Low-dose aspirin demonstrates no positive effect on clinical results in the first in vitro fertilization (IVF) cycle

Abstract

To determine efficacy of 100 mg Aspirin (Asp) (Calcium Carbasalate, Ascal®) on ovarian response and pregnancy rates in patients undergoing their first IVF or ICSI cycle. A prospective, randomized, double-blind placebo-controlled multicentre trial including 170 patients. A total of 170 patients undergoing their first IVF or IVF/ICSI cycle were randomized to receive either 100 mg Asp or placebo. We included women according national guidelines, younger than 39 years with regular cycles. Stratification was performed for primary / secondary infertility. On cycle day (CD) 3, patients started oral contraceptives; on CD16 a GnRH agonist (Decapeptyl®) and study medication was given. After a minimum of 14 days with GnRH-a patients started their ovarian stimulation with gonadotrophins (Puregon®). By regular ultrasound, the moment of HCG injection (Pregnyl® 10.000IE) was identified. On HCG day, patients started progesterone vaginal capsules (Progestan®). 36 Hours after HCG, oocyt retrieval took place. Study medication was continued until menstruation or, in case of pregnancy, up till 10 weeks pregnancy. We noted the duration of stimulation, the cumulative FSH dose, number of oocytes, number of embryos, endometrial thickness on hCG time, incidence of cancellation or OHSS and of course pregnancy rates. Both groups demonstrated similar median age (32 yrs; range 22–44 yrs) and median period of infertility (3yrs range 1–14 yrs). Cause of infertility was similar in both groups as well as the number of patients having or ICSI or IVF/ICSI treatment. Median duration of stimulation did not differ between both treatment modalities (Asp-placebo): (median 12day's range 9–18 vs. 7–22 days). The cumulative FSH dose was equal in both treatment arms (median 1800 IU (1050–3300 vs. 1000–5100). The number of dominant follicles at the moment of follicle aspiration was 9 in the placebo-group (range 0–36) and 10 (0–50) in the Asp group. The median number of oocytes in both groups were similar (8[0–30]), as well as the amount of cryo embryo's (mean 0.8 SEM 0.3) vs. 0.5 (0.15). The median number of viable embryo's was 5(range 0–25) in the Asp group, vs. 4 (0–20) in the control group. The endometrial thickness on the moment of HCG did not differ significantly, 9.5mm (6–14) vs. 10mm (6–13) between both treatment modalities. Incidence of cancellation due to low (12 vs., 7 in the placebo group) or high response (0 vs. 3 in the placebo group) was low, despite fixed treatment regimens. Pregnancy rates (before 12 weeks and[ongoing]) did not differ significantly between both groups (aspirin group: 31/85=36.5% and[24/85=28.3%]; placebo group: 29/85=34.1% and[25 /85=29.4%]), respectively. A prospective, randomized, double-blind placebo-controlled multicentre trial including 170 patients demonstrates no clinical advantages of low dose aspirin compared to placebo in an IVF treatment population.