Characterization and risk factors for unexplained female infertility in Sudan: A case-control study

Table 1 Characterization of selected anthropometry and socio-demographic variables of study participants, n (%)

Variable	Categories	Cases (n = 210), N%	Control (n = 190), N%	Effect size Cramer’s V	P value
Age group (yr)	18-24	49 (23.3)	40(21.05)	0.083	0.61
	25-29	87 (41.4)	91(47.9)
	30-34	44 (21)	35(18.4)
	35-39	23 (11)	21(11.05)
	40-44	7 (3.3)	3(1.6)
	mean ± SD	28.59 ± 5.22	28.44 ± 4.95	NA	NA
BMI (kg/m2)	Underweight	1 (0.5)	4 (2.1)	0.073	0.53
	Normal weight	127 (60.5)	111 (58.4)
	Overweight	59 (28.1)	54 (28.4)
	Obesity	23 (10.9)	21 (11.1)
	mean ± SD	24.67 ± 4.08	24.41 ± 4.38	NA	NA
WHR	Less than 0.75	46 (22)	54 (28.4)	0.113	0.08
	075-0.84	53 (25.2)	35 (18.4)
	0.85-0.90	45 (21.4)	41 (21.6)
	Greater than 90	66 (31.4)	60 (31.6)
	mean ± SD	0.844 ± 0.108	0.837 ± 0.114	NA	NA
Residence	Rural	45 (21.4)	21 (11.1)	0.143	0.005
	Urban	165 (78.6)	169 (88.9)
Marital status	Married	208 (99.1)	170 (89.5)	0.214	0.001
	Divorced1	2 (0.9)	13 (6.8)
	Widow	0 (0)	7 (3.7)
Education status	Diploma or above	89 (42.4)	85 (44.7)	0.053	0.85
	Secondary edu	72 (34.3)	65 (34.2)
	Primary edu	39 (18.6)	34 (17.9)
	No formal edu2	10 (4.8)	6 (3.2)
Religious affiliation	Muslim	198 (94.3)	184 (96.8)	0.063	0.22
	Christian	12 (5.7)	6 (3.2)
Occupation	Farmer	9 (4.3)	2 (1.1)	0.164	0.06
	Governmental	34 (16.2)	29 (15.3)
	Housewife	132 (62.9)	110 (57.9)
	Private business	28 (13.3)	34 (17.9)
	NGOs	1 (0.5)	6 (3.2)
	Student	6 (2.9)	9 (4.7)

¹Information about, age, body mass index, and waist-to-hip ratio were reused from reference[81].

²Divorced women must have remained in regular sex in the last year intending to conceive.

³This includes the type of religious education (Khalwa). In the last column to the right, bold values indicate a significant level at P < 0.05. Cramer’s V effect size was classified according to Kim[41], 2017 as small effect size.

⁴Medium effect size. Differences between groups were compared with chi-square test. Estimated effect sizes were calculated using Cramer’s V statistic which is expressed as mean. Body mass index and waist-to-hip ratio status were follows World Health Organization and Centers for Disease Control and Prevention's classifications[36,37]. BMI: Body mass index; n: Sample size; NA: Not available; NGOs: Non-governmental organizations; SD: Standard deviation; WHR: Waist–hip ratio.