”) occurred in 11.3% of women.
FIGURE 3.
Spontaneous pregnancy loss distribution by The International Classification of Diseases (ICD‐10) diagnoses. ICD‐10 codes: N96 – habitual abortion; O02.0 – blighted ovum and non‐hydatidiform mole; O02.1 – missed abortion; O03.0 – spontaneous abortion, incomplete, complicated by genital tract and pelvic infection; O03.1 – spontaneous abortion, incomplete, complicated by delayed or excessive hemorrhage; O03.2 – spontaneous abortion, incomplete, complicated by embolism; O03.3 – spontaneous abortion, incomplete, with other and unspecified complications; O03.4 – spontaneous abortion, incomplete, without complication; O03.7 – spontaneous abortion, complete or unspecified, complicated by embolism; O03.8 – spontaneous abortion, complete or unspecified, with other and unspecified complications; O03.9 – spontaneous abortion, complete or unspecified, without complication.
Of all analyzed records, 93.5% of patients were admitted via the emergency route due to vaginal bleeding (Table 2), except for RPL cases, where 53.7% were planned, compared with 46.3% of urgent hospitalizations. The vast majority of patients with SPL were discharged after treatment (98.3%) with recovery or improvement (65.5% and 34.5%, respectively).
TABLE 2.
Spontaneous pregnancy loss hospital‐based management indicators (2014–2019).
| Variables | Median (IQR) or N (%) | Diagnosis, n (%) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N96 | O02.0 | O02.1 | O03.0 | O03.1 | O03.2 | O03.3 | O03.4 | O03.7 | O03.8 | O03.9 | P‐value | ||
| Admission | |||||||||||||
| Emergency | 193 795 (93.5%) | 62 (46.3%) | 54 970 (84.4%) | 26 740 (95.7%) | 7267 (98.4%) | 22 854 (97.3%) | 59 (84.3%) | 275 (93.5%) | 77 156 (98.6%) | 4 (80.0%) | 579 (98.5%) | 3829 (95.5%) | <0.001 |
| Planned | 13 522 (6.5%) | 72 (53.7%) | 10 173 (15.6%) | 1189 (4.3%) | 115 (1.6%) | 630 (2.7%) | 11 (15.7%) | 19 (6.5%) | 1124 (1.4%) | 1 (20.0%) | 9 (1.5%) | 179 (4.5%) | |
| Outcome of stay | |||||||||||||
| Death | 18 (0.0%) | 0 (0.0%) | 5 (<1%) | 1 (<1%) | 2 (<1%) | 6 (<1%) | 0 (0.0%) | 0 (0.0%) | 4 (<1%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | <0.001 |
| Discharge | 203 850 (98.3%) | 134 (100%) | 64 532 (99.1%) | 27 462 (98.3%) | 7133 (96.6%) | 22 811 (97.1%) | 69 (98.6%) | 285 (96.9%) | 76 870 (98.2%) | 5 (100.0%) | 579 (98.5%) | 3970 (99.1%) | |
| Transfer | 229 (0.1%) | 0 (0.0%) | 38 (0.1%) | 35 (0.1%) | 10 (0.1%) | 33 (0.1%) | 0 (0.0%) | 3 (1.0%) | 101 (0.1%) | 0 (0.0%) | 3 (0.5%) | 6 (0.1%) | |
| Voluntary discharge | 3220 (1.6%) | 0 (0.0%) | 568 (0.9%) | 431 (1.5%) | 237 (3.2%) | 634 (2.7%) | 1 (1.4%) | 6 (2.0%) | 1305 (1.7%) | 0 (0.0%) | 6 (1.0%) | 32 (0.8%) | |
| Outcome of treatment | |||||||||||||
| Deterioration | 19 (0.0%) | 0 (0.0%) | 2 (<1%) | 3 (<1%) | 1 (<1%) | 5 (<1%) | 0 (0.0%) | 0 (0.0%) | 8 (<1%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | <0.001 |
| Improvement | 71 417 (34.5%) | 26 (19.4%) | 20 235 (31.1%) | 14 059 (50.3%) | 3020 (40.9%) | 6156 (26.2%) | 20 (28.6%) | 107 (36.4%) | 26 516 (33.9%) | 3 (60.0%) | 51 (8.7%) | 1224 (30.5%) | |
| Recovery | 135 717 (65.5%) | 108 (80.6%) | 44 868 (68.9%) | 13 850 (49.6%) | 4350 (58.9%) | 17 297 (73.7%) | 50 (71.4%) | 184 (62.6%) | 51 693 (66.0%) | 2 (40.0%) | 536 (91.2%) | 2779 (69.3%) | |
