A Study of the Fluid Intake, Hydration Status, and Health Effects among Pregnant Women in Their Second Trimester in China: A Cross-Sectional Study

Abstract

The fluid intake and hydration status during pregnancy may influence the health outcomes of both the mother and the fetus. However, there are few studies related to this. The aim of the present study was to investigate fluid intake behaviors among pregnant women in their second trimester, to evaluate their hydration status and pregnancy complications, and to further explore the association of fluid intake and the amniotic fluid index (AFI). Participants’ total fluid intake (TFI) levels were determined using a 7-day 24 h fluid intake questionnaire. The levels of water intake from food were not recorded or measured. Morning urine samples were collected, and both urine osmolality levels and urine specific gravity (USG) were tested to evaluate their hydration status. Fasting blood samples were also collected and measured for osmolality and complete blood count (CBC). A total of 324 participants completed the study. They were divided into four groups based on quartiles of TFI, including participants with lower (LFI1 and LFI2) and higher (HFI1 and HFI2) fluid intake levels. The median TFI was 1485 mL, and the median values of the four groups with different TFI levels were 1348, 1449, 1530, and 1609 mL, respectively. Only 3.4% of the participants attained the recommended value following an adequate water intake (1.7 L) level for pregnant women in China. Plain water was the main TFI resource (78.8~100.00%), and differences in the plain water intake levels among the four groups were evident (χ2 = 222.027, p < 0.05). The urine osmolality decreased sequentially with increasing TFI values from the LFI1 to HFI2 group, and significant differences in the urine osmolality levels among the four groups were evident (p < 0.05). Meanwhile, the percentage of dehydrated participants decreased from 26.8% in the LFI1 group to 0.0% in the HFI2 group (χ2 = 131.241, p < 0.05). Participants with higher TFI values had higher AFI values (χ2 = 58.386, all p < 0.05), and moderate-intensity correlations were found between TFI and urine osmolality, hydration status, and AFI (all p < 0.05). A large proportion of the participants had insufficient TFIs during the second trimester of pregnancy, and a proportion of the participants were dehydrated. The preliminary analysis showed that the AFI was correlated with the TFI during the second trimester of pregnancy. A sufficient TFI is necessary for pregnant women to improve their hydration status and may have effects on their health. The results can provide appropriate scientific references for the development of beneficial recommendations concerning adequate water intake levels for pregnant women in China.

Every sip counts: Understanding hydration behaviors and user-acceptability of digital tools to promote adequate intake during early and late pregnancy

“…Our findings also highlight the need for education and increased knowledge prior to conception and early in the pregnancy to continue healthy hydration behaviors throughout the entire pregnancy and into postpartum as many women were not meeting the hydration recommendations. This gap may increase the risks for adverse pregnancy and postpartum outcomes (i.e., excessive gestational weight gain, hypertensive disorders, preterm births, and gestational diabetes [ 32 ]), which increases the risk for maternal mortality. Thus, there is a need for strategies to promote knowledge and adequate intake recommendations and strategies during pregnancy.…”

“…There were several strengths of this study, one of which was that it was one of the first to understand pregnant women’s thoughts, beliefs, preferences, and needs regarding hydration, hydration behaviors, and the use of digital tools overall but also based on trimester. Previous research has focused on associations of hydration levels on pregnancy outcomes [ 10 , 35 ], measuring hydration levels during pregnancy [ 11 , 32 ] and intravenous hydration [ 36 ], while this study focused on understanding how researchers can promote hydration behaviors during pregnancy. These findings highlight the major knowledge and research gaps when it comes to hydration behaviors during pregnancy.…”

Water Intake and Hydration Status among Pregnant Women in the Second Trimester in China: A Three-Day Metabolic Trial

“…Previous studies on water intake among pregnant women in Mexico [ 22 ], Indonesia [ 23 ], and Hainan [ 21 ] only evaluated TFI and did not consider water from food. In fact, the water in food plays an important role in replenishing the body’s water.…”

“…The study conducted by Erica Perrier et al in adults [ 28 ] also confirmed that there was a positive correlation between fluid intake and 24 h urine volume ( r = from 0.74 to 0.79), while there was a negative correlation between fluid intake and 24 h urine osmolality, USG, as well as the concentrations of sodium, potassium, phosphorus, creatinine, urea, and uric acid, respectively ( r = from −0.49 to −0.73). In the latest study of pregnant women in Haikou [ 21 ], it was also found that fluid intake was negatively correlated with morning urine osmolality and USG in pregnant women in Haikou ( r = from −0.397 to −0.111). However, the correlation coefficient was lower than the results in our study, which may be attributed to the morning urine collected in this study, rather than the 24 h urine.…”

“…Although this method improved the accuracy of the data, it was still not comprehensive as it did not consider physical activity and hydration biomarkers. The latest research in 2023 showed that the average water intake of pregnant women in Haikou was 1485 mL/day [ 21 ]. Unlike previous two studies, this study used a 7-day 24 h fluid intake questionnaire and evaluate hydration biomarkers in pregnant women’s morning urine and fasting venous blood.…”