The Effect of Early Excessive Weight Gain on the Development of Hypertension in Pregnancy

Adverse Childbirth and Perinatal Outcomes Among Healthy, Low-Risk Pregnant Women with Abnormal Total Gestational Weight Gain

Purpose: Little is known on the potential effects of abnormal gestational weight gain (GWG) among low-risk, healthy pregnant women with no comorbidities or gestational complications. We investigated perinatal outcomes of these pregnancies according to GWG as per the 2009 National Academy of Medicine (NAM) recommendations. Materials and Methods: A retrospective analysis of prospectively collected data of low-risk pregnant women giving birth at term between January 2016 and December 2020. Inclusion criteria were normal pregestational body mass index (pBMI) (18.5-24.9 kg/m²) and no pregestational or gestational complication. Self-reported prepregnancy weight was used to calculate pBMI; GWG was the difference between maternal weight at childbirth and prepregnancy weight. Women were classified according to the 2009 NAM guidelines for GWG: insufficient (iGWG, <11.5 kg), adequate (aGWG, 11.5-16 kg), and excessive (eGWG, >16 kg). Logistic regression analysis with aGWG as referent was performed to independently estimate dose-response associations. Results: During the study period, there were 4,127 (33.1%) births fulfilling the inclusion criteria. Fifty-two percent of women gained outside the recommended range: 33.5% had iGWG and 18.7% had eGWG. iGWG women were 40% more likely to have early-term births and small for gestational age neonates. In turn, eGWG women displayed increased odds of prolonged pregnancy (adjusted odds ratio [aOR] 1.32), cesarean section in labor (aOR 1.50), high-degree perineal tears (aOR 2.04), postpartum hemorrhage ≥1,000 mL (aOR 1.54), and large for gestational age newborns (aOR 1.83). Conclusion: Our data show that abnormal GWG independently associates with heightened risk of adverse outcomes among healthy, low-risk pregnant women with normal pBMI and no comorbidity or gestational complication.

Preeclampsia subtypes: Clinical aspects regarding pathogenesis, signs, and management with special attention to diuretic administration

During normal pregnancy, blood volume increases by nearly two liters. Distinctively, the absence coupled with the extreme extent regarding the volume expansion, are likely accompanied with pathological conditions. Undoubtedly, preeclampsia, defined as the appearance of hypertension and organ deficiency, such as proteinuria during the second half of pregnancy, is not a homogenous disease. Clinically speaking, two main types of preeclampsia can be distinguished, in which a marked difference between them is vascular condition, and consequently, the blood volume. The "classic" preeclampsia, as a two-phase disease, described in the first, latent phase, in which, placenta development is diminished. Agents from this malperfused placenta generate a maternal disease, the second phase, in which endothelial damage leads to hypertension and organ damage due to vasoconstriction and thrombotic microangiopathy. In this hypovolemia-associated condition, decreasing platelet count, signs of hemolysis, renal and liver involvement are characteristic findings; proteinuria is marked and increasing. In the terminal phase, visible edema develops due to increasing capillary transparency, augmenting end-organ damages. "Classic" preeclampsia is a severe and quickly progressing condition with placental insufficiency and consequent fetal growth restriction and oligohydramnios. The outcome of this condition often leads to fetal hypoxia, eclampsia or placental abruption. The management is limited to a diligent prolongation of pregnancy to accomplish improved neonatal pulmonary function, careful diminishing high blood pressure, and delivery induction in due time. The other subtype, associated with relaxed vasculature and high cardiac output, is a maternal disease, in which obesity is an important risk factor since predisposes to enhanced water retention, hypertension, and a weakened endothelial dysfunction. Initially, enhanced water retention leads to lowered extremity edema, which oftentimes progresses to a generalized form and hypertension. In several cases, proteinuria appears most likely due to tissue edema. This condition already fully meets preeclampsia criteria. Laboratory alterations, including proteinuria, are modest and platelet count remains within the normal range. Fetal weight is also normal or frequently over average due to enhanced placental blood supply. It is very likely, further water retention leads to venous congestion, a parenchyma stasis, responsible for ascites, eclampsia, or placental abruption. During the management of this hypervolemia-associated preeclampsia, the administration of diuretic furosemide treatment seemingly offers promise.

