Damn you and your law-learning...
I agree that post-partum depression is a very real problem for some women. My initial reaction was "discrimination!" (The exclaimation point was even included) but after some thought I realized that there are cases where women do need to recover from the physical damage birth can cause, and that women who have recently given birth are at risk for mental illness. I am not arguing that they do not deserve additional time to recover, but I would argue that as a mental illness, post-partum depression be included under disability, not mat. leave. Pregnancy is not the only biological cause of mental illness.
Another reason post-partum depression should be included under disability instead of mat. leave is that it would increase awareness of the problem, and maybe even remove some of the stigma attached to post-partum depression. Although there is increasing awareness of post-partum depression, there are still too many stories of women going untreated. Women are too often thought of as "weak" or "bad mothers" when they are suffering a serious mental illness, and since, as you point out, the recovery time has been included with mat. leave there is no reason to raise awareness that it is not just "baby blues" and that it is a problem.
I would also argue that if post-partum depression is the main reason that you believe that women who have just given birth are entitled to mat. leave, why aren't fathers and husbands entitled to take that 15 weeks off as well? Wouldn't it be better for a woman's recovery from post-partum depression to have her mate with her, to help her through the dark times, work with her to get better, and look after the child? Or, if she's suffering a difficult pregnancy, that he be entitled to take time off before the birth, as pregnant women are, to care for her, and ensure that she, and his child are both ready for their new lives?
Mat. leave is not just discriminatory to adoptive mothers, I feel that fathers are being ignored here as well, and that this comes directly from what I thought was my main point, the medicalization of pregnancy. Women's bodies suffer the most from pregnancy, but that does not mean that they always need so much medical attention. Fathers and adoptive parents have a huge role in the child's life, they deserve their chance to become care takers in the same way pregnant women do. The birth of a child is not just about the medical treatment that women "need" before, during and after birth, it should be about parents getting a chance to bond with their child, and learning about their new lives. \Since pregnancy has become something that requires hospitalization, and turns women's bodies into objects instead of subjects we live under the idea that pregnancy is always a traumatic experience. I am not arguing that this never happens, I am aware that often birth and post-partum depression are traumatic experiences and need additional medical attention. I simply feel that since we have been taught for so long that women are not capable of looking after themsleves during pregnancy, things such as mat. leave are re-enforcing the idea.