Laboratory testing for cytomegalovirus among pregnant women in the United States: a retrospective study using administrative claims data

Validation of Insurance Billing Codes for Monitoring Antenatal Screening

BACKGROUND

Prevalence statistics for pregnancy complications identified through screening such as gestational diabetes usually assume universal screening. However, rates of screening completion in pregnancy are not available in many birth registries or hospital databases. We validated screening-test completion by comparing public insurance laboratory and radiology billing records with medical records at three hospitals in British Columbia, Canada.

METHODS

We abstracted a random sample of 140 delivery medical records (2014-2019), and successfully linked 127 to valid provincial insurance billings and maternal-newborn registry data. We compared billing records for gestational diabetes screening, any ultrasound before 14 weeks gestational age, and Group B streptococcus screening during each pregnancy to the gold standard of medical records by calculating sensitivity and specificity, positive predictive value, negative predictive value, and prevalence with 95% confidence intervals (CIs).

RESULTS

Gestational diabetes screening (screened vs. unscreened) in billing records had a high sensitivity (98% [95% CI = 93, 100]) and specificity (>99% [95% CI = 86, 100]). The use of specific glucose screening approaches (two-step vs. one-step) were also well characterized by billing data. Other tests showed high sensitivity (ultrasound 97% [95% CI = 92, 99]; Group B streptococcus 96% [95% CI = 89, 99]) but lower negative predictive values (ultrasound 64% [95% CI = 33, 99]; Group B streptococcus 70% [95% CI = 40, 89]). Lower negative predictive values were due to the high prevalence of these screening tests in our sample.

CONCLUSIONS

Laboratory and radiology insurance billing codes accurately identified those who completed routine antenatal screening tests with relatively low false-positive rates.

Hepatitis B Surface Antigen Testing Among Pregnant Women, United States 2014

BACKGROUND

Post-exposure prophylaxis administered to infants shortly after birth prevents approximately 90% of cases of perinatal hepatitis B virus (HBV) transmission. The Advisory Committee on Immunization Practices recommends that all pregnant women be tested for hepatitis B surface antigen (HBsAg) at an early prenatal visit during each pregnancy to detect active infection with HBV. This study sought to determine the proportion and characteristics of pregnant women tested\not tested according to Advisory Committee on Immunization Practices recommendations.

METHODS

We analyzed MarketScan databases to assess prenatal HBsAg testing among women with commercial and Medicaid health care coverage according to demographic and clinical characteristics. Pregnant women 15-44 years of age continuously enrolled in a health plan in the MarketScan database during 2013 and 2014 and with a live birth in 2014 were included.

RESULTS

Among commercially insured women, 239,955 (87.7%) received HBsAg testing and 59.6% were tested during their first trimester. Among Medicaid-enrolled women, 57,268 (83.6%) received HBsAg testing and 39.4% were tested during their first trimester. Among women with high risk pregnancies, HBsAg testing occurred in 87.3% of those with commercial insurance and 84.8% with Medicaid. Testing also varied by maternal age; among women with commercial insurance, testing was greatest among women 26-44 years of age, and among women with Medicaid, testing was greatest among younger women (15-25 years). Testing was lowest among women residing in the Northeast (commercial insurance only).

CONCLUSIONS

Prenatal HBsAg testing identifies HBV-infected pregnant women so their infants can receive timely immunoprophylaxis. Efforts to optimize HBsAg testing among all pregnant women are needed to further prevent perinatal HBV transmission.

Killer-cell immunoglobulin-like receptors and cytomegalovirus reactivation during late pregnancy

Human cytomegalovirus (CMV) represents an important public health concern as it is associated with severe morbidity and mortality in transplant recipients, HIV-infected individuals and pregnant women given the risk of congenital infection. Congenital CMV is a leading cause of neurological sequelae, developmental delay and birth defects worldwide. Cytomegalovirus can be transmitted to the foetus following maternal infection or reactivation. NK cells expressing killer-cell immunoglobulin-like receptors (KIR) are part of the innate immune system and the first line of defence against viral incursions. Previous reports have shown that KIR genes are associated with CMV infections in the post-transplant setting. In this study, we set out to determine whether a protective effect of KIR genes over CMV infection is seen in Mexican pregnant women. Cytomegalovirus infection was assessed through nucleic acid testing in 200 pregnant women and 600 healthy blood donors comprising the Mexican mestizo reference population. Killer-cell immunoglobulin-like receptors and HLA-C genotypes were obtained from 200 pregnant women and 300 reference samples using a comprehensive PCR-SSP approach. We observed statistically lower carrier frequencies of cB03|tA01 gene-content haplotype, of cB03 haplotype motif, of the KIR2DL5 + 2DS3/2DS5 gene pair and of KIR2DL5 amongst CMV-positive pregnant women in comparison with those CMV negative. None of these were associated with CMV status in the reference population. Logistic regression analysis revealed that the most important factor determining CMV status during third-trimester pregnancies was the KIR2DL5 + 2DS3/2DS5 gene pair (OR 0.376 (95%CI 0.174, 0.811, P = 0.013). Our results indicate that CMV-protective KIR gene associations described in Caucasoid populations are also present in the genetically distinct Mexican mestizo population. Our results suggest that certain KIR gene combinations provide protection against CMV infections occurring during late-term pregnancies, a finding of utmost epidemiological importance given its implication with congenital CMV infections.

Cytomegalovirus infection among infants in California neonatal intensive care units, 2005-2010

AIM

To assess the burden of congenital and perinatal cytomegalovirus (CMV) disease among infants hospitalized in neonatal intensive care units (NICUs).

METHODS

CMV infection was defined as a report of positive CMV viral culture or polymerase chain reaction at any time since birth in an infant hospitalized in a NICU reporting to California Perinatal Quality Care Collaborative during 2005-2010.

RESULTS

One hundred and fifty-six (1.7 per 1000) infants were reported with CMV infection, representing an estimated 5% of the expected number of live births with symptomatic CMV disease. Prevalence was higher among infants with younger gestational ages and lower birth weights. Infants with CMV infection had significantly longer hospital stays and 14 (9%) died.

CONCLUSIONS

Reported prevalence of CMV infection in NICUs represents a fraction of total expected disease burden from CMV in the newborn period, likely resulting from underdiagnosis and milder symptomatic cases that do not require NICU care. More complete ascertainment of infants with congenital CMV infection that would benefit from antiviral treatment may reduce the burden of CMV disease in this population.