Which of the following hormones are produced only during pregnancy?

Options

A. Prolactin and human placental lactogen
B. Relaxin and inhibin
C. Oxytocin and progesterone
D. Human chorionic gonadotropin and human placental lactogen

Answer

To determine which hormones are produced only during pregnancy, we will analyze the options provided and identify the hormones associated with pregnancy.

### Step-by-Step Solution:

1. **Understand the Context of Hormones During Pregnancy**:
- After fertilization, the zygote develops into a blastocyst, which then implants into the uterine wall (endometrium). This triggers the formation of the placenta, which produces specific hormones.

2. **Identify the Hormones Produced During Pregnancy**:
- The hormones produced during pregnancy include:
- Human Chorionic Gonadotropin (hCG)
- Human Placental Lactogen (hPL)
- Relaxin
- Estrogen
- Progesterone

3. **Evaluate Each Option**:
- **Option 1: Prolactin and Human Placental Lactogen**: Prolactin is not exclusively produced during pregnancy; it is also produced during lactation. Thus, this option is incorrect.
- **Option 2: Relaxin and Inhibin**: Relaxin is produced during pregnancy, but inhibin is not exclusive to pregnancy. Hence, this option is also incorrect.
- **Option 3: Oxytocin and Progesterone**: Oxytocin is not exclusively produced during pregnancy; it plays a role in childbirth and lactation. Progesterone is produced during pregnancy, but since oxytocin is not, this option is incorrect.
- **Option 4: Human Chorionic Gonadotropin and Human Placental Lactogen**: Both hCG and hPL are produced only during pregnancy, making this option correct.

4. **Conclusion**:
- The hormones that are produced only during pregnancy are Human Chorionic Gonadotropin (hCG) and Human Placental Lactogen (hPL). Therefore, the correct answer is **Option 4**.