Vertical Transmission of SARS-CoV-2: A Systematic Review of Systematic Reviews

The COVID-19 pandemic has hugely impacted global public health and economy. The COVID-19 has also shown potential impacts on maternal perinatal and neonatal outcomes. This systematic review aimed to summarize the evidence from existing systematic reviews about the effects of SARS-CoV-2 infections on maternal perinatal and neonatal outcomes. We searched PubMed, MEDLINE, Embase, and Web of Science in accordance with PRISMA guidelines, from 1 December 2019 to 7 July 2021, for published review studies that included case reports, primary studies, clinical practice guidelines, overviews, case-control studies, and observational studies. Systematic reviews that reported the plausibility of mother-to-child transmission of COVID-19 (also known as vertical transmission), maternal perinatal and neonatal outcomes, and review studies that addressed the effect of SARS-CoV-2 infection during pregnancy were also included. We identified 947 citations, of which 69 studies were included for further analysis. Most (>70%) of the mother-to-child infection was likely due to environmental exposure, although a significant proportion (about 20%) was attributable to potential vertical transmission of SARS-CoV-2. Further results of the review indicated that the mode of delivery of pregnant women infected with SARS-CoV-2 could not increase or decrease the risk of infection for the newborns (outcomes), thereby emphasizing the significance of breastfeeding. The issue of maternal perinatal and neonatal outcomes with SARS-CoV-2 infection continues to worsen during the ongoing COVID-19 pandemic, increasing maternal and neonatal mortality, stillbirth, ruptured ectopic pregnancies, and maternal depression. Based on this study, we observed increasing rates of cesarean delivery from mothers with SARS-CoV-2 infection. We also found that SARS-CoV-2 could be potentially transmitted vertically during the gestation period. However, more data are needed to further investigate and follow-up, especially with reports of newborns infected with SARS-CoV-2, in order to examine a possible long-term adverse effect.     

Smokers and marriage: attitude of youth in the United Arab Emirates

Introduction: In order to control the tobacco scourge, an array of measures is required. Among them is focusing on adolescent relationships as it has been shown that being in a close relationship with a smoker or a non smoker will in the long run be a major factor in deciding whether the individual adopts smoking for initial non-smokers or ceases the habit for initial smokers. Objectives: To assess the attitude of youth towards other smokers and towards marrying a smoker. Materials and Methods: A cross-sectional study was carried out among 415 students from five universities in the United Arab Emirates (UAE). Self-administered structured questionnaires were used for data collection. The Chi square test was used to detect significant differences between frequencies. Results: Of the 415 participants who provided their gender information, 99 (24%) were males and 314 (76%) were females. Of all the participants, 83.5% were not willing to marry smokers, while 16.5% were willing. Of those whose parents smoked (106) 68% did not like it when their parents smoked, 13.6% had no opinion, 17.5% did not mind, while the other 1% had other thoughts. Of those whose close friends smoked, 43.4% did not like it, 16.2% did not have any opinion, 36.9% did not mind while 3.5% had other thoughts. Conclusion: Most participants, both males and females are not willing to marry smokers and prefer to have non-smokers as spouses. Also, smokers are seen as less attractive by both genders in contrast to what appears as popular beliefs amongst youngsters and what is depicted in tobacco advertisements. Tobacco control activities can be undertaken in the community and colleges by incorporating students as facilitators.     

Obesity subtypes and risk of spontaneous versus medically indicated preterm births in singletons and twins

Using data from the Missouri maternally linked files (1989-1997), the authors examined the association among maternal obesity, obesity subtypes, and spontaneous and medically indicated preterm (<37 weeks) and very preterm (<33 weeks) births in singletons and twins. Adjusted odds ratios were obtained with correction for intracluster correlation. The prevalence of obesity increased by 77% over the study period (p(trend) < 0.001). Obese mothers had a lower risk for spontaneous preterm birth, and this was more pronounced among twins (odds ratio = 0.68, 95% confidence interval: 0.62, 0.75) than singletons (odds ratio = 0.84, 95% confidence interval: 0.82, 0.87). However, this association was present only among obese women who gained less than 0.69 kg/week for singletons and between 0.23 and 0.69 kg/week for twins. By contrast, obese mothers with singleton gestation had about 50% greater odds of medically indicated preterm (odds ratio = 1.46, 95% confidence interval: 1.39, 1.54) and very preterm (odds ratio = 1.49, 95% confidence interval: 1.34, 1.65) births, and the risk increases with ascending severity of obesity (p(trend) < 0.01). For extreme obesity, the risk of medically indicated preterm and very preterm births was almost double that for nonobese women. Similar findings were observed in twins. These data suggest that obesity increases the risk for medically indicated but not spontaneous preterm birth in both singletons and twins.     

