Title : Quintuplets: Birth incidence associations and mortality rates and its comparisons to singleton and other multiple pregnancies in United States 2014 to 2017
Abstract:
Background: Quintuplet pregnancies (defined by the conception of five offspring in a single birth) are extremely rare and influenced by both clinical and socioeconomic factors. Despite advances in obstetric care, U.S. data connecting socioeconomic status, maternal health, and multiple births remain limited.
Objective: To evaluate the incidence, infant mortality rates, and association with risk factors of quintuplets in comparison to singleton, twins, triplets, and quadruplets.
Methods: Population-based data from 2014-2017 was analyzed, including 15,261,303 singleton and 151 quintuplet births. Analyses were stratified by birth multiplicity to assess relative risk patterns across groups. Risk factors included maternal age, marital status, BMI, race/ethnicity, WIC participation, health status, and prenatal care visits. Multivariable logistic regression models were applied to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs), accounting for maternal and socioeconomic variables.
Results: Between 2014 and 2017, the majority of non-singleton births in the United States were twin births (n = 529,862), followed by triplets (n = 15,589), quadruplets (n = 896), and quintuplets (n = 151). Infant mortality rate (IMR) showed a strong inverse relationship with the number of live births per pregnancy, increasing from 5.16 per 1,000 in singletons to 23.09 in twins, 55.74 in triplets, 127.23 in quadruplets, and 377.48 in quintuplets. In multivariable analyses, families not enrolled in the WIC program had significantly higher odds of quintuplet births compared to those receiving WIC support (OR = 2.34; 95% CI: 1.41–3.88), suggesting a greater likelihood among more affluent families. Marital status was also strongly associated with quintuplets (aOR = 5.76, 95% CI 2.92–11.36). Similarly, Latina mothers demonstrated higher odds of quintuplet births compared to Non-Latina White mothers (OR = 2.11; 95% CI: 1.40–3.17). This trend was persistent when the data were further stratified by birth multiplicity, ranging from singleton to quadruplet births. Poor health was significantly associated with quintuplets (aOR = 1.90, 95% CI 1.24–2.91), but this trend was not observed when further stratified by lower-order multiples.
Conclusion: Quintuplet pregnancies were extremely rare and had the highest infant mortality rates among all birth types. Adverse outcomes increased sharply with higher-order multiplicity. Quintuplet births were more common among non-WIC, married, and Latina mothers, highlighting socioeconomic and demographic influences and the need for targeted interventions.
