ABSTRACT In China, a range of anemia prevention and treatment measures have been developed and implemented in recent decades. These measures provide a regulatory basis for implementing standardized maternal anemia prevention and treatment services in China. However, little is known about the adoption of these interventions by health professionals, the capacity of health facilities to screen for iron deficiency and anemia, or the level of compliance among pregnant and lactating women (PLW). Thus, this study explored the alignment between maternal anemia prevention and control services provided and generated evidence for potential policy and program revisions and updates. A cross‐sectional survey was conducted between November 2019 and January 2020. A total of 11 counties from 6 provinces across eastern, central and western regions of China were selected for the survey. In the surveyed sites, a total of 42 health institutions were enrolled in the survey, and a total of 201 health providers and 1714 PLW were enrolled in the suervey and completed the questionnaires. The results of this study showed that iron supplements containing 30 and 60 mg of iron were available in one third of the health facilities surveyed. All obstetricians reported ordering the Hb test for pregnant women receiving antenatal care (ANC) services, and 87.6% ordered the ferritin test. The proportion of obstetricians who ordered the ferritin test at the township level facilities (79.4%) was significantly lower than that at the provincial (100%), prefectural (87.5%) and county (87.1%) level facilities (p < 0.05). Around 89.6% and 90.5% of obstetricians prescribed iron to pregnant women when they were diagnosed with anemia and ID, respectively. 41.3% of obstetricians advised women to take preventive iron throughout their pregnancy. The proportion of obstetricians from township level hospitals that advised women to take preventative iron throughout their pregnancy (61.5%) was significantly lower than that from provincial facilities (23.5%) (p < 0.05). A total of 95.2% and 47.9% of PLW reported receiving the Hb test and the serum ferritin test during their pregnancy, respectively. There are some barriers and bottlenecks in the effective implementation of anemia intervention measures for pregnant women in China. Therefore, to achieve international and national targets on further reducing maternal anemia prevalence, comprehensive actions need to be taken.

What is already known about this topic?:Low fertility rates have become the most important risk affecting the balanced development of the population in China. What is added by this report?:About 80.0% of childless women had fertility intentions, 31.9% of women with one child and 11.3% of women with two children intended to have a second and third child, respectively. Women with one child who had an agricultural Hukou, were younger than 30 years old, were remarried, and had received a deduction or reimbursement for childbirth expenses during their first delivery were more willing to have a second child. Women with two children who had an agricultural Hukou and a upper-middle personal income, were self-employed, and had two daughters were more willing to have a third child. What are the implications for public health practice?:In China, women's willingness to have more children is not optimistic. To increase their desire for more children, creating a more favorable fertility environment for reproductive-age women and providing more preferential fertility policies for pregnant women will be necessary.

What is already known about this topic?:In recent years, there has been a significant increase in the proportion of women of advanced maternal age (AMA), accompanied by a rise in adverse pregnancy outcomes in certain regions of China. What is added by this report?:From 2016 to 2022, there was an observed increase in the proportion of AMA, educational levels, and incidences of preterm birth and low birth weight (LBW) in both primiparous and multiparous women. Concurrently, there was a declining trend in the rate of cesarean deliveries and the incidence of macrosomia among multiparous women. What are the implications for public health practice?:In addition to focusing on health management for AMA individuals, proactive steps should be undertaken to enhance the quality of medical services and promote childbirth at optimal ages, thereby reducing the incidence of adverse pregnancy outcomes.

Antenatal care (ANC) plays a crucial role in ensuring maternal and child safety and reducing adverse delivery outcomes. This study aimed to analyze the association between the quality of ANC and the occurrence of preterm birth and low birth weight in a sample of the population from 16 regions in 8 provinces in China. Data from all closed cases of pregnant women and newborns reported in the Maternal and Child Health Monitoring System from January 1, 2018, to December 31, 2018, in 16 monitoring regions across 8 provinces in China were collected and included in the analysis, resulting in a total of 49,084 pregnant women and 49,026 newborns. The mean number of ANC visits was 6.95 ± 3.45. By percentage, 78.79