The First-Trimester Gestational Weight Gain Associated With de novo Hypertensive Disorders During Pregnancy: Mediated by Mean Arterial Pressure

The relationship between first-trimester GWG (_T1GWG) and risk of hypertensive disorders of pregnancy (HDP) remained uncertain. This study aimed to investigate the association between _T1GWG and risk of de novo HDP. Meanwhile, we explored the mediated effect and constructed an early GWG category to evaluate the predictive capacity for HDP. _T1GWG was defined as the weight difference between 13 ± 1 gestational weeks and pre-conception. HDP group was defined as having diagnosis of de novo HDP, including gestational hypertension or de novo pre-eclampsia (PE) during the current pregnancy. Early GWG category was constructed according to the risk of HDP within each pre-pregnancy body mass index (BMI) group. Cox regression model was utilized to check the association between the _T1GWG and HDP. Serial mediation model was adopted to evaluate the potential mediators including mean arterial pressure (MAP) at 13th and 20th week. The logistic regression model with bootstrap was performed to assess the predictive capacity of Early GWG category and MAP for the risk of HDP. A total of 17,901 pregnant women (mean age, 29.0 years) were recruited from 2013 to 2017 at the Tongzhou Maternal and Child Health Hospital in Beijing, China. Compared to women in Class 1 of early GWG category, women in the Class 2, 3, 4 have increased risks of HDP by 1.42, 4.27, and 4.62 times, respectively (hazard ratio [HR] = 2.42, 95% CI: 2.11–2.77; HR = 5.27, 95% CI: 4.05–6.86; HR = 5.62, 95% CI: 4.05–7.79). The MAP measured at 13th and 20th week totally mediated 33.1 and 26.7% of association between _T1GWG GWG and HDP in total participants and overweight/obesity pregnancies, respectively. The area under receiver operator characteristic curve for predictive model utilizing early GWG category and MAP measured at 13th and 20th week for the risk of HDP is 0.760 (95% CI: 0.739–0.777). The _T1GWG was associated with de novo HDP, which was partially mediated by MAP measured at 13th and 20th week. Early GWG category showed a better predictive capacity for the risk of HDP compared to the National Academy of Medicine criteria for _T1GWG.

Effect of individualized weight management intervention on excessive gestational weight gain and perinatal outcomes: a randomized controlled trial

It is unclear whether weight management is still effective for pregnant women with excessive weight gain in the second or third trimester in China. This study adopted individualized weight management intervention for pregnant women with abnormal weight gain in the second or third trimester, to analyze the effect of intervention by observing the gestational weight gain and perinatal outcomes. This randomized controlled trial was performed at Aerospace Center Hospital. The obstetrician determined whether the pregnant women gained too much weight in the second or third trimester according to the Institute of Medicine guidelines, and randomly divided the pregnant women who gained too much weight in the second or third trimester into the intervention group or the control group according to the inclusion and exclusion criteria. The pregnant women in the intervention group and in the control group all received routine prenatal examination and diet nutrition education by the doctors in the Department of Obstetrics and Gynecology. The intervention group underwent individualized weight management, including individualized diet, exercise, psychological assessment, cognitive intervention and continuous communication, the whole process is tracked and managed by professional nutritionists. The obstetrician collected the prenatal examination data and pregnancy outcome data of all enrolled pregnant women. The primary outcome measure was weight gain during pregnancy. A generalized linear model and a logistic regression model were used to compare the outcomes between the two groups. In total, 348 pregnant women participated in this study with 203 in the intervention group and 145 in the control group. The whole gestational weight gain in the intervention group (15.8 ± 5.4 Kg) was lower than that in the control group (17.5 ± 3.6 Kg; adjusted β =  - 1.644; 95% CI [-2.660--0.627]; P = 0.002). The percent of pregnant women with excessive weight gainbefore delivery was 54.2% (110/203) in the intervention group, which was lower than 69.7% (101/145) in the control group (adjusted RR = 0.468; 95% CI [0.284-0.769] P = 0.003). The pregnant women given the individualized weight management intervention from the second to the third trimester experienced less weight gain than that from the third trimester (15.5 ± 5.6 Kg vs. 16.2 ± 5.2 Kg), but without significant difference (P = 0.338). Lower rates of GDM, preeclampsia and gestational hypertension, higher rates of fetal distress and puerperal infection were observed in the intervention group than in the control group (all P < 0.05). Individualized weight management during the second or third trimesters is still beneficial for pregnant women who gain excessive weight and can decrease the associated adverse outcomes.

