Gestational weight gain below recommendations and adverse maternal and child health outcomes for pregnancies with overweight or obesity: a United States cohort study.

BACKGROUND: The current Institute of Medicine (IOM) pregnancy weight gain guidelines were developed using the best available evidence but were limited by substantial knowledge gaps. Some have raised concern that the guidelines for individuals affected by overweight or obesity are too high and contribute to short- and long-term complications for the mother and child. OBJECTIVES: To determine the association between pregnancy weight gain below the lower limit of the current IOM recommendations and risk of 10 adverse maternal and child health outcomes among individuals with overweight and obesity. METHODS: We used data from a prospective cohort study of United States nulliparae with prepregnancy overweight (n = 955) or obesity (n = 897) followed from the first trimester to 2-7 y postpartum. We used multivariable Poisson regression to relate pregnancy weight gain z-scores with a severity-weighted composite outcome consisting of ≥1 of 10 adverse outcomes (gestational diabetes, preeclampsia, unplanned cesarean delivery, maternal postpartum weight increase >10 kg, maternal postpartum metabolic syndrome, infant death, stillbirth, preterm birth, small-for-gestational age birth, and childhood obesity). RESULTS: Pregnancy weight gain z-scores below, within, and above the IOM-recommended ranges occurred in 5%, 13%, and 80% of pregnancies with overweight and 17%, 13%, and 70% of pregnancies with obesity. There was a positive association between pregnancy weight gain z-scores and all adverse maternal outcomes, childhood obesity, and the composite outcome. Pregnancy weight gain z-scores below the lower limit of the recommended ranges (<6.8 kg for overweight, <5 kg for obesity) were not associated with the severity-weighted composite outcome. For example, compared with the lower limit, adjusted rate ratios (95% confidence interval) for z-scores of -2 standard deviations in pregnancies with overweight (equivalent to 3.6 kg at 40 wk) and obesity (-2.8 kg at 40 wk) were 0.99 (95% confidence interval [CI]: 0.91, 1.06) and 0.97 (95% CI: 0.87, 1.07). CONCLUSIONS: These findings support arguments to decrease the lower limit of recommended weight gain ranges in these prepregnancy body mass index groups.

Do current pregnancy weight gain guidelines balance risks of adverse maternal and child health in a United States cohort?

BACKGROUND: The Institute of Medicine pregnancy weight gain guidelines were developed without evidence linking high weight gain to maternal cardiometabolic disease and child obesity. The upper limit of current recommendations may be too high for the health of the pregnant individual and child. OBJECTIVES: The aim of this study was to identify the range of pregnancy weight gain for pregnancies within a normal body mass index (BMI) range that balances the risks of high and low weight gain by simultaneously considering 10 different health conditions. METHODS: We used data from an United States prospective cohort study of nulliparae followed until 2 to 7 y postpartum (N = 2344 participants with a normal BMI). Pregnancy weight gain z-score was the main exposure. The outcome was a composite consisting of the occurrence of ≥1 of 10 adverse health conditions that were weighted for their seriousness. We used multivariable Poisson regression to relate weight gain z-scores with the weighted composite outcome. RESULTS: The lowest risk of the composite outcome was at a pregnancy weight gain z-score of -0.6 SD (standard deviation) (equivalent to 13.1 kg at 40 wk). The weight gain ranges associated with no more than 5%, 10%, and 20% increase in risks were -1.0 to -0.2 SD (11.2-15.3 kg), -1.4 to 0 SD (9.4-16.4 kg), and -2.0 to 0.4 SD (7.0-18.9 kg). When we used a lower threshold to define postpartum weight increase in the composite outcome (>5 kg compared with >10 kg), the ranges were 1.6 to -0.7 SD (8.9-12.6 kg), -2.2 to -0.3 SD (6.3-14.7 kg), and ≤0.2 SD (≤17.6 kg). Compared with the ranges of the current weight gain guidelines (-0.9 to -0.1 SD, 11.5-16 kg), the lower limits from our data tended to be lower while upper limits were similar or lower. CONCLUSIONS: If replicated, our results suggest that policy makers should revisit the recommended pregnancy weight gain range for individuals within a normal BMI range.

Investigating the Shape and Strength of the Relationship Between Maternal Weight Gain and Gestational Age at Delivery in Twin and Singleton Pregnancies.

