Birth registration policies in the United States and their relevance to sexual and/or gender minority families: Identifying existing strengths and areas of improvement

Birth certificates are some of the most critical identity documents available to current residents of the United States, yet sexual and gender minority (SGM) parents frequently face barriers in obtaining accurate documents for their children. It is essential for SGM parents to have accurate birth certificates for their children at the time of birth registration so that they do not experience undue burden in raising their children and establishing their status as legal parents. In this analysis, we focused on the birth registration process in the US as they apply to SGM family-building and the assignation of parentage on birth certificates at the time of a child's birth. We utilized keyword-based search criteria to identify, collect, and tabulate official state policies related to birth registration. Birth registration policies rely on gendered, heteronormative assumptions about the sex and gender of a child's parents in all but three states when identifying the birthing person and in all but eight states when identifying the non-birthing person. We found additional barriers for SGM parents who give birth outside of a marriage or legal union. These barriers leave SGM parents particularly vulnerable to inaccuracies on their children's identity documents and incomplete recognition of their parental roles and rights. Existing birth registration policies also do little to ensure the inclusion of diverse family structures in administrative data collection. There are many ways to modify existing birth registration policies and enhance the inclusion of SGM parents within governmental administrative structures. We conclude with suggestions to improve upon existing birth registration systems by de-linking parental sex and gender from birthing role, parental role, and contribution to the pregnancy.

Association of Epilepsy and Severe Maternal Morbidity

OBJECTIVE

To evaluate severe maternal morbidity (SMM) among patients with epilepsy and patients without epilepsy.

METHODS

We retrospectively examined SMM using linked birth certificate and maternal hospital discharge records in California between 2007 and 2012. Epilepsy present at delivery admission was the exposure and was subtyped into generalized, focal and other less specified, or unspecified. The outcomes were SMM and nontransfusion SMM from delivery up to 42 days' postpartum, identified using Centers for Disease Control and Prevention indicators. Multivariable logistic regression models were used to adjust for confounders, which were selected a priori. We also estimated the association between epilepsy and SMM independent of comorbidities by using a validated obstetric comorbidity score. Severe maternal morbidity indicators were then compared using the same multivariable logistic regression models.

RESULTS

Of 2,668,442 births, 8,145 (0.3%) were to patients with epilepsy; 637 (7.8%) had generalized, 6,250 (76.7%) had focal or other less specified, and 1,258 (15.4%) had unspecified subtypes. Compared with patients without epilepsy, patients with epilepsy had greater odds of SMM (4.3% vs 1.4%, adjusted odds ratio [aOR] 2.91, 95% CI 2.61-3.24) and nontransfusion SMM (2.9% vs 0.7%, aOR 4.16, 95% CI 3.65-4.75). Epilepsy remained significantly associated with increased SMM and nontransfusion SMM after additional adjustment for the obstetric comorbidity score, though the effects were attenuated. When grouped by organ system, all SMM indicators were significantly more common among patients with epilepsy-most notably those related to hemorrhage and transfusion.

CONCLUSION

Severe maternal morbidity was significantly increased in patients with epilepsy, and SMM indicators across all organ systems contributed to this.

Pre-pregnancy Obesity and the Risk of Peripartum Cardiomyopathy

OBJECTIVE

The aim of this study is to evaluate the contribution of pre-pregnancy obesity and overweight to peripartum cardiomyopathy.

STUDY DESIGN

This population-based study used linked birth record and maternal hospital discharge data from live births in California during 2007 to 2012 (n = 2,548,380). All women who had a diagnosis of peripartum cardiomyopathy during the childbirth hospitalization or who were diagnosed with peripartum cardiomyopathy during a postpartum hospital readmission within 5 months of birth were identified as cases. Pre-pregnancy body mass index (BMI, kg/m²) was classified as normal weight (18.5-24.9), overweight (25.0-29.9), obesity class 1 (30.0-34.9), obesity class 2 (35.0-39.9), and obesity class 3 (≥40). Because of small numbers, we excluded women with underweight BMI, and in some analyses, we combined obesity classes into one group. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) expressing associations between BMI and peripartum cardiomyopathy, adjusted for maternal age, race/ethnicity, education, health care payer, parity, plurality, and comorbidities.

