La paciente está embarazada.

Spanish uses estar for many states or conditions, and embarazada is treated as a condition, not a permanent identity.

• está embarazada = is pregnant
• es would sound wrong here

A useful pattern is:

• está enferma = is ill
• está cansada = is tired
• está embarazada = is pregnant

So even though pregnancy may last months, Spanish still uses estar, not ser.

Because paciente can refer to either a male or a female patient. The article shows the gender here.

• el paciente = the male patient
• la paciente = the female patient

The ending -e does not automatically mean masculine or feminine. Many Spanish nouns ending in -e can be either, and you find out from the article or the context.

Because embarazada agrees with la paciente, which is feminine singular.

In Spanish, adjectives usually agree with the noun in:

• gender: masculine/feminine
• number: singular/plural

So:

• la paciente está embarazada = the female patient is pregnant
• el paciente está embarazado would match grammatically, but in real usage pregnancy normally applies to a woman, so you usually hear embarazada

Yes. In this sentence, paciente is a noun: the patient.

But paciente can also be an adjective meaning patient in the personality sense:

• Ella es muy paciente = She is very patient

So the same word can mean different things depending on how it is used.

It may look similar, but no: this is a classic false friend.

• embarazada = pregnant
• embarrassed = avergonzado / avergonzada or tener vergüenza

So:

• Estoy embarazada = I am pregnant
• Estoy avergonzada = I am embarrassed

This is a very important word pair not to confuse.

No. Spanish often omits subject pronouns when the meaning is already clear.

So you normally say:

• La paciente está embarazada

You could say:

• Ella está embarazada

but that means She is pregnant, not The patient is pregnant. Since your sentence already has the subject la paciente, adding ella would usually be unnecessary.

The accent mark shows the correct stress: es-TÁ.

It also helps distinguish forms in writing:

• esta = this
• está = is

So the accent matters both for pronunciation and for meaning.

Normally, no. In standard Spanish, you usually need the article here:

• La paciente está embarazada

Leaving out the article sounds unnatural in an ordinary full sentence. In very special contexts like notes, headlines, or medical shorthand, you might see article omission, but for normal speech and writing, use la paciente.

You make the article, noun reference, verb, and adjective match the plural subject:

• Las pacientes están embarazadas = The patients are pregnant

Changes:

• la → las
• está → están
• embarazada → embarazadas

Notice that paciente itself does not change much in the singular/plural except by adding -s:

• la paciente
• las pacientes

Yes, it sounds fairly neutral to formal, especially because of la paciente.

You are likely to hear it in:

• medical contexts
• reports
• professional speech

In everyday conversation, people would more often say:

• Está embarazada = She is pregnant
• Mi hermana está embarazada = My sister is pregnant
• La mujer está embarazada = The woman is pregnant

So la paciente is perfectly correct, but it clearly sounds like a medical or clinical context.