| Without changes | 146 (0.1%) | 0 (0.0%) | 33 (0.1%) | 16 (0.1%) | 9 (0.1%) | 20 (0.1%) | 0 (0.0%) | 3 (1.0%) | 59 (0.1%) | 0 (0.0%) | 1 (0.2%) | 5 (0.1%) | |
| Total | 207 317 (100%) | 134 (0.06%) | 65 143 (31.4%) | 27 929 (13.5%) | 7382 (3.5%) | 23 484 (11.3%) | 70 (<0.1%) | 294 (0.1%) | 78 280 (37.8%) | 5 (<0.1%) | 588 (0.3%) | 4008 (1.9%) | |
Note: Outcome of stay terminology description: discharge – patient went home after treatment; transfer – patient was transferred to another hospital; voluntary discharge – patient left hospital before treatment was completed due to personal demand; death – patient death associated with treatment/surgery. Outcome of treatment terminology description: without changes – patient was discharged without improvement; recovery – patient was discharged with recovery; improvement – patent was discharged with improvement; deterioration – patent was discharged/transferred to another hospital with deterioration.
3.3. Surgical procedures performed for the management of spontaneous pregnancy loss
These surgical procedures are summarized in Table 3. As seen from the Table, the most common invasive procedure was dilation and curettage of the uterus (ICD‐9 code “69.0”) in 84.7% of cases. The second most common procedure was aspiration curettage of the uterus (ICD‐9 code “65.0”) in 15% of cases. Table 3 shows evidence of the decreasing numbers of dilation and curettage procedure cases over a 6‐year period (2014–2019), whereas the numbers of aspiration and curettage of uterus increased in the same period.
TABLE 3.
Procedures performed for the management of spontaneous pregnancy loss.
| Procedure type | ICD‐9 code | n (%) | Years | P‐value | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | ||||
| Dilation and curettage | 69 | 175 554 (84.7%) | 35 044 (90.1%) | 33 156 (89.9%) | 30 574 (88.5%) | 27 818 (81.7%) | 25 573 (80.1%) | 23 389 (75.5%) | <0.001 |
| Dilation and curettage of uterus | 69.0 | 5005 (2.4%) | 1307 (3.4%) | 948 (2.6%) | 968 (2.8%) | 761 (2.2%) | 872 (2.7%) | 149 (0.5%) | |
| Dilation and curettage for termination of pregnancy | 69.01 | 34 750 (16.8%) | 4414 (11.3%) | 4517 (12.2%) | 4815 (13.9%) | 5299 (15.6%) | 5307 (16.6%) | 10 398 (33.5%) | |
| Dilation and curettage following delivery or abortion | 69.02 | 127 141 (61.3%) | 26 647 (68.5%) | 25 854 (70.1%) | 23 585 (68.2%) | 20 782 (61.0%) | 18 635 (58.4%) | 11 638 (37.5%) | |
| Other dilation and curettage | 69.09 | 8658 (4.2%) | 2676 (6.9%) | 1837 (5.0%) | 1206 (3.5%) | 976 (2.9%) | 759 (2.4%) | 1204 (3.9%) | |
| Aspiration curettage of uterus | 31 275 (15%) | 3780 (9.7%) | 3654 (9.9%) | 3916 (11.3%) | 6157 (18.1%) | 6264 (19.6%) | 7504 (24.2%) | ||
| Aspiration curettage of uterus for termination of pregnancy | 69.51 | 6716 (3.2%) | 77 (0.2%) | 134 (0.4%) | 641 (1.9%) | 1608 (4.7%) | 1464 (4.6%) | 2792 (9.0%) | |
| Aspiration curettage following delivery or abortion | 69.52 | 22 473 (10.8%) | 3642 (9.4%) | 3486 (9.5%) | 3140 (9.1%) | 4060 (11.9%) | 4168 (13.1%) | 3977 (12.8%) | |
| Other aspiration curettage of uterus | 69.59 | 2086 (1.0%) | 61 (0.2%) | 34 (0.1%) | 135 (0.4%) | 489 (1.4%) | 632 (2.0%) | 735 (2.4%) | |
