By the twelfth week of pregnancy, __________.

Correct Answer: A

Rationale: In pharmacology, understanding fetal development is crucial for assessing drug safety during pregnancy. During the twelfth week of pregnancy, the correct answer is A) the sex of the fetus can be detected with ultrasound. This is because by this time, the genitalia have developed sufficiently to be visualized on an ultrasound scan, allowing for the determination of the fetus's sex. Option B) stating that the mother can feel the movements of the fetus is incorrect for the twelfth week as fetal movements, known as quickening, are typically felt between 16-25 weeks of pregnancy. Option C) claiming the fetus is viable and can survive if born early is inaccurate at 12 weeks as fetal viability, generally considered around 24 weeks, depends on various factors including lung development and weight. Option D) mentioning synchrony between fetal heart rate and motor activity peaks is not relevant at the twelfth week of pregnancy as fetal movements and cardiac activity do not yet exhibit such coordinated patterns. Educationally, knowing the timeline of fetal development is essential in pharmacology to understand how drugs may impact the developing fetus at different stages of pregnancy. Ultrasound plays a vital role in monitoring fetal growth and development, allowing healthcare providers to assess the health of the fetus and detect any potential abnormalities early on.

Correct Answer: D

Rationale: High doses of caffeine contained in coffee and tea have been linked to an increased risk of low birth weight. Consuming large amounts of caffeine during pregnancy can interfere with the baby's growth and development, leading to a lower birth weight than expected. It is important for pregnant women to limit their caffeine intake to reduce the risk of complications such as low birth weight.

Correct Answer: B

Rationale: Newborns of smoking mothers display more muscle tension. This is because nicotine in cigarettes can lead to increased muscle tension in babies, which can affect their physical development and potentially lead to future health issues. This is one of the negative effects of smoking during pregnancy on the developing fetus.

Correct Answer: C

Rationale: In pharmacology, understanding the impact of maternal alcohol consumption on fetal development is crucial. Fetal alcohol syndrome (FAS) is a serious concern that can result from maternal alcohol use during pregnancy. In this scenario, the expectant mother with the greatest risk of having a baby born with FAS is Yvonne, a Native American. Yvonne, as a Native American, has a higher risk due to genetic factors that can influence alcohol metabolism differently compared to other ethnicities. Native Americans tend to have a higher prevalence of alcohol use disorder, which can increase the likelihood of excessive alcohol consumption during pregnancy, leading to a higher risk of FAS in their babies. Conversely, the other options (Caucasian American, African American, and Asian American) do not have the same genetic predisposition or cultural factors that may contribute to increased alcohol consumption during pregnancy, thus lowering their risk compared to Native Americans. This educational context highlights the intersection of genetics, cultural factors, and pharmacological effects on fetal development, emphasizing the importance of considering individual risk factors in maternal healthcare and the prevention of FAS. Understanding these nuances is critical for healthcare providers to deliver targeted interventions and support to at-risk populations.

Correct Answer: B

Rationale: The statement that the organ damage inflicted by prenatal rubella can lead to lifelong health problems is true. Rubella infection during pregnancy can cause serious harm to the developing fetus, including organ damage, deafness, heart defects, and intellectual disabilities. This highlights the importance of prevention and vaccination to protect both pregnant women and their unborn babies from the harmful effects of rubella.