Fertility jargon buster

General terms

• Uterus: Womb
• Endometrium: The inner lining of the womb where the embryo is going to implant
• Follicle: Ovarian follicles are small, fluid-filled sacs in your ovaries that each contain an unfertilized egg. You’re born with a set number of eggs and ovarian follicles — usually anywhere from 1 to 2 million — and the total declines over time. 
• Oocyte: An oocyte is an immature egg
• Luteal phase: The luteal phase is the second half of your menstrual cycle. It begins straight after ovulation, and it lasts until you start your next period. The average luteal phase is around 14 days, and during this time your body prepares for the possibility of pregnancy. Progesterone is released from the ovaries to thicken the womb lining ready for a fertilised egg.
• LH surge: Luteinising Hormone is released naturally just before ovulation. Your ‘LH surge’ indicates when ovulation is about to happen, usually in the next 12 to 24 hours.
• Blastocyst: A blastocyst is an embryo that has developed to day five of development.  A blastocyst has different cell types – inner mass cells which develop into the foetus, and Trophectoderm cells which become the placenta. If you’re having Pre-Implantation Genetic Screening as part of your IVF cycle, the biopsied cells are Trophectoderm cells