RESULTS

The overall prevalence of peripartum cardiomyopathy during hospital admissions was 1.3 per 10,000 live births (n = 320). Unadjusted ORs were 1.32 (95% CI: 1.01-1.74) for women with overweight BMI and 2.03 (95% CI: 1.57-2.62) for women with obesity, compared with women with normal pre-pregnancy BMI. Adjusted ORs were 1.26 (95% CI: 0.95-1.66) for overweight women and 1.38 (95% CI: 1.04-1.84) for women with obesity. The ORs suggested a dose-response relationship with increasing levels of obesity, but the 95% CIs for the specific classes of obesity included 1.00.

CONCLUSION

Pre-pregnancy obesity was associated with an increased risk of peripartum cardiomyopathy. These findings underscore the importance of BMI during pregnancy. There is a need to recognize the increased risk of peripartum cardiomyopathy in women with high BMI, especially in the late postpartum period.

KEY POINTS

· Pre-pregnancy obesity affects maternal health.. · Effects may extend to peripartum cardiomyopathy.. · The risk includes peripartum cardiomyopathy that emerges postpartum..

Development and validation of a risk prediction index for severe maternal morbidity based on preconception comorbidities among infertile patients

OBJECTIVE

To develop and validate a preconception risk prediction index for severe maternal morbidity (SMM), defined by the Centers for Disease Control and Prevention as indicators of a life-threatening complication, among infertile patients.

DESIGN

Retrospective analysis of live births and stillbirths from 2007 to 2017 among infertile women.

SETTING

National commercial claims database.

PATIENT(S)

Infertile women identified on the basis of diagnosis, testing, or treatment codes.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was SMM, identified as any indicator from the Centers for Disease Control and Prevention Index except blood transfusion alone, which was found to overestimate cases. Twenty preconception comorbidities associated with a risk of SMM were selected from prior literature. Targeted ensemble learning methods were used to rank the importance of comorbidities as potential risk factors for SMM. The independent strength of the association between each comorbidity and SMM was then used to define each comorbidity's risk score.

RESULT(S)

Among 94,097 infertile women with a delivery, 2.3% (n = 2,181) experienced an SMM event. The highest risk of SMM was conferred by pulmonary hypertension, hematologic disorders, renal disease, and cardiac disease. Associated significant risks were lowest for substance abuse disorders, prior cesarean section, age ≥40 years, gastrointestinal disease, anemia, mental health disorders, and asthma. The receiver operating characteristic area under the curve for the developed comorbidity score was 0.66. Calibration plots showed good concordance between the predicted and actual risk of SMM.

CONCLUSION(S)

We developed and validated an index to predict the probability of SMM on the basis of preconception comorbidities in patients with infertility. This tool may inform preconception counseling of infertile women and support maternal health research initiatives.

The impact of the COVID-19 pandemic on postpartum contraception planning

OBJECTIVE

The COVID-19 pandemic necessitated rapid adjustment of obstetrical delivery models including fewer antenatal appointments and increased use of telehealth. We hypothesized that an increase in telemedicine and a decrease in antepartum visits owing to the COVID-19 pandemic led to a decreased proportion of people with a postpartum contraception plan at the time of the birth-hospitalization admission and a reduced uptake of top-tier forms of contraception at birth-hospitalization admission and discharge, and the routine postpartum visit, which has otherwise been increasing in recent years.^1,2