Both inadequate and excessive maternal weight gain are correlated with preterm delivery in singleton pregnancies, yet this relationship has not been adequately studied in twins. We investigated the relationship between time-varying maternal weight gain and gestational age at delivery in twin pregnancies and compared it with that in singletons delivered in the same study population. We used serial weight measurements abstracted from charts for twin and singleton pregnancies delivered during 1998-2013 in Pittsburgh, Pennsylvania. Our exposure was time-varying weight gain z score, calculated using gestational age-standardized and prepregnancy body mass index-stratified twin- and singleton-specific charts, and our outcome was gestational age at delivery. Our analyses used a flexible extension of the Cox proportional hazards model that allowed for nonlinear and time-dependent effects. We found a U-shaped relationship between weight gain z score and gestational age at delivery among twin pregnancies (lowest hazard of delivery observed at z score = 1.2), which we attributed to increased hazard of early preterm spontaneous delivery among pregnancies with low weight gain and increased hazard of late preterm delivery without labor among pregnancies with high weight gain. Our findings may be useful for updating provisional guidelines for maternal weight gain in twin pregnancies.

Association between gestational age at delivery and indicator-specific severe maternal morbidity.

OBJECTIVE: Individuals who deliver preterm are disproportionately affected by severe maternal morbidity. Limited data suggest that indicator-specific maternal morbidity varies by gestational age at delivery. We sought to evaluate the relationship between gestational age at delivery and the incidence of severe maternal morbidity and indicator-specific severe maternal morbidity. METHODS: We used a hospital administrative delivery database to identify all singleton deliveries between 16 and 42 weeks gestation from 2002 to 2018. We defined severe maternal morbidity as the presence of any International Classification of Disease diagnosis or procedure codes outlined by the Centers for Disease Control and Prevention, intensive care unit admission, and/or prolonged postpartum hospital length of stay. Indicator-specific severe maternal morbidity was based on the diagnosis and procedure codes and was characterized across gestational age epochs. We categorized gestational age into three epochs to capture extremely preterm birth (less than 28 weeks gestation), preterm birth (28-36 weeks gestation) and term birth (37 weeks gestation and above). Multivariable binomial regression was used to assess the association between categories of gestational age at delivery and severe maternal morbidity adjusting for confounders including age, race, body mass index (BMI), insurance status, and preexisting hypertension or diabetes. RESULTS: Severe maternal morbidity occurred in 2.5% of all deliveries. The unadjusted incidence of severe maternal morbidity by gestational age epoch was 12% at less than 28 weeks gestation, 8.4% at 28 to 36 weeks of gestation, and 1.7% at greater than or equal to 37 weeks gestation. After controlling for potential confounders the predicted probability of severe maternal morbidity was 16% (95% CI 14,17%) at 24 weeks compared to 2.2% (95% CI 2.1,2.3%) at 38 weeks. Sepsis, acute respiratory distress syndrome, mechanical ventilation, and shock were the most common diagnostic codes in deliveries less than 28 weeks gestation. Heart failure and cardiac arrhythmias were more common in patients with severe maternal morbidity delivering at term. CONCLUSION: A high proportion of severe maternal morbidity occurred in preterm patients, with the highest rates occurring at less than 28 weeks gestation. Individuals with severe maternal morbidity who deliver preterm had distinct indicators of morbidity compared to those who deliver at term.

Early Gestational Weight Gain and the Risk of Preeclampsia in Dichorionic Twin Pregnancies.

OBJECTIVE: The purpose of our study was to evaluate the body mass index (BMI)-specific association between early gestational weight gain (GWG) in dichorionic twin pregnancies and the risk of preeclampsia. STUDY DESIGN: We conducted a retrospective cohort study of all dichorionic twin pregnancies from 1998 to 2013. Data were obtained from a perinatal database and chart abstraction. Prepregnancy BMI was categorized as normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥30 kg/m2). Early GWG was defined as the last measured weight from 160/7 to 196/7weeks' gestation minus prepregnancy weight. GWG was standardized for gestational duration using BMI-specific z-score charts for dichorionic pregnancies. Preeclampsia was diagnosed using American College of Obstetricians and Gynecologists criteria and identified with International Classification of Diseases-9 coding. Early GWG z-score was modeled as a three-level categorical variable (≤ - 1 standard deviation [SD], 0, 3 +1 SD), where -1 to +1 was the referent group. We estimated risk differences and 95% confidence intervals (CIs) via marginal standardization. RESULTS: We included 1,693 dichorionic twin pregnancies in the cohort. In adjusted analysis, the incidence of preeclampsia increased with increasing early GWG among women with normal BMI. Women with normal BMI and a GWG z-score < - 1 (equivalent to 2.6 kg by 20 weeks) had 2.5 fewer cases of preeclampsia per 100 births (95% CI: -4.7 to - 0.3) compared with the referent; those with GWG z-score > +1 (equivalent to gaining 9.8 kg by 20 weeks) had 2.8 more cases of preeclampsia per 100 (95 % CI: 0.1-5.5) compared with the referent. In adjusted analyses, early GWG had minimal impact on the risk of preeclampsia in women with overweight or obesity. CONCLUSION: GWG of 2.6 kg or less by 20 weeks was associated with a decreased risk of preeclampsia among women pregnant with dichorionic twins and normal prepregnancy BMI. Current GWG guidelines focus on optimizing fetal weight and gestational length. Our findings demonstrate the importance of considering other outcomes when making GWG recommendations for twin pregnancy. KEY POINTS: · Early GWG decreased with increasing BMI category.. · Among women with normal weight, as early GWG increased so did the risk of preeclampsia.. · There was no association between early GWG and preeclampsia among women with overweight or obesity..

