Maternal genitourinary infections and risk of birth defects in the National Birth Defects Prevention Study

Joint British Association for Sexual Health and HIV and Royal College of Obstetricians and Gynaecologists national UK guideline for the management of herpes simplex virus (HSV) in pregnancy and the neonate (2024 update)

This updated national UK guideline offers recommendations on the management of genital herpes simplex virus (HSV) in mothers and pregnant people during pregnancy and within 4 weeks following birth. It includes recommendations for first episode and recurrent HSV, HSV in preterm pre-labour rupture of membranes and in co-infection with HSV and HIV. Recommendations around management of the neonate are made, on prevention of postnatal transmission, management of breastfeeding, and the management of clinically discordant couples. This guideline is aimed at healthcare professionals working in sexual health clinics, maternity units, and those working on postnatal wards and neonatal units in the UK. However, the principles of the recommendations should be adopted across all services, including community care.

First Trimester Tetracycline Exposure and Risk of Major Congenital Malformations

Importance

Safety data on tetracycline antibiotic use during pregnancy are limited.

Objective

To investigate the association between first trimester exposure to tetracyclines and the risk of major congenital malformations (MCMs).

Design, Setting, and Participants

This cohort study used data from nationwide registers for singleton infants live-born in Sweden from July 1, 2006, to December 31, 2018, with follow-up through December 2019. Tetracycline-exposed and unexposed infants were matched on propensity scores (ratio 1:10). Data analysis was performed from June 2023 to May 2024.

Exposure

First trimester exposure to tetracyclines determined from maternal prescription fills, compared with no exposure.

Main Outcomes and Measures

The primary outcome was any MCM diagnosed in the first year of life; secondary outcomes were 12 major malformation organ system subgroups and 16 individual malformations selected on the basis of prior safety signals and/or fulfillment of prespecified statistical power criteria. Malformations were identified by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes aligned to the European Surveillance of Congenital Anomalies (EUROCAT) classification. Log binomial regression was used to estimate relative risks (RRs) with 95% CIs.

Results

From a source cohort of 1 245 889 eligible infants (640 892 male [51.4%]), a propensity score-matched analytical cohort of 69 656 infants (35 903 male [51.5%]) was generated. Of 6340 infants exposed to tetracyclines during the first trimester (3325 male [52.4%]), 252 received a diagnosis of any MCM (39.75 cases per 1000 infants; 95% CI, 35.14-44.93 cases per 1000 infants) compared with 2454 of 63 316 unexposed infants (38.76 cases per 1000 infants; 95% CI, 37.27-40.30 cases per 1000 infants). Tetracycline exposure was not associated with any MCM (RR, 1.03; 95% CI, 0.90-1.16). The RRs for specific tetracycline substances were 1.07 (95% CI, 0.93-1.23) for doxycycline, 0.83 (95% CI, 0.60-1.15) for lymecycline, and 0.78 (95% CI, 0.32-1.92) for tetracycline-oxytetracycline. There was no increased risk for 10 of 12 malformation subgroups or for any of the 16 individual malformations analyzed. The higher RRs in the main analysis for nervous system anomalies (1.92; 95% CI, 0.98-3.78) and eye anomalies (1.76; 95% CI, 1.07-2.91) were attenuated in a sensitivity analysis with follow-up extended to age 3 years (nervous system anomalies, RR, 1.08; 95% CI, 0.52-2.24; eye anomalies, RR, 1.42; 95% CI, 0.88-2.29).

Conclusions and Relevance

In this cohort study, first trimester tetracycline exposure was not associated with increased risks of any MCMs. Additional studies are needed to rule out potential risks owing to power limitations for several MCM subgroups and individual malformations.

