Maternal autoimmune disease and birth defects in the National Birth Defects Prevention Study

Maternal exposure to heparin products and risk of birth defects in the National Birth Defects Prevention Study

BACKGROUND

Heparin and low-molecular-weight heparin are the preferred anticoagulants during pregnancy as they do not cross the placenta. Although research on the safety of heparin products has been reassuring, previous studies have considered birth defects as a single outcome or by larger organ system and have not examined associations with specific birth defects.

METHODS

We analyzed data from the National Birth Defects Prevention Study, a multisite, population-based case-control study from 1997 to 2011. We used unconditional logistic regression with Firth's penalized likelihood to calculate adjusted odds ratios (ORs) and profile likelihood 95% confidence intervals (CIs) for defects with at least five exposed cases. For defects with 3-4 exposed cases, we estimated crude ORs and exact 95% CIs.

RESULTS

Of the 42,743 women in our analysis, 117 (0.4%) case and 44 (0.4%) control mothers reported using a heparin product in early pregnancy. The adjusted ORs ranged from 0.9 to 3.9 and were elevated for anorectal atresia (OR = 2.0, 95% CI = 0.8-4.3), longitudinal limb deficiency (3.5, 1.3-7.8), transverse limb deficiency (1.8, 0.6-4.3), atrioventricular septal defect (3.9, 1.4-9.0), and secundum atrial septal defect (2.2, 1.2-3.8).

CONCLUSIONS

We observed elevated associations for some birth defects, although heparin is a rare exposure, which limited our ability to evaluate many associations. Future studies that can explore specific birth defects and adequately control for confounding by indication are needed. Given that women with an indication for heparin products during pregnancy often need to take medication, one must remain mindful of the underlying risk of a birth defect that exists regardless of medication use.

Reported congenital malformations after exposure to non-tumour necrosis factor inhibitor biologics: A retrospective comparative study in EudraVigilance

AIMS

To evaluate the number and nature of reported congenital malformations (CMs) after intrauterine exposure to non-tumour necrosis factor inhibitor biologics (non-TNFi biologics) compared to certolizumab pegol (CZP).

METHODS

A retrospective comparative study was conducted in the EudraVigilance (EV) database. A safe biologic (CZP) was considered as the reference group. Odds ratios (ORs) for CMs were calculated for each non-TNFi biologic (including abatacept, anakinra, belimumab, ixekizumab, rituximab, secukinumab, tocilizumab, ustekinumab and vedolizumab), versus CZP (quantitative assessment). Then, CM patterns were reviewed in consultation with a clinical geneticist (qualitative assessment).

RESULTS

ORs were not statistically significant except for belimumab and vedolizumab (similar in magnitude). Except for vedolizumab, no specific CM patterns were observed for the included non-TNFi biologics. Three cases of corpus callosum agenesis (CCA) were identified for vedolizumab (versus none in CZP and other investigated non-TNFi biologics). Two of the CCA cases were associated with other neurological CMs (one cerebral ventriculomegaly with microcephaly and one polymicrogyria). This may indicate that these CCAs are related to undiagnosed genetic alterations or are associated with the underlying maternal disease, although a definite relationship with vedolizumab exposure cannot be ruled out.

CONCLUSION

No special safety signal was identified regarding the occurrence of CMs after exposure to abatacept (n = 64), anakinra (n = 20), belimumab (n = 93), ixekizumab (n = 29), rituximab (n = 57), secukinumab (n = 128), tocilizumab (n = 124) and ustekinumab (n = 215). Regarding observed CCAs in the vedolizumab group (n = 113), no firm conclusions can be made based on available information.

Maternal exposure to hydroxychloroquine and birth defects

Background

Hydroxychloroquine is a treatment for rheumatic disease and considered safe during pregnancy. Interest in hydroxychloroquine has increased as it is being examined as a potential treatment and prophylaxis for coronavirus disease 2019. Data on the risks of specific birth defects associated with hydroxychloroquine use are sparse.

Methods

Using data from two case–control studies (National Birth Defects Prevention Study and Slone Epidemiology Center Birth Defects Study), we described women who reported hydroxychloroquine use in pregnancy and the presence of specific major birth defects in their offspring. Cases had at least one major birth defect and controls were live‐born healthy infants. Women self‐reported medication use information in the few months before pregnancy through delivery.