Gestational weight gain and blood pressure control in physiological pregnancy and pregnancy complicated by hypertension

BACKGROUND

Obesity is a widely recognised risk factor for chronic and gestational hypertension. Influence of gestational weight gain on blood pressure control throughout the pregnancy is not well characterised.

MATERIAL AND METHODS

Women in the third trimester of a singleton pregnancy were recruited to the study. Medical records were analysed and a special survey was conducted to obtain history on hypertensive disorders in pregnancy and weight changes during pregnancy. Blood pressure measurements were taken during the office visit in line with international guidelines. Relationships between gestational weight gain and maximal and office values of systolic and diastolic blood pressure values were analysed.

RESULTS

Data of 90 women in normal pregnancy, 40 with gestational hypertension and 21 with chronic hypertension were analysed. Gestational weight gain was 11.9 ± 4.6 kg in the normal pregnancy group, 13.0 ± 5 kg in the gestational hypertension group and 10.6 ± 3.4 kg in the chronic hypertension group. Gestational weight gain positively correlated with both office (r = 0.48; p < 0.001) and maximal blood pressure values (r = 0.34; p = 0.004) in normal pregnancy and with maximal blood pressure values (r = 0.57; p = 0.02) in women with chronic hypertension. No correlation was observed between gestational weight gain and blood pressure values among women with gestational hypertension.

CONCLUSION

In normal pregnancy and in women with chronic hypertension greater gestational weight gain is related to higher blood pressure values in the third trimester.

Weight Gain Before the Third Trimester and Risk of Hypertensive Disorders of Pregnancy: A Prospective Cohort Study

BACKGROUND The association between excessive gestational weight gain (GWG) and the risk of hypertensive disorders of pregnancy (HDP) remains uncertain in women with increased water retention in late gestation associated with the pathophysiology of HDP. This study aimed to investigate the association between GWG before the third trimester and the risk of HDP. MATERIAL AND METHODS This was a prospective cohort study in singleton-pregnant women in Tianjin, China, from 2016. Generalized linear models were used to analyze the relationship between weight gain and the risk of HDP. RESULTS A total of 5295 singleton-pregnant women were included. Even after adjusting for relevant confounders, weight gain at approximately 28 weeks remained an independent risk factor for HDP in the normal-weight group. Compared to the reference of low weight gain (+1 SD was associated with an approximately 2.0 times greater likelihood of HDP (RR: 2.08, 95% CI: 1.06-4.08). Moreover, there was a positive relationship between weight gain in the short interval of early pregnancy and risk of HDP in overweight women. CONCLUSIONS Excessive weight gain before the third trimester was associated with a greater risk of developing HDP among women with early-pregnancy normal weight, which may provide a chance to identify subsequent hypertensive disorders. Additional research is needed to determine whether early-pregnancy weight gain is associated with HDP risk.

