You may be 43 and healthy in body but the ovaries will not be as healthy now.
As a woman ages, her supply of eggs gradually declines over time until the eggs are depleted at menopause. The term "ovarian reserve" refers to a woman's current supply of eggs, and is closely associated with reproductive potential. In general, the greater the number of remaining eggs, the better the chance for conception. Conversely, low ovarian reserve greatly diminishes a patient's chances for conception.
Since a woman's chronological age is the single most important factor in predicting a couple's reproductive potential, age has often guided infertility treatment choices. However, age alone doesn't tell the whole story. Consequently, researchers have developed (and are continuing to develop) more refined methods of predicting a couple's response to infertility treatment. Some of the more sophisticated tools for assessing fertility potential include the measurement of FSH, LH, estradiol, and inhibin-B. Additionally, because patients should not be subjected to all tests, decisions regarding which method(s) to use are guided by practitioner experience.
Even though several sophisticated tools exist for measuring ovarian reserve, most fall short of what we consider ideal sensitivity and specificity. Also, how best to interpret ovarian reserve tests is controversial, since clinical experience with these tests is still evolving. Even so, most infertility patients should be periodically evaluated for the possibility of impaired ovarian reserve before pursuing any advanced fertility treatment.
Even before birth, a woman's eggs begin to diminish in number. During the 20th gestation week, a female embryo contains about seven million eggs. At birth, the number of eggs has already dropped to about 200,000. The number of eggs continues to decline as the woman ages, until no eggs remain (menopause).
Fortunately, women are naturally equipped with an ample supply of extra eggs. The number of eggs a woman has at birth far exceeds the average number of menstrual cycles she will have during her lifetime. Therefore, when women undergo fertility treatment to boost egg production, the risk for premature menopause is no different than it would be for other women.
I would pay and go private in your particular circumstances. Do your researches however very carefully before parting with your hard earned cash as it is fair to say some clinics are far better than others. Private treatment can be poor as well as expensive so be careful and ask lots of questions.