For most surrogate mothers, the most critical factor in determining receptivity of the uterus is the thickness of the endometrium. This is the nutrient-rich layer that appears in the uterus wall during a woman’s menstrual cycle. Endometrial thickness should be greater than 8 mm and less than 15 mm. Doctors will disagree on the “perfect” measurement, but a good target will be around 12 mm.
To help develop the endometrium, surrogates undergo stimulation injections, which are light hormone treatments that will boost her body’s readiness to receive an embryo. Stimulation usually lasts from 15 to 20 days.
There are also other factors in the readiness of your surrogate, including her hormone levels and her overall health. Your doctor will be monitoring all of these throughout the stimulation process.
Remember that stimulation of your surrogate mother is a biological process, not all women react the same to the stimulation medication. Some women need a higher dosage (or the same dosage for more days) and some need less.
Assuming your surrogate is following the doctor’s orders and attending to her consultations, she will be well informed of the process and comfortable with the next steps. On each consultation the doctor will explain to her how she is responding and what they may do to improve her receptivity and likelihood of pregnancy.
Meanwhile, your consultant should be doing the same for you (with help from your chosen IVF doctor).
It’s important to note that the stimulation procedure is not a single recipe for all patients. There are different combinations of medicines, dosages and durations that can be used under different situations. In some cases your doctor may switch between stimulation strategies if he finds your surrogate is not responding to the first choice. Acknowledging that will help you overcome a lot of stress.
If the doctor makes adjustments to your surrogate’s stimulation protocol, that does not mean that it will be less successful or more successful. The changes are all made to reach the same ultimate goal, a healthy surrogate mother with a receptive uterus to carry your pregnancy.
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