Pregnancy and postpartum periods represent critical life stages, predisposing women to obesity development. Excessive gestational weight gain (GWG) is a known predictor of postpartum weight retention [1, 2]. Globally, nearly 39 million pregnancies per year are complicated by maternal obesity, with some countries reporting prevalence rates of overweight and obesity in pregnancy exceeding 60% (South Africa 64%, Mexico 65%, USA 55%–63%) [3, 4]. In England, overweight and obesity prevalence among women aged 16–24 years is 35%, rising to 61% among those aged 35–44 years, emphasizing the potential risk among women of reproductive age [5].

According to the Pregnancy Risk Assessment Monitoring System, the prevalence of obesity prior to conception in the United States of America (USA) has increased by 69.3% over the past decade, with rates as high as 22% [6, 7]. In China, a national nutrition survey conducted in 2002 indicated that the prevalence of overweight and obesity among women aged 18–44 was 21.8% and 6.1%, respectively [8], with an increasing trend observed particularly among women of childbearing age [9]. In the United Kingdom (UK), approximately 1 in 1000 births involve women with a body mass index (BMI) $>$50 kg/m${}^2$ [10], while Australia reports a super-obesity prevalence of 2.1 per 1000 births [11, 12].

In comparison to women of normal weight, those who were diagnosed as obese or overweight at the beginning of pregnancy, are two to three times more likely to exceed the Institute of Medicine’s GWG recommendations and are less likely to regain their prepregnancy weight [13]. A higher risk of different unfavorable pregnancy outcomes in subsequent pregnancies is linked to postpartum weight retention, or an increase in BMI between pregnancies [14]. The obesity pandemic among women is fueled in part by excessive prenatal weight gain and postpartum weight retention [2, 15, 16, 17]. Research has indicated that GWG is linked to the risk of pregnancy complications, maternal postpartum weight retention, and obesity in offspring [18]. While GWG is necessary for ensuring the health of the fetus, excessive weight gain during pregnancy has been associated with unfavorable outcomes [19, 20, 21, 22, 23, 24].

The nutritional status of expectant mothers is widely regarded as a valuable prognostic indicator for perinatal and long-term adverse outcomes in both the infant and the mother [25]. Preexisting overweight or obesity before conception constitutes a significant risk factor for gestational diabetes mellitus, hypertensive syndrome, and fetal growth disorders [26, 27]. Postpartum weight retention is also more common among mothers with excessive weight gain. In terms of fetal and neonatal risks, excessive weight gain can lead to macrosomia, neonatal hypoglycemia, and an elevated risk of childhood obesity for the offspring [28, 29, 30, 31, 32, 33]. Additionally, excessive weight gain is associated with an increased risk of developing gestational diabetes mellitus [34], gestational hypertension [35], preeclampsia [30], and the need for cesarean sections [36].

This study aimed to examine the effectiveness of pregnancy and postpartum self-monitoring (SM) on postpartum weight retention in patients with obesity during pregnancy. We hypothesized that women receiving higher-term SM activities would retain less weight during postpartum than women receiving fewer-term independent SM activities, or no independent SM (no-SM, NSM) activities.

The baseline characteristics of the 448 participants revealed a mean age of 32.6 years (standard deviation (SD): 12.1) at recruitment. The average BMI of the cohort was 34.8 kg/m${}^2$ (SD = 6.4) in prepregnancy. For different time points, the mean prepregnancy weight was 86.6 kg (SD: 18.5), the mean baseline weight was 89.2 kg (SD: 16.9), and the mean weight at delivery was 103.8 kg (SD: 18.7). In terms of family income, 28.8% earned less than $\$$20,000, 15.0% had income between $\$$20,000 and $\$$40,000, 18.5% had income between $\$$40,000 and $\$$60,000, and 36.4% had income higher than $\$$60,000. A portion (38.2%) held a lower or 12th-grade education or were high school graduates, while 61.8% had a better educational background, including 1 to 3 years of college or higher education, as displayed in Table 1.

Table 2 and Fig. 2 illustrate the changes in weight from prepregnancy, baseline, and delivery room BMI to 3, 6, and 12 months postpartum. The results showed an increase in weight from prepregnancy to delivery, followed by a rapid decline from delivery to 3 months postpartum. However, the weight began to gradually rebound after 3 months postpartum, with a significant SM effect observed at different time points (p 0.001). Specifically, from prepregnancy to 3 months postpartum, SM participants retained less weight than the NSM group participants (1.1 kg vs. 5.9 kg). At 12 months postpartum, the SM effect remained slightly significant, with the SM group retaining 2.4 kg less weight than the NSM group (95% CI: –4.5$\sim$–0.3).

Fig. 2.

Weight at different time points. SM, self-monitoring; NSM, no-self-monitoring. Prepregnancy: before pregnancy; Baseline: $\le$18 weeks’ gestation; 0 month: delivery room; 3, 6, 12 months: 3rd, 6th, and 12th month postpartum.

Compared to NSM participants, the SM group had 2.5 times higher odds (95% CI: 1.2–4.8) of experiencing no weight retention at 3 months postpartum from their prepregnancy weight. And the SM group had 3.9 times higher odds (95% CI: 2.2–7.8) of experiencing no weight retention at 3 months postpartum from baseline. However, at 6 months postpartum, both groups showed similar trends in weight retention outcomes. In terms of the percentage of participants who retained $\ge$5% of weight from prepregnancy, SM participants had lower odds than the NSM group (3 months: 0.3 (0.1–0.4); 6 months: 0.3 (0.2–0.6); 12 months: 0.3 (0.3–0.7)) (Table 3). In participants with adequate (5–9 kg) or excessive ($>$9 kg) GWG, the participants with excessive GWG had higher postpartum weight retention, 58.9% (112/190) of participants with excessive GWG retained $\ge$5% of weight, and 31.2% (58/186) of participants with adequate GWG had records of retained $\ge$5% of weight.

