Risks and causes of mortality among low-birthweight infants in childhood and adolescence

Association of residential greenness, air pollution with adverse birth outcomes: Results from 61,762 mother‑neonatal pairs in project ELEFANT (2011-2021)

BACKGROUND

Emerging evidence has demonstrated the benefits of greenness exposure on human health, while conflicts remain unsolved in issue of adverse birth outcomes.

METHODS

Utilizing data from project ELEFANT spanning the years 2011 to 2021, we assessed residential greenness using the NDVI from MODIS data and residential PM2.5 exposure level from CHAP data. Our primary concerns were PTD, LBW, LGA, and SGA. Cox proportional hazard regression model was used to examine the association of residential greenness and air pollution exposure with risk of adverse birth outcomes. We performed mediation and modification effect analyses between greenness and air pollutant.

RESULTS

We identified 61,762 mother‑neonatal pairs in final analysis. For per 10 μg/m3 increase in PM2.5 concentration during entire pregnancy was associated with 19.8 % and 20.7 % increased risk of PTD and LGA. In contrast, we identified that an 0.1 unit increment in NDVI were associated with 24 %, 43 %, 26.5 %, and 39.5 % lower risk for PTD, LBW, LGA, and SGA, respectively. According to mediation analysis, NDVI mediated 7.70 % and 7.89 % of the associations between PM2.5 and PTD and LGA. Residential greenness could reduce the risk of PTD among mothers under 35 years old, living in rural areas, primigravidae and primiparity..

CONCLUSIONS

In summary, our results highlighted the potential of residential greenness to mitigate the risk of adverse birth outcomes, while also pointing to the adverse impact of PM2.5 on increased risk of multiple adverse birth outcomes (PTD and LGA). The significant mediation effect of NDVI emphasizes its potential as an important protective factor of PM2.5 exposure. Additionally, the identification of susceptible subgroups can inform targeted interventions to reduce adverse birth outcomes related to air pollution and lack of green spaces. Further research and understanding of these associations can contribute to better public health strategies aimed at promoting healthier pregnancies and birth outcomes.

Associations between introduction and withdrawal of a financial incentive and timing of attendance for antenatal care and incidence of small for gestational age: natural experimental evaluation using interrupted time series methods

OBJECTIVES

To determine whether introduction or withdrawal of a maternal financial incentive was associated with changes in timing of first attendance for antenatal care ('booking'), or incidence of small for gestational age.

DESIGN

A natural experimental evaluation using interrupted time series analysis.

SETTING

A hospital-based maternity unit in the north of England.

PARTICIPANTS

34 589 women (and their live-born babies) who delivered at the study hospital and completed the 25th week of pregnancy in the 75 months before (January 2003 to March 2009), 21 months during (April 2009 to December 2010) and 36 months after (January 2011 to December 2013) the incentive was available.

INTERVENTION

The Health in Pregnancy Grant was a financial incentive of £190 ($235; €211) payable to pregnant women in the UK from the 25th week of pregnancy, contingent on them receiving routine antenatal care.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was mean gestational age at booking. Secondary outcomes were proportion of women booking by 10, 18 and 25 weeks' gestation; and proportion of babies that were small for gestational age.

RESULTS

By 21 months after introduction of the grant (ie, immediately prior to withdrawal), compared with what was predicted given prior trends, there was an reduction in mean gestational age at booking of 4.8 days (95% CI 2.3 to 8.2). The comparable figure for 24 months after withdrawal was an increase of 14.0 days (95% CI 2.8 to 16.8). No changes in incidence of small for gestational age babies were seen.

CONCLUSIONS

The introduction of a universal financial incentive for timely attendance at antenatal care was associated with a reduction in mean gestational age at first attendance, but not the proportion of babies that were small for gestational age. Future research should explore the effects of incentives offered at different times in pregnancy and of differing values; and how stakeholders view such incentives.

Optimal embryo transfer strategy in poor response may include freeze-all

PURPOSE

In this retrospective cohort study, we investigated the best embryo transfer strategy in ICSI cycles with ≤4 oocytes collected at oocyte retrieval.

