Adverse birth outcome across the generations: the contribution of paternal factors.

PURPOSE: There is literature suggesting an intergenerational relationship between maternal and infant size for gestational age status and preterm birth, but much less is known about the contribution of paternal birth outcome to infant birth outcome. This study seeks to determine the association between paternal and infant small-for-gestational-age status (weight for gestational age < 10th percentile, SGA) and preterm birth (< 37 weeks gestation, PTB) in a large, diverse population-based sample in the United States. METHODS: Stratified and log-binomial multivariable regression analyses were computed on the vital records of Illinois-born infants (1989-1991) and their Illinois-born parents (born 1956-1976). RESULTS: Among non-Hispanic Whites (n = 83,218), the adjusted (controlling for maternal SGA or PTB, age, parity, education, marital status, prenatal care, and cigarette smoking) relative risk (95% confidence interval) of infant SGA and PTB for former SGA (compared to non-SGA) and preterm (compared to term) fathers equaled 1.65 (1.53, 1.77) and 1.07 (0.92, 1.24), respectively. Among African-Americans (n = 8401), the adjusted relative risk (95% confidence interval) of infant SGA and PTB for former SGA (compared to non-SGA) and preterm (compared to term) fathers equaled 1.32 (1.14, 1.52) and 1.19 (0.98, 1.45), respectively. CONCLUSION: Paternal adverse birth outcome, particularly SGA, is a modest risk factor for corresponding adverse infant outcome, independent of maternal risk status. This phenomenon appears to occur similarly among non-Hispanic White and African-American women.

Risks of stillbirth and neonatal death with advancing gestation at term: A systematic review and meta-analysis of cohort studies of 15 million pregnancies.

BACKGROUND: Despite advances in healthcare, stillbirth rates remain relatively unchanged. We conducted a systematic review to quantify the risks of stillbirth and neonatal death at term (from 37 weeks gestation) according to gestational age. METHODS AND FINDINGS: We searched the major electronic databases Medline, Embase, and Google Scholar (January 1990-October 2018) without language restrictions. We included cohort studies on term pregnancies that provided estimates of stillbirths or neonatal deaths by gestation week. We estimated the additional weekly risk of stillbirth in term pregnancies that continued versus delivered at various gestational ages. We compared week-specific neonatal mortality rates by gestational age at delivery. We used mixed-effects logistic regression models with random intercepts, and computed risk ratios (RRs), odds ratios (ORs), and 95% confidence intervals (CIs). Thirteen studies (15 million pregnancies, 17,830 stillbirths) were included. All studies were from high-income countries. Four studies provided the risks of stillbirth in mothers of White and Black race, 2 in mothers of White and Asian race, 5 in mothers of White race only, and 2 in mothers of Black race only. The prospective risk of stillbirth increased with gestational age from 0.11 per 1,000 pregnancies at 37 weeks (95% CI 0.07 to 0.15) to 3.18 per 1,000 at 42 weeks (95% CI 1.84 to 4.35). Neonatal mortality increased when pregnancies continued beyond 41 weeks; the risk increased significantly for deliveries at 42 versus 41 weeks gestation (RR 1.87, 95% CI 1.07 to 2.86, p = 0.012). One additional stillbirth occurred for every 1,449 (95% CI 1,237 to 1,747) pregnancies that advanced from 40 to 41 weeks. Limitations include variations in the definition of low-risk pregnancy, the wide time span of the studies, the use of registry-based data, and potential confounders affecting the outcome. CONCLUSIONS: Our findings suggest there is a significant additional risk of stillbirth, with no corresponding reduction in neonatal mortality, when term pregnancies continue to 41 weeks compared to delivery at 40 weeks. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015013785.

Risk of Cesarean Delivery among Nulliparous Asian-Indian Women with Term Singleton Pregnancies.

