In times when medical knowledge was scarce, desperate and fearful Jews often turned to black magic and sheer quackery to influence conception and birth.

The amazing lengths they went to are detailed in a fascinating new book, "A Time to be Born: Customs and Folklore of Jewish Birth," by Michele Klein, a psychologist who lives in Israel. After bearing her third child, she began to wonder what Jewish customs existed beyond circumcision.

The book turned into a 15-year labor in which she interviewed more than 200 Israelis and dove into Jewish texts. Focusing heavily on the past millennium, she divides the book into four sections: conception, pregnancy, birthing and welcoming the newborn.

In the face of infertility, couples as recently as this century were often told to repent, give charity, honor Shabbat and keep faith in God. When that didn't work, rabbis or doctors sometimes tried to decide who was to blame.

Tobias Cohn, an Ashkenazi physician born in 1629, advised the husband and wife to urinate on separate piles of grain. A spouse was considered fertile if their pile of grains sprouted.

Jews long believed that the "evil eye, wicked demons and nasty spells" could prevent conception, so they also turned to "tried and proved" folk remedies.

In some communities, women entered a mikvah immediately after a woman who had given birth. In others, they might drink a potion of human placenta or even consume non-kosher foods such as a pig's testicles or a hare's stomach.

Consuming mandrakes was also popular, based on the biblical reference of Rachel using the root to help her bear a child.

"In the 19th century, Jews in Morocco placed mandrake roots on a small fire, and the barren woman bent over it, thus enabling smoke to enter her private parts," the author writes.

Women also donned reddish gems, especially rubies, to induce fertility. The color is again associated with Rachel, who received Reuben's aid in conceiving a son. Of the 12 precious stones on the high priest's breastplate, the red one symbolized Reuben's tribe.

On the other end of the fertility spectrum, women also tried various tricks to prevent pregnancy. A 15th-century Yiddish remedy book suggested that a woman hang a mouse heart around her neck.

Once a woman became pregnant, Ashkenazi Jews tried to hide the news as long as possible. They feared that announcing it "would invite catastrophe." They also worried about the evil eye, a glance from a sinister person that caused malevolent effects.

To prevent miscarriage, pregnant women in late 19th-century Tunisia and Salonika bound their bellies with a string wound seven times around the grave of a renowned rabbi to absorb his holiness. Reflecting that custom, some Orthodox women in Israel today wind a scarlet embroidery twine seven times around the Tomb of Rachel near Bethlehem.

In her interviews and studies, Klein found a consistent preference over the centuries toward bearing boys. Jews would pray, try to predict and go to extreme measures to ensure the birth of a son. Daughters were considered a burden.

Talmudic sages asserted that parents-to-be could pray for a boy until the 40th day after conception when they believed gender was formed.

The book describes even more extreme customs. Into the early 20th century, a Moroccan woman who wanted a son would swallow a circumcised foreskin while Sephardic women in Palestine "imbibed a potion made of burned and powdered umbilical cord of another women's newborn son."

A remedy book from Damascus offered a kabbalistic formula in determining gender: Add the numerical value of the parents' Hebrew names and expected month of delivery and divide by nine. If the remainder is one, two, three, four or seven, the baby is female.

Klein devotes an entire chapter to Lilith, the legendary first wife of Adam, who later became a demon. Lilith supposedly spent her nights stealing men's sperm and killing babies. In ancient Babylon, Jewish bills of divorce against Lilith and her escorts were written on pottery bowls to annul "weddings" between mortal men and demon women.

Fear of Lilith lasted up to modern times. Jews in Kurdistan in the 19th century believed a kosher mezuzah would keep this demon at bay.

In one of the few references to Ethiopian Jewish customs, the author describes the "huts of malediction" or "huts of blood" in which women gave birth. Situated a short distance from a village, the huts were also used by menstruating women for seven days. The new mother stayed in the hut for up to 14 days after giving birth.

With high infant mortality rates, superstitions didn't end with the birth.

From biblical times up to the 20th century, "salting" a baby's skin was a common practice in many Jewish communities. Salt was thought vital to thickening and hardening the skin in order to protect internal organs. Although it may help a navel heal, it was also considered an aid against the evil eye.

Customs also developed around handling the afterbirth. Until around 1900, Klein writes, Jews in Palestine buried a girl's placenta "near the hearth, in hopes she would remain housebound when she grew up: a wayward daughter was 'one whose afterbirth was lost.'"

Medieval rabbis advised a mother to begin nursing with her left breast because it is nearer to the heart, the seat of wisdom. A few rabbis in the 16th and 17th centuries said the advice applied only to sons; daughters needn't worry about wisdom.

Although female performing circumcisions are generally considered a late 20th-century trend, the author points out that some women performed the task during the Renaissance in Italy. The practice was allowed because Moses' wife Zipporah circumcised her sons.

Overall, it's apparent that Jewish superstition was an attempt to make up for the gross lack of medical knowledge. The vast majority of such beliefs have waned as science has matured.

Klein undertook an incredible amount of work to write her book. This is reflected at the book's end in her 50 pages of single-spaced notes, 15 pages of bibliography and six pages of biblical and talmudic references.

Despite her scholarly penchant, the book itself is a friendly and fast read. Her writing is lively and organized. Moreover, Klein rarely judges the practices. She just lays them all out and lets the reader marvel, sigh or cringe.