Abstract Objective To assess the prevalence of anemia among pregnant women across their entire pregnancy and the factors affecting it in the monitoring areas. Methods A total of 108,351 pregnant women who received antenatal health care and delivered from January 1, 2016 to December 31, 2020 in 15 monitoring counties of 8 provinces in the Maternal and Newborn Health Monitoring Program (MNHMP) of National Center for Women and Children’s Health (NCWCH) were selected as the study subjects. The anemia status among the subjects across their first, second and third trimester of pregnancy and the influencing factors were analyzed. Results From 2016 to 2020, the prevalence of anemia at any stage during pregnancy in the monitoring areas was 43.59%. The prevalence of anemia among pregnant women across all three trimesters was 3.95%, and the prevalence of mild and moderate-to-severe anemia was 1.04% and 2.90%, respectively. Protective factors were living in the northern area (OR = 0.395) and being a member of an ethnic minority (OR = 0.632). The risk factors were residing in rural areas (OR = 1.207), with no more than junior high school education (OR = 1.203), having ≥ 3 gravidities (OR = 1.195) and multiple fetuses (OR = 1.478). Conclusions Although the prevalence of anemia among pregnant women across all trimesters in the monitoring area was low, the severity of anemia was high. Since the prevalence of anemia among pregnant women across their entire pregnancy in the monitoring area is affected by many different factors, more attention should be paid to pregnant women living in rural areas, with low literacy, ≥ 3 gravidities and multiple fetuses for early intervention.

Objectives: To analyze the dose-response relationship between maternal Blood pressure (BP) in different trimesters and preterm birth(PTB). Design: A monitoring data (cohort) study. Setting and population: All single-fetus pregnant women who delivered during 2014-2018 in 13 counties of 6 provinces in China. Methods: Through the Maternal and Newborn Health Monitoring System in China, the monitoring data were obtained, including essential maternal information, all previous antenatal examination and pregnancy outcomes of all pregnant women lived in the monitoring area. Main outcome measures: PTB(delivered between 28 and 37 weeks); Hypertensive disorders of pregnancy(HDP)(SBP ≥140mmHg and/or DBP ≥90mmHg once); Hypotension (SBP<90mmHg and/or DBP<60mmHg once). Results: A total of 212,941 single-fetus pregnant women were included. The overall incidences of HDP and PTB were 7.07% and 4.04% respectively. Taking the group of normal BP as reference, the odds ratios(OR) of PTB for the groups of HDP in 1st, 2nd and 3rd trimesters was 3.23, 2.70 and 2.05 respectively(P<0.001). Hypotension in 3rd trimester was associated with a 1.5-fold higher risk of PTB(P<0.001). ORs of PTB had a nonlinearly U-shaped association with SBP and DBP in 1st, 2nd and 3rd trimesters. Conclusions: The risks of PTB varied among pregnant women with the same BP in different trimesters. An increase of BP within the normal range during pregnancy could prevent PTB. Hypotension in 3rd trimester was associated with a high risk of PTB. Funding: Funded by the government of China (No.1311300011301). Key words: Maternal blood pressure, preterm birth, dose-response relationship, restricted cubic spline, hypertensive disorders of pregnancy, hypotension

BACKGROUND:Heat exposure during pregnancy can increase the risk of preterm birth (PTB) through a range of potential mechanisms including pregnancy complications, hormone secretion and infections. However, current research mainly focuses on the effect of heat exposure on pathophysiological pathways of pregnant women, but ignore that maternal heat exposure can also cause physiological changes to the fetus, which will affect the risk of PTB. OBJECTIVE:In this study, we aimed to explore the mediating role of fetal heart rate (FHR) in the relationship between maternal heat exposure and PTB incidence. METHODS:We assigned heat exposure to a multi-center birth cohort in China during 2015-2018, which included all 162,407 singleton live births with several times FHR measurements during the second and third trimesters. We examined the associations between heat exposure, FHR and PTB in the entire pregnancy, each trimester and the last gestational month. The inverse odds ratio-weighted approach applied to the Cox regression was used to identify the mediation effect of heat exposure on PTB and its clinical subtypes via FHR. FINDINGS:Exposure to heat significantly increased the risk of PTB during the third trimester and the entire pregnancy, hazard ratios and 95 % CIs were 1.266 (1.161, 1.379) and 1.328 (1.218, 1.447). Heat exposure during the third trimester and entire pregnancy increased FHR in the third trimester by 0.24 bpm and 0.14 bpm. The proportion of heat exposure mediated by FHR elevation on PTB and its subtype ranged from 3.68 % to 24.06 %, with the significant mediation effect found for both medically indicated PTB and spontaneous PTB. CONCLUSIONS:This study suggests that heat exposure during pregnancy has an important impact on fetal health, and FHR, as a surrogate marker of fetal physiology, may mediate the increased risk of PTB caused by extreme heat. Monitoring and managing physiological changes in the fetus would constitute a promising avenue to reduce adverse birth outcomes associated with maternal heat exposure.

