Our study consisted of Ulaanbaatar city and four geographic and economic regions of Mongolia (West, East, Central and Khangai). Total of 1920 couples were included. The characteristics of the couples are shown in Table 1.
Table 1 shows the characteristics of the female participants: age, Body Mass index (BMI), occupational conditions, and educational level.
As defined by WHO, 7.2% (n = 138) couples were infertile with 2.2% (n = 42) having primary infertility, and 5% (n = 96) with secondary infertility. The prevalence of infertility in the 4 regions and Ulaanbaatar is shown in Table 2.
Table 2 shows the prevalence of infertility in 4 regions of Mongolia and the capital city Ulaanbaatar. The prevalence of infertility is significantly higher amongst rural couples than those in urban areas (p<0.001).
The age of the female is well known to be a key factor in fertility (Figure 1).
Figure 1 shows the rate of infertility of women 20 and 25 years of age. As expected women between the ages of 40 to 45 years of age had the highest rate of infertility of 10.6%
In agreement with previous studies, women between 40–45 years of age had the highest rate of infertility (10.6%) compared to women between 20–24 years of age who had a low infertility rate (1.4%) (n = 40)(p<0.0001). Using a binary logistic regression, we find that each additional year of maternal age increases the risk of infertility by 1% (OR: 0.012 CI: 1.03–1.08, p<0.0001).
We have divided the participants into age groups and have calculated the risk in comparison to the 20–24 year age group (Table 3)
Table 3 shows that infertility increases with increase in maternal age with the 40–45 year age group being at the highest risk (OR: 8.402 CI: 2.45–27.5, p<0.0001).
Risk factors for infertility
We divided our participants into two groups of infertile and fertile females. Adjusting for age (aOR) with a 95% CIs we calculated for the association between infertility and risk factors among women. Using social factors such as educational level, monthly household income, region of residence, and occupation conditions we calculated the odds ratio. Social factors, such as: occupational conditions and monthly household income were not a significant risk factor, but rural residency and lower levels of education had a significant impact on fertility (Table 4).
Table 4 shows the socio-economic risk factors that affect infertility. The highest risk factors for infertility were the level of education and rural living.
A questionnaire was used to evaluate lifestyle factors that impacted infertility. Factors such as physical activity, smoking and alcohol consumption were assessed (Table 5)
Table 5 shows lifestyle factors, which affect fertility.
Calculating aOR intrauterine growth-retardation, ectopic pregnancy had a 2.1 and 2.6 times the risk for infertility, respectively. A key risk factor for infertility is the diseases of the female reproductive system. Therefore, we used the participant’s self-reported gynecological history to calculate the risk it imposed. Gynecological chronic diseases played a major role in the development of infertility, along with participants who had a gynecological operative history (95%) with a risk of 3.4 times more.
Clinical consultations for infertile couples
Only 29.7% (n = 41) of infertile women in the study received some form of treatment for their condition (Figure 2). This was broken down as follows: 77.5% (n = 107) of infertile women sought clinical consultation regarding their infertility, while 22.5% (n = 31) never sought clinical consultation. Of those who sought clinical consultation, 44 %( n = 62) had radiological and laboratory testing. Of those infertile women that were tested only 29.7% received some form of treatment. Most treatments were hormonal therapy but assisted reproductive technology (ART) was hardly used (Figure 2).
Figure 2 shows the types of treatment for infertile women. Most infertility was treated with hormone therapy while intrauterine insemination (IUI) or in vitro fertilization (IVF) was seldom used.
Although the same definition of infertility and study methods were used, the prevalence of infertility varies greatly between nations due to governmental policy on reproduction, inclusion criteria, the age of the participants, socio-economic values and other factors (Table 6). Larsen et al.’s study of primary and secondary infertility in sub-Saharan Africa showed a prevalence of primary and secondary infertility of 3% and 5% respectively . This was in keeping with our study, which showed a prevalence of primary and secondary infertility of 2.2% and 5% respectively. However, their definition of infertility as 5 years or more of failure to conceive was not the same as our definition of infertility, which was 12 months of failed conception. Both Mongolia and the Sub-Saharan region had a high rate of gonorrhea and chlamydia [11, 12], which are risk factors for secondary infertility and could explain the similar results of the two studies.