Hormones act as our body's messengers, signaling the body when to prepare, when to release, and when to nurture. Yet, as powerful as these chemical messengers are, their balance can be easily disrupted: by stress, lifestyle choices or underlying health conditions.
To understand how these hormonal shifts influence fertility, it’s important to look closely at two primary players: oestrogen and progesterone. Says Dr. Nishi Singh, Head of Fertility at PRIME IVF, “Hormonal changes are vital for the menstrual cycle and the possibility of conception. The key hormones responsible for ovulation, and which allow an egg to be released in the body for fertilization, are oestrogen and progesterone.”
How Hormones Control the Menstrual Cycle
The menstrual cycle is a tightly regulated process divided into phases, each governed by hormonal changes. In the follicular phase, rising oestrogen levels stimulate the development of ovarian follicles, one of which matures into an egg ready for ovulation. “This phase sets the stage,” Dr. Singh says. “Oestrogen ensures the uterine lining thickens, creating a nurturing environment for potential implantation.”
Ovulation, the mid-cycle event, occurs when a surge of luteinizing hormone (LH) triggers the release of an egg. From there, progesterone takes over during the luteal phase, preparing the uterus for implantation. “For pregnancy, the right levels of hormones ensure proper implantation and foetal growth,” Dr. Singh says.
When The System Goes Awry
Despite the precision of this process, hormonal imbalances can throw it off track. Stress, diet, weight fluctuations, and medical conditions like polycystic ovary syndrome (PCOS) can alter the production of oestrogen and progesterone. “Any change in these hormones could disturb the cycle, leading to irregular periods or difficulty in conceiving,” explains Dr. Singh.
Such disruptions can manifest in various ways, including skipped cycles, anovulation (when the ovary fails to release an egg), or a luteal phase defect, where insufficient progesterone undermines implantation. These seemingly minor issues can have a significant impact on fertility.