OBJECTIVE: Asian-Indian women are a growing population in the United States, but little data exist about their risk of cesarean delivery (CD). We characterize the odds of CD among Asian-Indian women and determine whether neonatal birth weight modifies this relationship. STUDY DESIGN: This is a retrospective cohort study using an administrative perinatal database from California. We identified 1,029,940 nulliparous women with live, singleton, nonanomalous deliveries between 37 and 42 completed weeks of gestation. We performed multivariable logistic regression analyses to determine if Asian-Indian women were more likely to deliver by CD, compared with white non-Hispanic women, adjusting for sociodemographic and clinical variables. We explored if birth weight was an effect modifier, testing the interaction term's significance using Wald's test, and performed multivariable logistic regressions stratified by birth weight category. RESULTS: Asian-Indian women comprised 2.0% of the cohort. Compared with white non-Hispanic women, Asian-Indian women had an adjusted odds of 1.41 (95% confidence interval: 1.36-1.46) for CD. However, we noted effect modification of birth weight on the odds of CD by race/ethnicity (p < 0.001). Among all birth weight categories exceeding 3,000 g, Asian-Indian women had higher odds of CD than white non-Hispanic women. CONCLUSION: Asian-Indian women are at greater risk of CD than white non-Hispanic women when birthweight exceeds 3,000 g.

Recurrence of Preterm Birth and Early Term Birth.

OBJECTIVE: To examine recurrent preterm birth and early term birth in women's initial and immediately subsequent pregnancies. METHODS: This retrospective cohort study included 163,889 women who delivered their first and second liveborn singleton neonates between 20 and 44 weeks of gestation in California from 2005 through 2011. Data from hospital discharge records and birth certificates were used for analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models adjusted for risk factors. RESULTS: Shorter gestational duration in the first pregnancy increased the risk of subsequent preterm birth (both early, before 32 weeks of gestation, and later, from 32 to 36 weeks of gestation) as well as early term birth (37-38 weeks of gestation). Compared with women with a prior term birth, women with a prior early preterm birth (before 32 weeks of gestation) were at the highest risk for a subsequent early preterm birth (58/935 [6.2%] compared with 367/118,505 [0.3%], adjusted OR 23.3, 95% CI 17.2-31.7). Women with a prior early term birth had more than a twofold increased risk for subsequent preterm birth (before 32 weeks of gestation: 171/36,017 [0.5%], adjusted OR 2.0, 95% CI 1.6-2.3; from 32 to 36 weeks of gestation: 2,086/36,017 [6.8%], adjusted OR 3.0, 95% CI 2.9-3.2) or early term birth (13,582/36,017 [37.7%], adjusted OR 2.2, 95% CI 2.2-2.3). CONCLUSION: Both preterm birth and early term birth are associated with these outcomes in a subsequent pregnancy. Increased clinical attention and research efforts may benefit from a focus on women with a prior early term birth as well as those with prior preterm birth.

Maternal ethnicity, stillbirth and neonatal death risk in Western Australia 1998-2010.

This study investigated the scale of difference in stillbirth and neonatal death rates in Western Australia (1998-2010) by maternal ethnicity. Aboriginal and/or Torres Strait Islander (Indigenous) mothers, African mothers and mothers from 'Other' ethnic backgrounds were found to have increased risk of stillbirth compared with Caucasian mothers. Babies of Indigenous mothers also had increased risk of neonatal death. The gap between the stillbirth and neonatal death rates for Indigenous mothers and non-Indigenous mothers did not close over the study period.

Small-for-gestational age and preterm birth across generations: a population-based study of Illinois births.

Small for gestational age (weight for gestational age <10th percentile, SGA) and preterm birth (<37 weeks, PTB) are the major determinants of infant mortality rates and racial disparities therein. To determine the generational inheritance patterns of SGA and PTB among non-Hispanic Whites and African-Americans. Stratified and multivariable binominal regression analyses were performed on an Illinois transgenerational dataset of White and African-American infants (1989-1991) and their mothers (1956-1976) with appended US census income information. Former SGA White mothers (N = 8,993) had a twofold greater infant SGA frequency than former non-SGA White mothers (N = 101,312); 14.4 versus 6.9 %, RR = 2.1 (2.0-2.2). Former SGA African American (N = 4,861) mothers had a SGA birth frequency of 25.7 % compared to 16.1 % for former non-SGA mothers (N = 28,090); RR = 1.5 (1.5-1.6). The adjusted (controlling for maternal age, education, marital status, parity, prenatal care usage, cigarette smoking, and hypertension) RR (95 % CI) of infant SGA for former SGA (compared to non-SGA) White and African-American mothers equaled 2.0 (1.9-2.1 and 1.5 (1.5-1.6), respectively. The adjusted RR (95 % CI) of infant preterm birth for former preterm (compared to term) White and African-American mothers were 1.1 (1.0-1.2). The findings were minimally changed among mothers with a lifelong residence in impoverished or affluent neighborhoods. In both races, approximately 8 % of SGA births were attributable to maternal SGA. There is a transgenerational association of SGA but not preterm birth among non-Hispanic Whites and African-Americans. In both races, a similar proportion of SGA births are attributable to maternal SGA.

