After teaching a pregnant woman about the hormones produced by the placenta, the nurse determines that the teaching was successful when the woman identifies which hormone produced as being the basis for pregnancy tests?

Choice A reason:

Uteroplacental insufficiency is a condition where the placenta cannot deliver enough oxygen and nutrients to the fetus. This can cause fetal hypoxia and distress, which can be detected by late decelerations on the fetal heart rate monitor. Late decelerations are defined as a decrease in the fetal heart rate that begins after the peak of the contraction and returns to baseline after the contraction ends. This indicates that the fetus is not tolerating the reduced blood flow during the contractions and needs immediate intervention. • Choice B reason:

Umbilical cord compression is a condition where the umbilical cord is squeezed or twisted, reducing the blood flow and oxygen to the fetus. This can cause variable decelerations on the fetal heart rate monitor. Variable decelerations are defined as a decrease in the fetal heart rate that varies in timing, shape, and duration, and may or may not be associated with contractions. This indicates that the fetus is experiencing intermittent or sustained cord compression and may need repositioning or other interventions. • Choice C reason:

Maternal bradycardia is a condition where the mother's heart rate is slower than normal, usually less than 60 beats per minute. This can cause reduced blood flow and oxygen to the placenta and the fetus, but it does not cause late decelerations on the fetal heart rate monitor. Maternal bradycardia can be caused by various factors, such as medications, hypothermia, hypothyroidism, or vagal stimulation. It may need treatment depending on the cause and severity. • Choice D reason:

Fetal head compression is a condition where the fetal head is pressed against the cervix or the pelvic floor during labor, stimulating the vagus nerve and slowing down the fetal heart rate. This can cause early decelerations on the fetal heart rate monitor. Early decelerations are defined as a decrease in the fetal heart rate that begins with the onset of the contraction and returns to baseline with the end of the contraction. This indicates that the fetus is descending in the birth canal and is usually a normal and benign finding.

The correct answer is choice B. Prolactin.

Choice A reason:

Estrogen. Estrogen is a hormone that plays a role in the development of the mammary glands and the ductal system during pregnancy. However, estrogen does not directly produce milk.

In fact, high levels of estrogen during pregnancy inhibit milk secretion by blocking prolactin. Therefore, estrogen is not the hormone necessary for milk production. • Choice B reason:

Prolactin. Prolactin is the hormone responsible for the production of breast milk. Prolactin is secreted by the pituitary gland in response to suckling or nipple stimulation. Prolactin levels rise during pregnancy and peak after delivery, when the sudden drop in estrogen and progesterone allows prolactin to take over and initiate lactation. Therefore, prolactin is the hormone necessary for milk production. • Choice C reason:

Progesterone. Progesterone is a hormone that also contributes to the development of the mammary glands and the alveoli during pregnancy. However, like estrogen, progesterone does not directly produce milk. Progesterone also inhibits milk secretion by blocking prolactin during pregnancy. Therefore, progesterone is not the hormone necessary for milk production. •

Choice D reason:

Lactogen. Lactogen is not a hormone, but a general term for any substance that stimulates lactation. There are different types of lactogens, such as human placental lactogen (hPL), which is produced by the placenta during pregnancy and has some lactogenic effects on the mammary glands. However, hPL is not the main hormone responsible for milk production. That role belongs to prolactin. Therefore, lactogen is not the hormone necessary for milk production.