Pre-Pregnancy Obesity, Excessive Gestational Weight Gain, and the Risk of Pregnancy-Induced Hypertension and Gestational Diabetes Mellitus

Excessive pre-pregnancy weight is a known risk factor of pregnancy complications. The purpose of this analysis was to assess the relationship between several categories of maternal weight and the risk of developing hypertension and diabetes in pregnancy, and the relationship of these complications with the results of the newborn. It was carried out in a common cohort of pregnant women and taking into account the influence of disturbing factors. Our analysis was conducted in a prospective cohort of 912 Polish pregnant women, recruited during 2015-2016. We evaluated the women who subsequently developed diabetes with dietary modification (GDM-1) (n = 125) and with insulin therapy (GDM-2) (n = 21), as well as the women who developed gestational hypertension (GH) (n = 113) and preeclampsia (PE) (n = 24), compared to the healthy controls. Odds ratios of the complications (and confidence intervals (95%)) were calculated in the multivariate logistic regression. In the cohort, 10.8% of the women had pre-pregnancy obesity (body mass index (BMI) ≥ 30 kg/m²), and 36.8% had gestational weight gain (GWG) above the range of the Institute of Medicine recommendation. After correction for excessive GWG and other confounders, pre-pregnancy obesity (vs. normal BMI) was associated with a higher odds ratio of GH (AOR = 4.94; p < 0.001), PE (AOR = 8.61; p < 0.001), GDM-1 (AOR = 2.99; p < 0.001), and GDM-2 (AOR = 11.88; p <0.001). The threshold risk of development of GDM-2 occurred at lower BMI values (26.9 kg/m²), compared to GDM-1 (29.1 kg/m²). The threshold point for GH was 24.3 kg/m², and for PE 23.1 kg/m². For GWG above the range (vs. GWG in the range), the adjusted odds ratios of GH, PE, GDM-1, and GDM-2 were AOR = 1.71 (p = 0.045), AOR = 1.14 (p = 0.803), AOR = 0.74 (p = 0.245), and AOR = 0.76 (p = 0.672), respectively. The effect of maternal edema on all the results was negligible. In our cohort, hypertension and diabetes were associated with incorrect birth weight and gestational age at delivery. Conclusions: This study highlights the importance and influence of excessive pre-pregnancy maternal weight on the risk of pregnancy complications such as diabetes and hypertension which can impact fetal outcomes.

Weight gain in early, mid, and late pregnancy and hypertensive disorders of pregnancy

OBJECTIVE

To examine the relationship of weight change during early, mid, and late pregnancy with the development of a hypertensive disorder of pregnancy (HDP).

STUDY DESIGN

These data are from a prospective cohort study of nulliparous women with live singleton pregnancies. "Early" weight change was defined as the difference between self-reported pre-pregnancy weight and weight at the first visit (between 6 and 13 weeks' gestation); "mid" weight change was defined as the weight change between the first and second visits (between 16 and 21 weeks' gestation); "late" weight change was defined as the weight change between the second and third visits (between 22 and 29 weeks' gestation). Weight change in each time period was further characterized as inadequate, adequate, or excessive based on the Institute of Medicine's (IOM's) trimester-specific weekly weight gain goals based on pre-pregnancy body mass index. Multivariable Poisson regression was performed to adjust for potential confounders.

MAIN OUTCOME MEASURE

Development of any hypertensive disorder of pregnancy.

RESULTS

Of 8296 women, 1564 (18.9%) developed a HDP. Weight gain in excess of the IOM recommendations during the latter two time periods was significantly associated with HDP. Specifically, trimester-specific excessive weight gain in the mid period (aIRR 1.16, 95% CI 1.01-1.35) as well as in the late period (aIRR = 1.19, 95% CI = 1.02-1.40) was associated with increased risk of developing HDP. The weight gain preceded the onset of clinically apparent disease.

CONCLUSIONS

Excessive weight gain as early as the early second trimester was associated with increased risks of development of HDP.