Severe Maternal Morbidity in Twins.

OBJECTIVE: While twin gestations are at increased risk of severe maternal morbidity (SMM), there is limited information about timing and causes of SMM in twins. Furthermore, existing data rely on screening definitions of SMM because a gold standard approach requires chart review. We sought to determine the timing and cause of SMM in twins using a gold standard definition outlined by the American College of Obstetricians and Gynecologists (ACOG). STUDY DESIGN: We used a perinatal database to identify all twin deliveries from 1998 to 2013 at a single academic medical center (n = 2,367). Deliveries were classified as screen positive for SMM if they met any of the following criteria: (1) one of the Centers for Disease Control and Prevention (CDC) International Classification of Diseases Ninth Revision diagnosis and procedure codes for SMM; (2) a prolonged postpartum length of stay (>3 standard deviations beyond mean length of stay by mode of delivery); or (3) maternal intensive care unit admission. We identified true cases of SMM through medical record review of all screen-positive deliveries using the definition of SMM outlined in the ACOG Obstetric Care Consensus. We also determined cause and timing of SMM. RESULTS: A total of 165 (7%) of twin deliveries screened positive for SMM. After chart review of all screen-positive cases, 2.4% (n = 56) were classified as a true case of SMM using the ACOG definition for a positive predictive value of 34%. The majority of SMM occurred postpartum (65%). Hemorrhage was the most common cause of SMM, followed by hypertensive and pulmonary etiologies. CONCLUSION: Commonly used approaches to screen for SMM perform poorly in twins. This has important implications for quality initiatives and epidemiologic studies that rely on screening definitions of maternal morbidity. Our study demonstrates that the immediate postpartum period is a critical time for maternal health among women with twin pregnancies. KEY POINTS: · Screening approaches for SMM have low positive predictive value in twins.. · Hemorrhage, hypertensive, and pulmonary complications were the most common morbidities.. · SMM was most common postpartum..

Gestational weight gain in triplet pregnancies in the United States.

BACKGROUND: The Institute of Medicine has published national recommendations for optimal pregnancy weight gain ranges for singletons and twins but not for higher-order multiples. A common clinical resource suggests weight gain targets for triplet pregnancies, but they are based on a single, small study conducted over 20 years ago. OBJECTIVE: We sought to describe contemporary maternal weight gain patterns in triplet gestations in the United States, the weight gain patterns associated with good neonatal outcomes, and how these patterns compare with those of healthy twin pregnancies. STUDY DESIGN: We used data from 7705 triplet pregnancies drawn from the United States live birth and fetal death files (2012‒2018). We calculated total pregnancy weight gain as weight at delivery minus the prepregnancy weight. A good neonatal outcome was defined as delivery at ≥32 weeks' gestation of 3 liveborn infants weighing ≥1500 g with 5-minute Apgar scores of ≥3. We described the weight gain patterns of triplet pregnancies with good neonatal outcomes by calculating week-specific percentiles of the total weight gain distribution for deliveries at 32 to 37 weeks' gestation. For comparative purposes, we plotted these values against the percentiles of a previously published weight gain chart for monitoring and evaluating twin pregnancies from a referent cohort. RESULTS: Most participants were over weight (26%) or obese (30%), and 42% were normal weight or underweight. The 50th percentile (25th-75th) of total weight gain in triplet pregnancies was 17 (11-23) kg. As the body mass index category increased, the total weight gain declined: underweight or normal weight, median 19 (14-25) kg; overweight, 17 (12-23) kg; obese, 14 (7.7-20) kg. Approximately 46% of triplet pregnancies had a good neonatal outcome (n=3562). For underweight or normal weight triplet pregnancies with good neonatal outcomes, the 50th percentiles of weight gain at 32 weeks' and 36 weeks' gestation were 12.3 kg and 22.7 kg, respectively. The 10th and 90th percentiles were 12.3 kg and 32.7 kg, respectively, at 32 weeks, and 15.0 kg and 34.1 kg, respectively, at 36 weeks. Triplet pregnancies with prepregnancy overweight or obesity and a good neonatal outcome had lower weight gains. Compared with the reference values for pregnancy weight gain from a twin-specific weight gain chart, the median total weight gain in triplet pregnancies with good neonatal outcomes was approximately 3 to 5 kg more than twins, regardless of body mass index. CONCLUSION: Our study fills an important gap in understanding how much weight gain can be expected among triplet pregnancies by body mass index category. These descriptive data are a necessary first step to inform science-based triplet gestational weight gain guidelines. Additional research is needed to determine whether monitoring triplet pregnancy weight gain is useful for promoting healthy outcomes for pregnant individuals and children and what targets should be used to optimize maternal and neonatal health.

