Preeclampsia and the risk to the baby

What is it?

Early in pregnancy, the blood vessels supplying the placenta are remodeled so they can carry a large, low-pressure flow. In preeclampsia that remodeling is incomplete, so the placenta operates on a reduced supply. ¹

Everything else follows from that.

For the mother, the under-perfused placenta releases substances that damage the lining of blood vessels throughout her body, causing high blood pressure and effects on the kidneys, liver, blood and brain. See the maternal page.

For the baby, the reduced supply means less oxygen and fewer nutrients. Over weeks that can produce fetal growth restriction. Over hours, during labor, it means less reserve to draw on when contractions reduce blood flow further.

That reduced reserve is the practical point during labor. A baby who is already receiving a marginal supply has less capacity to tolerate the drops that happen with every contraction, which is why abnormal fetal heart rate patterns are more common in these pregnancies. ⁴

There is also a higher risk of placental abruption, where the placenta separates from the wall of the uterus. ¹

And there is the timing problem. The only cure is delivery, so the decision becomes a balance between the risk to the mother of continuing and the risk to the baby of being born early. ¹

What does standard care look like?

Blood pressure and urine checked at every prenatal visit, with high readings repeated and acted on. ¹

Low-dose aspirin from early in pregnancy for people at high risk. ¹

Assessment of the baby, including growth scans, nonstress testing, biophysical profile and Doppler study studies of blood flow. ⁴

Antenatal corticosteroids if preterm delivery is anticipated. ^{3 5}

Magnesium sulphate before 32 weeks for the baby's brain, which is a separate indication from the magnesium given to prevent maternal seizures. ⁶

Delivery at a hospital with the right level of newborn care where an early birth is expected. ⁷

A decision on timing of delivery, which guidance addresses by gestational age and by whether severe features are present. ¹

Continuous fetal monitoring in labor. ⁴

What can go wrong?

Blood pressure not measured, or high readings not repeated and acted on. ¹

Symptoms dismissed. New severe headache, visual changes, upper abdominal pain, sudden swelling and breathlessness are warning signs rather than ordinary pregnancy complaints. ¹

Aspirin not offered to someone at high risk. ¹

Fetal growth not monitored, so growth restriction was not identified.

Antenatal steroids not given when early delivery was anticipated. ³

Magnesium for the baby's brain not given before 32 weeks. ⁶

Delivery delayed past the point guidance addresses, or performed without steroids where there was time. ¹

A concerning fetal heart rate not acted on in a baby already receiving a marginal supply. ⁴

Delivery at a hospital without the level of newborn care needed. ⁷

Whether any of this amounts to a departure from the standard takes a physician expert reading the whole record.

Which injuries can follow?

For the baby

• Fetal growth restriction, which is the most direct consequence. ¹
• Preterm birth and everything that follows from it. ²
• HIE, where a baby with limited reserve is not delivered when the tracing calls for it. ⁸
• Periventricular leukomalacia and intraventricular hemorrhage where birth is very early. ⁹
• Cerebral palsy, largely through the preterm route. ²
• Low blood sugar in a growth-restricted baby with few stores. ¹⁰
• Stillbirth, where placental function fails. ¹

For the mother, see preeclampsia and eclampsia. ¹

What does this look like in the records?

From the prenatal record

• Every blood pressure reading with the date.
• Urine protein results.
• Blood tests: platelets, liver enzymes, kidney function. ¹
• Whether low-dose aspirin was offered or prescribed. ¹
• Growth scans, Doppler study studies and biophysical profiles, with dates.
• Any reported symptoms and what was done.

From the labor and delivery record

• Whether antenatal steroids were given, how many doses, and when. ⁵
• Whether magnesium was given, and for which indication. ⁶
• The fetal monitoring strip. ⁴
• The reason for and timing of delivery. ¹
• The cord blood gas and Apgar score scores. ¹¹

Afterward

• The placental pathology report, which frequently shows the changes of poor placental perfusion and is one of the most informative documents in this situation. ⁸

What can you do this week?

1. Request the complete labor and delivery record for you and your baby. The records request builder writes the letters for you.
2. Write down what you remember while it is fresh, using the delivery timeline builder.
3. Read how to read your labor and delivery records before the records arrive.
4. Check the deadline to file in your state with the statute of limitations lookup.