Maternal occupation and term low birth weight in a predominantly latina population in los angeles, california.

OBJECTIVES: Focusing on Latinas, we investigated whether maternal occupations during pregnancy increase term low birth weight (TLBW) (less than 2500 g; 37 weeks or more). METHODS: In a case-control study (n = 1498) nested within a 2003 birth cohort (n = 58,316) in Los Angeles County, California (65% Latina), we assessed the influence of maternal occupation on TLBW, using Occupational Codes based on the 2000 US Census Occupational Classification System. RESULTS: Odds ratios (ORs) for TLBW were increased among women working during pregnancy in "transportation and material moving operations" (adjusted OR = 3.28; 95% confidence interval = 1.00 to 10.73), "food preparation and serving occupations" (adjusted OR = 3.03, 95% confidence interval = 1.21 to 7.62), or "production occupations" (adjusted OR = 2.63, 95% confidence interval = 1.01 to 6.82) compared with "office occupations;" 73% to 93% of women working in these higher-risk jobs were immigrant Latinas. CONCLUSIONS: Working conditions in various jobs held mainly by first-generation immigrant Latinas increase risks for TLBW and need to be addressed to develop strategies to reduce TLBW.

African American women's views of factors impacting preterm birth.

PURPOSE: To explore pregnant African American women's views of factors that may impact preterm birth. STUDY DESIGN AND METHODS: Qualitative descriptive exploratory cross-sectional design. A convenience sample of 22 low-risk pregnant African American women participated in focus group interviews. Women were asked questions regarding their belief about why women have preterm birth and factors impacting preterm birth. Data were analyzed using content analysis. RESULTS: Pregnant African American women encounter multiple physical, psychological, and social stressors. The four themes included knowledge of preterm birth, risk factors for preterm birth, protective factors for preterm birth, and preterm birth inevitability. The risk factors for preterm birth were health-related conditions, stressors, and unhealthy behaviors. Stressors included lack of social and financial support, interpersonal conflicts, judging, dangerous neighborhoods, racism, and pregnancy- and mothering-related worries. Protective factors for preterm birth included social support and positive coping/self-care. CLINICAL IMPLICATIONS: Clinicians may use the results of this study to better understand women's perceptions of factors that affect preterm birth, to educate women about risk factors for preterm birth, and to develop programs and advocate for policies that have the potential to decrease health disparities in preterm birth.

Differing first year mortality rates of term births to White, African-American, and Mexican-American US-born and foreign-born mothers.

To determine whether maternal nativity (US-born versus foreign-born) is associated with the first year mortality rates of term births. Stratified and multivariable binomial regression analyses were performed on the 2003-2004 National Center for Health Statistics linked live birth-infant death cohort files. Only term (37-42 weeks) infants with non-Latina White, African-American, and Mexican-American mothers were studied. The infant mortality rate (<365 days, IMR) of births to US-born non-Latina White mothers (n = 3,684,569) exceeded that of births to foreign-born White mothers (n = 226,621): 2.4/1,000 versus 1.3/1,000, respectively; relative risk (RR) = 1.8 [95 % confidence interval (CI) 1.6-2.0]. The IMR of births to US-born African-American mothers (n = 787,452) exceeded that of births to foreign-born African-American mothers (n = 118,246): 4.1/1,000 versus 2.2/1,000, respectively; RR = 1.8 (1.6-2.1). The IMR of births to US-born Mexican-American mothers (n = 338,337) exceeded that of births to Mexican-born mothers (n = 719,837): 2.4/1,000 versus 1.8/1,000, respectively; RR = 1.3 (1.2-1.4). These disparities were not limited to a singular cause of death and were widest among deaths due to Sudden Infant Death Syndrome. In multivariable binomial regression models, the adjusted RR of infant mortality for non-LBW, term births to US-born (compared to foreign-born) for White, African-American, and Mexican-American mothers equaled 1.5 (1.3-1.7), 1.7 (1.5-2.1) and 1.6 (1.4-1.8), respectively. The IMR of term births to White, African-American, and Mexican-American mothers exceeds that of their counterparts with foreign-born mothers independent of traditional individual level risk factors.