Impacts of prenatal environmental exposures on fetal-placental-maternal bile acid homeostasis and long-term health in offspring

During pregnancy, the maternal body undergoes a series of adaptative physiological changes, leading to a slight increase in serum bile acid (BA) levels. Although the fetal liver can synthesize BAs since the first trimester through the alternative pathway, the BA metabolic system is immature in the fetus. Compared to adults, the fetus has a distinct composition of BA pool and limited expression of BA synthesis enzymes and transporters. Besides, the "enterohepatic circulation" of BAs is absent in fetus. Thus, fetal BAs need to be transported to the mother through the placenta for further metabolism and excretion, and maternal BAs can also be transported to the fetus. That is what we call the "fetal-placental-maternal BA circulation". Various BA transporters and nuclear receptors are essential for maintaining the balance of this BA circulation to ensure normal fetal development. However, prenatal adverse environments can alter fetal BA metabolism, resulting in intrauterine developmental abnormalities and susceptibility to a variety of adult chronic diseases. This review summarizes the current understanding of the fetal-placental-maternal BA circulation and discusses the effects of prenatal adverse environments on this particular BA circulation, aiming to provide a theoretical basis for exploring early prevention and treatment strategies for BA metabolism-associated adverse pregnancy outcomes and long-term impairments.

Fever and antibiotic use in maternal urinary tract infections during pregnancy and risk of congenital heart defects: Findings from the National Birth Defects Prevention Study

BACKGROUND

Previous studies report an association between prenatal maternal urinary tract infections (UTI) and specific congenital heart defects (CHDs); however, the role of fever and antibiotic use on this association is poorly understood. Using data from the National Birth Defects Prevention Study, we examined whether the relationship between maternal UTIs during the periconceptional period and occurrence of CHDs is modified by the presence of fever due to UTI and corresponding antibiotic use among 11,704 CHD case infants and 11,636 live-born control infants.

METHODS

Information on UTIs, fever associated with UTI and antibiotic use (sulfonamides, nitrofurantoin, cephalosporins, penicillin, macrolides, and quinolones) during pregnancy were obtained using a computer-assisted telephone interview. Using unconditional multivariable logistic regression, we calculated adjusted odds ratios (ORs) to determine the association between maternal UTIs and subtypes of CHDs. Analyses were stratified by the presence of fever and medication use associated with UTI.

RESULTS

The prevalence of UTIs during the periconceptional period was 7.6% in control mothers, and 8.7% in case mothers. In the absence of fever, UTI was associated with secundum atrial septal defects (ASD) (OR 1.3; 95% confidence interval [CI] 1.1-1.5) and in the absence of antibiotics, UTI was associated with conotruncal defects as a group and for four specific CHDs. When fever and UTI occurred concomitantly, no significantly elevated odds ratios were noticed for any subtypes of CHD. Among women with UTIs who used antibiotics, an elevated but statistically non-significant estimate was observed for secundum ASD (OR 1.4; 95% CI 1.0-2.0).

CONCLUSION

Findings in the present study suggest that fever due to UTI and corresponding maternal antibiotic use do not substantially modify the association between maternal UTIs and specific CHDs in offspring. Further studies with larger sample sizes are warranted to guide clinical management of UTIs during the periconceptional period.

Pregnancy Outcomes in Patients with Urosepsis and Uncomplicated Urinary Tract Infections-A Retrospective Study

Background and Objectives: Urinary tract infections (UTIs) are an important cause of perinatal and maternal morbidity and mortality. The aim of this study was to describe and compare the main pregnancy outcomes among pregnant patients with complicated and uncomplicated UTIs; Materials and Methods: This retrospective study included 183 pregnant patients who were evaluated for uncomplicated UTIs and urosepsis in the Urology Department of 'C.I. Parhon' University Hospital, and who were followed up at a tertiary maternity hospital-'Cuza-voda' from Romania between January 2014 and October 2023. The control group (183 patients) was randomly selected from the patient's cohort who gave birth in the same time frame at the maternity hospital without urinary pathology. Clinical and paraclinical data were examined. Descriptive statistics and a conditional logistic regression model were used to analyze our data. Results: Our results indicated that patients with urosepsis had increased risk of premature rupture of membranes (aOR: 5.59, 95%CI: 2.02-15.40, p < 0.001) and preterm birth (aOR: 2.47, 95%CI: 1.15-5.33, p = 0.02). We could not demonstrate a statistically significant association between intrauterine growth restriction and pre-eclampsia with the studied urological pathologies. Conclusions: Careful UTI screening during pregnancy is needed for preventing maternal-fetal complications.

Racial and ethnic disparities in the association of maternal infection during pregnancy and risk of cyanotic congenital heart defects in the United States, 2011-2020

PURPOSE

The etiology of cyanotic congenital heart defects (CCHD) is not well understood. There are scarce data on racial/ethnic disparities in maternal infection and CCHD. We evaluated the relation of maternal infections during pregnancy and risk of CCHD in the United States, and to assess if this association varies by race/ethnicity.

