TOPLINE:

In women with chronic hypertension, those whose fetuses had lower estimated fetal weight (EFW) and fetal growth restriction at 35-36 weeks’ gestation had a higher likelihood of developing maternal manifestations of superimposed preeclampsia. In contrast, women whose fetuses had lower EFW but did not have fetal growth restriction did not demonstrate increased rates of preeclampsia.

METHODOLOGY:

• Researchers conducted a secondary analysis of data from two cohorts in the UK between 2014 and 2023, including 1258 women with chronic hypertension and single pregnancies who gave birth to a liveborn or stillborn baby at or after 35 weeks of gestation.
• Participants were categorized as those whose fetuses had EFW < 10th percentile (n = 167) or those whose fetuses had EFW ≥ 10th percentile (control group; n = 1091); the < 10th percentile group was further subdivided into those whose fetuses had fetal growth restriction (abnormal fetal Doppler results; n = 64) and those whose fetuses did not (normal Doppler results; n = 103).
• Ultrasound examinations at the 35- to 36-week visit included assessment of fetal anatomy; biometry for EFW calculation using specific growth charts; Doppler examination of uterine, umbilical, and fetal middle cerebral arteries; and other variables.
• The primary outcome was superimposed preeclampsia, defined in three ways: traditional definition (new-onset proteinuria at ≥ 20 weeks); 2019 American College of Obstetricians and Gynecologists (ACOG) criteria (proteinuria or renal insufficiency, hepatic involvement, thrombocytopenia, neurologic complications, or pulmonary edema); and 2021 International Society for the Study of Hypertension in Pregnancy (ISSHP) criteria (proteinuria or maternal end-organ dysfunction).
• After propensity score matching, women whose fetuses had EFW < 10th percentile (n = 167) were compared with those whose fetuses had EFW ≥ 10th percentile (n = 334).

TAKEAWAY:

• Overall, 18.6% of women developed superimposed preeclampsia by the traditional definition, 20.2% by ACOG criteria, and 21.9% by 2021 ISSHP maternal criteria.
• Women whose fetuses had EFW < 10th percentile and fetal growth restriction more frequently developed preeclampsia according to all three definitions than matched control women. They also had a shorter ultrasound-to-birth interval by 1.8 weeks.
• Women whose fetuses had EFW < 10th percentile and fetal growth restriction delivered 1.7 weeks earlier. They more often had babies with birth weight < 10th percentile or admitted to the neonatal unit.
• Women whose fetuses had EFW < 10th percentile without fetal growth restriction showed no difference in preeclampsia development compared with matched control women but delivered 0.7 weeks earlier and had a shorter ultrasound-to-birth interval by 0.8 weeks.

IN PRACTICE:

“Our findings support that women with chronic hypertension and FGR [fetal growth restriction] more often develop maternal manifestations of PE [preeclampsia], and warrant enhanced maternal surveillance, in addition to the enhanced fetal surveillance that they will already be offered because of fetal growth concerns,” the authors wrote.

SOURCE:

The study was led by Laura A. Magee, MD, of the School of Life Course and Population Sciences at King’s College London, London, England. It was published online on April 14, 2026, in the American Journal of Obstetrics and Gynecology.

LIMITATIONS:

The study examined women with chronic hypertension at late preterm gestational age, so findings may not apply to earlier gestational ages. Only singleton pregnancies were included, and information on secondary hypertension was lacking. Data on gestational age at preeclampsia diagnosis and specific indications for birth were not available.

DISCLOSURES:

The Fetal Medicine Foundation provided a grant supporting this study. Canon Medical Systems Europe BV supplied ultrasound machines for maternal echocardiography and software for speckle tracking analysis at no charge. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.