Structured antenatal milk expression education for nulliparous pregnant people: results of a pilot, randomized controlled trial in the United States.

BACKGROUND: Hand-expression, collection, and storage of breast milk during pregnancy (i.e., antenatal milk expression or AME) is a safe, potentially effective practice to reduce early, undesired infant formula supplementation among women with diabetes. The feasibility and potential impact of AME on lactation outcomes in the United States (U.S.) and among non-diabetic birthing people is unknown. METHODS: The purpose of this study was to examine the feasibility of a structured AME intervention among nulliparous birthing people in the United States. We recruited 45 low-risk, nulliparous individuals at 34-366/7 weeks of gestation from a hospital-based midwife practice. Participants were randomized to AME or a control group receiving lactation education handouts. Interventions were delivered at weekly visits at 37-40 weeks of pregnancy. The AME intervention involved technique demonstration and feedback from a lactation consultant and daily independent practice. Lactation outcomes were assessed during the postpartum hospitalization, 1-2 weeks postpartum, and 3-4 months postpartum. RESULTS: Between December 2016 and February 2018, 63 individuals were approached and screened for eligibility, and 45 enrolled into the study (71%). Of 22 participants assigned to AME, 18 completed at least one AME study visit. Participants reported practicing AME on at least 60% of days prior to their infant's birth. Most were able to express milk antenatally (15/18), more than half collected and froze antenatal milk (11/18), and 39% (7/18) supplemented their infants with antenatal milk after birth. No major problems were reported with AME. Perinatal and lactation outcomes, including infant gestational age at birth, neonatal intensive care unit admissions, delayed onset of lactogenesis II, and use of infant formula were similar between AME and control groups. Among participants in both groups who were feeding any breast milk at each assessment, breastfeeding self-efficacy increased and perceptions of insufficient milk decreased over the postpartum course. CONCLUSIONS: In a small group of nulliparous birthing people in the U.S., AME education and independent practice beginning at 37 weeks of pregnancy was feasible. In some cases, AME provided a back-up supply of milk when supplementation was indicated or desired. The relationship between AME and lactation outcomes requires further study with adequately powered samples. TRIAL REGISTRATION: This trial was retrospectively registered at ClinicalTrials.gov on May 11, 2021 under the following registration ID: NCT04929301. https://clinicaltrials.gov/ct2/show/NCT04929301 .

Use of a Doubly Robust Machine-Learning-Based Approach to Evaluate Body Mass Index as a Modifier of the Association Between Fruit and Vegetable Intake and Preeclampsia.

The Dietary Guidelines for Americans rely on summaries of the effect of dietary pattern on disease risk, independent of other population characteristics. We explored the modifying effect of prepregnancy body mass index (BMI; weight (kg)/height (m)2) on the relationship between fruit and vegetable density (cup-equivalents/1,000 kcal) and preeclampsia using data from a pregnancy cohort study conducted at 8 US medical centers (n = 9,412; 2010-2013). Usual daily periconceptional intake of total fruits and total vegetables was estimated from a food frequency questionnaire. We quantified the effects of diets with a high density of fruits (≥1.2 cups/1,000 kcal/day vs. <1.2 cups/1,000 kcal/day) and vegetables (≥1.3 cups/1,000 kcal/day vs. <1.3 cups/1,000 kcal/day) on preeclampsia risk, conditional on BMI, using a doubly robust estimator implemented in 2 stages. We found that the protective association of higher fruit density declined approximately linearly from a BMI of 20 to a BMI of 32, by 0.25 cases per 100 women per each BMI unit, and then flattened. The protective association of higher vegetable density strengthened in a linear fashion, by 0.3 cases per 100 women for every unit increase in BMI, up to a BMI of 30, where it plateaued. Dietary patterns with a high periconceptional density of fruits and vegetables appear more protective against preeclampsia for women with higher BMI than for leaner women.