Pre-eclampsia in the first pregnancy and subsequent risk of stillbirth in black and white gravidas

Objective

To examine the association between prior pre-eclampsia and subsequent stillbirth in black women and white women.

Study design

This is a population-based retrospective study of Missouri maternally linked birth cohort files from 1989 to 2005. We analyzed singleton first and second births to mothers in the state of Missouri. The study population comprised women who experienced pre-eclampsia in their first pregnancy and a comparison group consisting of women who did not. The two groups were followed to their second pregnancy to document stillbirth occurrence. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between prior pre-eclampsia and subsequent stillbirth were obtained from logistic regression models.

Results

Women who experienced prior pre-eclampsia had a 43% increased risk of subsequent stillbirth [OR = 1.43; 95% CI = 1.08–1.89]. Whereas women with a history of late-onset pre-eclampsia had no elevated risk for subsequent stillbirth, those whose first pregnancy resulted in early-onset pre-eclampsia had a more than 4-fold increased risk of stillbirth in their second pregnancy [OR = 4.07; 95% CI = 2.32–7.14]. When sub-analysis was performed on the two main racial groups in the State, we found that elevated risk for subsequent stillbirth in a second pregnancy was observed among black women with prior early-onset pre-eclampsia (OR = 8.21; 95% CI = 4.03–16.70) but not in whites (OR = 1.95; 95% CI = 0.72–5.26).

Conclusion

Initiation of pregnancy with pre-eclampsia elevates the risk for subsequent stillbirth. The risk elevation is most pronounced in black women with early-onset pre-eclampsia in their first pregnancy. This information is valuable for inter-pregnancy counseling of affected women.     

The impact of obesity on spontaneous and medically indicated preterm birth among adolescent mothers

Purpose  

We sought to evaluate the impact of obesity on the risk of spontaneous and medically indicated preterm birth in young women compared to adult women.     

The Association Between HIV/AIDS During Pregnancy and Fetal Growth Parameters in Florida: A Population Based Study

In this population-based retrospective study, we sought to investigate the association between HIV/AIDS during pregnancy and adverse birth outcomes, including low birth weight (LBW), very low birth weight (VLBW), preterm birth (PTB), very preterm birth (VPTB), and small for gestational age (SGA), among women in Florida by sociodemographic variables. Using data from Florida's maternally linked birth cohort files, we examined singleton live births in the state during 1998 to 2007 (N = 1,698,107). The study population was categorized based on the maternal HIV/AIDS status. Poisson regression models were used to generate adjusted rate ratios (ARR) to estimate the association between HIV/AIDS status and fetal growth parameters. The main outcome measures were fetal growth parameters, including LBW, VLBW, PTB, VPTB, and SGA. As compared to HIV/AIDS-negative women, mothers with HIV/AIDS had elevated risks for LBW (ARR = 1.40; 95% CI = 1.30-1.50), VLBW (ARR = 1.25; 95% CI = 1.04-1.51), SGA (ARR = 1.26; 95% CI = 1.17-1.35), PTB (ARR = 1.23; 95% CI = 1.03-1.47), and VPTB (ARR = 1.27; 95% CI = 1.20-1.36). Risk estimates for LBW and SGA were highest among Hispanics mothers with HIV/AIDS, while white mothers with HIV/AIDS had the highest risk levels for VLBW and PTB, compared to their HIV/AIDS negative counterparts. Our findings show that women with HIV/AIDS have elevated risks for inhibited fetal growth and shortened gestation with important racial/ethnic variation. This is the first known population-based study that reveals racial/ethnic differences in HIV/AIDS-related fetal growth morbidity outcomes.     

