What is the Implantation Dip?
The "implantation dip" is not a medically recognized phenomenon or term in fertility treatment or reproductive medicine, and it does not appear in any clinical guidelines, fertility preservation protocols, or letrozole treatment literature.
What You May Be Asking About
If you're referring to temperature changes during early pregnancy:
- Basal body temperature (BBT) patterns during conception cycles sometimes show a brief temperature drop around 7-10 days post-ovulation, which some lay sources call an "implantation dip" 1
- This is not a reliable indicator of implantation or pregnancy and has no clinical utility in fertility treatment monitoring 1, 2
- No medical guidelines recommend tracking or interpreting this pattern for fertility treatment decisions 1, 2
What Actually Matters in Letrozole Treatment Monitoring
Ultrasound monitoring is the essential clinical tool during letrozole cycles, not temperature tracking 1, 2:
- Mandatory ultrasound monitoring during each treatment cycle to ensure appropriate follicular development and reduce multiple pregnancy risk 1, 2
- Monitor follicle size and number during each cycle to confirm adequate response 1
- Ovulation typically occurs 7-9 days after the last letrozole pill (around cycle days 14-16 if starting on day 3) 1
Critical Monitoring Requirements
The American College of Obstetricians and Gynecologists mandates specific monitoring that has actual clinical value 1, 2:
- Follicular development assessment via ultrasound
- Endometrial thickness monitoring (letrozole maintains adequate endometrial development even at high doses) 1
- Prevention of multiple pregnancies through proper cycle monitoring 2
Do not rely on subjective temperature patterns or "implantation dips" for clinical decision-making in fertility treatment 1, 2.