| Hysterectomy overall | 146 (<1%) | 25 (0.1%) | 21 (0.1%) | 25 (0.1%) | 34 (0.1%) | 24 (0.1%) | 17 (0.1%) | ||
| Subtotal abdominal hysterectomy | 68.3 | 60 (0.1%) | 12 (<1%) | 12 (<1%) | 8 (<1%) | 15 (<1%) | 13 (<1%) | 0 (0.0%) | |
| Laparoscopic supracervical hysterectomy | 68.31 | 3 (<1%) | 0 (0.0%) | 1 (<1%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 2 (<1%) | |
| Other subtotal abdominal hysterectomy, not specified | 68.39 | 9 (<1%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 9 (<1%) | |
| Total abdominal hysterectomy | 68.4 | 68 (<1%) | 13 (<1%) | 8 (<1%) | 17 (<1%) | 18 (0.1%) | 11 (<1%) | 1 (<1%) | |
| Other and unspecified total abdominal hysterectomy | 68.49 | 6 (<1%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 1 (<1%) | 0 (0.0%) | 5 (<1%) | |
| Uterine repair | 38 (<1%) | 3 (<1%) | 5 (<1%) | 4 (<1%) | 1 (<1%) | 3 (<1%) | 22 (0.1%) | ||
| Suture of laceration of uterus | 69.41 | 9 (<1%) | 2 (<1%) | 2 (<1%) | 1 (<1%) | 0 (0.0%) | 1 (<1%) | 3 (<1%) | |
| Other repair of uterus | 69.49 | 29 (<1%) | 1 (<1%) | 3 (<1%) | 3 (<1%) | 1 (<1%) | 2 (<1%) | 19 (0.1%) | |
| Cesarean section and removal of fetus | 283 (<1%) | 44 (0.1%) | 41 (0.1%) | 44 (0.1%) | 53 (0.2%) | 43 (0.1%) | 58 (0.2%) | ||
| Cesarean section of other specified type | 74.4 | 129 (0.1%) | 27 (0.1%) | 22 (0.1%) | 18 (0.1%) | 23 (0.1%) | 15 (<1%) | 24 (0.1%) | |
| Hysterotomy to terminate pregnancy | 74.91 | 175 (0.1%) | 18 (<1%) | 21 (0.1%) | 27 (0.1%) | 36 (0.1%) | 31 (0.1%) | 42 (0.1%) | |
In rare cases due to the existing uterine scars, placenta previa and severe life‐threatening bleeding for management of SPL, hysterectomy and cesarean section had to be done (Table 3). Management with medications (misoprostol) was as rare, as 2.6% and 0.1% of patients had repeated dilation and curettage procedure performed due to retained chorionic tissue of hematometra.
3.4. Complications
Complications reported in the UNEHS are shown in Table 4. Only 957 cases of complications (0.5%) were registered for the 207 317 cases of SPL before 22 weeks of gestation. The most common complications were acute posthemorrhagic anemia (ICD‐10 code “D62”) and hematometra (ICD‐10 code “N85.7”), reported in 15.3% and 14.4% of cases, respectively. Shock following abortion (ICD‐10 code “O08.3”) was registered in 10.2%. Acute inflammatory disease of the uterus (ICD‐10 code “N71.0”) was reported in 2.8% after SPL. Rare complications such as damage to pelvic organs and tissues following abortion and ectopic and molar pregnancy (ICD‐10 code “O08.6”) and disseminated intravascular coagulation (ICD‐10 code “D65”) were registered in 13% and 0.9% of cases, respectively (Table 4). According to the data analyzed, 18 patients died due to complications (Table 2): six cases due to incomplete spontaneous abortion, complicated by delayed or excessive hemorrhage (ICD‐10 code “O03.1”), five patients with the blighted ovum and non‐hydatidiform mole (ICD‐10 code “O02.0”), four cases of incomplete spontaneous abortion, without complications (ICD‐10 code “O03.4”), two cases due to incomplete spontaneous abortion complicated by pelvic infection (ICD‐10 code “O03.0”), and one patient with missed abortion complicated by bleding (ICD‐10 code “O02.1”).
