Severity of Pulmonary Hypertension Raises Risk of Fetus Death, Review Finds

Patricia Inácio, PhD avatar

by Patricia Inácio, PhD |

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The severity of pulmonary hypertension (PH) increases the risk of fetus death, although mortality among PH pregnant women is low, according to a Chinese review study.

The study, “Pregnancy and pulmonary hypertension: An exploratory analysis of risk factors and outcomes” was published in the journal Medicine.

Pregnancy induces massive changes in a woman’s body, including blood flow, which can be intolerable for a woman with PH. PH guidelines advise against pregnancy because of the high risk of complications or death for both the mother and the fetus — reports have estimated rates of 30-56 percent in maternal mortality among pregnant women with PH.

Now, a team of researchers performed a retrospective review to identify potential risk factors associated with maternal outcomes among PH women.

They reviewed the medical records — including demographics, characteristics of PH and pregnancy, management and outcomes — of 36 pregnant women at China’s Peking Union Medical College Hospital between January 2009 and June 2018. The women’s median age was 26.

According to the PH WHO Classification, the majority of the women — 83.3 percent — belonged to WHO’s group 1,  followed by 13.9 percent in WHO’s group 2, and 2.8 percent in group 4. No cases were reported in groups 3 or 5.

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Twenty-five (69.4 percent) of the 36 patients analyzed had never given birth. Seventeen patients had an abortion (before week 24 of gestation), and 19 had a preterm delivery (between 24 and 36 weeks of gestation). The median duration of pregnancy was 24 weeks (6–36 weeks). More than half of the patients (20 of 36) underwent emergency delivery.

Uncontrolled PH or other diseases were the cause of terminated pregnancy in almost all (34 patients, 94.4 percent); the other two cases of terminated pregnancy were due to fetal abnormality.

In 38.9 percent of the cases, women underwent vaginal delivery of the aborted fetus. Cesarean section was performed in 22 patients (61.1 percent).

In approximately half of the women (52.8 percent), pregnancies lasted longer than 24 weeks.

Most women (72.2 percent) were unaware of their PH before the pregnancy. Those who knew about it received more frequent treatment with pulmonary vascular-targeted medications than those who were diagnosed during pregnancy.

Overall, the mortality rate among women was 8.3 percent (3 of 36), and 31.6 percent among fetuses (6 of 19 born). All the women were in PH-WHO group 1, and all died from uncontrolled PH and cardiorespiratory failure after surgery. None had been diagnosed with PH before the pregnancy.

One woman had primary Sjögren syndrome; two others had a cardiac ventricular septal defect along with Eisenmenger syndrome, a condition that results from abnormal blood circulation caused by a defect in the heart.

All three had a cesarean section under general anesthesia, and died within a week after delivery.

According to the level of disease severity, all women with mild PH survived, while pregnant women with moderate or severe PH had an 11.5 percent mortality rate.

Overall, “we demonstrate a relatively low maternal mortality but a high late fetal mortality, which are probably attributable to a short median pregnancy duration,” researchers said.

“Maternal mortality is associated with PH classification, severity of PH, delayed diagnosis of PH, and NYHA [New York Heart Association] classification,” they concluded.