Accuracy of estimated fetal weight in extremely preterm infants and the impact of prepregnancy body mass index.

BACKGROUND: Antenatally, we rely on ultrasound estimated fetal weight as a proxy for birthweight to inform discussions regarding perinatal morbidity and mortality. Maternal obesity may negatively impact the quality of ultrasound imaging, and thus, understanding the associations between obesity and estimated fetal weight in the preterm period is important. OBJECTIVE: Given the rising obesity rates and association with preterm birth, we sought to determine the accuracy of ultrasound-derived estimated fetal weight in predicting birthweight in preterm infants by prepregnancy body mass index and to evaluate the accuracy of estimated fetal weight in predicting birthweight between small-for-gestational-age and appropriate-for-gestational-age infants. STUDY DESIGN: We included all women who delivered a live-born singleton infant between 23 0/7 and 31 6/7 weeks of gestation and had an ultrasound estimated fetal weight within 7 days before delivery. We calculated the mean percentage difference between estimated fetal weight and birthweight and the absolute percent difference. Excess error was defined as an absolute percentage difference of >20%. We used multivariable modified Poisson models to determine the association between prepregnancy body mass index and small for gestational age and excess ultrasound error. RESULTS: Our cohort included 641 infants with a mean gestational age of 28.0±2.6 weeks and a mean birthweight of 1110±425 g. More than one-third of our cohort were obese (227 [35%]). The mean percentage difference between estimated fetal weight and birthweight was 7.7%±11.2% among all infants. Ultrasound overestimated birthweight in 77% of the cohort (n=492). Stratified by body mass index, the mean percentage differences between estimated fetal weight and birthweight were 6.7%±11.0% in women with normal weight and 9.5%±12.0% in women with obesity (P=.02). The mean percentage differences between estimated fetal weight and birthweight were 11.0%±11.0% in small-for-gestational-age infants (n=80) and 7.1%±11.0% in appropriate-for-gestational-age infants (P<.001). Small-for-gestational-age infant was associated with an increased risk of excess ultrasound error with an adjusted relative risk of 2.3 (95% confidence interval, 1.2-4.3). CONCLUSION: Although ultrasound estimated fetal weight overestimated birthweight, particularly in small-for-gestational-age infants, most estimates were within 10% of actual birthweight. Obesity and small-for-gestational-age birth were both associated with an increased risk of excess ultrasound error (≥20%) in estimating birthweight.

Adverse Cardiovascular Events Following Severe Maternal Morbidity.

Severe maternal morbidity (SMM) affects 50,000 women annually in the United States, but its consequences are not well understood. We aimed to estimate the association between SMM and risk of adverse cardiovascular events during the 2 years postpartum. We analyzed 137,140 deliveries covered by the Pennsylvania Medicaid program (2016-2018), weighted with inverse probability of censoring weights to account for nonrandom loss to follow-up. SMM was defined as any diagnosis on the Centers for Disease Control and Prevention list of SMM diagnoses and procedures and/or intensive care unit admission occurring at any point from conception through 42 days postdelivery. Outcomes included heart failure, ischemic heart disease, and stroke/transient ischemic attack up to 2 years postpartum. We used marginal standardization to estimate average treatment effects. We found that SMM was associated with increased risk of each adverse cardiovascular event across the follow-up period. Per 1,000 deliveries, relative to no SMM, SMM was associated with 12.1 (95% confidence interval (CI): 6.2, 18.0) excess cases of heart failure, 6.4 (95% CI: 1.7, 11.2) excess cases of ischemic heart disease, and 8.2 (95% CI: 3.2, 13.1) excess cases of stroke/transient ischemic attack at 26 months of follow-up. These results suggest that SMM identifies a group of women who are at high risk of adverse cardiovascular events after delivery. Women who survive SMM may benefit from more comprehensive postpartum care linked to well-woman care.

Can Ensemble Machine Learning Improve the Accuracy of Severe Maternal Morbidity Screening in a Perinatal Database?

