Which of the following education statements are correct? Select the three that apply.

Choice A rationale

Amniotic fluid is primarily produced by the fetal kidneys, with the fetus excreting sterile urine into the amniotic sac. The fluid is constantly being produced and reabsorbed by the fetus swallowing it. The umbilical cord contains the blood vessels that connect the fetus to the placenta, not a producer of amniotic fluid.

Choice B rationale

The umbilical cord contains two arteries and one vein. The two arteries carry deoxygenated blood and waste products from the fetus to the placenta, while the single vein carries oxygenated and nutrient-rich blood from the placenta to the fetus. This is a common and important anatomical fact in fetal circulation.

Choice C rationale

The placenta is a temporary organ that develops during pregnancy and serves as the primary interface between the mother and fetus. It facilitates the exchange of gases (oxygen and carbon dioxide), nutrients (glucose, amino acids, fatty acids), and waste products (urea, creatinine). It also produces hormones essential for maintaining pregnancy.

Choice D rationale

The placental bed, or intervillous space, is where maternal blood from the spiral arteries bathes the fetal villi. However, maternal and fetal bloodstreams do not mix directly. The placental barrier, a thin membrane, separates the two circulations, allowing for the exchange of substances without the risk of an immune reaction or blood type incompatibility issues. *.

Choice A rationale

Iron absorption is actually hindered by dairy sources and foods high in calcium, as these minerals compete with iron for absorption sites in the intestines. While it is often recommended to take iron with a meal to reduce gastrointestinal upset, it is crucial to avoid calcium-rich foods like dairy products for optimal absorption of the iron supplement.

Choice B rationale

Iron is a crucial component of hemoglobin, which is responsible for oxygen transport in the red blood cells. In pregnancy, the demand for iron increases significantly due to the expansion of red blood cell mass and the needs of the developing fetus and placenta, so iron supplementation is used to increase, not decrease, the red blood cell mass.

Choice C rationale

While red meats, fish, and poultry are excellent sources of heme iron, which is highly bioavailable, starchy vegetables and eggs are not considered rich sources of highly bioavailable iron. Eggs, for example, contain a protein called phosvitin that can inhibit iron absorption, and plant-based iron (non-heme) is less readily absorbed than heme iron.

Choice D rationale

While increasing fluids and walking are important interventions for preventing constipation, a common side effect of iron supplements, performing Kegel exercises is not relevant. Kegels are for strengthening the pelvic floor muscles to prevent or treat urinary incontinence and uterine prolapse, and have no effect on gastrointestinal motility or constipation.

Choice E rationale

Iron is a positive ion and is best absorbed in an acidic environment. Ascorbic acid, or vitamin C, which is abundant in orange juice, enhances the conversion of ferric iron ($Fe^{3+}$) to the more absorbable ferrous iron ($Fe^{2+}$). This reaction increases the intestinal uptake and bioavailability of the iron supplement, making this an effective strategy for maximizing iron absorption. *.