METHODS

Data were from the National Vital Statistics System comprising 35.3 million singleton livebirths among mothers aged 15-49 years from 2011 to 2020. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

After adjustment for sociodemographic and maternal health factors, including prepregnancy body mass index, diabetes, hypertension, and smoking during pregnancy, time to prenatal care was initiated and pregnancy complications, any maternal infection, was associated with elevated odds of CCHD (OR: 1.25, 95% CI: 1.15-1.37). The odds of CCHD were mainly evident for sexually transmitted infections, namely chlamydia and hepatitis-C viral infection. The association was limited to non-Hispanic Black (OR: 1.22, 95% CI: 1.03-1.45), Hispanic (OR: 1.61, 95% CI: 1.33-1.95), and Asian (OR: 2.03, 95% CI: 1.42-2.91) mothers.

CONCLUSIONS

In this population-based study, maternal infection during pregnancy was associated with a modest risk of CCHD in offspring, which was the highest in racial/ethnic minority mothers.

Maternal hereditary hemolytic anemia and birth defects in the National Birth Defects Prevention Study

OBJECTIVES

Hereditary hemolytic anemia (HHA) results from genetic mutations that cause red blood cell abnormalities. Little research exists on the relationship between HHA and birth defects. Using data from the National Birth Defects Prevention Study (NBDPS), we described characteristics of HHA-exposed women and estimated associations between HHA during pregnancy and specific birth defects.

METHODS

The NBDPS was a population-based, case-control study of major birth defects and included pregnancies with estimated delivery dates from October 1997 through December 2011. Participants were ascertained from hospital discharge lists or birth defect registries at 10 sites. Trained interviewers collected information about pregnancy exposures via telephone questionnaire. We described characteristics among HHA-exposed women and calculated crude odds ratios and exact 95% confidence intervals for defects with ≥3 exposed cases.

RESULTS

Among 31 HHA-exposed women (28 cases/3 controls), 13 (42%) reported sickle cell anemia, 17 (55%) reported thalassemia, and one (3%) reported hereditary spherocytosis. The average age at delivery for HHA-exposed case women was 27.3 years (range: 17-38). The majority (82%) of HHA-exposed case women reported additional conditions during pregnancy, including hypertension, genitourinary infections, and respiratory illnesses. Additionally, 93% of case women reported using medication during pregnancy. Among the 28 cases, 18 (64%) had isolated birth defects. The defects with ≥3 exposed cases were anencephaly, atrial septal defect, gastroschisis, and cleft palate. Except for anencephaly, the 95% confidence intervals for all estimates were close to or included the null.

CONCLUSION

This hypothesis-generating study adds to the sparse literature on the association between HHA and birth defects.

Descriptive and risk factor analysis of infantile cataracts: National Birth Defects Prevention Study, 2000-2011

Using National Birth Defects Prevention Study (NBDPS) data, we sought to estimate birth prevalence, describe clinical characteristics, and examine risk factors for infantile cataracts. We calculated birth prevalence using the numbers of NBDPS-eligible cataract cases and live births in the study area. We described case infants by the presence of associated ipsilateral eye defects (IEDs) and non-eye-related major birth defects. Using maternal exposure information collected via telephone interview, we conducted logistic regression analyses among the interviewed cases and controls. Birth prevalence of infantile cataracts was 1.07/10,000 live births. Unilateral cataracts were more often associated with IEDs, while infants with bilateral cataracts were more often preterm, full-term with low birth weight, or had non-eye-related major birth defects. Unilateral cataracts were positively associated with maternal nulliparity (adjusted odds ratio [aOR] = 1.61, 95% confidence interval [CI] = 1.18, 2.20; reference: multiparity), whereas bilateral cataracts were positively associated with maternal education <12 years (aOR = 2.08, 95% CI = 1.13, 3.82; reference: education >12 years), and foreign-born nativity (aOR = 1.92, 95% CI = 1.04, 3.52; reference: U.S.-born nativity). The current analysis can inform future epidemiological studies aimed at identifying mechanisms underlying the associations between infantile cataracts and complex maternal exposures, such as lower levels of education and foreign-born nativity.

Investigation of the risk factors of anorectal malformations

PURPOSE

To investigate the factors that influence the occurrence of anorectal malformations (ARMs).