BACKGROUND: Severe maternal morbidity (SMM) is an important maternal health indicator, but existing tools to identify SMM have substantial limitations. Our objective was to retrospectively identify true SMM status using ensemble machine learning in a hospital database and to compare machine learning algorithm performance with existing tools for SMM identification. METHODS: We screened all deliveries occurring at Magee-Womens Hospital, Pittsburgh, PA (2010-2011 and 2013-2017) using the Centers for Disease Control and Prevention list of diagnoses and procedures for SMM, intensive care unit admission, and/or prolonged postpartum length of stay. We performed a detailed medical record review to confirm case status. We trained ensemble machine learning (SuperLearner) algorithms, which "stack" predictions from multiple algorithms to obtain optimal predictions, on 171 SMM cases and 506 non-cases from 2010 to 2011, then evaluated the performance of these algorithms on 160 SMM cases and 337 non-cases from 2013 to 2017. RESULTS: Some SuperLearner algorithms performed better than existing screening criteria in terms of positive predictive value (0.77 vs. 0.64, respectively) and balanced accuracy (0.99 vs. 0.86, respectively). However, they did not perform as well as the screening criteria in terms of true-positive detection rate (0.008 vs. 0.32, respectively) and performed similarly in terms of negative predictive value. The most important predictor variables were intensive care unit admission and prolonged postpartum length of stay. CONCLUSIONS: Ensemble machine learning did not globally improve the ascertainment of true SMM cases. Our results suggest that accurate identification of SMM likely will remain a challenge in the absence of a universal definition of SMM or national obstetric surveillance systems.

Gestational Diabetes in Twin Versus Singleton Pregnancies With Normal Weight or Overweight Pre-Pregnancy Body Mass Index: The Mediating Role of Mid-Pregnancy Weight Gain.

BACKGROUND: Gestational diabetes might be more common in twin versus singleton pregnancies, yet the reasons for this are unclear. We evaluated the extent to which this relationship is explained by higher mid-pregnancy weight gain within normal weight and overweight pre-pregnancy body mass index (BMI) strata. METHODS: We analyzed serial weights and glucose screening and diagnostic data abstracted from medical charts for twin (n = 1397) and singleton (n = 3117) pregnancies with normal or overweight pre-pregnancy BMI delivered from 1998 to 2013 at Magee-Womens Hospital in Pennsylvania. We used causal mediation analyses to estimate the total effect of twin versus singleton pregnancy on gestational diabetes, as well as those mediated (natural indirect effect) and not mediated (natural and controlled direct effects) by pathways involving mid-pregnancy weight gain. RESULTS: Odds of gestational diabetes were higher among twin pregnancies [odds ratios (ORs) for total effect = 2.83 (95% CI = 1.54, 5.19) for normal weight and 2.09 (95% CI = 1.16, 3.75) for overweight pre pregnancy BMI], yet there was limited evidence that this relationship was mediated by mid-pregnancy weight gain [ORs for natural indirect effect = 1.21 (95% CI = 0.90, 1.24) for normal weight and 1.06 (95% CI = 0.92, 1.21) for overweight pre-pregnancy BMI] and more evidence of mediation via other pathways [ORs for natural direct effect = 2.34 (95% CI = 1.24, 4.40) for normal weight and 1.97 (95% CI = 1.08, 3.60) for overweight pre-pregnancy BMI]. CONCLUSIONS: While twin pregnancies with normal weight or overweight pre-pregnancy BMI experienced higher odds of gestational diabetes versus singletons, most of this effect was explained by pathways not involving mid-pregnancy weight gain.

Optimizing reproductive health management in lupus and Sjogren's syndrome.

PURPOSE OF REVIEW: People with childbearing capacity who are diagnosed with systemic lupus erythematosus (SLE) and Sjogren's syndrome (SS) have specific and important reproductive health considerations. RECENT FINDINGS: Recommendations from the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) provide rheumatologists and other clinicians with guidance for reproductive health management of patients with rheumatic diseases. Patient-centered reproductive health counseling can help clinicians to operationalize the EULAR and ACR guidelines and enhance patient care. SUMMARY: Disease activity monitoring, risk factor stratification, and prescription of pregnancy-compatible medications during pregnancy help to anticipate complications and enhance pregnancy outcomes in SLE and SS. Assisted reproductive technologies are also safe among people with well-controlled disease. Safe and effective contraceptive methods are available for patients with SLE and SS, and pregnancy termination appears to be safe among these patients.

A New Approach for Classifying Fetal Growth Restriction.