STUDY DESIGN

A retrospective cohort study comparing a randomly selected sample of people giving birth at a large, tertiary referral center during a regional “shelter in place” order, March 16, 2020, to July 31, 2020, with a previously abstracted random sample of people delivering between November 1, 2017, and April 30, 2018, was conducted. This study was reviewed and approved by the Stanford University Institutional Review Board before its initiation. The study was powered to detect a 10% difference in the proportion of those arriving at birth-hospitalization with a contraceptive plan (power 80%, alpha 0.05). The final sample size included 586 people (318 in the pre-COVID cohort and 268 in the COVID cohort). Multivariable modified Poisson regression model was used to estimate the relative risk of arriving at birth-hospitalization with a contraceptive plan in pre-COVID vs COVID cohorts, adjusting for age, parity, insurance status, and delivery mode. Secondary outcomes included tier of contraception plan at admission, discharge, and 6 weeks postpartum (classified by World Health Organization Tiered-Effectiveness³), attendance at postpartum visit, and whether the postpartum visit was conducted via telehealth. Tiered effectiveness was used for this study's purposes because it was hypothesized that telehealth would mostly affect the provision of top-tier forms of contraception that require in-person initiation. Fisher exact test was used to compare the secondary outcomes.

RESULTS

For the 2 cohorts, the median age was 32 years (range, 17–48 years) and median parity was 1 (range, 0–6). The majority (78%) had private insurance and most commonly identified as non-Hispanic White (38%) and Asian (36%). Baseline demographics did not differ between the cohorts. At birth-hospitalization admission, a smaller proportion of people had a postpartum contraceptive plan in the COVID cohort than in the pre-COVID cohort (73.9% vs 99.4%, adjusted risk ratio, 0.87; 95% confidence interval, 0.84–0.91, P<.001). A smaller proportion of people had a plan for top-tier contraception among the COVID cohort compared with the pre-COVID cohort at both admission and discharge (46.0% vs 71.0%, P<.01 and 31.0% vs 37.9%, P=.05) (Figure). More than 80% of the people attended a routine postpartum visit in both cohorts (P=.30) with 17.7% being telehealth visits in the COVID cohort compared with telehealth not being offered pre-COVID. Among those who attended their postpartum visit, the proportion discharged with a plan for interval top-tier contraception that was fulfilled was high in both groups (76.3% pre-COVID vs 71.2% post-COVID, P=.56).

CONCLUSION

The study found a significant decrease in people arriving at birth-hospitalization with a contraception plan in the months following a COVID-19 “shelter in place” order when compared with the pre-COVID cohort. It is suspected that changes in the obstetrical service models indirectly deprioritized the most effective forms of postpartum contraception because sterilization requires a signed consent before birth-hospitalization and postplacental intrauterine devices require consent before delivery.^4,5 Current state legislation requiring in-person signature to consent for federally funded sterilization remains a barrier. We found that fewer individuals left with top-tier contraception than with plan on admission, especially within the COVID cohort. In addition to clinical contraindications that arise during labor, which preclude placement of an intrauterine device in the postpartum setting, many patients requested an expedited discharge during the peak of the COVID-19 pandemic. As the prenatal care model continues, this transition to adopt virtual visits, reduce visit schedules, and expedite postpartum discharge, actualizing patients’ contraceptive plans is increasingly more dependent on early inpatient provision. Maternity care providers should consider initiating postpartum contraception counseling and completing mandatory consents earlier in the antenatal period. This study is inherently limited by its retrospective nature of review and additional qualitative studies may better characterize this trend in contraceptive uptake. In the meantime, obstetrical care providers should carefully evaluate institutional barriers to postpartum contraception during this movement to telehealth.

Association of preconception paternal health and adverse maternal outcomes among healthy mothers

BACKGROUND

Maternal morbidity continues to be an issue of national and global concern. Paternal preconception health may play a significant role in pregnancy outcomes and has received less attention than maternal health.

OBJECTIVE

This study aimed to examine the association between preconception paternal health and the risk for adverse maternal outcomes among healthy mothers.