Relationships among neighborhood environment, racial discrimination, psychological distress, and preterm birth in African American women.

OBJECTIVES: To (a) examine the relationships among objective and perceived indicators of neighborhood environment, racial discrimination, psychological distress, and gestational age at birth; (b) determine if neighborhood environment and racial discrimination predicted psychological distress; (c) determine if neighborhood environment, racial discrimination, and psychological distress predicted preterm birth; and (d) determine if psychological distress mediated the effects of neighborhood environment and racial discrimination on preterm birth. DESIGN: Descriptive correlational comparative. SETTING: Postpartum unit of a medical center in Chicago. PARTICIPANTS: African American women (n(1)  = 33 with preterm birth; n(2)  = 39 with full-term birth). METHODS: Women completed the instruments 24 to 72 hours after birth. Objective measures of the neighborhood were derived using geographic information systems (GIS). RESULTS: Women who reported higher levels of perceived social and physical disorder and perceived crime also reported higher levels of psychological distress. Women who reported more experiences of racial discrimination also had higher levels of psychological distress. Objective social disorder and perceived crime predicted psychological distress. Objective physical disorder and psychological distress predicted preterm birth. Psychological distress mediated the effect of objective social disorder and perceived crime on preterm birth. CONCLUSION: Women's neighborhood environments and racial discrimination were related to psychological distress, and these factors may increase the risk for preterm birth.

Trends and correlates of good perinatal outcomes in assisted reproductive technology.

OBJECTIVE: To estimate trends in good perinatal outcomes (singleton live births at term with birthweight more than 2,500 g) among live births after assisted reproductive technology in the United States from 2000 to 2008, and associated factors among singletons in 2008. METHODS: Using retrospective cohort data from the National Assisted Reproductive Technology Surveillance System from 2000 to 2008, we calculated relative change and χ tests for trend in the proportion of good perinatal outcomes among assisted reproductive technology live births (n=444,909) and liveborn singletons (n=222,500). We conducted univariable analyses followed by multiple logistic regression to estimate the effects of various characteristics on the outcome among singletons born in 2008 after fresh, nondonor assisted reproductive technology cycles (n=20,780). RESULTS: The proportion of good perinatal outcomes among all liveborn neonates increased from 38.6% in 2000 to 42.5% in 2008, whereas it declined marginally among singletons from 83.6% to 83.4%. One previous birth, transfer of fewer than three embryos, and the presence of fewer than three fetal hearts on 6-week ultrasound examination were associated with good perinatal outcome among singletons. Non-Hispanic black race, tubal factor infertility, uterine factor infertility, ovulatory disorder, and 5-day embryo culture were associated with reduced odds for a good outcome. The strongest association was the presence of one fetal heart compared with more than two (adjusted odds ratio 2.43, 95% confidence interval 1.73-3.42). CONCLUSION: From 2000 to 2008, good perinatal outcomes increased among assisted reproductive technology live births. Among singleton live births, odds for good outcome were greatest with the presence of a single fetal heart and lowest in women of non-Hispanic black race. LEVEL OF EVIDENCE: II.

Maternal micronutrient status and preterm versus term birth for black and white US women.

OBJECTIVE: Micronutrient deficiencies are hypothesized to play a role in spontaneous preterm birth (PTB; <37 weeks of gestation) and possibly the racial disparity in rates of PTB between black and white women. Yet relatively few studies have addressed the role of micronutrient deficiencies in spontaneous PTB among black and white women in the United States. The purpose of this study was to investigate whether 25-hydroxy vitamin D (25-OH-D), folate, and omega-6/omega-3 fatty acid status are associated with spontaneous PTB among black and white women in the United States. METHODS: Biospecimens and medical record data for this study were derived from a subsample of the 1547 women enrolled into the Nashville Birth Cohort during 2003-2006. We randomly selected 80 nulliparous and primiparous women for whom stored plasma samples from the delivery admission were available and analyzed the stored plasma for 25-OH-D, folate, and total omega-6/omega-3 fatty acids. We used multivariate logistic regression to assess the odds of spontaneous PTB among women with 25-OH-D <20 ng/mL, folate <5 ug/L, and omega-6/omega-3 >15. RESULTS: An omega-6/omega-3 ratio >15 was significantly associated with spontaneous PTB for white (adjusted odds ratio [aOR] 4.25, 95% confidence interval [CI] 1.25-14.49) but not black women (aOR 1.90, 95% CI: 0.69-5.40), whereas no significant relationships were observed for folate and 25-OH-D status and PTB for black or white women. CONCLUSION: Maternal plasma total omega-6/omega-3 fatty acid ratio >15 at delivery was significantly associated with spontaneous PTB for white, but not black, women.