METHODS

From December 2018 to December 2019, 136 children treated for ARMs at the Children's Hospital of Chongqing Medical University were included in the case group. The control group consisted of children with intussusception or perianal abscesses. A uniform questionnaire was filled by the parents of the enrolled children.

RESULTS

The birth weight of the cases was significantly lower than that of the controls (p < .01), and children with ARMs were more likely to be complicated with single umbilical artery (SUA) (p < .001). Maternal upper respiratory tract infection (adjusted odds ratio [OR_adj ], 2.44; 95% confidence interval [CI], 1.29-4.63) and urogenital infection (OR_adj , 2.67; 95% CI 1.11-6.38) during the first trimester of pregnancy, anemia during pregnancy (OR_adj , 5.69; 95% CI, 1.01-32.07), and exposure to hazardous substances 6 months before pregnancy and during the first trimester of pregnancy (OR_adj , 13.82; 95% CI, 3.86-49.35) are associated with increased risk of ARMs. Folic acid supplements (OR_adj , 0.31; 95% CI, 0.14-0.65) and multivitamin (OR_adj , 0.34; 95% CI, 0.15-0.79) had a protective effect on ARMs. Paternal drug use (OR_adj , 9.17; 95% CI, 2.19-38.49) 6 months before their wives' conception increased the risk of ARMs.

CONCLUSION

Maternal infection, anemia during pregnancy, and maternal hazardous substances exposure are possible risk factors for ARMs. Folic acid supplements and multivitamin can reduce the occurrence of ARMs. Meanwhile, paternal drug use may also be a risk factor for ARMs.

The relationship between genitourinary microorganisms and oxidative stress, sperm DNA fragmentation and semen parameters in infertile men

An imbalance in the genitourinary microbiome is emerging as a contributing factor to male infertility. The purpose of this study was to determine whether there is an association between genitourinary microorganisms and seminal oxidative stress, sperm DNA fragmentation and semen parameters. It included 770 men attending for diagnostic testing for subfertility. Genitourinary microorganisms were identified in 43.0% men; 20.1% had microorganisms in semen; 18.7% in urine; and 5.8% had microorganisms in urine and semen. Enterococcus faecalis was the most prevalent organism in semen (22.0% samples; 61.5% organisms) with Ureaplasma spp. (16.9% samples; 53.3% organisms) and Gardnerella vaginalis (11.4% samples; 37.4% organisms) most prevalent in urine. Semen parameters were unaffected by microorganisms (p > 0.05). Seminal ROS were significantly higher in men with microorganisms compared to those without (p < 0.001), particularly when present in both urine and semen (p < 0.01). Microorganisms were associated with significantly higher DNA fragmentation, irrespective of whether they were in semen or urine (p < 0.001). An imbalance in the genitourinary microbiome is associated with DNA damage and oxidative stress which may have considerable consequences for achieving an ongoing pregnancy. This highlights the need for incorporating genitourinary microorganism screening for all men as part of diagnostic evaluation prior to undergoing treatment for infertility.

Association between maternal infections during pregnancy and congenital defects in their offspring: a population-based case-control study in Bogota and Cali, Colombia 2001-2018

Infections are frequent during pregnancy and their teratogenic role is well documented in Toxoplasmosis, other infections, Rubella, Cytomegalovirus, and Herpes simplex (TORCH). However, the in-utero development effects of the rest of the infections that affect pregnant women are unknown. We described a cohort of patients with major Birth Defects (BD) and the exposure to infections during pregnancy from the information of Congenital Defects Surveillance Programs of two Colombian cities (Bogota and Cali) between 2001 and 2018. We evaluated associations between groups of maternal infections and BD among 3096 cases and 7446 controls that were registered. BD presentation was more frequent as isolated (64.3%), polymalformed (23.2%), and syndromic (12.4%). Infections during pregnancy were present in 52.5% of cases and 44.6% of controls. The most common single infection between cases and controls was vaginal infection. The most common polyinfection was vaginal and urinary tract infection. We found an association between BD and vaginal infections with an odds ratio (OR) 1.18 (CI 1.08-1.30), urinary tract infections OR 1.16 (CI 1.05-1.28), gastrointestinal infections OR 2.06 (IC 1.18-3.59), respiratory infections OR 1.56 (IC 1.28-1.9) and viral infections OR 1.88 (IC 1.18-3.0). Knowing the teratogenic effect of infections is important to extend prevention, screening, timely diagnosis, and appropriate treatment to pregnant women.