Heat exposure is associated with an increased risk of preterm birth (PTB), with previous work suggesting that maternal blood pressure may play a role in these associations. Here we conducted a cohort study of 197,080 singleton live births across 8 provinces in China from 2015 to 2018. The study first estimated the associations between heat exposure, maternal hypertension and clinical subtypes of PTB, and then quantified the role of maternal hypertension in heat and PTB using mediation analyses. We show that heat exposure (>85th, 90th and 95th percentiles of local temperature distributions) spanning from conception to the 20th gestational week was associated with a 15-21% increase in PTB, and a 20-22% increase in medically indicated PTB. Heat exposure is likely to increase the risk of maternal hypertension and elevated blood pressure. Maternal hypertension mediated 15.7% and 33.9% of the effects of heat exposure (>90th percentile) on PTB and medically indicated PTB, respectively. Based on this large-population study, we found that exposure to heat in early pregnancy can increase the risk of maternal hypertension, thereby affecting the incidence of PTB.

What is already known about this topic?:Cervical cancer is a significant public health problem with approximately 570,000 cases and 311,000 deaths occurring in 2018 globally. It is imperative to raise awareness of cervical cancer and human papillomavirus (HPV).What is added by this report?:Compared to previous studies, this is one of the largest cross-sectional studies of cervical cancer and HPV in Chinese adult females in recent years. We found that knowledge level of cervical cancer and HPV vaccine was still inadequate among women aged 20-45 years old, and the willingness to receive HPV vaccination was highly associated with knowledge level.What are the implications for public health practice?:Intervention programs should aim to improve awareness and knowledge about cervical cancer and HPV vaccines, primarily focusing on women of lower socio-economic status.

This study analyzed the anemia status and change trend of 219 835 pregnant women in eight provinces from 2016 to 2020 in the Maternal and Newborn Health Monitoring Program(MNHMP). The results showed that from 2016 to 2020, the anemia rate of pregnant women in eight provinces was 41.27%, and the rates of mild, moderate and severe anemia were 28.56%, 12.59% and 0.12% respectively; the anemia rates in eastern, central and western regions were 41.87%, 36.09% and 44.63% respectively, and the anemia rates in urban and rural areas were 39.87% and 42.23%. From 2016 to 2020, the anemia rate of pregnant women decreased from 44.93% to 38.22%, with an average annual decline of 3.86% (95% CI:-5.84%, -1.85%). The anemia rate among pregnant women of the eastern region (AAPC=-6.16%, 95% CI:-9.79%, -2.38%) fell faster than that among pregnant women of the central region (AAPC=0.71%, 95% CI:-6.59%, 8.57%) and western region (AAPC=-1.53%, 95% CI:-5.19%, 2.28%). From 2016 to 2020, the moderate anemia rate in pregnant women decreased from 14.98% to 10.74%, with an average annual decline of 8.72% (95% CI:-12.90%, -4.34%), with a statistically significant difference ( P<0.05); AAPC for mild and severe anemia in pregnant women was 1.56% (95% CI: 3.44%, 0.36%) and 18.86% (95% CI: 39.88%, 9.52%), respectively, without statistically significant difference ( P>0.05).

Background Heat events increase the risk of preterm birth (PTB), and identifying the risk-related event thresholds contributes to developing early warning system for pregnant women and guiding their public health response. However, the event thresholds that cause the risk remain unclear. We aimed to investigate the effects of heat events defined with different intensities and durations on PTB throughout pregnancy, and to determine thresholds for the high-risk heat events. Methods Using a population-based birth cohort data, we included 210,798 singleton live births in eight provinces in China during 2014-2018. Daily meteorological variables and inverse distance weighted methods were used to estimate exposures at a resolution of 1 km x 1 km. A series of cut off temperature intensities (50th-97.5th percentiles, or 18 degrees C-35 degrees C) and durations (at least 1, 2, 3, 4 or 5 consecutive days) were used to define the heat events. Cox regression models were used to estimate the effects of heat events on PTB in various gestational weeks during the entire pregnancy, and event thresholds were determined by calculating population attributable fractions. Findings The hazard ratios of heat event exposure on PTB ranged from 1.07 (95% CI: 1.00, 1.13) to 1.43 (1.15, 1.77). Adverse effects of heat event exposure were prominently detected in gestational week 1-4, week 21-32 and the four weeks before delivery. The heat event thresholds were determined to be daily maximum temperature at the 90th percentile of the distribution or 30 degrees C lasting for at least one day. If pregnant women were able to avoid the heat exposures from the early warning systems triggered by these thresholds, approximately 15% or 17% of the number of total PTB cases could have been avoided. Interpretation Exposure to heat event can increase the risk of PTB when thermal event exceeds a specific intensity and duration threshold, particularly in the first four gestational weeks, and between week 21 and the last four weeks. This study provides compelling evidence for the development of heat-health early warning systems for pregnant women that could substantially mitigate the risk of PTB.