STUDY DESIGN

This was a retrospective analysis of live births from 2009 through 2016 to healthy women aged 20 to 45 years recorded in the IBM Marketscan research database. Infants were linked to paired mothers and fathers using family ID. Preconception paternal health was assessed using the number of metabolic syndrome component diagnoses and the most common individual chronic disease diagnoses (hypertension, diabetes mellitus, obesity, hyperlipidemia, chronic obstructive pulmonary disease, cancer, and depression). Women with metabolic syndrome components were excluded to avoid potential confounding of maternal and paternal factors. Adverse maternal outcomes that were assessed included (1) abnormal placentation including placenta accreta spectrum, placenta previa, and placental abruption; (2) preeclampsia with and without severe features including eclampsia; and (3) severe maternal morbidity, identified as any indicator from the Centers for Disease Control and Prevention Index of life-threatening complications at the time of delivery to 6 weeks postpartum. The trend between preconception paternal health and each maternal outcome was determined using the Cochran-Armitage Trend test. The independent association of paternal health with maternal outcomes was also determined using generalized estimating equations models, accounting for some mothers who contributed multiple births during the study period, and by adjusting for maternal age, paternal age, region of birth, year of birth, maternal smoking, and average number of outpatient visits per year.

RESULTS

Among 669,256 births to healthy mothers, there was a significant trend between all adverse maternal outcomes and worsening preconception paternal health defined either as the number of metabolic syndrome diagnoses or number of chronic disease diagnoses (P<.001; Cochran-Armitage Trend test). In the generalized estimating equations model, the odds for preeclampsia without severe features increased in a dose-dependent fashion and were 21% higher (95% confidence interval, 1.17-1.26) among women whose partners had ≥2 metabolic syndrome diagnoses than among women whose partners had no metabolic syndrome diagnosis. The odds for preeclampsia with severe features and eclampsia increased in a dose-dependent fashion and were 19% higher (95% confidence interval, 1.09-1.30) among women whose partners had ≥2 metabolic syndrome diagnoses than among women whose partners had no metabolic syndrome diagnosis. The odds for severe maternal morbidity were 9% higher (95% confidence interval, 1.002-1.19) among women whose partners had ≥2 metabolic syndrome diagnoses than among women whose partners had no metabolic syndrome diagnosis. The odds for abnormal placentation were similar between the groups (adjusted odds ratio, 0.96; 95% confidence interval, 0.89-1.03).

CONCLUSION

Among healthy mothers, we report that preconception paternal health is significantly associated with increased odds of preeclampsia with and without severe features and weakly associated with increased odds of severe maternal morbidity. These findings suggest that paternally derived factors may play significant roles in the development of adverse maternal outcomes in healthy women with a low a priori risk of obstetrical complications.

Karyotype of first clinical miscarriage and prognosis of subsequent pregnancy outcome

RESEARCH QUESTION

Is the karyotype of the first clinical miscarriage in an infertile patient predictive of the outcome of the subsequent pregnancy?

DESIGN

Retrospective cohort study of infertile patients undergoing manual vacuum aspiration with chromosome testing at the time of the first (index) clinical miscarriage with a genetic diagnosis and a subsequent pregnancy. Patients treated at two academic-affiliated fertility centres from 1999 to 2018 were included; those using preimplantation genetic testing for aneuploidy were excluded. Main outcome was live birth in the subsequent pregnancy.

RESULTS

One hundred patients with euploid clinical miscarriage and 151 patients with aneuploid clinical miscarriage in the index pregnancy were included. Patients with euploid clinical miscarriage in the index pregnancy had a live birth rate of 63% in the subsequent pregnancy compared with 68% among patients with aneuploid clinical miscarriage (adjusted odds ratio [aOR] 0.75, 95% CI 0.47-1.39, P = 0.45, logistic regression model adjusting for age, parity, body mass index and mode of conception). In a multinomial logistic regression model with three outcomes (live birth, clinical miscarriage or biochemical miscarriage), euploid clinical miscarriage for the index pregnancy was associated with similar odds of clinical miscarriage in the subsequent pregnancy compared with aneuploid clinical miscarriage for the index pregnancy (32% versus 24%, respectively, aOR 1.49, 95% CI 0.83-2.70, P = 0.19). Euploid clinical miscarriage for the index pregnancy was not associated with likelihood of biochemical miscarriage in the subsequent pregnancy compared with aneuploid clinical miscarriage (5% versus 8%, respectively, aOR 0.46, 95% CI 0.14-1.55, P = 0.21).

CONCLUSION

Prognosis after a first clinical miscarriage among infertile patients is equally favourable among patients with euploid and aneuploid karyotype, and independent of the karyotype of the pregnancy loss.