Delivery-to-Delivery Weight Gain and Risk of Hypertensive Disorders in a Subsequent Pregnancy

OBJECTIVE

To estimate whether weight gain between deliveries is associated with an increased risk of hypertensive disorders in a subsequent pregnancy.

METHODS

This is a case-control study of women who had two live singleton births of at least 24 weeks of gestation at a single maternity hospital from January 1, 2005, to December 31, 2015, with no hypertensive disorder documented in the index pregnancy. Maternal weight gain between deliveries was measured as the change in body mass index (BMI) at delivery. Women who were diagnosed with any hypertensive disorder in the subsequent pregnancy were compared with those who experienced no hypertensive disorder in the subsequent pregnancy using χ statistics for categorical variables and t tests for continuous variables. Logistic regression was used to determine whether weight gain remained independently associated with hypertensive disorders after adjusting for potential confounders.

RESULTS

Of 1,033 women, 188 (18.2%) were diagnosed with a hypertensive disorder in the subsequent pregnancy. Of these, 166 (88.3%) had a hypertensive disorder specific to pregnancy (gestational hypertension; preeclampsia; superimposed preeclampsia; or hemolysis, elevated liver enzymes, and low platelet count syndrome), and 22 (11.7%) had chronic hypertension only. Greater weight gain between deliveries was significantly associated with a higher frequency of hypertensive disorders, which remained significant for a BMI increase of at least 2 kg/m in multivariable analyses (adjusted odds ratio [OR] 1.76, 95% CI 1.14-2.74 for 2 to less than 4 kg/m, adjusted OR 3.19, 95% CI 1.86-5.47 for 4 kg/m or more). Conversely, weight loss of 2 kg/m or more was associated with a decreased risk of a hypertensive disorder (adjusted OR 0.41, 95% CI 0.21-0.81).

CONCLUSION

Among women with no hypertensive disorder noted in an index pregnancy, an increase in BMI of at least 2 kg/m between deliveries was independently associated with an increased risk of a hypertensive disorder in a subsequent pregnancy.

An Intergenerational Approach to Break the Cycle of Malnutrition

PURPOSE OF REVIEW

This article examines how nutritional status is treated throughout the lifecycle. In doing so, the review identifies promising life stages during which intervention may improve nutritional status of future generations.

RECENT FINDINGS

A life course perspective suggests that nutritional changes are most likely to be sustained when they occur during times of developmental transition, such as pregnancy or adolescence. Adolescence is a unique period in which malnutrition in future generations may be addressed because it is the first life stage at which pregnancy becomes feasible and individuals seek independence from parents. A need exists to begin investigating not just how nutrition changes are sustained throughout the lifespan, but how nutritional intervention in one generation impacts the next. This intergenerational approach should be undertaken with cross-discipline collaboration to have the best chance at impacting underlying determinants of malnutrition like poverty and women's education.

Mood and quality of life changes in pregnancy and postpartum and the effect of a behavioral intervention targeting excess gestational weight gain in women with overweight and obesity: a parallel-arm randomized controlled pilot trial

BACKGROUND

Intensive lifestyle interventions in pregnancy have shown success in limiting gestational weight gain, but the effects on mood and quality of life in pregnancy and postpartum are less known. The purpose was to quantify changes in mental and physical quality of life and depressive symptoms across pregnancy and the postpartum period, to determine the association between gestational weight gain and change in mood and quality of life, and to assess the effect of a behavioral intervention targeting excess gestational weight gain on these outcomes.

METHODS

A three group parallel-arm randomized controlled pilot trial of 54 pregnant women who were overweight or obese was conducted to test whether the SmartMoms® intervention decreased the proportion of women with excess gestational weight gain. Individuals randomized to Usual Care (n = 17) did not receive any weight management services from interventionists. Individuals randomized to the SmartMoms® intervention (n = 37) were provided with behavioral weight management counseling by interventionists either in clinic (In-Person, n = 18) or remotely through a smartphone application (Phone, n = 19). In a subset of 43 women, mood and mental and physical quality of life were assessed with the Beck Depression Inventory-II and the Rand 12-Item short form, respectively, in early pregnancy, late pregnancy, 1-2 months postpartum, and 12 months postpartum.

