Maternal, Pregnancy, and Birth Characteristics of Asians and Native Hawaiians/Pacific Islanders --- King County, Washington, 2003--2008

Maternal, Pregnancy, and Birth Characteristics of Asians and Native Hawaiians/Pacific Islanders --- King County, Washington, 2003--2008
Weekly
February 25, 2011 / 60(07);211-213




In 1997, the Office of Management and Budget issued revised standards for reporting race and ethnicity in federal datasets (1). In addition to permitting the reporting of two or more races for each record, the revised standards separated the "Asian or Pacific Islander" category into two categories: "Asian" and "Native Hawaiian or other Pacific Islander" (NHPI). To quantify the health status of NHPI mothers and infants in King County, Washington, 2003--2008 vital statistics for NHPI disaggregated from Asians were used to assess several key maternal and birth outcome indicators. This analysis determined that, compared with Asians in King County, NHPI mothers were significantly more likely to be adolescents, overweight or obese before pregnancy, or to have smoked during pregnancy, and their infants were more likely to be born preterm, weigh >4,500 g, or receive either third trimester only or no prenatal care. These results identify important differences and support routine presentation of health data separately for Asians and NHPIs.

To conform to the federal standards for collecting and reporting data on race and ethnicity (1), the Washington State Department of Health (DOH) adopted the 2003 revision of the U.S. Standard Certificate of Live Birth (2). Using the new reporting categories, the person completing the data collection form can check one or more races to indicate which the mother considers herself to be. Following the standards, DOH reports data for Asians and NHPIs separately. Under federal guidelines (1), Asian refers to a person having ancestral origins in any of the original peoples of the Far East, Southeast Asia, or the Indian subcontinent (e.g., Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippine Islands, Thailand, or Vietnam). NHPI refers to a person having origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands (including Fiji, Tonga, Micronesia, Melanesia, French Polynesia, Palau, the Northern Mariana Islands, and the Marshall Islands). Information on birth weight, length of gestation, maternal prepregnancy height and weight, initiation of prenatal care, maternal age, and smoking status during pregnancy are collected on the birth certificate.

The DOH birth certificate statistical file was used to calculate population health measures of maternal characteristics and birth risk factors for Asians and NHPIs in King County. Comparisons were made using a Pearson chi-square test. All persons identified as only Asian race or as multiple races that included Asian as one of the races were included in the Asian category. Similarly, single and multiracial persons identified as only NHPI or as NHPI in combination with another race were included in the NHPI reporting category. Prevalences are presented for single race and multiracial persons combined because of identification as a single community. However, multiracial persons reporting both Asian and NHPI race were excluded from this analysis. Self-reported height and weight data were used to calculate prepregnancy body mass index (BMI) (weight [kg] / height [m2]). Respondents were considered overweight if their BMI was 25.0--29.9 and obese if their BMI was ≥30.0. Infants were considered preterm if born at <37 completed weeks of gestation. Prenatal care initiation in the third trimester was considered to be late initiation.

Washington had the third-largest NHPI community in the United States (43,000 single or multiracial NHPI persons), after Hawaii (283,000) and California (221,000), according to U.S. Census counts for 2000 (3). Approximately 22,000 NHPI and 303,000 Asian single race and multiracial persons lived in King County in 2009, based on U.S. Census Bureau estimates.*

Combining data from 2003--2008, King County recorded 142,350 births, of which 2,442 were to NHPI mothers (79.2% NHPI only and 20.8% NHPI in combination with another race). During that period, 26,229 births in the county were to Asian mothers (92.4% Asian only and 7.6% Asian in combination with another race). A total of 242 births were to multiracial women who considered themselves to be both Asian and NHPI and were excluded from further analyses.

In King County, NHPI mothers were significantly more likely than Asian mothers to be overweight (23.9% versus 19.5%; p<0.001) or obese (49.9% versus 7.6%; p<0.001) before pregnancy. NHPI mothers also were more likely than Asian mothers to smoke during pregnancy (9.8% versus 1.4%; p<0.001) or to be adolescents (aged 15--17 years) (2.4% versus 0.6%; p<0.001). Infants born to NHPI mothers were significantly more likely than infants of Asian mothers to be born preterm (12.6% versus 9.7%; p<0.001), at high birth weight (>4,500 g) (3.0% versus 0.6%; p<0.001), or to have received either late or no prenatal care (15.8% versus 4.2%; p<0.001). No significant differences were observed for very low birth weight (<1,500 g; p=0.2), and infants of Asian mothers were more likely to be born at low birth weight (<2,500 g; p<0.001) (Table).

Reported by
EY Wong, PhD, D Solet, PhD, Assessment, Policy Development, and Evaluation Unit, Public Health--Seattle & King County, Washington.


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Maternal, Pregnancy, and Birth Characteristics of Asians and Native Hawaiians/Pacific Islanders --- King County, Washington, 2003--2008