Lactate and procalcitonin levels in peripartum women with intraamniotic infection

BACKGROUND

Pregnant women are vulnerable to infection as their immune response is modulated.

OBJECTIVE

Serum biomarkers are used to diagnose and manage severe infections, but data on their utility during labor are limited. We compared lactate and procalcitonin levels in women with and without an intraamniotic infection to determine whether they are useful biomarkers for infection during labor.

STUDY DESIGN

We performed a prospective, observational cohort study of term, singleton pregnancies admitted with planned vaginal delivery in 2019 at a university medical center. The lactate and procalcitonin levels were determined during early labor, within 2 hours following delivery, and on postpartum day 1. Women with an intraamniotic infection in addition had their lactate and procalcitonin levels determined following an intraamniotic infection diagnosis. Samples were processed immediately in the hospital clinical laboratory. The primary outcome was the mean lactate level following delivery. The secondary outcomes were the lactate and procalcitonin levels at other time points. Comparisons based on infection status were performed using multivariate linear regressions.

RESULTS

A total of 22 women with intraamniotic infection and 29 uninfected women were included. The mean early labor lactate level (1.47 vs 1.49 mmol/L) and mean procalcitonin level (0.048 vs 0.039 ng/mL) did not differ and were normal in the uninfected and intraamniotic infection groups. The mean lactate level was highest following delivery for women in both the uninfected and intraamniotic infection groups (2.00 vs 2.33 mmol/L; adjusted P=.08; 95% confidence interval, 0.98-1.53). The lactate level returned to normal by postpartum day 1 and did not differ significantly based on the infection status at any time point in the adjusted models. The procalcitonin level following delivery was higher among women with vs without an intraamniotic infection (0.142 vs 0.091 ng/mL; adjusted P=.03). The procalcitonin level rose further in both the intraamniotic infection and uninfected groups on postpartum day 1 (0.737 vs 0.408 ng/mL; adjusted P=.05).

CONCLUSION

The lactate level is not significantly elevated in pregnant women with an intraamniotic infection above the physiological increase that is observed in women without infection at delivery. The procalcitonin level is elevated at delivery in women with an intraamniotic infection and warrants further investigation as a peripartum infection marker.

Birth hospital and racial and ethnic differences in severe maternal morbidity in the state of California

BACKGROUND

Birth hospital has recently emerged as a potential key contributor to disparities in severe maternal morbidity, but investigations on its contribution to racial and ethnic differences remain limited.

OBJECTIVE

We leveraged statewide data from California to examine whether birth hospital explained racial and ethnic differences in severe maternal morbidity.

STUDY DESIGN

This cohort study used data on all births at ≥20 weeks gestation in California (2007-2012). Severe maternal morbidity during birth hospitalization was measured using the Centers for Disease Control and Prevention index of having at least 1 of the 21 diagnoses and procedures (eg, eclampsia, blood transfusion, hysterectomy). Mixed-effects logistic regression models (ie, women nested within hospitals) were used to compare racial and ethnic differences in severe maternal morbidity before and after adjustment for maternal sociodemographic and pregnancy-related factors, comorbidities, and hospital characteristics. We also estimated the risk-standardized severe maternal morbidity rates for each hospital (N=245) and the percentage reduction in severe maternal morbidity if each group of racially and ethnically minoritized women gave birth at the same distribution of hospitals as non-Hispanic white women.

RESULTS

Of the 3,020,525 women who gave birth, 39,192 (1.3%) had severe maternal morbidity (2.1% Black; 1.3% US-born Hispanic; 1.3% foreign-born Hispanic; 1.3% Asian and Pacific Islander; 1.1% white; 1.6% American Indian and Alaska Native, and Mixed-race referred to as Other). Risk-standardized rates of severe maternal morbidity ranged from 0.3 to 4.0 per 100 births across hospitals. After adjusting for covariates, the odds of severe maternal morbidity were greater among nonwhite women than white women in a given hospital (Black: odds ratio, 1.25; 95% confidence interval, 1.19-1.31); US-born Hispanic: odds ratio, 1.25; 95% confidence interval, 1.20-1.29; foreign-born Hispanic: odds ratio, 1.17; 95% confidence interval, 1.11-1.24; Asian and Pacific Islander: odds ratio, 1.26; 95% confidence interval, 1.21-1.32; Other: odds ratio, 1.31; 95% confidence interval, 1.15-1.50). Among the studied hospital factors, only teaching status was associated with severe maternal morbidity in fully adjusted models. Although 33% of white women delivered in hospitals with the highest tertile of severe maternal morbidity rates compared with 53% of Black women, birth hospital only accounted for 7.8% of the differences in severe maternal morbidity comparing Black and white women and accounted for 16.1% to 24.2% of the differences for all other racial and ethnic groups.