RESULTS

The SmartMoms® intervention and Usual Care groups had higher depressive symptoms (p < 0.03 for SmartMoms® intervention, p < 0.01 for Usual Care) and decreased physical health (p < 0.01) from early to late pregnancy. Both groups returned to early pregnancy mood and physical quality of life postpartum. Mental health did not change from early to late pregnancy (p = 0.8), from early pregnancy to 1-2 months (p = 0.5), or from early pregnancy to 12 months postpartum (p = 0.9), respectively. There were no significant intervention effects. Higher gestational weight gain was associated with worsened mood and lower physical quality of life across pregnancy.

CONCLUSION

High depressive symptoms and poor quality of life may be interrelated with the incidence of excess gestational weight gain. The behavioral gestational weight gain intervention did not significantly impact these outcomes, but mood and quality of life should be considered within future interventions and clinical practice to effectively limit excess gestational weight gain.

TRIAL REGISTRATION

NCT01610752 , Expecting Success, Registered 31 May 2012.

The effect of an educational intervention in early pregnancy with spouse's participation on optimal gestational weight gain in pregnancy: a randomized controlled trial

Gaining weight above the Institute of Medicine recommended range contributes to the development of obesity, which increases risk for diseases. We evaluated the effectiveness of an educational program with the spouse's participation on the optimal gestational weight gain (GWG) in pregnancy. We conducted a randomized controlled trial on 128 nulliparous women attending Najmieh Hospital-Antenatal Clinic based in Tehran-Iran. Participants randomly allocated into two groups of interventions and one control group. In group A, the women received education with their spouse's participation. In group B, the women received education without the participation of the spouses. In the control group, women received only routine prenatal care. Data were analysed by the ANOVA and Chi-square coefficient. The mean of the total GWG in the groups A and B was significantly lower than the control group (13.50 ± 3.85, 13.55 ± 3.20 and 15.53 ± 4.20 kg, respectively, P > 0.05). The rate of optimal GWG in groups A and B was 1.97 and 1.77 times of the control group, respectively (P < 0.05). The percentage of non-optimal GWG significantly decreased (P < 0.05). Groups A and B were not significantly different indicating no effect of spousal presence.

Association Between Gestational Weight Gain and Pregnancy Complications or Adverse Delivery Outcomes in Chinese Han Dichorionic Twin Pregnancies: Validation of the Institute of Medicine (IOM) 2009 Guidelines

Background

Excessive or insufficient gestational weight gain (GWG) is associated with increased risks of pregnancy complications and adverse delivery outcomes in dichorionic twin pregnancies. The provisional Institute of Medicine (IOM) 2009 guidelines suggested the optimal GWG based on limited epidemiological data collected from Western populations. However, such a recommendation has not yet been validated in a Chinese Han population, the world’s largest ethnic group. The objective of this study was to assess the effect of IOM guidelines by determining the neonatal and maternal outcomes associated with gaining weight below, within, and above the IOM provisional guidelines on GWG in Chinese Han twin pregnancies.

Material/Methods

A historical cohort study of 350 twin-conceiving Han women in Chongqing Women and Children’s Health Center delivering liveborn twin infants between January 2015 and November 2016 was conducted. The participants were divided into 3 groups according to the 2009 Institute of Medicine recommendations of GWG: a low GWG group, an adequate GWG group, and a high GWG group. The incidence of pregnancy complications and the delivery outcomes were compared between the groups, and the correlation of GWG and pregnancy complications or delivery outcome was investigated by logistic regression analysis.