TABLE 4.
Complications reported after spontaneous pregnancy loss among the study cases.
| Complication | ICD‐10 code | n (%) | Years | P‐value | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | ||||
| Acute posthemorrhagic anemia | D62 | 147 (15.3%) | 36 (3.8%) | 20 (2%) | 12 (1.2%) | 25 (2.6%) | 27 (2.8%) | 27 (2.8%) | <0.001 |
| Hematometra | N85.7 | 138 (14.4%) | 38 (3.9%) | 25 (2.6%) | 27 (2.8%) | 19 (1.9%) | 18 (1.8%) | 11 (1.1%) | |
| Iron deficiency anemia secondary to blood loss | D50.0 | 120 (12.5%) | 30 (3.1%) | 24 (2.5%) | 14 (1.4%) | 12 (1.2%) | 29 (3%) | 11 (1.1%) | |
| Shock following abortion | O08.3 | 98 (10.2%) | 16 (1.6%) | 27 (2.8%) | 18 (1.8%) | 17 (1.7%) | 6 (0.6%) | 14 (1.4%) | |
| Maternal care due to uterine scar from previous surgery | O34.2 | 36 (3.8%) | 7 (0.7%) | <5 (0.5%) | 5 (0.5%) | 3 (0.3%) | 11 (1.1%) | 9 (0.9%) | |
| Acute inflammatory disease of uterus | N71.0 | 27 (2.8%) | 6 (0.6%) | 9 (0.9%) | 4 (0.4%) | 5 (0.5%) | 2 (0.2%) | <5 (0.5%) | |
| Delayed or excessive hemorrhage following abortion | O08.1 | 25 (2.6%) | 7 (0.7%) | 4 (0.4%) | 5 (0.5%) | 2 (0.2%) | 2 (0.2%) | 5 (0.5%) | |
| Other iron deficiency anemias | D50.8 | 24 (2.5%) | <5 (<1%) | 5 (0.5%) | 4 (0.4%) | 2 (0.2%) | 4 (0.4%) | 8 (0.8%) | |
| Genital tract and pelvic infection following abortion and ectopic and molar pregnancy | O08.0 | 13 (1.3%) | 4 (0.4%) | 2 (0.2%) | 0 (0.0%) | 0 (0.0%) | 3 (0.3%) | 4 (0.4%) | |
| Damage to pelvic organs and tissues following abortion and ectopic and molar pregnancy | O08.6 | 13 (13%) | 3 (0.3%) | <5 (<1%) | 2 (0.3%) | 2 (0.2%) | <5 (<1%) | 4 (0.4%) | |
| Disseminated intravascular coagulation (defibrination syndrome) | D65 | 9 (0.9%) | 5 (0.5%) | <5 (<1%) | 2 (0.2%) | <5 (<1%) | 0 (0.0%) | 0 (0.0%) | |
| Other complications following abortion and ectopic and molar pregnancy | O08.8 | 307 (32%) | 50 (5%) | 58 (6%) | 52 (5%) | 57 (6%) | 53 (5%) | 37 (3%) | |
| Total | ‐ | 957 (100%) | 203 | 177 | 145 | 145 | 156 | 131 | |
4. DISCUSSION
Spontaneous pregnancy losses and induced abortions contribute up to 13.2% of all maternal deaths globally, 31 , 32 of which 99% occur in low‐ and middle‐income countries. 33 Despite the special focus of the Kazakhstani government on maternal healthcare aiming to improve the birthrate in the country, 34 , 35 there is still much to be done to refine the quality of medical aid. The Ministry of Healthcare annual reports on the population's health indicators in the country reflect the number of registered pregnant females, the number of delivery, induced abortions and maternal mortality every year. 28 However, these reports do not take into account the number of spontaneous pregnancy losses, their complications and outcomes. Thus, in this study, the epidemiology, complications and outcomes of SPL before 22 weeks of gestation was investigated by analyzing large‐scale Kazakhstani healthcare data from the UNEHS.