CONCLUSION

In California, excess odds of severe maternal morbidity among racially and ethnically minoritized women were not fully explained by birth hospital. Structural causes of racial and ethnic disparities in severe maternal morbidity may vary by region, which warrants further examination to inform effective policies.

Integrating oral immunotherapy into clinical practice

In 2020, the first food allergy treatment, an oral immunotherapy (OIT) product for peanut allergy, was approved by the Food and Drug Administration, and a peanut epicutaneous immunotherapy patch was under review. As food allergy therapies become available and widespread, allergy offices will need to adjust practices to be able to offer their patients these new treatments. OIT is an intensive therapy that requires commitment from patients and their families, and open communication with the practice is paramount. OIT may not be the right therapy for every patient, and although identifying good candidates is still an area rich for research opportunity, experience from cohorts and clinical trials provides some insight. It is important to understand the scope of practice for each member of the OIT team based on state regulations for a particular location. Staffing and space will likely dictate how many patients at an individual office could be on active OIT at one time. Emergency medications, supplies, and protocols must be in place. Screening, scheduling, visit procedures, monitoring, home dosing, dose modifications, safety precautions, adverse reactions, and maintenance will be addressed in this article. Finally, adjunct therapies under investigation will be reviewed.

Continuous and Daily Oral Immunotherapy for Peanut Allergy: Results from a 2-Year Open-Label Follow-On Study

BACKGROUND

The randomized, controlled PALISADE trial demonstrated the benefit of daily oral immunotherapy with Peanut (Arachis Hypogaea) allergen powder-dnfp (PTAH, formerly AR101) in peanut-allergic children and adolescents.

OBJECTIVE

ARC004, the open-label follow-on study to PALISADE, used 5 dosing cohorts to explore PTAH treatment beyond 1 year and alternative dosing regimens in peanut-allergic individuals.

METHODS

Active arm (PTAH-continuing) PALISADE participants who tolerated 300-mg peanut protein at the exit double-blind placebo-controlled food challenge and placebo arm (PTAH-naive) participants could enter ARC004. PTAH-continuing participants were assigned to receive daily (cohorts 1 and 3A) or non-daily (cohorts 2, 3B, and 3C) dosing regimens; PTAH-naive participants were built up to 300 mg/d PTAH, followed by maintenance dosing. At study completion, participants underwent an exit double-blind placebo-controlled food challenge with doses up to 2000 mg peanut protein. Data were assessed using descriptive statistics.

RESULTS

Overall, 358 (87.5%) eligible participants (4-17 years) entered ARC004 (PTAH-continuing, n = 256; PTAH-naive, n = 102). Among PTAH-continuing participants, exposure-adjusted adverse event rates were 12.94 to 17.54/participant-year and 25.95 to 42.49/participant-year in daily and non-daily dosing cohorts, respectively; most participants (83%) experienced mild or moderate adverse events. Daily dosing cohorts appeared to have higher desensitization rates than non-daily dosing cohorts. Of all PTAH-continuing cohorts, cohort 3A had the longest daily dosing duration and the highest desensitization rates. Changes in immune markers with PTAH continuation demonstrated ongoing immunomodulation. Outcomes in PTAH-naive participants mirrored those of the PALISADE active arm.

CONCLUSIONS

Continued daily PTAH treatment beyond 1 year showed sustained safety and efficacy. Ongoing immunomodulation was observed during the second year of treatment.

