Race and ethnicity are among the predisposing factors for fetal malpresentation at term

OBJECTIVE

Fetal malpresentation complicates approximately 3% to 4% of all term births. It requires special considerations for delivery and exposes the mother and neonate to obstetrical interventions and potential adverse outcomes, such as umbilical cord prolapse, head entrapment and birth trauma, hypoxic ischemic encephalopathy, cesarean delivery, and cesarean delivery-related complications. We set out to explore the maternal and fetal factors associated with noncephalic malpresentation at term, with specific interest on the impact of maternal race and ethnicity on fetal malpresentation.

STUDY DESIGN

This was a retrospective analysis of the Centers for Disease Control and Prevention Natality Live Birth database for the years from 2016 through 2018. All term, singleton deliveries for the following racial and ethnic groups were included: non-Hispanic White, non-Hispanic Black, Asian, and Hispanic. Race and ethnicity were assigned based on self-identification and individuals with >1 racial category were excluded from the analysis. Malpresentation was defined as a noncephalic presentation at term and included breech and transverse presentations. The malpresentation group included all noncephalic births and cephalic births that occurred following successful external cephalic version, whereas all other cephalic births served as controls. A multivariable logistic regression analysis was used to assess the rate of malpresentation, with adjustment for potential confounders including maternal age, race and ethnicity, parity, birthweight, fetal malformations, malformations of the central nervous system (CNS), and chromosomal anomalies. The results are displayed as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Statistical significance was set at a P value of <.05. Institutional review board approval was not required because the de-identified data are publicly available through a data use agreement.

RESULTS

There were 9,692,203 term, singleton births during the study period. The malpresentation group included 354,689 births (3.66% of the total). The Table shows the rate of malpresentation for various maternal and fetal factors. We found a substantial racial and ethnic disparity in the malpresentation rates. Non-Hispanic White women had the highest malpresentation risk, whereas non-Hispanic Black women had the lowest risk (3.93% vs 2.81%; aOR, 1.38; 95% CI, 1.36-1.39). Hispanic and Asian women were also at increased risk for malpresentation when compared with non-Hispanic Black women (aOR, 1.30; 95% CI, 1.29-1.32 and aOR, 1.12; 95% CI, 1.10-1.14, respectively). In addition, several maternal and fetal conditions were noted to be associated with an increased risk for malpresentation at term, including older maternal age (aOR, 2.81; 95% CI, 2.74-2.88; for patients >40 years), nulliparity (aOR, 1.50; 95% CI, 1.48-1.51), low birthweight (aOR, 1.80; 95% CI, 1.77-1.83 for birthweight under 2500 g), and fetal malformations of the CNS and chromosomal anomalies (aOR, 3.53; 95% CI, 3.06-4.06 and aOR, 2.32; 95% CI, 2.05-2.63, respectively).

CONCLUSION

Based on a large US population database, we identified several maternal, fetal, and racial and ethnic factors that are associated with an increased rate of noncephalic malpresentation at term. Specifically, fetal CNS malformations, congenital or chromosomal anomalies, advanced maternal age, low birthweight, and nulliparity are risk factors for noncephalic presentation. Interestingly, non-Hispanic White women have the highest risk for malpresentation, whereas non-Hispanic Black women have the lowest risk. Previous publications found that low birthweight, advanced maternal age, nulliparity, and congenital fetal malformations are risk factors for malpresentation.^1-3 Nonetheless, the current data available on race and ethnicity are sporadic, with limited reports suggesting that sub-Saharan ethnicity is associated with a lower rate of malpresentation² and that White race is associated with a higher rate.⁴ We present a large-scale, nationwide US-based study to confirm the racial and ethnic disparity regarding malpresentation in the United States. This may be explained by the known variation in the shape of the bony birth canal in different racial and ethnic groups and populations from different geographic locations.⁵ Further investigation is needed to explore the racial and ethnic disparity described.

The independent and combined influences of small for gestational age and socioeconomic status on newborn metabolite levels

OBJECTIVES

To determine whether socioeconomic status (SES) and small birthweight for gestational age (SGA) exhibit independent or joint effects on infant levels of 42 metabolites.

STUDY DESIGN

Population-based retrospective cohort of metabolic newborn screening information linked to hospital discharge data. SGA infants defined by birthweight <10th percentile for gestational age by sex. SES was determined by a combined metric including education level, participation in the WIC nutritional assistance program, and receiving California MediCal insurance. We performed linear regression to determine the effects of SES independently, SGA independently, and the interaction of SGA and SES on 42 newborn metabolite levels.

RESULTS

736,435 California infants born in 2005-2011 were included in the analysis. SGA was significantly associated with 36 metabolites. SES was significantly associated with 41 of 42 metabolites. Thirty-eight metabolites exhibited a dose-response relationship between SGA and metabolite levels as SES worsened. Fourteen metabolites showed significant interaction between SES and SGA. Eight metabolites showed significant individual and joint effects of SES and SGA: alanine, glycine, free carnitine, C-3DC, C-5DC, C-16:1, C-18:1, and C-18:2.

CONCLUSIONS

SES and SGA exhibited independent effects on a majority of metabolites and joint effects on select metabolites. A better understanding of how SES and SGA status are related to infant metabolites may help identify maternal and newborn interventions that can lead to better outcomes for infants born SGA.

Repetitive Breech Presentations at Term

The authors present a case of 38-year-old laboring woman with four-time repetitive breech presentation of the fetus at term. This rare condition affects the mode of delivery and represents serious obstetrical problem as it is associated with increased perinatal morbidity or mortality. The authors give details on risk factors for breech presentation, its diagnosis, and the discussion points on possible causes leading to repetitive breeches in laboring women.