METHODS

Women who underwent antagonist co-treatment COS for ICSI treatment between January 2010 and December 2015 at a private ART clinic (N = 2263). Eight hundred seventy-nine women (group 1) had ≤4 oocytes collected at oocyte retrieval, of whom 645 (group A) had cleavage stage embryo transfer (ET), and 234 (group B) had blastocyst ET. One thousand three hundred eighty-four women (group 2) had 10-15 oocytes collected at oocyte retrieval, of whom 676 (group C) had cleavage stage ET, and 708 women (group D) had blastocyst ET. Blastocyst vitrification was performed using the Cryotop method and FET using artificial cycles.

RESULTS

In group 1, the cancellation rate was significantly lower in group A (25.2 vs 38 %). The pregnancy rate (PR), clinical PR, implantation rate (IR), and live birth rate (LBR) per ET and per oocyte retrieval were all lower in group A. The clinical PR, IR, and LBR per ET of vitrified-warmed blastocyst ET were significantly the highest. In group 2, the cycle cancellation rate was significantly lower in group C (3.5 vs 13.4 %). The PR, clinical PR, and IR per ET and per oocyte retrieval were all lower in group C. The LBR per ET was significantly lower, but the LBR per oocyte retrieval was not significantly lower in group C. Again, the PR, clinical PR, and IR per ET of vitrified-warmed blastocyst ET were significantly the highest.

CONCLUSIONS

Day 5 ET strategy has been reserved for normal or high responders. The improved pregnancy outcomes from blastocyst culture and cryopreservation may challenge ART to extend this benefit to poor responders.

Incentives for increasing prenatal care use by women in order to improve maternal and neonatal outcomes

BACKGROUND

Prenatal care is recommended during pregnancy as a method to improve neonatal and maternal outcomes. Improving the use of prenatal care is important, particularly for women at moderate to high risk of adverse outcomes. Incentives are sometimes utilized to encourage women to attend prenatal care visits.

OBJECTIVES

To determine whether incentives are an effective tool to increase utilization of timely prenatal care among women.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015) and the reference lists of all retrieved studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs), quasi-RCTs, and cluster-RCTs that utilized direct incentives to pregnant women explicitly linked to initiation and frequency of prenatal care were included. Incentives could include cash, vouchers, coupons or products not generally offered to women as a standard of prenatal care. Comparisons were to no incentives and to incentives not linked directly to utilization of care. We also planned to compare different types of interventions, i.e. monetary versus products or services.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and methodological quality. Two review authors independently extracted data. Data were checked for accuracy.

MAIN RESULTS

We identified 11 studies (19 reports), six of which we excluded. Five studies, involving 11,935 pregnancies were included, but only 1893 pregnancies contributed data regarding our specified outcomes. Incentives in the studies included cash, gift card, baby carrier, baby blanket or taxicab voucher and were compared with no incentives. Meta-analysis was performed for only one outcome 'Return for postpartum care' and this outcome was not pre-specified in our protocol. Other analyses were restricted to data from single studies.Trials were at a moderate risk of bias overall. Randomization and allocation were adequate and risk of selection bias was low in three studies and unclear in two studies. None of the studies were blinded to the participants. Blinding of outcome assessors was adequate in one study, but was limited or not described in the remaining four studies. Risk of attrition was deemed to be low in all studies that contributed data to the review. Two of the studies reported or analyzed data in a manner that was not consistent with the predetermined protocol and thus were deemed to be at high risk. The other three studies were low risk for reporting bias. The largest two of the five studies comprising the majority of participants took place in rural, low-income, homogenously Hispanic communities in Central America. This setting introduces a number of confounding factors that may affect generalizability of these findings to ethnically and economically diverse urban communities in developed countries.The five included studies of incentive programs did not report any of this review's primary outcomes: preterm birth, small-for-gestational age, or perinatal death.In terms of this review's secondary outcomes, pregnant women receiving incentives were no more likely to initiate prenatal care (risk ratio (RR) 1.04, 95% confidence interval (CI) 0.78 to 1.38, one study, 104 pregnancies). Pregnant women receiving incentives were more likely to attend prenatal visits on a frequent basis (RR 1.18, 95% CI 1.01 to 1.38, one study, 606 pregnancies) and obtain adequate prenatal care defined by number of "procedures" such as testing blood sugar or blood pressure, vaccinations and counseling about breastfeeding and birth control (mean difference (MD) 5.84, 95% CI 1.88 to 9.80, one study, 892 pregnancies). In contrast, women who received incentives were more likely to deliver by cesarean section (RR 1.97, 95% CI 1.18 to 3.30, one study, 979 pregnancies) compared to those women who did not receive incentives.Women who received incentives were no more likely to return for postpartum care based on results of meta-analysis (average RR 0.75, 95% CI 0.21 to 2.64, two studies, 833 pregnancies, Tau² = 0.81, I² = 98%). However, there was substantial heterogeneity in this analysis so a subgroup analysis was performed and this identified a clear difference between subgroups based on the type of incentive being offered. In one study, women receiving non-cash incentives were more likely to return for postpartum care (RR 1.26, 95% CI 1.09 to 1.47, 240 pregnancies) than women who did not receive non-cash incentives. In another study, women receiving cash incentives were less likely to return for postpartum care (RR 0.43, 95% CI 0.30 to 0.62, 593 pregnancies) than women who did not receive cash incentives.No data were identified for the following secondary outcomes: frequency of prenatal care; pre-eclampsia; satisfaction with birth experience; maternal mortality; low birthweight (less than 2500 g); infant macrosomia (birthweight greater than 4000 g); or five-minute Apgar less than seven.

