Question

The client visits the prenatal clinic stating she believes she is pregnant. A pregnancy test is done to detect elevated levels of: A. Prolactin B. Human chorionic gonadotropin C. Lecithin-sphingomyelin D. Estriol

Short answer

Answer: Human chorionic gonadotropin (hCG)

Step-by-step solution

Reviewing option A - Prolactin

Prolactin is a hormone that plays a role in milk production in pregnant and nursing females. However, the levels of prolactin do not change significantly in early pregnancy and therefore, it is not used to detect pregnancy. So, option A is incorrect.

Reviewing option B - Human chorionic gonadotropin

Human chorionic gonadotropin (hCG) is a hormone produced by the placenta after implantation. The levels of hCG begin to rise rapidly in the early stages of pregnancy, making it a reliable indicator for pregnancy tests. Hence, option B is likely the correct answer.

Reviewing option C - Lecithin-sphingomyelin

Lecithin-sphingomyelin (L/S) ratio is a test used to assess fetal lung maturity, but not for detecting pregnancy. So, option C is incorrect.

Reviewing option D - Estriol

Estriol is an estrogen hormone produced by the placenta and fetus. Although it increases during pregnancy, it is not used as a primary marker to detect pregnancy. Thus, option D is incorrect.

Conclusion

Based on the analysis of each option, the correct answer is: B. Human chorionic gonadotropin (hCG) A pregnancy test is done to detect elevated levels of human chorionic gonadotropin (hCG), as it is a reliable indicator of early pregnancy.

Key concepts

Human Chorionic Gonadotropin (hCG)

Human chorionic gonadotropin, commonly abbreviated as hCG, is a crucial hormone in pregnancy. It is produced by the cells of the developing placenta shortly after a fertilized egg implants in the uterus. This hormone plays several important roles in early pregnancy, such as promoting the maintenance of the corpus luteum, which in turn produces progesterone to prevent menstruation and support the uterine lining.
hCG levels can be detected as soon as 11 days after conception through a blood test, and around 12-14 days via a urine test. The hormone levels typically double every 48 to 72 hours in early pregnancy, peaking around the 10th week and then declining. The presence and amount of hCG in the body serves as a key indicator that a person is pregnant, making it an essential component of most pregnancy tests.

Pregnancy Detection

Pregnancy detection often relies on the measurement of human chorionic gonadotropin (hCG) levels. These tests can be performed using either blood or urine samples. Both types of tests aim to identify the presence of hCG, though they differ slightly in how they are conducted and their sensitivity.

• Urine Pregnancy Tests: These are common home pregnancy tests. They detect the presence of hCG in urine and are convenient for quick results. Most home tests can be taken from the first day of a missed period.
• Blood Pregnancy Tests: Conducted at a doctor's office, these can detect pregnancy about 7-12 days after possible conception. They measure the actual amount of hCG in the blood and can provide more detailed information, such as the exact level of the hormone and its progression over time.

Detecting pregnancy early is pivotal for receiving timely prenatal care and ensuring both maternal and fetal health throughout the pregnancy.

Fetal Development

Fetal development is a complex process that occurs over approximately nine months. It begins with conception when the sperm fertilizes the egg, forming a zygote. This zygote implants itself into the uterine wall, developing into an embryo and then a fetus as it grows.
Fetal development is commonly divided into three trimesters, each with unique milestones:

• First Trimester (Weeks 1-12): Major organs and body systems begin to form. The heart starts to beat, and the brain begins to develop early in this stage. By the end of the first trimester, the baby is about 3 inches long.
• Second Trimester (Weeks 13-26): During this period, the fetus grows rapidly and begins moving, which can often be felt by the pregnant person. Organs like the liver start functioning, and features such as fingers and toes become more distinct.
• Third Trimester (Weeks 27-40): The fetus continues to grow in size and weight. Its organs mature and prepare for life outside the womb. The baby moves into a head-down position, getting ready for birth by the end of this stage.

Each trimester is crucial for specific developmental processes, and close monitoring by healthcare providers ensures the health and well-being of both the mother and the developing fetus.