During 2003–2005, 506 mothers (0.2%) of 240,131 singleton deliveries were reported to have HCV, and 2022 women were randomly selected to be HCV-negative controls. In addition, 1439 (0.6%) HCV-negative women and 124 (25%) of the HCV-positive mothers were identified as drug users.
As shown in , HCV-positive women were similar to HCV-negative drug users in many respects, and less similar to the randomly selected comparison group. Drug-using women, regardless of HCV status, were more likely to be unmarried, have less education, have inadequate prenatal care, have received Medicaid, and smoke than their randomly selected HCV-negative counterparts. The lowest rates of prenatal care and highest rates of Medicaid use were found in the HCV-negative drug-using group.
Selected maternal characteristics of pregnancies from within specific cohorts, Washington State 2003–2005
HCV-positive women were somewhat more likely to have GDM than HCV-negative women (OR, 1.53; 95% CI, 0.85, 2.27) (). However, among women with excess weight gain during pregnancy, HCV infection was strongly associated with GDM (OR, 2.51; 95% CI, 1.04, 6.03). This association was not observed in women with insufficient or adequate weight gain, (OR, 0.89; 95% CI, 0.28, 2.80 and OR, 1.14; 95% CI, 0.38, 3.39). There was also a trend toward an association between HCV and PROM (OR, 1.66; 95% CI, 0.93, 2.96).
Risk of selected maternal and infant outcomes in HCV pregnant mothers relative to randomly selected HCV-negative mothers
To determine the impact of drug use, a stratified analysis was performed based on drug use history (). Among non-drug-using mothers, HCV-positivity (n=382) remained associated with GDM in women with excess weight gain (OR, 3.09; 95% CI, 1.29, 7.42). In addition, a similar trend toward an association between HCV infection and PROM (OR, 1.74; 95% CI, 0.98, 3.25) was observed.
Risk of selected maternal and infant outcomes in HCV-positive mothers relative to HCV-negative mothers stratified by drug use
Similarly, when the analysis was limited to HCV-positive (n=124) and HCV-negative (n=1439) mothers with a history of drug use, HCV remained somewhat associated with increased risk of PROM (OR, 1.33; 95% CI, 0.60, 2.95) (). Due to the small number of HCV-positive drug users with GDM (n=2) no comment could be made in regard to this outcome.
HCV infection was associated with an increased risk of the infant being LBW (OR, 2.17; 95 % CI, 1.24, 3.80), SGA (OR, 1.46; 95% CI, 1.00, 2.13), requiring NICU admission (OR, 2.91; 95% CI, 1.86, 4.55), and needing assisted ventilation (OR, 2.37; 95% CI, 1.46, 3.85) (). There were non-significant trends for low apgar score (OR, 1.53; 95% CI, 0.93, 2.54), prematurity (OR, 1.54; 95% CI, 0.97, 2.43), and neonatal jaundice (OR, 1.25; 95% CI, 0.82, 1.90) being associated with HCV.
Analyses stratified by drug use again yielded similar findings for non-drug-using mothers (). HCV was associated with increased risk of being LBW (OR, 2.15; 95% CI 1.19, 3.90), SGA (OR, 1.62; 95% CI, 1.07, 2.43), requiring NICU admission (OR, 3.00; 95% CI, 1.85, 4.86), needing assisted ventilation (OR, 2.25; 95% CI, 1.40, 3.63), and prematurity (OR, 1.69; 95% CI, 1.04, 2.73). Neonates born to HCV-positive mothers were somewhat more likely to have a low apgar score (OR, 1.42; 95% CI, 0.85, 2.37), but this association did not reach statistical significance. In non-drug-using mothers, HCV was not associated with neonatal jaundice (OR, 1.06; 95% CI, 0.67, 1.69).
Finally, when analysis was restricted to mothers with a history of drug use, maternal HCV remained strongly associated with NICU admission (OR, 2.80; 95% CI, 1.83, 4.29) and with need for assisted ventilation (OR, 1.82; 95% CI, 1.03, 3.22) (). Neonates born to HCV-positive drug-using mothers did not have an increased risk of being LBW (OR, 1.19; 95% CI, 0.74, 1.91), prematurity (OR, 1.03; 95% CI, 0.66, 1.61), SGA (OR, 0.97; 95% CI, 0.57, 1.64), or having a low apgar score (OR, 1.12; 95% CI 0.60, 2.08). There was a non-significant trend toward an association between HCV and neonatal jaundice (OR, 1.50; 95% CI, 0.94, 2.41).
Reasons for NICU admission
Children born to HCV positive mothers were admitted to the NICU (n=93) for a variety of reasons, most commonly with respiratory problems (38.7%), due to maternal drug use/withdrawal (35.5%), early gestational age/prematurity (37.6%), and infections (26.9%). When stratified by drug use, HCV status in non-drug-using mothers was associated with admission to the NICU for respiratory (OR 3.25; 95% CI, 1.62, 6.51) and congenital reasons (OR 4.17; 95% CI, 1.18, 14.8) (). In these same two cohorts there were also non-significant trends toward an association between maternal HCV status and gestational age/prematurity (OR 1.71; 95% CI, 0.83, 3.56), infectious (OR 2.08; 95% CI, 0.92, 4.72), cardiac (OR 1.41; 95% CI, 0.49, 4.01), metabolic/gastrointestinal (OR 1.24; 95% CI, 0.49, 3.18), and hematologic reasons (OR 3.41; 95% CI, 0.87, 13.3) for NICU admission.
NICU admission reason and risk in HCV-positive and HCV-negative mothers stratified by drug-using status
In drug-using women, similar findings were seen (). Maternal HCV status was associated with admission to the NICU for respiratory (OR 1.91; 95% CI, 1.05, 3.46), infectious (OR 2.41; 95% CI, 1.31, 4.44), and metabolic/gastrointestinal reasons (OR 2.80; 95% CI, 1.49, 5.28). For the remaining outcomes in the drug-using cohorts there were again non-significant trends in all other reasons for admission. Due to small numbers, no conclusions could be drawn in NICU admissions due to congenital abnormalities.