Maternal ethnic ancestry and adverse perinatal outcomes in New York City.

OBJECTIVE: We sought to examine the association between narrowly defined subsets of maternal ethnicity and birth outcomes. STUDY DESIGN: We analyzed 1995-2003 New York City birth certificates linked to hospital discharge data for 949,210 singleton births to examine the multivariable associations between maternal ethnicity and preterm birth, subsets of spontaneous and medically indicated preterm birth, term small for gestational age, and term birthweight. RESULTS: Compared with non-Hispanic whites, Puerto Ricans had an elevated odds ratio (1.9; 95% confidence interval, 1.9-2.0) for delivering at 32-36 weeks (adjusted for nativity, maternal age, parity, education, tobacco use, prepregnancy weight, and birth year). We found an excess of adverse outcomes among most Latino groups. Outcomes also varied within regions, with North African infants nearly 100 g (adjusted) heavier than sub-Saharan African infants. CONCLUSION: The considerable heterogeneity in risk of adverse perinatal outcomes is obscured in broad categorizations of maternal race/ethnicity and may help to formulate etiologic hypotheses.

Amniotic fluid interleukin-6 increase is an indicator of spontaneous preterm birth in white but not black Americans.

OBJECTIVE: This study examined the differences in the inflammatory cytokine interleukin (IL)-6 and the immunoinhibitory cytokine IL-10 in the amniotic fluid of black and white women in spontaneous preterm birth. METHODS: In this study, 321 amniotic fluids from cases (preterm birth 36 or fewer weeks' gestation) and controls (normal term delivery longer than 37 weeks' gestation) were collected (147 cases [49 blacks and 98 whites] and 174 controls [85 blacks and 89 whites]) at the time of active labor. IL-6 and IL-10 concentrations were measured by immunoassays. Using normal-term delivery as controls, logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CIs) for preterm birth. RESULTS: A significant difference in IL-6 concentration was observed in white cases (cases: 3773 pg/mL; controls: 1682 pg/mL; P = .0003), compared with controls, but not in blacks (cases: 2042 pg/mL; controls: 2366 pg/mL; P = .6). In a combined multivariable analysis, when the highest and the lowest quartiles of IL-6 were compared in whites, the ORs (95% CI) for preterm birth across quartiles were 1.74 (0.62-4.88), 1.09 (0.39-3.02), and 5.68 (2.15-15.0). No such association was found in blacks. IL-10 concentration was not different between cases and controls in either race. CONCLUSIONS: Race-specific associations exist between IL-6 but not IL-10 concentration and preterm birth. Elevated IL-6 concentrations are associated with preterm birth in whites but not blacks.

Comparison of the phospholipid classes in human milk in Japanese mothers of term and preterm infants.

BACKGROUND: Phospholipids (PLs) play an essential role in the growth and brain development of infants. AIM: To investigate PL composition in human milk (HM), including lysophosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylcholine (PC) and sphingomyelin (SM), from healthy Japanese mothers. Analyses were performed on colostrum, transitional milk and mature milk from mothers of preterm and term infants. METHODS: HM samples were collected from mothers of 15 term infants (term group) and of 19 preterm infants (preterm group). PL composition was determined by two-dimensional thin-layer chromatography in conjunction with phosphorus analysis. RESULTS: In both groups, the PL content (% of total lipid) of mature milk was significantly lower than in colostrum. SM and PC were the main PLs in HM, but in the preterm group, the percentage of SM in mature milk was significantly higher and PC in mature milk was significantly lower than in the term group. CONCLUSION: The transition from colostrum to mature milk leads to an increase in SM and a decrease in PC in the HM of preterm infants, along with a decrease in PL content. This is the first report to demonstrate the differences in PL composition in HM between mothers of preterm and term infants.