Maternal pre-pregnancy underweight and the risk of small-for-gestational-age in Asian-American ethnic groups

Trends, statistics, and policy recommendations on maternal, fetal, and infant mortality before and after COVID-19: a review of the past decade (2012-2022) based on national health information data

OBJECTIVE

To examine the impact of the coronavirus disease 2019 (COVID-19) pandemic on maternal, fetal, and infant mortality in South Korea using national statistics, in order to inform policy development and enhance maternal and child health outcomes with the provided data.

METHODS

Pregnancy-related mortality in women, as well as deaths of infants, in South Korea was identified using cause-of-death statistics from Statistics Korea. Records from death certificates, cremation reports on infant and fetal deaths, and the complementary cause-of-death investigation system were reviewed for the 2012-2022 period. The classification criteria for cause of death followed the recommendations of World Health Organization and the Korean standard classification of diseases and causes of death.

RESULTS

The maternal mortality rate decreased from 11.3 per 100,000 live births in 2018 to 9.9 in 2019, rose to 11.8 in 2020, and fell to 8.8 in 2021. The actual number of maternal deaths declined from 37 in 2018 to 23 in 2021 due to fewer births. The fetal death rate increased from 11.3 per 1,000 live births in 2018 to 11.6 in 2019, continuing to rise to 12.0 in 2021. The number of fetal deaths dropped from 3,743 in 2018 to 3,152 in 2021.

CONCLUSION

Despite the COVID-19 pandemic, Korea experienced a sharp decline in births as well as in maternal, infant, and fetal deaths. However, maternal, infant, and fetal mortality rates remained at similar levels.

Trajectory of gestational weight gain is related to birthweight: The TAWS cohort study in China

Few studies have reported the timing and amount of gestational weight gain (GWG) to prevent large-for-gestational-age (LGA) or small-for-gestational-age (SGA). This study aimed to evaluate the association of GWG velocity in each trimester with LGA or SGA based on data from the Taicang and Wuqiang cohort study (TAWS, n = 2008). We used a linear mixed model to evaluate the association of trimester-specific GWG velocity with birthweight categories and stratified by prepregnancy body mass index category and parity. For normal-weight pregnant women, mothers with LGA births had higher GWG velocities than mothers with appropriate-for-gestational-age (AGA) births in the first trimester (0.108 vs. 0.031 kg/week, p < 0.01), second trimester (0.755 vs. 0.631 kg/week, p < 0.01) and third trimester (0.664 vs. 0.594 kg/week, p < 0.01); in contrast, mothers with SGA births had lower GWG velocities than mothers with AGA births in the second trimester (0.528 vs. 0.631 kg/week, p < 0.01) and third trimester (0.541 vs. 0.594 kg/week, p < 0.01). For normal-weight pregnant women with AGA births, multiparous women had lower GWG velocities than primiparous women in the second (0.602 vs. 0.643 kg/week, p < 0.01) and third trimesters (0.553 vs. 0.606 kg/week, p < 0.01). Therefore, for normal-weight women, LGA prevention would begin in early pregnancy and continue until delivery and the second and third trimesters may be critical periods for preventing SGA; in addition, among normal-weight pregnant women with AGA births, multiparous women tend to have lower weight gain velocities than primiparous women.

The Risk of Hypertension and Diabetes Mellitus According to Offspring's Birthweight in Women With Normal Body Mass Index: A Nationwide Population-Based Study

BACKGROUND

Maladaptation to vascular, metabolic, and physiological changes during pregnancy can lead to fetal growth disorders. Moreover, adverse outcomes during pregnancy can further increase the risk of cardiovascular and metabolic diseases in mothers. Delivering a large-for-gestational-age (LGA) baby may indicate a pre-existing metabolic dysfunction, whereas delivering a small-for-gestational-age (SGA) baby may indicate a pre-existing vascular dysfunction. This study aims to assess the risk of hypertension (HTN) and diabetes mellitus (DM) in women with normal body mass index (BMI) scores who did not experience gestational DM or hypertensive disorders during pregnancy based on the offspring's birthweight.

METHODS

This retrospective nationwide study included women with normal BMI scores who delivered a singleton baby after 37 weeks. Women with a history of DM or HTN before pregnancy and those with gestational DM or hypertensive disorders, were excluded from the study. We compared the risk of future maternal outcomes (HTN and DM) according to the offspring's birthweight. Multivariate analyses were performed to estimate the hazard ratio (HR) for the future risk of HTN or DM.

RESULTS

A total of 64,037 women were included in the analysis. Of these, women who delivered very LGA babies (birthweight > 97th percentile) were at a higher risk of developing DM than those who delivered appropriate-for-gestational-age (AGA) babies (adjusted HR = 1.358 [1.068-1.727]), and women who delivered very SGA babies (birthweight < 3rd percentile) were at a higher risk of developing HTN than those who delivered AGA babies (adjusted HR = 1.431 [1.181-1.734]), even after adjusting for age, parity, gestational age at delivery, fetal sex, maternal BMI score, and a history of smoking.

CONCLUSION

These findings provide a novel support for the use of the offspring's birthweight as a predictor of future maternal diseases such as HTN and DM.

