Is one allowed according to Jewish law to do in vitro fertilization of an egg so that one will have a boy?

IVF for the purpose of selecting a male child touches on several intersecting halachic issues — the mitzvah of pru u'rvu (procreation), the permissibility of IVF itself, and the ethics of gender selection. The consensus among contemporary poskim (halachic decisors) is that gender selection through IVF for non-medical reasons is generally discouraged or prohibited, though some authorities permit it under specific circumstances, particularly when a couple has children of only one gender and desires the other.

Key Takeaways

IVF itself is generally permitted by many poskim when used to fulfill the mitzvah of pru u'rvu, though it involves serious halachic concerns that must be managed carefully.
Gender selection for purely personal preference (e.g., wanting a firstborn son) is viewed negatively by most authorities as interfering with Divine providence without sufficient justification.
Some poskim permit gender selection via IVF when a couple already has several children of one gender and seeks shimcha (family balance/joy), particularly if emotional wellbeing is at stake.
The "key of childbirth" is considered by the Talmud to be exclusively in God's hands, raising theological concerns about human manipulation of conception.
For any practical decision, consultation with both a rabbi and a fertility specialist is essential.

The Mitzvah of Pru U'rvu (Procreation)

Genesis 1:28 establishes the foundational commandment: "פְּר֥וּ וּרְב֛וּ" — "Be fruitful and multiply." [Genesis 1:28]

The Talmud in Yevamot specifies the minimum fulfillment of this mitzvah: a man must have at least one son and one daughter [Yevamot 61b]. This is relevant because a man who has only daughters has technically not yet fulfilled pru u'rvu with respect to a son — which gives some halachic grounding to gender selection in that specific circumstance.

The "Key of Childbirth" — Divine Sovereignty

The Talmud in Taanit 2a states:

"שְׁלֹשָׁה מַפְתְּחוֹת בְּיָדוֹ שֶׁל הַקָּדוֹשׁ בָּרוּךְ הוּא שֶׁלֹּא נִמְסְרוּ בְּיַד שָׁלִיחַ" — "Three keys are in the hand of the Holy One, Blessed be He, that were not entrusted to any agent... the key of childbirth (chaya)." [Taanit 2a]

This Talmudic principle — that the "key of the womb" (mafteach shel chaya) belongs exclusively to God — is frequently invoked by poskim who are hesitant about aggressive reproductive intervention, particularly when motivated by preference rather than medical need.

Rabbi Yitzchak's teaching in Yevamot adds another dimension:

"מִפְּנֵי מָה הָיוּ אֲבוֹתֵינוּ עֲקוּרִים — מִפְּנֵי שֶׁהַקָּדוֹשׁ בָּרוּךְ הוּא מִתְאַוֶּה לִתְפִלָּתָן שֶׁל צַדִּיקִים" — "Why were our forefathers barren? Because the Holy One, Blessed be He, desires the prayers of the righteous." [Yevamot 64a]

This suggests that infertility and the struggle for children is part of a Divine design meant to draw humans into relationship with God through prayer — a point that colors the broader discussion of reproductive technology.

IVF Itself — Is It Permitted?

Before reaching gender selection, the permissibility of IVF must be established. Key concerns include:

Wasting of seed (hotza'at zera l'vatalah): The collection of sperm raises concerns, though most poskim permit it when the goal is procreation.
Legitimacy of the child: Most authorities rule that a child born via IVF from the husband's sperm and wife's egg is fully legitimate with no issues of mamzerut.
Medical risk: IVF involves hormonal treatments and procedures that carry risk, which must be weighed.

Rabbi Moshe Feinstein zt"l (Igrot Moshe, Even HaEzer) was cautious about IVF but acknowledged its permissibility under proper conditions, primarily when a couple cannot otherwise conceive. Rabbi Eliezer Waldenberg (Tzitz Eliezer) expressed more reservations. The Lubavitcher Rebbe and many Sephardic authorities (following Rabbi Ovadiah Yosef) were more permissive about IVF for infertile couples.

Gender Selection Specifically — The Debate

Those Who Prohibit or Discourage

Most poskim who address gender selection for non-medical reasons view it unfavorably:

It involves creating and potentially discarding embryos of the "unwanted" gender, which raises serious concerns about the status of embryos in Jewish law.
It is seen as an unwarranted intrusion into Divine providence when there is no compelling need.
Rabbi Shlomo Zalman Auerbach zt"l expressed discomfort with gender selection for preference, seeing it as a misuse of medical technology.

Those Who Allow Under Limited Circumstances

Some authorities permit gender selection when:

A couple has multiple children of one gender and desires a child of the other for shalom bayit (marital harmony) or emotional wellbeing.
The mitzvah of pru u'rvu is unfulfilled — e.g., a couple with only daughters wishing to have a son. In this case, there is a positive Torah obligation being served.
Rabbi Yigal Shafran and some Israeli poskim have permitted IVF gender selection in cases of family balancing, with significant caveats about embryo handling.

The Embryo Question

A critical sub-issue is: what is the status of the embryos of the undesired gender? If they are implanted anyway, the couple may end up with a child of the "wrong" gender. If they are discarded or frozen indefinitely, this raises its own set of halachic problems. Most poskim require that unused embryos be implanted (even if donated) rather than destroyed.

Practical Summary

| Scenario | General Halachic View | |---|---| | IVF to conceive when infertile | Permitted by most poskim with proper conditions | | Gender selection to fulfill pru u'rvu (no son yet) | Some permit; still debated | | Gender selection for family balancing | Minority permit; majority discourage | | Gender selection for pure personal preference | Broadly discouraged or prohibited |

For personal guidance, consult your local rabbi or posek, as this question involves complex intersecting issues of reproductive ethics, embryo status, and individual circumstance that require a personalized psak (halachic ruling).