Results

In total, 0.06% (19/31,468) of case and 0.04% (5/11,614) of control mothers in National Birth Defects Prevention Study, and 0.04% (11/29,838) of case and 0.05% (7/12,868) of control mothers in Birth Defects Study reported hydroxychloroquine use. Hydroxychloroquine users had complicated medical histories and frequent medication use for a variety of conditions. The observed birth defects among women taking hydroxychloroquine were varied and included nine oral cleft cases; the elevated observed:expected ratios for specific oral cleft phenotypes and for oral clefts overall had 95% confidence intervals that included 1.0.

Conclusion

While teratogens typically produce a specific pattern of birth defects, the observed birth defects among the hydroxychloroquine‐exposed women did not present a clear pattern, suggesting no meaningful evidence for the risk of specific birth defects. The number of exposed cases is small; results should be interpreted cautiously.

Maternal rheumatoid arthritis and systemic lupus erythematosus and risk of cryptorchidism and hypospadias in boys: a Danish nationwide study

OBJECTIVES

RA and SLE are the most prevalent autoimmune rheumatic diseases affecting young women. Both diseases are characterized by systemic inflammation that may affect placental function and fetal development during pregnancy, and both diseases are associated with adverse pregnancy and child outcomes. We investigated the associations between maternal RA or SLE and the two genital malformations, cryptorchidism and hypospadias.

METHODS

In this nationwide register-based study including all male singleton live births in Denmark from 1995 to 2016, we assessed the occurrence of cryptorchidism and hypospadias according to the prenatal disease-state of the mothers. Using Cox proportional hazards models we calculated adjusted hazard ratios, accounting for varying age at diagnosis.

RESULTS

Among 690 240 boys, 1026 had a mother with RA and 352 had a mother with SLE. We found adjusted hazard ratios of 1.72 (95% CI: 1.15; 2.57) for cryptorchidism among boys born to mothers with RA and 1.46 (95% CI: 0.69; 3.06) for boys born to mothers with SLE, compared with the general population. As the number of hypospadias cases was low, multivariate analysis was not feasible. The crude hazard ratios were 0.51 (95% CI: 0.16; 1.58) and 1.00 (95% CI: 0.25; 4.03) for RA and SLE, respectively.

CONCLUSION

Boys born to mothers with RA had higher risk of cryptorchidism, compared with unexposed boys. Boys born to mothers with SLE showed a similar tendency, however with less precision of the estimate. No conclusion could be reached on the risk of hypospadias, due to the low number of events.

Complement factors and alpha-fetoprotein as biomarkers for noninvasive prenatal diagnosis of neural tube defects

Neural tube defects (NTDs) are serious congenital malformations. In this study, we aimed to identify more specific and sensitive maternal serum biomarkers for noninvasive NTD screenings. We collected serum from 37 pregnant women carrying fetuses with NTDs and 38 pregnant women carrying normal fetuses. Isobaric tags for relative and absolute quantitation were conducted for differential proteomic analysis, and an enzyme-linked immunosorbent assay was used to validate the results. We then used a support vector machine (SVM) classifier to establish a disease prediction model for NTD diagnosis. We identified 113 differentially expressed proteins; of these, 23 were either up- or downregulated 1.5-fold or more, including five complement proteins (C1QA, C1S, C1R, C9, and C3); C3 and C9 were downregulated significantly in NTD groups. The accuracy rate of the SVM model of the complement factors (including C1QA, C1S, and C3) was 62.5%, with 60% sensitivity and 67% specificity, while the accuracy rate of the SVM model of alpha-fetoprotein (AFP, an established biomarker for NTDs) was 62.5%, with 75% sensitivity and 50% specificity. Combination of the complement factor and AFP data resulted in the SVM model accuracy of 75%, and receiver operating characteristic curve analysis showed 75% sensitivity and 75% specificity. These data suggest that a disease prediction model based on combined complement factor and AFP data could serve as a more accurate method of noninvasive prenatal NTD diagnosis.

Nongenetic risk factors for holoprosencephaly: An updated review of the epidemiologic literature

Holoprosencephaly (HPE) is a major structural birth defect of the brain that occurs in approximately 1 in 10,000 live births. Although some genetic causes of HPE are known, a substantial proportion of cases have an unknown etiology. Due to the low birth prevalence and rarity of exposure to many potential risk factors for HPE, few epidemiologic studies have had sufficient sample size to examine risk factors. A 2010 review of the literature identified several risk factors that had been consistently identified as occurring more frequently among cases of HPE, including maternal diabetes, twinning, and a predominance of females, while also identifying a number of potential risk factors that had been less widely studied. In this article, we summarize a systematic literature review conducted to update the evidence for nongenetic risk factors for HPE.