Normal fertilisation rates and serum 25-OHD levels among couples undergoing in-vitro fertilisation: a prospective cohort study

Table 1 Baseline characteristics grouped by serum 25-OHD groups in women

Characteristics	Group A	Group B	Group C	P value
Number of cycles	232	768	232
25-OHD in women (ng/ml)	10.26 ± 2.29	19.47 ± 3.52	31.13 ± 5.25	.000
Female age (y)	30.50 ± 4.09	30.61 ± 4.31	30.30 ± 4.38	.620
Male age (y)	32.63 ± 5.06	32.28 ± 5.22	32.23 ± 5.28	.628
Baseline FSH (mIU/ml)	6.84 ± 1.12	6.97 ± 1.18	6.89 ± 1.19	.278
BMI (kg/m²)	21.58 ± 2.71	21.65 ± 2.39	21.39 ± 2.61	.355
Previous pregnancy				.950
No	142 (61.2%)	432 (56.3%)	124 (53.2%)	.211
Yes	90 (38.8%)	136 (43.7%)	108 (46.8%)
Duration of infertility (y)	3.62 ± 2.37	3.34 ± 2.59	3.25 ± 2.68	.253
COH protocol				.158
Long protocol	134 (57.8%)	431 (56.2%)	122 (52.4%)
Prolonged protocol	37 (15.9%)	160 (20.9%)	59 (25.3%)
Antagonist protocol	61 (26.3%)	177 (22.9%)	51 (22.3%)
Duration of Gn treatment (days)	9.92 ± 1.39	10.11 ± 1.57	10.18 ± 1.70	.416
Dose of gonadotrophins (IU)	2167.69 ± 536.18	2172.84 ± 715.73	2125.27 ± 741.07	.665
Number of oocytes retrieved	13.00 ± 5.68	13.65 ± 6.39	14.09 ± 6.58	.167
Number of MII oocytes	11.72 ± 5.36	12.43 ± 5.88	12.98 ± 6.20	.064
Normal fertilization rate (%)	62.50 (50.00,71.43)^*	64.29 (50.00,76.52)^*	68.75 (53.33,80.00)^*	.001

Data are expressed as mean ± SD or Number (Percentage) or median (interquartile range). Serum 25-OHD levels in women were classified into three groups: < 13.3 ng/ml (Group A),13.3–25.9 ng/ml (Group B), > 25.9 ng/ml (Group C). The symbol "*" meant that the median of normal fertilisation rates in women were 62.50%, 64.29%, and 68.75%, respectively (P = 0.001); with significant differences between Groups A and B, Groups A and C, Groups B and C (P = 0.043, 0.000, and 0.032, respectively). Abbreviations: 25-hydroxyvitaminD (25-OHD); Follicle-stimulating hormone (FSH); Body mass index (BMI); Controlled ovarian hyperstimulation (COH); Gonadotrophins (Gn); Metaphase II (MII)

ISSN: 1471-2393