Association of Maternal Comorbidity With Severe Maternal Morbidity: A Cohort Study of California Mothers Delivering Between 1997 and 2014

BACKGROUND

Rates of maternal mortality and severe maternal morbidity (SMM) are higher in the United States than in other high-resource countries and are increasing further.

OBJECTIVE

To examine the association of maternal comorbid conditions, age, body mass index, and previous cesarean birth with occurrence of SMM.

DESIGN

Population-based cohort study using linked delivery hospitalization discharge data and vital records.

SETTING

California, 1997 to 2014.

PATIENTS

All 9 179 472 mothers delivering in California during 1997 to 2014.

MEASUREMENTS

SMM rate, total and without transfusion-only cases; 2019 maternal comorbidity index.

RESULTS

Total SMM increased by 160% during this time, and SMM excluding transfusion-only cases increased by 53%. Medical comorbid conditions were associated with an increasing portion of SMM occurrences. Medical comorbid conditions increased over the study period by 111%, and obstetric comorbid conditions increased by 30% to 40%. Identified medical comorbid conditions had high relative risks ranging from 1.3 to 14.3 for total SMM and even higher relative risks for nontransfusion SMM (to 32.4). The obstetric comorbidity index that is most often used may be undervaluing the degree of association with SMM.

LIMITATIONS

Hospital discharge diagnosis files and birth certificate records can have misclassifications and may not include all relevant clinical data or social determinants. The period for analysis ended in 2014 to avoid the transition to the International Classification of Diseases, 10th Revision, Clinical Modification, and therefore missed more recent years.

CONCLUSION

Obstetric and, particularly, medical comorbid conditions are increasing among women who develop SMM. The maternal comorbidity index is a promising tool for patient risk assessment and case-mix adjustment, but refinement of factor weights may be indicated.

PRIMARY FUNDING SOURCE

National Institutes of Health.

An Expanded Obstetric Comorbidity Scoring System for Predicting Severe Maternal Morbidity

OBJECTIVE

To develop and validate an expanded obstetric comorbidity score for predicting severe maternal morbidity that can be applied consistently across contemporary U.S. patient discharge data sets.

METHODS

Discharge data from birth hospitalizations in California during 2016-2017 were used to develop the score. The outcomes were severe maternal morbidity, defined using the Centers for Disease Control and Prevention index, and nontransfusion severe maternal morbidity (excluding cases where transfusion was the only indicator of severe maternal morbidity). We selected 27 potential patient-level risk factors for severe maternal morbidity, identified using International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes. We used a targeted causal inference approach integrated with machine learning to rank the risk factors based on adjusted risk ratios (aRRs). We used these results to assign scores to each comorbidity, which sum to a single numeric score. We validated the score in California and national data sets and compared the performance to that of a previously developed obstetric comorbidity index.

RESULTS

Among 919,546 births, the rates of severe maternal morbidity and nontransfusion severe maternal morbidity were 168 and 74 per 10,000 births, respectively. The highest risk comorbidity was placenta accreta spectrum (aRR of 30.5 for severe maternal morbidity and 54.7 for nontransfusion severe maternal morbidity) and the lowest was gestational diabetes mellitus (aRR of 1.06 for severe maternal morbidity and 1.12 for nontransfusion severe maternal morbidity). Normalized scores based on the aRR were developed for each comorbidity, which ranged from 1 to 59 points for severe maternal morbidity and from 1 to 36 points for nontransfusion severe maternal morbidity. The overall performance of the expanded comorbidity scores was good (C-statistics were 0.78 for severe maternal morbidity and 0.84 for nontransfusion severe maternal morbidity in California data and 0.82 and 0.87, respectively, in national data) and improved on prior comorbidity indices developed for obstetric populations. Calibration plots showed good concordance between predicted and actual risks of the outcomes.

CONCLUSION

We developed and validated an expanded obstetric comorbidity score to improve comparisons of severe maternal morbidity rates across patient populations with different comorbidity case mixes.