BACKGROUND: Fetal growth restriction is commonly defined using small for gestational age (SGA) birth (birthweight < 10th percentile) as a proxy, but this approach is problematic because most SGA infants are small but healthy. In this proof-of-concept study, we sought to develop a new approach for identifying fetal growth restriction at birth that combines information on multiple, imperfect measures of fetal growth restriction in a probabilistic manner. METHODS: We combined information on birthweight, placental weight, placental malperfusion lesions, maternal disease, and fetal acidemia using latent profile analysis to classify fetal growth in births at the Royal Victoria Hospital in Montreal, Canada, 2001-2009. We examined the clinical characteristics and health outcomes of infants classified as growth-restricted and nongrowth-restricted by our model, and among the subgroup of growth-restricted infants who had a birthweight ≥10th percentile (i.e., would have been missed by the conventional SGA proxy). RESULTS: Among 26,077 births, 345 (1.3%) were classified as growth-restricted by our latent profile model. Growth-restricted infants were more likely than nongrowth-restricted infants to have an Apgar score <7 (10% vs. 2%), have hypoglycemia at birth (17% vs. 3%), require neonatal intensive care unit admission (59% vs. 6%), die in the perinatal period (3.8% vs. 0.2%), and require an emergency cesarean delivery (42% vs. 15%). Risks remained elevated in growth-restricted infants who were not SGA, suggesting our model identified at-risk infants not detected using the SGA proxy. CONCLUSIONS: Latent profile analysis is a promising strategy for classifying growth restriction at birth in fetal growth restriction research.

Perinatal outcomes in twin pregnancies complicated by gestational diabetes.

BACKGROUND: Gestational diabetes in singleton pregnancies increases the risk for large for gestational age infants, hypertensive disorders of pregnancy, and neonatal morbidity. Compared with singleton gestations, twin gestations are at increased risk for fetal growth abnormalities, hypertensive disorders, and neonatal morbidity. Whether gestational diabetes further increases the risk for these outcomes is unclear. OBJECTIVE: We sought to determine the relationship between gestational diabetes and the risk for preeclampsia, fetal growth abnormalities, and neonatal intensive care unit admissions in a large cohort of women with twin pregnancies. STUDY DESIGN: We used a retrospective cohort of all twin gestations that were delivered at our institution from 1998 to 2013. We excluded pregnancies delivered before 24 weeks' gestation, monochorionic-monoamniotic twins, and patients with preexisting diabetes for a final cohort of 2573 twin deliveries. Gestational diabetes was defined as 2 abnormal values on a 100 g, 3-hour glucose challenge test as defined by the Carpenter-Coustan criteria or a 1-hour value of 200 mg/dL after a 50 g glucose test. Multivariable Poisson regression models were used to estimate the associations between gestational diabetes and preeclampsia, small for gestational age infants, large for gestational age infants, and admission to the neonatal intensive care unit after adjusting for prepregnancy body mass index, maternal race, maternal age, parity, use of in vitro fertilization, prepregnancy smoking status, and chronic hypertension as confounders. RESULTS: The unadjusted incidence of gestational diabetes was 6.5% (n=167). Women with gestational diabetes were more likely to be aged 35 years or older, living with obesity, and have conceived via in vitro fertilization than women without gestational diabetes. Preeclampsia was more common among women with twin pregnancies complicated by gestational diabetes (31%) than among women with twin pregnancies without gestational diabetes (18%) (adjusted risk ratio, 1.5; 95% confidence interval, 1.1-2.1). A diagnosis of small for gestational age infant was less common among women with gestational diabetes (17%) than among women without gestational diabetes (24%), although the results were imprecise (adjusted risk ratio, 0.8; 95% confidence interval, 0.5-1.1). There was no association between gestational diabetes and the incidence of large for gestational age neonates or neonatal intensive care unit admissions. Among women with gestational diabetes who reached 35 weeks' gestation, 62% (n=60) required medical management. CONCLUSION: Gestational diabetes is a risk factor for preeclampsia among women with twin pregnancies. Close blood pressure monitoring and patient education are critical for this high-risk group. The association between gestational diabetes and neonatal outcomes among women with twin pregnancies is less precise, although it may reduce the incidence of small for gestational age infants. Prospective studies to determine if glycemic control decreases the risk for preeclampsia in twin pregnancies with gestational diabetes are needed.

Comparison of methods for interpolating gestational weight gain between clinical visits in twin and singleton pregnancies.