Alcohol Consumption During Pregnancy and Risk of Placental Abruption and Placenta Previa

The purpose of this study was to examine the association between prenatal alcohol consumption and the occurrence of placental abruption and placenta previa in a population-based sample. We used linked birth data files to conduct a retrospective cohort study of singleton deliveries in the state of Missouri during the period 1989 through 2005 (n = 1,221,310). The main outcomes of interest were placenta previa, placental abruption and a composite outcome defined as the occurrence of either or both lesions. Multivariate logistic regression was used to generate adjusted odd ratios, with non-drinking mothers as the referent category. Women who consumed alcohol during pregnancy had a 33% greater likelihood for placental abruption during pregnancy (adjusted odds ratio (OR), 95% confidence interval (CI) = 1.33 [1.16–1.54]). No association was observed between prenatal alcohol use and the risk of placenta previa. Alcohol consumption in pregnancy was positively related to the occurrence of either or both placental conditions (adjusted OR [95% CI] = 1.29 [1.14–1.45]). Mothers who consumed alcohol during pregnancy were at elevated risk of experiencing placental abruption, but not placenta previa. Our findings underscore the need for screening and behavioral counseling interventions to combat alcohol use by pregnant women and women of childbearing age.     

Teen twin pregnancies: differences in fetal growth outcomes among blacks and whites

We set out to determine the magnitude of black-white disparity in intrauterine fetal growth inhibition among twin births to teenagers (age 15 to 19) in the United States using a retrospective cohort study design. We compared the risk for low and very low birthweight, preterm and very preterm, and small for gestational age between black and white twins born to teen mothers during the period 1995 through 1998. The methodology of generalized estimating equations was used to adjust for the presence of intracluster correlation within twin pairs. A total of 29,307 individual twins were analyzed. For all fetal growth indices examined, infants born to black mothers remained disadvantaged except for preterm birth, for which the risk was comparable to that of whites (adjusted OR, 1.03; 95% confidence interval [CI] 0.95 to 1.11). The racial gap was most marked for low birthweight (OR, 1.27; 95% CI, 1.19, 1.37]) and very low birthweight (OR, 1.30; 95% CI, 1.19 to 1.42). Black twins had an equal level of elevated risk for very preterm and small for gestational age (OR, 1.17; 95% CI, 1.07 to 1.27 and OR, 1.17; 95% CI, 1.07 to 1.28, respectively). In conclusion, we found significant differences in fetal growth parameters between black and white twins born to teen gravidas. Our findings confirm similar black disadvantage reported for singletons. Current prevention strategies aimed at reducing adverse fetal outcomes among teenagers in the United States need to consider the heightened risk among neonates born to black mothers.     

Significant paternal contribution to the risk of small for gestational age

OBJECTIVE: The aim of this study is to investigate both maternal and paternal contributions in the familial aggregation of small for gestational age. DESIGN: Nested case-control study. SETTING: Metropolitan area of Haguenau, France. POPULATION: Data were drawn from a French population-based maternity registry. After selection, 256 cases born either small for gestational age or average for gestational age were included. METHODS: Controlling for known pregnancy-related risk factors, logistic regression models were used to determine the risk of the child being small for gestational age, given that the mother, father or both were small for gestational age, and to examine interactions between maternal small for gestational age and pregnancy risk factors. MAIN OUTCOME MEASURES: Specifically, we investigate to what extent having either or both parents born small for gestational age increases the risk of small for gestational age in their offspring, after controlling for the established risk factors of small for gestational age and maternal and paternal characteristics. We also explore the extent to which the intergenerational predictors of small for gestational age may modify the effect of current pregnancy-related risk factors. RESULTS: The risk of a small for gestational age offspring was 4.7 times greater for mothers and 3.5 times greater for fathers who were small for gestational age, compared with average for gestational age counterparts. Furthermore, the risk of a small for gestational age offspring was 16.3 times greater when both parents were small for gestational age. No significant interactions between maternal small for gestational age and maternal smoking, hypertension or parity were observed. CONCLUSION: These results indicate that small for gestational age in both mother and father significantly influences the risk of their offspring being small for gestational age. While previous research has indicated that the birth outcome of the mother is an important determinant of the birth outcome of her offspring, these data indicate that the birth outcome of the father plays an equally critical role in determining fetal growth, strongly suggesting a genetic component in the familial aggregation of small for gestational age.