Characteristics of Women with Urinary Tract Infection in Pregnancy

Background: Urinary tract infection (UTI) is the most common bacterial infection in pregnancy. Known risk factors for UTI in pregnancy include diabetes and certain urologic conditions. Other maternal characteristics might also be associated with risk and could provide clues to the etiology of UTI in pregnancy. Our objective was to identify maternal characteristics associated with UTI in pregnancy. Materials and Methods: We used data from pregnant women participating in the National Birth Defects Prevention Study, a population-based study of risk factors for major structural birth defects in 10 U.S. sites, from 1997 to 2011. In cross-sectional analyses, we used multivariable log-binomial regression to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for associations between self-reported maternal characteristics and UTI in pregnancy. Results: In our sample of 41,869 women, the overall prevalence of reported UTI in pregnancy was 18%, but ranged from 11% to 26% between study sites. In adjusted models, diabetes was moderately associated with higher UTI prevalence (PR 1.39, 95% CI: 1.24-1.57). Higher UTI prevalence was associated even more strongly with low educational attainment (PR 2.06, 95% CI: 1.77-2.40 for some high school vs. graduate school), low household income (PR 1.64, 95% CI: 1.46-1.84 for <$10,000 vs. ≥$50,000), and race/ethnicity (PR 1.45, 95% CI: 1.13-1.80 for American Indian or Alaska Native vs. White women). Conclusions: About one in six women reported UTI in pregnancy but the prevalence varied markedly by geography and maternal characteristics. This variability could provide clues to the causes of UTI in pregnancy.

Role of Maternal Infections and Inflammatory Responses on Craniofacial Development

Pregnancy is a tightly regulated immunological state. Mild environmental perturbations can affect the developing fetus significantly. Infections can elicit severe immunological cascades in the mother's body as well as the developing fetus. Maternal infections and resulting inflammatory responses can mediate epigenetic changes in the fetal genome, depending on the developmental stage. The craniofacial development begins at the early stages of embryogenesis. In this review, we will discuss the immunology of pregnancy and its responsive mechanisms on maternal infections. Further, we will also discuss the epigenetic effects of pathogens, their metabolites and resulting inflammatory responses on the fetus with a special focus on craniofacial development. Understanding the pathophysiological mechanisms of infections and dysregulated inflammatory responses during prenatal development could provide better insights into the origins of craniofacial birth defects.

Maternal Urinary Tract Infection: Is It Associated With Neonatal Urinary Tract Infection?

Objective: Maternal urinary tract infection is associated with intrauterine growth restriction, preterm delivery and low birth weight. The purpose of this study was to evaluate whether maternal urinary tract infection is related to neonatal urinary tract infection.

Materials and methods: The present prospective study included 230 singleton neonates. The participants were divided into two groups based on in utero exposure to maternal urinary tract infections. The study group (exposure to maternal urinary tract infection) included 115 neonates and the control group (without exposure to maternal urinary tract infection) included 115 healthy neonates. Physical examination, urinalysis, urine culture and urinary system ultrasonography were carried out for all neonates.

Results: There were 153 deliveries by cesarean section and 77 vaginal births. There was no statistically significant difference between the groups in terms of gender distribution, maternal age, birth weight, mode of delivery, gravida and gestational age. Although the difference was not significant, the incidence of low birth weight and preterm delivery were higher in the study group in comparison to that in the control group. There was a statistically significant higher rate of neonatal urinary tract infection in the study group compared with control group (25.2% vs. 7.8%, p<0.001). The most commonly discovered pathogens were Escherichia coli, followed by Klebsiella spp., Proteus spp., and Serratia spp. in the study group.

Conclusion: The results of this study showed that the presence of maternal urinary tract infection may contribute to increased urinary tract infection frequency in the neonatal period. Neonates at risk for a urinary tract infection should be regularly monitored due to nonspecific clinical presentation.

Nongenetic risk factors for infantile cataracts: Systematic review of observational studies

INTRODUCTION

While infantile cataracts are a major cause of childhood blindness, risk factors remain unknown for approximately two-thirds of cases.