Risk of severe maternal morbidity in relation to prepregnancy body mass index: Roles of maternal co-morbidities and caesarean birth

BACKGROUND

An association between prepregnancy body mass index (BMI) and severe maternal morbidity (SMM) has been reported, but evidence has been mixed and potential explanations have not been examined.

OBJECTIVE

To evaluate the association between prepregnancy BMI and SMM in a large, diverse birth cohort and assess potential mediation by obesity-related co-morbidities and caesarean birth.

METHODS

This cohort study used linked birth certificate and hospitalisation discharge records from Californian births during 2007-2012. We assessed associations between prepregnancy BMI and SMM, and used inverse probability weighting for multiple mediators to estimate relative and absolute natural direct and indirect effects accounting for mediation by co-morbidities (hypertensive conditions, diabetes, asthma) and caesarean birth.

RESULTS

Among 2 650 182 births, the prevalence of SMM was 1.42%. Adjusted risk ratios for the total association between prepregnancy BMI category and SMM were 1.12 (95% confidence interval [CI] 1.07, 1.18) for underweight, 1.02 (95% CI 0.99, 1.04) for overweight, 1.04 (95% CI 1.00, 1.07) for obesity class 1, 1.14 (95% CI 1.09, 1.20) for obesity class 2, and 1.28 (95% CI 1.22, 1.36) for obesity class 3 compared to women with normal weight. After accounting for mediation by co-morbidity and caesarean birth, the risk ratios were 1.19 (95% CI 1.14, 1.26) for underweight, 0.91 (95% CI 0.89, 0.94) for overweight, 0.86 (95% CI 0.84, 0.89) for obesity class 1, 0.88 (95% CI 0.84, 0.92) for obesity class 2, and 0.89 (95% CI 0.83, 0.95) for obesity class 3.

CONCLUSIONS

Co-morbidities and caesarean birth explained an association between high prepregnancy BMI and SMM. These findings suggest that promotion of healthy prepregnancy weight, along with management of co-morbidities and support of vaginal birth in pregnant women with high BMI, could reduce the risk of SMM. However, these mediators did not reduce the elevated risk of SMM observed in women with low BMI.

Weight gain during pregnancy and the risk of severe maternal morbidity by prepregnancy BMI

BACKGROUND

High and low prepregnancy BMI are risk factors for severe maternal morbidity (SMM), but the contribution of gestational weight gain (GWG) is not well understood.

OBJECTIVES

We evaluated associations between GWG and SMM by prepregnancy BMI group.

METHODS

We analyzed administrative records from 2,483,684 Californian births (2007-2012), utilizing z score charts to standardize GWG for gestational duration. We fit the z scores nonlinearly and categorized GWG as above, within, or below the Institute of Medicine (IOM) recommendations after predicting equivalent GWG at term from the z score charts. SMM was defined using a validated index. Associations were estimated using multivariable logistic regression models.

RESULTS

We found generally shallow U-shaped relations between GWG z score and SMM in all BMI groups, except class 3 obesity (≥40 kg/m2), for which risk was lowest with weight loss. The weight gain amount associated with the lowest risk of SMM was within the IOM recommendations for underweight and class 2 obesity, but above the IOM recommendations for normal weight, overweight, and class 1 obesity. The adjusted risk ratios (RRs) and 95% CIs for GWG below the IOM recommendations, compared with GWG within the recommendations, were the following for underweight, normal weight, overweight, class 1 obesity, class 2 obesity, and class 3 obesity: 1.13 (0.99, 1.29), 1.09 (1.04, 1.14), 1.10 (1.01, 1.19), 1.07 (0.95, 1.21), 1.03 (0.88, 1.22), and 0.89 (0.73, 1.08), respectively. For GWG above the recommendations, the corresponding RRs and 95% CIs were 0.99 (0.84, 1.15), 1.04 (0.99, 1.08), 0.98 (0.92, 1.04), 1.03 (0.95, 1.13), 1.07 (0.94, 1.23), and 1.08 (0.91, 1.30), respectively.

CONCLUSIONS

High and low GWG may be modestly associated with increased risk of SMM across BMI groups, except in women with class 3 obesity, for whom low weight gain and weight loss may be associated with decreased risk of SMM.