Abstract Background Allergic diseases are highly prevalent in the women of childbearing age. As we know, the immune system could change when pregnancy, which may affect the course of allergic diseases. Meanwhile, they also can affect the course and outcome of pregnancy. The data on incidence of allergies during pregnancy is lacking and conducting clinical trials in pregnant women was limited, therefore, we observed a prebirth cohort to supplement the relevant data and strengthen concerned research conductions. Objective We aim to obtain the incidence of allergies in urban pregnancy and explore the relevant factors of allergic diseases in urban pregnancy. Methods We design a multicenter and prospective cohort in 20 institutions above municipal level which were eligible according to the study design from 14 provinces covering all-side of China. This cohort was conducted from 13+6 weeks of gestation to 12 months postpartum and in our study, we chose the prenatal part to analyze. The outcome was developing allergies during pregnancy, which were diagnosed by clinicians according to the uniform criterion from National Health Commission. All the data was collected by electronic questionnaires through tablet computers. Results The incidence of allergic diseases in urban pregnant women was 21.0% (95%CI 20.0% ~ 22.0%). From social demography data, the history of allergies of pregnant women and their parents had statistical significance(p < 0.01); For exposure to living or working environment, house decoration for less than half a year, exposure to plush toys, disinfectants, insecticides, antihistamines, glucocorticoids, antipyretic analgesics, tocolytic agent and probiotics had statistical significance (all p < 0.05); For psychological status, self-rated depression and anxiety had statistical significance (p = 0.026;p = 0.006). Conclusion The incidence of allergic diseases in urban pregnant women was similar to the former study and kept a medium–high level. The history of allergies of pregnant women and their parents, house decoration time, exposure to plush toys, disinfectants, insecticides, antihistamines, glucocorticoids, antipyretic analgesics, tocolytic agents, probiotics, self-rated depression, and anxiety were relevant factors of allergic diseases during pregnancy.

ObjectiveTo examine revenue situation of maternal and child health (MCH) institutions at all administrative levels in China and to provide evidences for governmental decision-making. MethodsThe data on revenue of 3 094 MCH institutions in 31 provincial level administrative regions across the mainland of China in 2020 were collected through the national monitoring and direct reporting system for MCH institutions; other relevant information were also extracted from China Health Statistical Yearbook of 2020. The revenue and financial subsidy income of the MCH institutions in 2020 were analyzed and compared. ResultsThe entire financial subsidy income of 63.09 billion yuan RMB accounted for 28.7% of the total revenue of MCH institutions in 2020 and the proportion was much lower than that for other public welfare institutions including the centers for disease control and prevention (73.6%) and health supervision institutes (91.5%). There were obvious differences in the median values (million yuan) of the revenue for the MCH institutions in various regions, at different administrative levels, and belong to different financial management categories, with significant higher medians for the MCH institutions in the eastern region (25.81), at provincial level (712.17) and under the combined financial management for public welfare of first- and second-category (70.33) compared to other MCH institutions. ConclusionAt present, unreasonable composition, single source, and insufficient financial support are main problems for revenue of MCH institutions in China, suggesting that guarantee mechanism and policy flexibility relevant to revenue of MCH institutions need to be improved urgently.

孕产妇贫血是导致孕产妇死亡和不良妊娠结局的关键因素,目前在全球仍处于较高的流行水平.为降低孕产妇贫血患病率,提高母儿健康水平,各国政府先后出台了多项政策、策略措施,并提出了防控目标.但由于现有国内外很多研究中孕产妇贫血的诊断标准、研究对象等存在差异,导致孕产妇贫血患病率的范围较大,从而对我国制定政策及对现有策略措施的评价带来困扰.本研究对孕产妇贫血的诊断和流行状况进行综述,旨在为后续研究提供参考和新思路.