AUTHORS' CONCLUSIONS

The included studies did not report on this review's main outcomes: preterm birth, small-for-gestational age, or perinatal death. There is limited evidence that incentives may increase utilization and quality of prenatal care, but may also increase cesarean rate. Overall, there is insufficient evidence to fully evaluate the impact of incentives on prenatal care initiation. There are conflicting data as to the impact of incentives on return for postpartum care. Two of the five studies which accounted for the majority of women in this review were conducted in rural, low-income, overwhelmingly Hispanic communities in Central America, thus limiting the external validity of these results.There is a need for high-quality RCTs to determine whether incentive program increase prenatal care use and improve maternal and neonatal outcomes. Incentive programs, in particular cash-based programs, as suggested in this review and in several observational studies may improve the frequency and ensure adequate quality of prenatal care. No peer-reviewed data have been made publicly available for one of the largest incentive-based prenatal programs - the statewide Medicaid-based programs within the United States. These observational data represent an important starting point for future research with significant implications for policy development and allocation of healthcare resources. The disparate findings related to attending postpartum care should also be further explored as the findings were limited by the number of studies. Future large RCTs are needed to focus on the outcomes of preterm birth, small-for-gestational age and perinatal outcomes.

Trends in infant mortality rates in Hungary between 1963 and 2012

AIM

This study investigated annual and seasonal death trends for infants of <1 year of age in Hungary between 1963 and 2012 and analysed commonly accepted risk factors.

METHODS

Data on the numbers of live births and infant deaths were obtained from the published nationwide population register. Negative binomial regression was applied to investigate the yearly trends in rates and also the effect of possible risk factors - low birthweight, maternal education and sex - on infant mortality. Cyclic trends were investigated using logistic regression.

RESULTS

Annual infant mortality declined significantly (p < 0.001) from 42.9 to 4.9 per 1000 live births per year during the study period and significantly increased (p < 0.001) in the low birthweight group and lower maternal education groups. A significant (p < 0.001) cyclic trend in mortality was revealed, with a peak in deaths in late February for all infants and a double peak, in May and November, in the group of cases who died during the early neonatal period.

CONCLUSION

This Hungarian study suggests that there was a significant seasonal effect on neonatal and infant mortality at the end of winter between 1963 and 2012. We speculate that this may have been related to respiratory infections.

Clinical rationale for cryopreservation of entire embryo cohorts in lieu of fresh transfer

Recent dramatic increases in success rates with frozen-thawed embryo transfer (FET) are encouraging, as are numerous findings of several reduced risks with FET when compared with fresh transfer. These reduced risks include low birth weight and prematurity, among others. However, FET is also associated with increased risks of macrosomia and large for gestational age. There have been reports of greater implantation and pregnancy rates with FET than with fresh autologous embryo transfer, suggesting superior endometrial receptivity in the absence of ovarian stimulation. As cryo-technology evolves, there is potential for further increase in FET success rates, but for now it may be best to follow an individualized approach, balancing fresh transfer and embryo cohort cryopreservation options while considering patient characteristics, cycle parameters, and clinic success rates.

Risk factors and trends in the rate of stillbirth in Hungary between 1971 and 2010

OBJECTIVE

Possible risk factors and trends in the rate of stillbirth in Hungary between 1971 and 2010.