Results

In Han Chinese people, the gestational age (GA) at delivery was significantly different among various GWG groups, and low maternal GWG is associated with shorter GA. Although low GWG increased the incidence of VPTD, it did not impact PTD in twin pregnancies. Moreover, GWG was negatively correlated with the incidence of PPROM and was positively correlated with GHP development in twin pregnancies.

Conclusions

The recommendations of the 2009 IOM guidelines about GWG is beneficial in reducing the incidence of VPTD and PPROM in Han Chinese dichorionic twin pregnancies, but failed to eliminate the development of PTD, PROM, GDM, PE, ICP, and SGA.

Early-pregnancy weight gain and the risk of preeclampsia: A case-cohort study

OBJECTIVE

To investigate the association between early-pregnancy weight gain and risk of preeclampsia to inform pregnancy weight gain recommendations.

STUDY DESIGN

We performed a case-cohort study using a hospital database including 80,812 singleton deliveries from Magee-Womens Hospital, Pittsburgh, Pennsylvania (1998-2011). In each of 6 prepregnancy body mass index (BMI) groups, we abstracted serial antenatal weight measurements from the records of up to 339 preeclampsia cases and 1254 randomly selected pregnancies. Early gestational weight gain (16-19 weeks' gestation) was standardized for gestational duration using BMI-specific z-score charts. Multivariable log-binomial regression was used to assess the association between weight gain z-score and risk of preeclampsia. We determined the impact of preeclampsia misclassification using probabilistic bias analysis.

MAIN OUTCOME MEASURE

Risk of preeclampsia.

RESULTS

For normal weight women, there was a steady increase in preeclampsia risk with increasing early gestational weight gain z-score. For example, compared with a weight gain of 1.2 kg (z-score = -1 SD), a 7.2-kg weight gain (z-score = +1 SD) at 16 weeks was associated with 1.3 (0.50, 2.2) excess preeclampsia cases per 100 deliveries. Weight loss at 16-19 weeks among grade 2 or 3 obese women was associated with a reduced risk of preeclampsia. Associations were null among overweight and grade 1 obese women. The bias analysis supported the validity of the conventional analysis.

CONCLUSIONS

Early-pregnancy weight gain may be associated with preeclampsia in some BMI groups. Future revisions of pregnancy weight gain recommendations should account for preeclampsia risks from this and additional studies.

Dose-response relationship between maternal blood pressure in pregnancy and risk of adverse birth outcomes: Ma'anshan birth cohort study

OBJECTIVES

This study depicts the dose-response relationship between blood pressure (BP) during pregnancy and adverse birth outcomes in different trimesters.

STUDY DESIGN

We used restricted cubic spline to quantify the dose-response relationship between maternal BP in different trimesters and risk of adverse birth outcomes (small for gestational age, SGA; and pre-term birth, PTB). The data were from the Ma'anshan birth cohort study in China (N = 3273).

MAIN OUTCOME MEASURES

Risk of SGA and PTB.

RESULTS

There were dose-response associations of both systolic blood pressure (SBP) and diastolic blood pressure (DBP) with risk of SGA in the third trimester and with PTB in both second and third trimesters. In the third trimester, compared with SBP of 120 mmHg, the odds ratios (ORs) and 95% confidence intervals (CI) of SGA were 1.12 (1.01-1.19), 1.32 (1.10-1.60), 1.65 (1.20-2.27) and 2.05 (1.30-3.24) for SBP of 125, 130, 135 and 140 mmHg, respectively. The corresponding ORs and 95% CIs of PTB were 1.15 (1.00-1.32), 1.59 (1.28-1.98), 2.35 (1.66-3.33) and 3.47 (2.10-5.73), respectively. Compared with DBP of 70 mmHg, the ORs and 95% CIs of SGA were 1.44 (1.16-1.78) and 3.04 (2.06-4.50) for DBP of 80 and 90 mmHg, respectively. The corresponding ORs and 95% CIs of PTB were 1.32 (0.93-1.90) and 3.58 (2.21-5.78), respectively.