Background: Maternal gestational PM2.5 exposure was associated with small for gestational age (SGA). Identifying potential mediating factors may help design preventive strategies to reduce this risk. Objective: This study aimed to explore the roles of maternal blood pressure and hemoglobin may play in the PM2.5 exposure and SGA relationship among 117,162 births in 16 counties across China during 2014-2018. Methods: Daily PM2.5 concentration was collected from China National Environmental Monitoring Center. Ac-cording to maternal residency during pregnancy, the PM2.5 exposure for each trimester and the whole pregnancy was assessed using an inverse-distance weighting approach. Repeated measurements of maternal blood pressure and hemoglobin during pregnancy were collected for each woman. We estimated the total effect of gestational PM2.5 exposure on SGA, and further tested the mediation effects of maternal blood pressure and hemoglobin concentration during pregnancy. Results: Of 117,162 included mother-infant pairs, 11,361 (9.7 %) were SGA. The odds ratios of SGA associated with PM(2.5 )exposure (per 10 mu g/m(3) increase) in the second trimester and the whole pregnancy were 1.023 (95 % CI: 1.009, 1.037) and 1.024 (1.001, 1.048), respectively. We identified the independent mediating effect of blood pressure and hemoglobin in the second and third trimesters, with the proportion of mediation ranging from 1.64 % to 5.78 % and 2.40 % to 8.70 %, respectively. When considering the mediators jointly, we found a stronger mediating effect with a proportion of mediation ranging from 3.93 % to 13.69 %. Discussion: Increases in maternal blood pressure and hemoglobin in the second and third trimesters can inde-pendently and jointly mediate the effects of gestational PM2.5 exposure on SGA. Monitoring and managing maternal blood pressure and hemoglobin during prenatal care may constitute a promising avenue to reducing SGA risk associated with gestational PM2.5 exposure.

BACKGROUND:Primary human papillomavirus (HPV) screening is recommended for the detection of cervical intraepithelial neoplasia (CIN) in the general population; however, the triage for HPV-positive women remains a challenge. This study aimed to evaluate the age-specific effectiveness of primary HPV screening versus primary cytology screening for identifying optimal strategies for women of different ages. METHODS:The dataset of the prevalence round screening was derived from the National Cervical Cancer Screening Program in China. Primary cervical screening protocols included cytology only, HPV testing with cytology triage, and HPV testing with HPV-16/18 genotyping plus cytology triage. The primary outcomes were age-specific detection rate, colposcopy referral rate and positive predictive value (PPV) for CIN2+. Multivariate Poisson regression was used to evaluate the relative effectiveness of HPV testing and cytology according to age groups. The I2 statistic with a random-effect model was used to test the heterogeneity in relative effectiveness of HPV testing versus cytology between age groups. RESULTS:This study included 1,160,981 women. HPV testing with HPV-16/18 genotyping plus cytology triage significantly increased the CIN2+ detection by 36% (rate ratio [RR]: 1.36, 95% confidential interval [CI] 1.21-1.54) for women aged 35-44 years and by 34% (RR: 1.34, 95% CI 1.20-1.51) for women aged 45-54 years compared with cytology only. HPV testing with cytology triage had similar CIN2+ detection rate compared with cytology only. The PPVs were substantially increased for both HPV testing groups. Among women aged 55-64 years old, HPV testing with HPV-16/18 genotyping plus cytology triage increased the colposcopy referral rate by 19% (RR 1.19, 95% CI 1.10-1.29) compared with cytology only, but did not increase the CIN2+ detection (1.09, 0.91-1.30). The effectiveness of HPV testing with cytology triage did not change in older women. The between-age-group heterogeneity in the effectiveness was statistically significant for HPV testing with HPV-16/18 genotyping plus cytology triage versus cytology only. CONCLUSIONS:Our results suggested that the effectiveness of primary HPV screening with different triage strategies differed among age groups. HPV testing with HPV-16/18 genotyping plus cytology triage could be used for women aged 35-54 years to detect more lesions, and HPV testing with cytology triage could balance the CIN2+ detection and the number of colposcopies for women aged 55-64 years. Longitudinal data including both prevalence and incidence screening rounds are warranted to assess age-specific triage strategies.

