Risk for gestational diabetes and hypertension for women with twin pregnancy compared to singleton pregnancy

This study was undertaken to determine the incidence of pregnancy induced hypertension (PIH) and gestational diabetes (GDM) in twin pregnancies (TP) in comparison with singleton pregnancies (SP), and to test whether TP with GDM have a higher risk than TP without GDM, as is known to be the case in SP.

Eighty-nine patients with TP who sought prenatal care between 1 September 1994 and 30 October 1997, were asked to participate. One hundred and seventy-eight of the 1,416 patients were matched in a 1:2 ratio by age, body-mass-index, parity, gestational age at screening, and ethnicity with a singleton pregnancy from our database dating from the same period. The diagnosis "hypertension" or "preeclampsia" was made using clinical criteria including a repeated blood pressure above 140/90 mm Hg. Maternal and fetal outcome were compared between SP and TP, between TP with and without pathological screening, between TP with and without GDM.

Patients with TP did not have a higher rate of GDM but of PIH (GDM 3.4% vs. 3.4%, p=0.63; PIH 2.8% vs. 9.0%, p=0.036). Expectant mothers of twins whose glucose screening test was pathological have a higher incidence of hypertension than those whose screening test was normal (17.9% vs. 4.9%, p=0.048). Twins of gestational diabetics have a higher rate of admission to the neonatal intensive care unit than twins of healthy pregnant patients (100% vs. 31%, p=0.028).

TP are associated with a higher risk of hypertension than SP but not for GDM. Patients expecting twins who show a carbohydrate intolerance are at a higher risk for hypertension and fetal diabetes-associated complications.