In this study, the prevalence of spontaneous pregnancy losses among the 207 317 registered cases in 2014–2019 was estimated at 8.7%. This was generally comparable to the rates reported in Finland (13.7%), 36 Norway (12.8%), 37 Denmark (10.8%) 38 and Turkiye (9.2%). 39 Results of this research reveal a decreased prevalence of SPL in Kazakhstan by 20% during the 2014–2019 period, which reflects the improvements in reproductive healthcare and access to health facilities of Kazakhstani females in both urban and rural areas. Compared with the available similar reports, our study findings are not compatible with the results of Russian 40 and Finnish 41 studies, which reported increased rates of miscarriages. Unfortunately, a limited number of reports are available for comparison from neighboring Central Asian and post‐Soviet countries with the same income and similar healthcare system structures.
In this study, the majority of pregnancy loss cases occurred in age groups of 20–24, 25–29, and 30–34 years, which is in agreement with the findings of a Finnish study. 41 However, when rates of SPL per 1000 women of corresponding age were compared, it became evident that in our study the pregnancy loss rates are much higher than in the study by Linnakaari et al. 41 Another study in the same field from Norway reported peaks of miscarriages in women aged 15–19 and 40–49 years. 42 Our findings are in apparent disagreement with this Norwegian study, which could be explained by the cultural difference between countries and ethnic groups in family‐planning patterns. 43
The most common diagnosis was incomplete spontaneous abortion (ICD‐10 code “O03.4”), which was registered in 37.8% of cases, followed by blighted ovum (ICD‐10 code “O02.0”) in 34.1% and missed abortions (ICD‐10 code “O02.1”) in 13.5%. These findings of our study are comparable with the recent study by Helle et al., where the most common type of miscarriage was spontaneous abortion in 39.2%, missed abortion in 41.8% and blighted ovum in 19% of all cases analyzed. 36 In our study, the RPL was reported in UNEHS in only 0.06% of patients, which is lower than reported worldwide (1%–5%). 1 , 5 , 15 , 44 , 45 This low number of reported recurrent pregnancy losses suggests that RPL cases are underestimated in Kazakhstan and that the registration system should be updated regularly.
Most women (93.5%) were admitted by the emergency route, as expected, as bleeding, one of the main symptoms of SPL, requires urgent care. The highest rates of miscarriages were reported from the southern and south‐eastern parts of Kazakhstan: Almaty city (11.9%), Almaty region (10.7%) and Turkestan region (10.3%). This can be explained by the large populations of these Kazakhstani regions and their higher birth rates.
The management of SPL depends on the type and clinical presentation (especially the severity of bleeding). Whereas an expectant or medical management approach may be chosen if there are no acute indications for surgical management, a recent report suggested that expectant, medical and surgical management appear to be equally effective. 12 Dilation and curettage is the treatment of choice for moderate and severe bleeding and hemodynamic instability/shock. 46 Our findings indicate that surgical procedures (ICD‐9 codes “69.0” and “69.5”) were the most common methods for managing spontaneous pregnancy losses (97.4% of cases), with non‐surgical management utilized in only 2.6% of the cases. This was in sharp contrast to the findings of two independent Finnish studies, according to which only 26%–29% of affected women underwent surgical intervention, while the majority (71%–74%) received non‐surgical treatment for miscarriage. 37 , 41 According to this report, non‐surgical management with mifepristone and misoprostol should be used more often, as it is noninvasive and prevents the development of complications, including damage to pelvic organs and tissues following abortion (ICD‐10 code “O08.6”), which reportedly affects 1.4% of the cases.
The complication rates in this study constituted only 0.5%, which is comparable to the study by Musik et al., where the risk of serious complications was reported as 0.1%. 45 In our study, the most common complications were acute posthemorrhagic anemia and hematometra. In general, a more accurate registration of complications is required. It could help to improve risk‐management and contribute to prevention of expected complications in the future.
