Ovulation-Induction Medications and OHSS

Ovulation induction uses medications to stimulate follicular development and ovulation in patients with anovulation or selected other infertility conditions. Controlled ovarian stimulation is also used during assisted reproductive technology (ART), particularly in vitro fertilization (IVF), to promote development of multiple follicles for oocyte retrieval. The distinction matters. Ovulation induction typically aims to produce one mature follicle and achieve ovulation. Controlled ovarian stimulation often aims to develop multiple follicles for retrieval during IVF. Both require individualized treatment and monitoring, and excessive ovarian stimulation increases the risk of multiple pregnancy and ovarian hyperstimulation syndrome (OHSS). The treatment becomes dangerous when ovarian response is excessive. Several follicles may mature simultaneously, increasing multiple-gestation risk, and the stimulated ovary may release mediators that make capillaries abnormally permeable. That permeability shifts protein-rich fluid into the abdomen and sometimes the pleural space. The patient may look fluid overloaded because the abdomen is filling, while the circulation is actually depleted. The resulting haemoconcentration, falling urine output, electrolyte disturbance and thrombotic risk, not simply ovarian enlargement, make OHSS an emergency. Think of one mental model: a full abdomen and...