Comparative effects of pre-gestational doses of clomiphene citrate versus letrozole on the heart of developing wistar rats

Abstract

Drug-induced ovulation is a therapy that allows women to ovulate and have the chance of conceiving. This therapy is used either in women  with irregular ovulation or in patients undergoing In-vitro fertilization cycle to maximize egg production. The goal of drug-induced ovulation is to stimulate the ovaries to produce a single mature follicle and allow fertilization and pregnancy to occur. The drugs commonly used are clomiphene citrate and letrozole. There are indications that these drugs, when used prenatally, could interfere with the normal development of foetal hearts, though; there is a paucity of data on the lethal effects of drug-induced ovulation on the neonatal heart, particularly the left ventricle and ventricular septum. Forty-five adult female Wistar rats that weighed between 140-160g were used for the experiment. They were subdivided into three groups of 15 animals each. A vaginal smear was carried out to further divide the experimental animals based on their  oestrous phases. A one-time dose of clomiphene citrate (clomid) was administered at 0.5mg/kg bodyweight, to one of the experimental groups, during the diestrous phase. The other experimental group received Letrozole at  0.025mg/kg bodyweight while the control group received normal feed and water liberally. Mating was done a day after administration of these drugs. Pups were sacrificed on postnatal day 21, the hearts of the pups were dissected out and processed for histological analysis. The result showed that the pups whose mothers received clomid had the lowest heart weights compared to the letrozole and control groups. The left ventricular wall thickness was greater in the Letrozole group and the level of necrosis was observed to be greater in the clomid group as compared to the other groups. These findings show that both clomid and letrozole have some effects on the hearts of the developing wistar rats.