The main strength of this study is its novelty, as it is the first to provide epidemiologic data on the incidence, complications and outcomes of spontaneous abortions in Kazakhstan. Another strength is the large cohort analyzed, which provided comprehensive coverage of the female population of Kazakhstan for the 2014–2019 period. As the health records were linked to the sociodemographic information, this reduced missing data.
Nevertheless, the study had some limitations, mainly related to UNEHS, as the system was introduced in 2014 and is still under continuous refinement. For example, the UNEHS system did not provide detailed information on the patient's past medical and parity history, education, marital status or family income. In the future, the accessibility of these important data could improve the study results. Moreover, this database does not include women who experienced SPL outside of a healthcare setting and did not seek medical attention and thus were not registered in the system. This report does not include ectopic pregnancies, which previously were analyzed. 22
The findings of this study highlight the importance of proper prevention and personalized management of miscarriages. That is supported by an earlier study which documented a strong association between the history of SPL and RPL history with an increased risk of preterm delivery. 45 SPL is a common clinical diagnosis and is routinely managed by gynecologists using available methods, expectant, medical and surgical, of which expectant and medical management can be provided on an outpatient basis. However, in the case of complications or when dilation and curettage are indicated, treatment should be provided via a daycare clinic or inpatient admission.
5. CONCLUSION
The quality of medical care for reproductive‐age women has a significant impact on a country's maternal mortality rates and overall healthcare indicators. Based on our results, there is evidence of improvements in the Kazakhstani healthcare sector, as the rates of spontaneous miscarriages before 22 weeks of gestation are decreasing. Unfortunately, SPL cases are unavoidable due to the specific underlying factors, but cases of miscarriage should be managed with minimal surgical intervention and medical management should be used more often, whenever applicable.
AUTHOR CONTRIBUTIONS
Conceptualization: GA, KA, WYA. Methodology: GA, KA, WYA, AG. Data collection: AA, AG, AT, YS, ZK, AM, YM. Software: YS, AN, AT, AG. Data analysis: TU, AM, LK. Visualization: YS, AN, AT, AA. Drafting of paper: GA, TU, WYA, KA, YM, YS. Review and final article: GA, TU, WYA, KA, YM, YS, AT, AG, ZK, TU, LK.
FUNDING INFORMATION
This study was supported by grants from the Ministry of Education and Science of the Republic of Kazakhstan Grant Funding 2022–2024 (Funder Project Reference: AP14870609, Identification of genes associated with recurrent pregnancy loss among Kazakhstani population). KA is a principal investigator of the projects.
CONFLICT OF INTEREST STATEMENT
The authors have stated explicitly that there are no conflicts of interest in connection with this article.
Supporting information
Table S1.
Table S2.
ACKNOWLEDGMENTS
The authors would like to acknowledge the School of Medicine, Nazarbayev University, for the continuous support that enabled completion of this study.
Sakko Y, Turesheva A, Gaipov A, et al. Epidemiology of spontaneous pregnancy loss in Kazakhstan: A national population‐based cohort analysis during 2014–2019 using the national electronic healthcare system. Acta Obstet Gynecol Scand. 2023;102:1682‐1693. doi: 10.1111/aogs.14669
Yesbolat Sakko and Akbayan Turesheva equally contributed to the study.
DATA AVAILABILITY STATEMENT
All data related to this study are available from the Republican Center for Electronic Health of the Ministry of Health of the Republic of Kazakhstan, but restrictions apply to the availability of these data, which were used under the contract agreement for the current study and so are not publicly available. Data are, however, available from the authors (abduzhappar.gaipov@nu.edu.kz) upon reasonable request and with the permission of the Ministry of Health of the Republic of Kazakhstan.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Table S1.
Table S2.
Data Availability Statement
All data related to this study are available from the Republican Center for Electronic Health of the Ministry of Health of the Republic of Kazakhstan, but restrictions apply to the availability of these data, which were used under the contract agreement for the current study and so are not publicly available. Data are, however, available from the authors (abduzhappar.gaipov@nu.edu.kz) upon reasonable request and with the permission of the Ministry of Health of the Republic of Kazakhstan.