CONCLUSIONS

A consistent set of dose-response relationships between maternal BP and adverse birth outcomes were observed. Most importantly, we found that moderately elevated maternal BP, even within a normal range, increased the risk of adverse birth outcomes.

Pregnancy Weight Gain Before Diagnosis and Risk of Preeclampsia: A Population-Based Cohort Study in Nulliparous Women

Weight gain in early pregnancy may influence a woman's risk of developing preeclampsia. However, the consequences of weight gain throughout pregnancy up to the diagnosis of preeclampsia are unknown. The aim of this study was to determine whether pregnancy weight gain before the diagnosis of preeclampsia is associated with increased risks of preeclampsia (overall and by preeclampsia subtype). The study population included nulliparous pregnant women in the Swedish counties of Gotland and Stockholm, 2008 to 2013, stratified by early pregnancy body mass index category. Electronic medical records were linked with population inpatient and outpatient records to establish date of preeclampsia diagnosis (classified as any, early preterm <34 weeks, late preterm 34-36 weeks, or term ≥37 weeks). Antenatal weight gain measurements were standardized into gestational age-specific z scores. Among 62 705 nulliparous women, 2770 (4.4%) developed preeclampsia. Odds of preeclampsia increased by ≈60% with every 1 z score increase in pregnancy weight gain among normal weight and overweight women and by 20% among obese women. High pregnancy weight gain was more strongly associated with term preeclampsia than early preterm preeclampsia (eg, 64% versus 43% increased odds per 1 z score difference in weight gain in normal weight women, and 30% versus 0% in obese women, respectively). By 25 weeks, the weight gain of women who subsequently developed preeclampsia was significantly higher than women who did not (eg, 0.43 kg in normal weight women). In conclusion, high pregnancy weight gain before diagnosis increases the risk of preeclampsia in nulliparous women and is more strongly associated with later-onset preeclampsia than early-onset preeclampsia.

Trimester-Specific Weight Gain and Midpregnancy Diastolic Blood Pressure Rebound During Normotensive Pregnancy

The longitudinal exposure-response relationship between trimester-specific gestational weight gain (GWG) and blood pressure (BP) during pregnancy is not well understood. We retrospectively assessed 1112 uncomplicated, normotensive pregnant women whose body weight and BP were measured from 12⁺⁰ to 40⁺⁰ weeks of gestation from a hospital-based cohort. By using growth curve modeling, a J-shaped pattern dominated diastolic BP (DBP) changing dynamics, with a midpregnancy drop at 20⁺⁰ to 22⁺⁰ weeks followed by a rebound. Using group-based trajectory modeling, 3 distinctive trajectories of DBP were identified: high-J shaped (18.5%), moderate-J shaped (48.3%), and low-J shaped (33.1%), as well as 3 distinctive GWG trajectories: high increasing (14.7%), moderate increasing (48.6%) and low increasing (36.8%). A temporal coincidence between the maximal rate of GWG and DBP transition from its nadir to rebound was observed during 20⁺⁰ to 22⁺⁰ weeks. Moreover, women in the high-increasing GWG group had the highest probability of being in the high-J DBP group. The GWG rate during the late midsecond trimester (22⁺⁰ to 26⁺⁰ weeks) was consistently associated with an elevated DBP level: for every 200 g/wk increase, the multivariable-adjusted odds ratio was 1.27 (95% confidence interval, 1.13-1.43) for the trajectory shift to the high-J group and 1.20 (95% confidence interval, 1.07-1.35) for the occurrence of diastolic prehypertension after 37⁺⁰ weeks. Furthermore, adding a trimester-specific GWG rate (22⁺⁰ to 26⁺⁰ weeks) contributed to the incremental yield for the prediction of diastolic prehypertension after 37⁺⁰ weeks. Our results thus provide the timing and extent of gestational weight control relevant to the optimized BP level during pregnancy.