Is genetic sex selection of children permitted in Judaism?

Question: What is the Jewish perspective on genetic sex selection of children?

Answer: Pre-conception gender selection is now available in the medical marketplace. Gender selection is not a Jewish practice save for in a very few, case-by-case, determinations related to preventing the transmission of several horrific genetic diseases that are only carried and manifested, as it happens, by males. The method of choice is to do IVF—combine a sperm and egg outside of the womb—and then use PDG—a method of assessing the resulting zygote before it reaches the stage of becoming an implantable embryo (which is when the maternal and paternal gene pools combine).          

 In the absence of a major health issue, selection for gender, intelligence, height, athletic prowess, eye or hair color or other attributes that may become elective as technologies develop, fall outside the domain of Jewish values and practice. None of these are illnesses or diseases. Judaism values those who are different and provides a blessing to say upon viewing a person who looks unusual, the core of which is "mishaneh habriyot—for the diversity of living beings". Gender, our main topic here, we now know, spans a spectrum of possibilities. This has become well documented and far better appreciated in our times than in antiquity. In Western cultures and many others, prejudicial hiring, healthcare, education, etc. based upon gender preferences or differences is now illegal. In the Torah itself, we learn of how the midwives risk their own lives rather than following the pharaoh's decree for them to murder newborn Israelite males.

The Talmud, in Tractate Niddah 31, relates a folk tradition for how to ensure a conception will result in a male or female. Many ancient and Middle Eastern cultures have a strong preference for a male first-born. Such ancient biases when manifested in the 21^st century are no longer tolerable. Gender selection has already been proven foolhardy, creating imbalances widely reported to be the case in China. There is also a Jewish tradition of trying for at least one boy and one girl that some elect to follow through natural methods of reproduction. This tradition gives absolutely no justification for seeking out gender selection technologies; natural approaches to reproduction are a fundamental mitzvah to be interfered with only when infertility issues produce the need for medical intervention. IVF is not a benign procedure for women, there are risks that make it appropriate only when infertility or serious genetic diseases are involved.

Acceptance is a difficult and important spiritual practice evident in all traditions. The Book of Proverbs teaches: "Who is happy? One who is happy with what one has. Ultimately, for differences among humans such as advanced intelligence, significant height, preferred eye color, or other designer baby issues, Judaism would ask us to resist genetic meddling, for all are created b'zelem elohim—in the image of God. Given that we are not privy to how creation manages to attain homeostasis, we need to be gentle and live in yirah—respectful awe of Nature's ways. The Torah teaches that we are not to be destructive of nature, for there is no divine intervention available to set it aright again.

Our blessed differences help us to learn and live with compassion. In Jewish tradition souls do not accrue a good name, a keter shem tov, based on their degree of health or physical appearance, but rather upon how we each live mitzvah-centered lives. Diverting expensive medical resources to secure medically unnecessary elective characteristics in our progeny is not a mitzvah, ensuring the equal availability of resources to prevent and treat significant illness and disease most definitely is.

Note: This answer by Rabbi Goldie Milgram first appeared here, at Jewish Values Online, where answers are given by those from across the spectrum of Jewish practice.