PURPOSE: Researchers are interested in studying longitudinal patterns of gestational weight gain, yet this requires daily/weekly weights, and maternal weight is measured only during prenatal visits. We evaluated the relative accuracy and precision of methods for estimating maternal weight gain between prenatal visits among twin and singleton pregnancies. METHODS: We analyzed cohorts of dichorionic twin and singleton pregnancies delivered from 1998-2013 in Pittsburgh, Pennsylvania. We mimicked a typical study by retaining pre-pregnancy, first prenatal visit, glucose screening visit, and delivery weights, using these to fit interpolation models, estimating weight throughout pregnancy using 16 different methods, and calculating the difference in kilograms between predicted and measured values among remaining weights. We evaluated the performance of each model by calculating root mean squared error (RMSE). RESULTS: RMSE ranged from 1.55 to 6.09 kg in twins (n = 2067) and 1.45 to 4.87 kg in singletons (n = 7331). The most accurate and precise methods incorporated restricted cubic splines, random intercepts and slopes for pregnancy, and internal knots demarcating trimesters/quantiles (RMSE = 1.55/1.56 kg in twins, 1.45/1.45 kg in singletons), while individual-level linear interpolation between proximal measurements also performed well. CONCLUSIONS: Accuracy and precision of methods for estimating maternal weight gain between measurements differed by model, and were best among individually-tailored and flexible models.

Pregnancy weight gain in twin gestations and maternal and child health outcomes at 5 years.

OBJECTIVE: Current guidelines for maternal weight gain in twin pregnancy were established in the absence of evidence on its longer-term consequences for maternal and child health. We evaluated the association between weight gain in twin pregnancies and the risk of excess maternal postpartum weight increase, childhood obesity, and child cognitive ability. METHODS: We used 5-year follow-up data from 1000 twins born to 450 mothers in the Early Childhood Longitudinal Study-Birth Cohort, a nationally representative U.S. cohort of births in 2001. Pregnancy weight gain was standardized into gestational age- and prepregnancy body mass index (BMI)-specific z-scores. Excess postpartum weight increase was defined as ≥10 kg increase from prepregnancy weight. We defined child overweight/obesity as BMI ≥ 85th percentile, and low reading and math achievement as scores one standard deviation below the mean. We used survey-weighted multivariable modified Poisson models with a log link to relate gestational weight gain z-score with each outcome. RESULTS: Excess postpartum weight increase occurred in 40% of mothers. Approximately 28% of twins were affected by overweight/obesity, and 16 and 14% had low reading and low math scores. There was a positive linear relationship between pregnancy weight gain and both excess postpartum weight increase and childhood overweight/obesity. Compared with a gestational weight gain z-score 0 SD (equivalent to 20 kg at 37 weeks gestation), a weight gain z-score of +1 SD (27 kg) was associated with 6.3 (0.71, 12) cases of excess weight increase per 1000 women and 4.5 (0.81, 8.2) excess cases of child overweight/obesity per 100 twins. Gestational weight gain was not related to kindergarten academic readiness. CONCLUSIONS: The high prevalence of excess postpartum weight increase and childhood overweight/obesity within the recommended ranges of gestational weight gain for twin pregnancies suggests that these guidelines could be inadvertently contributing to longer-term maternal and child obesity.

Rating the seriousness of maternal and child health outcomes linked with pregnancy weight gain.

BACKGROUND: Current pregnancy weight gain guidelines were developed based on implicit assumptions of a small group of experts about the relative seriousness of adverse health outcomes. Therefore, they will not necessarily reflect the values of women. OBJECTIVE: To estimate the seriousness of 11 maternal and child health outcomes that have been consistently associated with pregnancy weight gain by engaging patients and health professionals. METHODS: We collected data using an online panel approach with a modified Delphi structure. We selected a purposeful sample of maternal and child health professionals (n = 84) and women who were pregnant or recently postpartum (patients) (n = 82) in the United States as panellists. We conducted three concurrent panels: professionals only, patients only, and patients and professionals. During a 3-round online modified Delphi process, participants rated the seriousness of health outcomes (Round 1), reviewed and discussed the initial results (Round 2), and revised their original ratings (Round 3). Panellists assigned seriousness ratings (0, [not serious] to 100 [most serious]) for infant death, stillbirth, preterm birth, gestational diabetes, preeclampsia, small-for-gestational-age (SGA) birth, large-for-gestational-age (LGA) birth, unplanned caesarean delivery, maternal obesity, childhood obesity, and maternal metabolic syndrome. RESULTS: Each panel individually came to a consensus on all seriousness ratings. The final median seriousness ratings combined across all panels were highest for infant death (100), stillbirth (95), preterm birth (80), and preeclampsia (80). Obesity in children, metabolic syndrome in women, obesity in women, and gestational diabetes had median seriousness ratings ranging from 55 to 65. The lowest seriousness ratings were for SGA birth, LGA birth, and unplanned caesarean delivery (30-40). CONCLUSION: Professionals and women rate some adverse outcomes as being more serious than others. These ratings can be used to establish the range of pregnancy weight gain associated with the lowest risk of a broad range of maternal and child health outcomes.