METHODS

Annual data of fetal birth weight, fetal gender, maternal age and marital status of the mother categories were available for both live and stillborn cases and were analyzed using negative binomial regression. A p value less than 0.05 was considered significant.

RESULTS

Male gender significantly increased risk of stillbirth (relative risk (RR):1.08; p < 0.001). The risk of stillbirth was also significantly associated with the maternal age (RR: 2.01 in the group older than 35 years, relative to younger mothers; p < 0.001), and the marital status (RR: 1.24 among the babies of an extramarital partnership; p < 0.001), this holding true for both fetal genders. However, a low birth weight ( < 2500 g) increased the risk of stillbirth more than 18-fold (RR: 18.47; p < 0.001) and there was a markedly higher risk of low birth weight in boys than in girls. Further, a strong negative correlation (r = -0.88) was detected between the real income per person of the overall population and the rate of stillbirth.

CONCLUSIONS

These findings support the known risk factors of stillbirth and gender-specific analyses given an estimation of the risk of stillbirth in both boys and girls.

Meta-analysis to estimate the correlation coefficients between birthweight and other anthropometric measurements at birth

OBJECTIVE

To pool the correlation coefficients between birthweight (BW) and other newborn anthropometric measurements at birth.

METHODS

Meta-analysis, using a random-effects model. Any study, published in the English language, showing the correlation coefficients between BW and other anthropometric measurements of living neonates at birth was eligible. The Z- scores, transformed from the correlation coefficients were pooled, and afterwards they were back transformed to the pooled correlation coefficients.

RESULTS

The correlations of BW with (mid upper-) arm circumference (MUAC) and chest circumference (CHC) were frequently studied (n, 76 and 71; pooled correlation coefficient, 0.81 and 0.84; 95%CI, 0.78-0.84 and 0.82-0.86). The Z- scores of the pooled correlation coefficient between BW vs. CHC, the highest among the correlation coefficients of BW, was not substantially different from the Z- scores between BW vs. calf circumference (CC), thigh circumference (TC), MUAC, or abdominal circumference (AC) (p, 0.889, 0.351, 0.076, and 0.053, respectively), but the study numbers of CC, TC, or AC were remarkably low (n, 13, 19, and 6, respectively) compared with CHC or MUAC.

CONCLUSIONS

CHC and MUAC may be among the most promising candidates as the surrogates of BW, based on the study numbers, and the level of pooled correlation coefficients.

Associations of long-chain polyunsaturated fatty acid concentrations with birth outcome in term Indian mothers and their neonates

The purpose of this study was to examine the maternal and cord long-chain polyunsaturated fatty acid (LCPUFA) concentrations and their associations with birth outcome in term deliveries. Pregnant women (n = 253) delivering at term were divided into two groups based on their babies' birth weights (1) normal birth weight (NBW), that is, ≥2.5 kg (n = 190) and (2) low-birth weight (LBW), that is, <2.5 kg (n = 63). Each group is further divided into two groups according to the baby's sex, that is, male NBW (M-NBW), female NBW (F-NBW), male LBW (M-LBW), and female LBW (F-LBW) groups. Maternal plasma docosahexaenoic acid and erythrocyte arachidonic acid (AA) levels were lower (P < 0.05 for both), while cord plasma docosahexaenoic acid and erythrocyte AA levels were higher (P < 0.05 for both) in LBW group when compared to the NBW group. Maternal erythrocyte AA levels were positively associated with birth weight (P = 0.001), while cord plasma docosahexaenoic acid levels were negatively (P = 0.05) associated with birth weight. Reduced maternal and increased cord LCPUFA levels exist in mothers delivering LBW babies, especially in mothers delivering female babies, indicative of sex-specific effects.

High Risk Community—Men’s Perceptions of Black Infant Mortality: A Qualitative Inquiry

Infant mortality has been identified as a key public health concern in the United States. Although infant mortality rates (IMRs) in the United States have declined during the past 10 years, the rates among Blacks are more than two times higher as compared with other racial and ethnic groups. This study used focus groups to explore Black men’s awareness and perceptions of the rising IMR in their community. Twenty-five men participated in an initial and follow-up focus group, which revealed that men had limited awareness of infant mortality, reduced sense of personal responsibility for pregnancy outcomes, and perceptions that stress, the age of the mother, and the health care system were responsible for poor birth outcomes. The role of the community and possible interventions to involve and educate men were also explored.