The impact of abnormal maternal body mass index during pregnancy on perinatal outcomes: a registry-based study from Qatar

OBJECTIVES

Abnormal body mass index (BMI) during pregnancy, a growing public health concern, increases maternal and neonatal complications. This study aimed to investigate the impact of abnormal BMI on perinatal outcomes compared to normal BMI.

METHODS

A total of 14,624 women having singleton births were categorized as underweight (BMI<18.5 kg/m2), overweight (25.0-29.9 kg/m2), obesity class I (30.0-34.9 kg/m2), obesity class II (35.0-39.9 kg/m2), and obesity class III (≥40.0 kg/m2) and compared to those with normal BMI (18.5-24.9 kg/m2). Outcomes included gestational diabetes (GDM), gestational hypertension (GHT), postpartum haemorrhage (PPH), cesarean delivery (CD), preterm birth (PTB), low birth weight (LBW), congenital anomalies and neonatal intensive care unit admission.

RESULTS

Women with increasing BMI had increasingly higher odds of developing specific adverse outcomes, the highest being in the class III obesity group (GDM-aOR 2.71, 95 % CI 2.25-3.27, p<0.001, GHT-aOR 5.32 95 % CI 3.49-8.11, p<0.001, CD-aOR 2.33 95 % CI 1.85-2.94, p<0.001, PPH-aOR 1.77 95 % CI 1.35-2.33, p<0.001). On the other hand, being underweight during pregnancy was associated with increased odds of PTB (aOR 2.09, 95 % CI 1.37-3.20, p=0.001), LBW (OR 1.88, 95 % CI 1.27-2.79, p=0.002) and congenital anomalies (aOR 2.52 95 % CI 1.12-5.64, p=0.025). Majority in the underweight category gained less than expected gestational weight gain during the pregnancy.

CONCLUSIONS

The findings of this study have important implications for the clinical management of pregnant women with abnormal BMI. Interventions to improve maternal and neonatal outcomes must focus on enhancing pre-pregnancy BMI and maintaining adequate gestational weight gain.

Effect of Particulate Matter 2.5 on Fetal Growth in Male and Preterm Infants through Oxidative Stress

Particulate matter 2.5 (PM2.5) levels are associated with adverse pregnancy outcomes. In this retrospective cohort study, we examined whether the concentration of indoor PM2.5 affected pregnancy outcomes. Additionally, we evaluated biomarkers of pregnancy-related complications caused by fine dust. We collected clinical information and data based on residential addresses from the Air Korea database to assess PM2.5 exposure levels. As a multicenter prospective cohort study, we measured the indoor PM2.5 concentration and inflammatory and oxidative stress markers. The PM2.5 concentration of the low-birth-weight (LBW) delivery group was 27.21 μg/m3, which was significantly higher than that of the normal-birth-weight (NBW) group (26.23 μg/m3) (p = 0.02). When the newborns were divided by sex, the PM2.5 concentration of the LBW group was 27.89 μg/m3 in male infants, which was significantly higher than that of the NBW group (26.26 μg/m3) (p = 0.01). In the prospective study, 8-hydroxy-2-deoxyguanosine significantly increased in the high-concentration group (113.55 ng/mL, compared with 92.20 ng/mL in the low-concentration group); in the high-concentration group, the rates of preterm birth (PTB) and small size for gestational age significantly increased (p < 0.01, p = 0.01). This study showed an association between PM2.5, oxidative stress, and fetal growth, with the PTB group being more vulnerable.

Pre-pregnancy blood pressure and pregnancy outcomes: a nationwide population-based study

Background

Hypertension has been known to increase the risk of obstetric complications. Recently, the American College of Cardiology endorsed lower thresholds for hypertension as systolic blood pressure of 130-139 mmHg or diastolic blood pressure 80-89 mmHg. However, there is a paucity of information regarding the impact of pre-pregnancy blood pressure on pregnancy outcomes. We aimed to evaluate the effect of pre-pregnancy blood pressure on maternal and neonatal complications.

Methods

In this nationwide, population based study, pregnant women without history of hypertension and pre-pregnancy blood pressure < 140/90 mmHg were enrolled. The primary outcome of composite morbidity was defined as any of the followings: preeclampsia, placental abruption, stillbirth, preterm birth, or low birth weight.

Results

A total of 375,305 pregnant women were included. After adjusting for covariates, the risk of composite morbidity was greater in those with stage I hypertension in comparison with the normotensive group (systolic blood pressure, odds ratio = 1.68, 95% CI: 1.59 – 1.78; diastolic blood pressure, odds ratio = 1.56, 95% CI: 1.42 – 1.72). There was a linear association between pre-pregnancy blood pressure and the primary outcome, with risk maximizing at newly defined stage I hypertension and with risk decreasing at lower blood pressure ranges.

Conclusions

‘The lower, the better’ phenomenon was still valid for both maternal and neonatal outcomes. Our results suggest that the recent changes in diagnostic thresholds for hypertension may also apply to pregnant women. Therefore, women with stage I hypertension prior to pregnancy should be carefully observed for adverse outcomes.