The most likely cause of her rash is pruritic urticarial papules and plaques of pregnancy (PUPPP), a condition affecting about 1 in every 200 pregnancies. While she could be having an allergic reaction (dermatitis herpetiformis or urticaria) or an inflammatory eruption such as heat rash, these are less likely due to their absence before pregnancy and the absence of any significant changes in her diet or lifestyle.

In the average normal pregnancy, the GFR increases by upwards of 50%. This correlates with an overall 50% increase in blood plasma volume. 

In placenta previa, the placenta develops in such a way that all or part of it is positioned in the lower one-third of the uterus, placing it between the fetus and the cervix. This can cause the placenta to tear and bleed. The most common sign is painless vaginal bleeding in the third trimester (generally after week 32). 

Hegar's sign is indicated by a softening of the portion of the uterus between the uterus and a portion of the cervix. The remaining choices are all examples of various skin discolorations commonly associated with pregnancy.

It is not necessary to limit water intake in women with pre-eclampsia. It is important that women with pre-eclampsia drink at least 8 glasses of water per day. The ingestion of water may even help reduce swelling. Checking blood pressure and body weight frequently are important in tracking fluid levels. It is also important to keep track of fetal movement and notify a provider immediately if decrease in movement is noted. Women who are preeclamptic may spill protein into their urine as a result of malfunctioning kidneys.

Placing the mother on her left side can increase placental blood flow and increase the baby's oxygenation. Placing the mother on her right side, in Trendelenburg (head down), in the tripod position (sitting forward, hands on knees), or with her feet in the air is not of equal benefit. 

The postpartum assessment includes vital signs (blood pressure, pulse), fundus (location, height, consistency), lochia (color, volume), urinary output (measure first void), and bonding between the mother and infant. The postpartum assessment is valuable because it allows for nursing interventions at warning signs of postpartum complications, including infection, hemorrhage, and uterine atony. Stool assessment is not a vital part of the postpartum assessment because it does not lend information to the assessment of potential danger signs.

Thalassemia, an inherited autosomal recessive blood disorder, is characterized by an abnormal form of hemoglobin. Those of Mediterranean ancestry may be carriers of the disease and genetic counseling is recommended. African Americans are at risk for carrying the gene for sickle-cell disease, another inherited blood disorder that alters the form of hemoglobin. Nothern European descendants of Jewish ancestry are at risk for carrying Tay-Sachs disease, a rare, inherited nervous system disorder. Native Americans are not commonly at risk for passing on genetically inherited disorders.

Endometriosis will increases risk of both infertility and of miscarriage. This may be due to a paracrine effect as hormones are released locally by ectopic endometrial tissue, causing disruptions in hormone levels required for implantation and for sustaining an implanted embryo before the formation of the placenta.

In a study surveying 120 women with endometriosis, the prevalence of celiac disease, an autoimmune condition triggered by ingestion of gluten, was nearly four times higher than the general population. No association has been made between the presence of endometriosis and lactose intolerance or incidence of anaphylaxis.