Maternal and neonatal characteristics associated with neonatal neutropenia in hypertensive pregnancies

The purpose of this study was to identify maternal and neonatal characteristics affecting marked neonatal neutropenia in pregnancies complicated by hypertension. A single institution retrospective chart review over 2 years of singleton and multifetal pregnancies with hypertensive disorders meeting American College of Obstetricians and Gynecologists criteria was performed. Neutropenia and sepsis occurring within the first 16 days of life (DOL) were studied. Neutropenia was defined as an absolute neutrophil count of <1500/microL and sepsis as any positive blood, cerebrospinal fluid, or urine culture. The study group contained neonates with neutropenia. From all other hypertensive pregnancies, a presumed nonneutropenic control group was randomly generated with a 4:1 ratio; these neonates may or may not have had a complete blood count (CBC) performed because they were clinically stable. Multiple gestations were separately analyzed and compared with hypertensive multifetal neonates with confirmed CBCs showing no neutropenia. Chi-square, Mann-Whitney U, and regression analyses were performed. Five hundred forty-three hypertensive pregnancies representing 633 births, 173 (27.3%) of which were from multiple gestations, were studied. There were 32 (5.9%) cases of neutropenia, with 22 (68.8%) from multiple gestations. Of premature multiple gestations, 45.2% born between 24 and 34 weeks' gestation developed neutropenia. The median time to diagnosis of neutropenia was 1.2 hours with 80.6% detected on the first DOL. Resolution of neutropenia occurred within 7 days in 84.4% of surviving neonates. Univariate analysis showed significant associations of neutropenia with gestational age at delivery, multiple gestations, birth weight, severe preeclampsia, and development of neonatal sepsis. When multiple gestations were analyzed, linear regression showed only sepsis to be significantly associated with neutropenia (p = 0.027). Hypertensive disorders of pregnancy and premature delivery are common in multiple gestations and are associated with neutropenia (12.7% versus 2.2% neutropenia in singletons (p < 0.001). Furthermore, multiple gestations with neutropenia had a higher incidence of sepsis than singletons with neutropenia.