A client is attempting to deliver vaginally despite the fact that her previous delivery was by cesarean birth.
Her contractions are 2-3 minutes apart, lasting from 75 to 100 seconds.
Suddenly, the client complains of intense abdominal pain, and the fetal monitor stops picking up contractions.
The nurse recognizes that which of the following has occurred?

Choice A rationale

Rapid plasma regain is not a standard laboratory test associated with hyperemesis gravidarum. Hyperemesis gravidarum involves significant fluid and electrolyte losses, but rapid plasma regain is not a specific indicator of this condition.

Choice B rationale

A urine culture is used to detect the presence of bacteria in the urine, typically to diagnose a urinary tract infection. While dehydration from hyperemesis gravidarum can increase the risk of a UTI, a urine culture is not a primary anticipated laboratory test for hyperemesis itself.

Choice C rationale

Prothrombin time (PT) is a blood test that measures how long it takes blood to clot. It is used to assess coagulation and is not directly related to the metabolic and electrolyte imbalances caused by hyperemesis gravidarum.

Choice D rationale

Urine ketones are a byproduct of fat breakdown for energy, which occurs when the body is not getting enough glucose. In hyperemesis gravidarum, persistent vomiting can lead to dehydration and starvation, forcing the body to break down fat for energy, resulting in ketonuria (ketones in the urine).

Choice A rationale: Weight loss

Weight loss during pregnancy, especially in the second trimester, is unexpected unless there is a medical condition such as hyperemesis gravidarum or other nutritional deficiencies. While mild weight fluctuations can occur, a consistent loss of weight rather than gradual gain suggests inadequate caloric intake due to persistent vomiting and dehydration.

Choice B rationale: Breast tenderness

Breast tenderness is a common and expected physiological change during pregnancy due to hormonal fluctuations, particularly increased estrogen and progesterone levels. It is not considered abnormal or unexpected at this stage of pregnancy.

Choice C rationale: Heart rate

A heart rate of 116/min is unexpected, as it is above the normal range for adults (typically 60–100/min). Pregnancy can cause a mild increase in heart rate, but tachycardia above 110/min may indicate dehydration, anemia, or electrolyte imbalance, all of which can stem from excessive vomiting and fluid loss.

Choice D rationale: Vomiting

While occasional nausea and vomiting (morning sickness) can be expected in early pregnancy, persistent vomiting up to eight times daily and symptoms of dehydration (dry mucosa, poor skin turgor, positive ketones in urine) raise concern for hyperemesis gravidarum, a more severe form of pregnancy-related nausea and vomiting.

Choice E rationale: Nasal congestion

Nasal congestion is common during pregnancy due to increased blood volume and vascular changes affecting the nasal mucosa. It is not unexpected and does not indicate a complication.

Choice F rationale: Respiratory rate

A respiratory rate of 20/min falls within the normal range for adults (typically 12–20/min), making it an expected finding.