Objective This study aims to examine the association of menopausal status and symptoms with depressive symptoms. Methods A community-based cross-sectional survey recruited 6745 women aged 40-55 years in the eastern, central and western regions of China in 2018. Menopausal status was categorized into reproductive stage, perimenopause or postmenopause according to the Stages of Reproductive Aging Workshop classification. Menopausal symptoms were determined by the modified Kupperman Menopausal Index and classified as none (total score < 15), mild (15 <= total score <= 24) or moderate to severe (total score >= 25). Logistic regression models were used to examine the associations of menopausal status and symptoms with depressive symptoms assessed by the Patient Health Questionnaire-9. Results The prevalence of depressive symptoms among women in the reproductive stage, perimenopause and postmenopause was 15.4%, 23.9% and 22.8%, respectively. After multivariable adjustment, perimenopause (odds ratio [OR] = 1.21, 95% confidence interval [CI]: 1.01-1.47) and postmenopause (OR = 1.28, 95% CI: 1.04-1.58) were associated with higher risk for depressive symptoms than during the reproductive stage. Mild (OR = 5.55, 95% CI: 4.68-6.59) and moderate-to-severe (OR = 14.77, 95% CI: 10.94-19.94) menopausal symptoms were associated with increased likelihood of depressive symptoms compared to the group reporting no menopausal symptoms. Conclusions Menopausal status and symptoms were independently associated with the risk of depressive symptoms in middle-aged Chinese women.

Background: Heatwave has been associated with higher risk of preterm birth (PTB) in numerous studies, but the potential mediators are unclear. Previous studies have suggested that maternal blood pressure (BP) may have a role in the associations between heatwave exposure and PTB.Methods: We conducted a multi-center birth cohort encompassed nearly all singleton live births from 16 counties in 8 provinces across China during 2015-2018. In total, 197 080 singleton pregnancies who measured BP after 20 weeks’ gestation were included. Based on the BP variation throughout pregnancy,we defined mediator as maternal hypertension and a rise in BP during middle and late pregnancy. Nine types of heatwaves were defined with percentiles of year-round daily maximum temperature and durations. We examined the associations between heatwave, mediators and PTB using logistic models. Mediation analyses were conducted to to clarify the role of maternal hypertension and rise in BP of heatwave exposure and PTB.Results: Depending on the all heatwave definition used, the odds ratios (ORs) and 95%CI of PTB associated with heatwave exposure during the entire 1-20 weeks ranged from 1.082 (1.025, 1.142) to 1.363 (1.292, 1.439). Heatwave exposure was also likely to increase the risk of maternal hypertension, and cause the rise in BP. The mediated proportion of different heatwaves on PTB by changing maternal hypertension could be up to 5%, while by rise in SBP or DBP could be as much as 13% and 11%. The mediated effect varied across different gestational periods, with stronger effects during 9-12 weeks. For the heatwave definitions, a higher mediation proportion was found in moderate heat compared with more extreme heat.Conclusions: Our findings suggest that maternal heatwave exposure affect the PTB mediated by increasing a risk of maternal hypertension and causing rise in BP during the middle and late pregnancy.

What is already known about this topic? Several studies have reported that maternal antenatal intention to breastfeed is a strong predictor of actual breastfeeding duration. However, little research has investigated whether maternal postpartum intention also extends breastfeeding duration. What is added by this report? Maternal postpartum intention to breastfeed was a protective factor for extending actual breastfeeding duration after controlling potential confounders. What are the implications for public health practice? It is crucial to address and promote intrinsic and extrinsic factors that influence a mother’s intention to breastfeed after delivery, thereby extending the actual breastfeeding duration.

Background Social media has become an important source of health information during the COVID-19 pandemic. Very little is known about the potential mental impact of social media use on pregnant women. Objective This study aims to examine the association between using social media for health information and risk perception for COVID-19, worry due to COVID-19, and depression among pregnant women in China. Methods A total of 4580 pregnant women were recruited from various provinces of China. The participants completed a cross-sectional, web-based survey in March 2020. Results More than one-third (1794/4580, 39.2%) of the participants reported always using social media for obtaining health information. Results of structural equation modeling showed that the frequency of social media use for health information was positively associated with perceived susceptibility (β=.05; P<.001) and perceived severity (β=.12; P<.001) of COVID-19, which, in turn, were positively associated with worry due to COVID-19 (β=.19 and β=.72, respectively; P<.001). Perceived susceptibility (β=.09; P<.001), perceived severity (β=.08; P<.001), and worry due to COVID-19 (β=.15; P<.001) all had a positive association with depression. Bootstrapping analysis showed that the indirect effects of frequency of social media use for health information on both worry due to COVID-19 (β=.09, 95% CI 0.07-0.12) and depression (β=.05, 95% CI 0.02-0.07) were statistically significant. Conclusions This study provides empirical evidence on how social media use for health information might have a negative impact on the mental health of pregnant women. Interventions are needed to equip this population with the skills to use social media properly and with caution.