METHODS

We systematically searched electronic databases PubMed, Ovid MEDLINE, Web of Science, and Scopus, from inception through March 2018, to identify relevant cohort, case-control, cross-sectional studies, case reports, and case series. We also manually screened bibliographies and consulted with experts in the field to identify additional publications. We reviewed cross-sectional studies, case reports, and case series and provided a narrative summary of the reported potential risk factors. We evaluated methodological qualities of cohort and case-control studies, extracted relevant data, and described statistically significant associations with infant, maternal, and paternal characteristics. Quality assessment and data extraction were conducted by two reviewers independently. All discrepancies were discussed with the senior author and resolved by consensus.

RESULTS

Overall, 110 publications were included in the review, 33 of which were cohort and case-control studies. Most of these studies (n = 32) used population-based data and had either excellent (n = 31) or good (n = 2) methodological quality. Nine studies reported statistically significant associations with infant characteristics (preterm birth, low birth weight), maternal occupations and diseases during pregnancy (untreated hypertension, infections), and paternal sociodemographics (younger age, employment in sawmill industry during pregnancy).

CONCLUSIONS

This systematic literature review provided a comprehensive summary of the known nongenetic risk factors for infantile cataracts, identified gaps in the literature, and provided directions for future research. Studies identifying modifiable risk factors are warranted to design interventions aimed at primary prevention of infantile cataracts.

Exome sequencing of family trios from the National Birth Defects Prevention Study: Tapping into a rich resource of genetic and environmental data

BACKGROUND

The National Birth Defects Prevention Study (NBDPS) is a multisite, population-based, case-control study of genetic and nongenetic risk factors for major structural birth defects. Eligible women had a pregnancy affected by a birth defect or a liveborn child without a birth defect between 1997 and 2011. They were invited to complete a telephone interview to collect pregnancy exposure data and were mailed buccal cell collection kits to collect specimens from themselves, their child (if living), and their child's father. Over 23,000 families representing more than 30 major structural birth defects provided DNA specimens.

METHODS

To evaluate their utility for exome sequencing (ES), specimens from 20 children with colonic atresia were studied. Evaluations were conducted on specimens collected using cytobrushes stored and transported in open versus closed packaging, on native genomic DNA (gDNA) versus whole genome amplified (WGA) products and on a library preparation protocol adapted to low amounts of DNA.

RESULTS

The DNA extracted from brushes in open packaging yielded higher quality sequence data than DNA from brushes in closed packaging. Quality metrics of sequenced gDNA were consistently higher than metrics from corresponding WGA products and were consistently high when using a low input protocol.

CONCLUSIONS

This proof-of-principle study established conditions under which ES can be applied to NBDPS specimens. Successful sequencing of exomes from well-characterized NBDPS families indicated that this unique collection can be used to investigate the roles of genetic variation and gene-environment interaction effects in birth defect etiologies, providing a valuable resource for birth defect researchers.

Descriptive and risk factor analysis of nonsyndromic sacral agenesis: National Birth Defects Prevention Study, 1997-2011

Sacral agenesis is a rare birth defect characterized by partial or complete absence of the sacrum. We sought to (a) describe case characteristics, (b) estimate birth prevalence, and (c) identify risk factors for nonsyndromic sacral agenesis using data from the National Birth Defects Prevention Study (NBDPS). The NBDPS was a population-based, case-control study involving pregnancies with estimated dates of delivery from October 1997 through December 2011. We estimated birth prevalence using all NBDPS eligible cases. Using self-reported maternal exposure information, we conducted multivariable logistic regression analysis to identify potential risk factors overall and among women without diabetes. The birth prevalence of sacral agenesis was 2.6/100,000 live births. In the multivariable analysis, multifetal pregnancy, pre-existing Type 1 diabetes, and pre-existing Type 2 diabetes were positively and significantly associated with sacral agenesis, albeit estimates were imprecise. Preexisting Type 1 diabetes was the strongest risk factor (adjusted odds ratio = 96.6, 95% confidence interval = 43.5-214.7). Among women without diabetes, periconceptional smoking was positively and significantly associated with sacral agenesis. Our findings underscore the importance of smoking cessation programs among women planning pregnancy and the importance of better understanding the role of glycemic control before and during pregnancy when designing interventions for primary prevention of sacral agenesis.