Table 4 presents the associations between independent SM and delivery methods. Compared with NSM group, the participants in SM group report more vaginal delivery (57.2% vs. 31.6%) and less caesarean section deliveries (42.8% vs. 68.4%) from delivery room (p = 0.046). Regarding neonatal outcome, both survival (94.0% vs. 93.5%) and death (6.0% vs. 6.5%) were evaluated, and there are no significant differences observed between the two groups (p = 0.144). In participants with adequate or excessive GWG, there are no significant differences observed between the groups (p = 0.064).

This study aimed to investigate the effectiveness of pregnancy and postpartum SM interventions on postpartum weight retention, among women with obesity during pregnancy. The results support our hypothesis that women receiving higher-term independent SM activities retain less weight during postpartum compared to those receiving fewer, or no independent SM activities.

Our findings revealed a significant reduction in weight retention among women in the SM group compared to the NSM group. The intervention participants experienced less weight retention at 3 months postpartum and maintained this advantage up to 12 months postpartum. These results align with previous studies demonstrating the benefits of independent SM in weight management during, and after pregnancy [38, 39, 40]. Our study extends these findings by specifically targeting women with obesity during pregnancy, who are at higher risk for adverse pregnancy outcomes and long-term obesity development.

We also observed that SM participants had higher odds of experiencing no weight retention at 3 months postpartum from their prepregnancy weight or baseline weight, as well as lower odds of retaining $\ge$5% of their prepregnancy weight after delivery. However, the advantage of SM participants having no weight retention was no longer significant at 6 months postpartum. This finding suggests the importance of continued independent SM and support during the postpartum period in order to maintain weight management benefits. Further research could explore the optimal duration and intensity of independent SM interventions for sustained weight management in this population. Furthermore, participants who experienced excessive GWG exhibited a greater likelihood of retaining at least 5% of their prepregnancy weight following childbirth in comparison to those who had appropriate GWG. As elucidated in the study by Martínez-Hortelano [41], the noteworthy prevalence of GWG surpassing the guidelines established by the Institute of Medicine in 2009, particularly among women with overweight or obesity, coupled with its persistent upward trajectory in most geographical regions, underscores the imperative for clinicians to recommend lifestyle interventions aimed at enhancing weight management in women of reproductive age. Our findings suggest that SM represents a suitable lifestyle intervention for women with overweight or obesity.

Our results show that independent SM behavior can indeed improve delivery methods to a certain extent. The possible reason is that individuals with obesity change their BMI through independent SM behavior, leading to changes in their delivery methods. Pettersen-Dahl’s report indicate that the delivery method will be affected by the pregnant women’s BMI of [42]. Additionally, independent SM behavior is secure as independent SM behavior, and cannot affect survival rate of infants. Furthermore, our findings indicate that independent SM behavior can, to some extent, enhance delivery methods. This improvement may be attributed to individuals with obesity altering their BMI through independent SM behavior, which in turn leads to changes in their delivery methods. Pettersen-Dahl’s study [42] supports this notion, as it demonstrates that the BMI of pregnant women influences their delivery method. Furthermore, independent SM behavior is considered safe, as it does not impact the survival rate of infants.

The strengths of our study include the multicenter prospective cohort design, the large sample size, and the use of mobile software for independent SM data collection, which allowed for real-time monitoring and feedback. However, there are several limitations to consider. First, we had a high exclusion rate due to missing data and lost follow-up, which may have introduced selection bias. Second, our study population was limited to women with obesity during pregnancy, and the results may not be generalizable to women with normal or overweight BMIs. Third, we did not assess the potential impact of other factors, such as physical activity, mental health, or social support, which could influence postpartum weight retention.

Despite these limitations, our study provides valuable insights into the potential benefits of pregnancy and postpartum independent SM interventions for weight management among women with obesity during pregnancy. Healthcare professionals should consider incorporating independent SM strategies into prenatal and postnatal care programs, in order to support healthy weight management and reduce the risk of adverse pregnancy outcomes and long-term obesity development. Future research should explore the mechanisms underlying the effectiveness of independent SM interventions, as well as the optimal duration, intensity, and format of such interventions to maximize their impact on postpartum weight management.

This multicenter observational study demonstrated the effectiveness of independent SM interventions, including dietary and weight measurements, in limiting postpartum weight retention among women with obesity during pregnancy, and enhancing delivery methods. Our findings suggest that healthcare professionals should integrate independent SM strategies into prenatal and postnatal care programs to promote healthy weight management and decrease the risk of adverse pregnancy outcomes and long-term obesity development. Further research is warranted to explore the optimal duration, intensity, and format of independent SM interventions to maximize their impact on postpartum weight management.

The data sets generated and/or analyzed during the current study are not publicly available due to ruler of hospital but are available from the corresponding author on reasonable request.

HT and ZL conceived and designed the experiments. HT and ZL performed the experiments. HT and ZL analyzed the data. HT and ZL contributed reagents/materials/analysis tools. HT and ZL wrote the manuscript. HT and ZL revised the manuscript. Both authors read and approved the final manuscript. Both authors have participated sufficiently in the work and agreed to be accountable for all aspects of the work.

All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of Jinan University (approval number: KY-2023-189).

Not applicable.

This research received no external funding.

The authors declare no conflict of interest.