Sonographic birth-weight prediction in obese patients using the gestation-adjusted prediction method

Identification of newborns with birthweight ≥ 4,500g: Ultrasound within one- vs. two weeks of delivery

OBJECTIVE

Our objective was to compare the diagnostic characteristics of sonographic estimated fetal weight (SEFW) done within 7 versus 8-14 days before delivery for detection of fetal macrosomia (birthweight ≥ 4500 g).

STUDY DESIGN

We performed a multicenter, retrospective cohort study of all non-anomalous singletons with SEFW ≥ 4000 g by Registered Diagnostic Medical Sonographers conducted within 14 days of delivery. Cohorts were grouped by time interval between ultrasound and delivery: 0-7 days versus 8-14 days. The detection rate (DR) and false positive rate (FPR) for detection of birthweight (BW) ≥ 4500 g were compared between groups with subgroup analysis for diabetic women. Area under the receiver operator curve (AUC) was calculated to analyze all possible SEFW cutoffs within our cohort.

RESULTS

A total of 330 patients met inclusion criteria with 250 (75.8 %) having SEFW within 7 days and 80 (24.2 %) with SEFW 8-14 days prior to delivery. The rate of macrosomia was 15.1 % (N = 51). The DR for macrosomia was significantly higher when SEFW was performed within 7 days of delivery compared to 8-14 days among non-diabetic (73.0 % vs 7.1 %; p < 0.001) and diabetic women (76.5 % vs 16.7 %; p = 0.02). There was no significant change in FPR in either group. The AUC for detection of macrosomia was significantly higher when SEFW was performed within 7 days versus 8-14 days (0.89 vs 0.63; p < 0.01).

CONCLUSION

With SEFW ≥ 4000 g, the detection of BW ≥ 4500 g is significantly higher when the sonographic examination is within 7 days of birth irrespective of maternal diabetes.

Identifying fetal growth disorders using ultrasound in obese nulliparous women

OBJECTIVE

We evaluated the ability of third trimester ultrasound to diagnose fetal growth disorders among obese women.

METHODS

This is a retrospective cohort study of obese nulliparous women who delivered term singleton neonates who had an ultrasound within 5 weeks of delivery. We characterized the sensitivity, specificity, positive predictive value and negative predictive value of ultrasound to detect large-for-gestational age (LGA) and small-for-gestational age (SGA) infants. Antenatally, LGA and SGA were defined as an ultrasound estimated fetal weight >90% or <10% based on the Hadlock formula. Postnatally, LGA or SGA designation was based on gestational age-based birthweight percentiles. Test characteristics were analyzed for the total cohort and by class of obesity (class II, body mass index [BMI] = 35.0-39.9 kg/m² versus class III, BMI ≥ 40 kg/m²). We compared the area under the curve for receiver-operating characteristic (ROC) curves for different classes of obesity.

RESULTS

Of 690 women, 13 (1.9%) screened positive for SGA and 19 (2.8%) delivered an SGA neonate. In contrast, 158 (22.9%) screened positive for LGA and 97 (14.1%) delivered an LGA neonate. The sensitivity of ultrasound for SGA was 26.3% and the specificity was 98.8%. The sensitivity for LGA was 75.3% and the specificity was 85.7%. The ROC curves did not differ significantly for different classes of obesity (p = .69 for SGA, p = .75 for LGA).

CONCLUSION

Ultrasound in obese women who delivered term pregnancies has a high specificity but poor sensitivity for SGA and a low positive predictive value for LGA.

Sonographic Estimated Fetal Weight and Cesarean Delivery among Nulliparous Women with Obesity

Objective  This study was aimed to examine the association between having an ultrasound estimate of fetal weight (US-EFW) and mode of delivery among obese women. Study Design  A retrospective cohort study of nulliparous women with a body mass index of ≥ 35 kg/m ² who delivered term singleton gestations. We examined whether having had an US-EFW within 35 days of delivery, or an US-EFW ≥ 90th percentile for gestational age, was associated with intrapartum cesarean delivery. Results  Of 2,826 women, 22.5% ( n  = 636) had an US-EFW within 35 days of delivery. Having an US-EFW was associated with increased frequency of cesarean (43.1% for those with an US-EFW versus 30.0% for those without, p  < 0.001); this finding persisted when controlling for confounders (adjusted odds ratio [aOR] 1.48, 95% confidence interval [CI] 1.21-1.81). Of the 636 women with an US-EFW, 22.5% ( n  = 143) had an US-EFW ≥ 90th percentile for gestational age, which was associated with increased frequency of an intrapartum cesarean (60.8% for those with an US-EFW ≥ 90th percentile vs. 37.9% for those with an US-EFW of < 90th percentile, p  < 0.001), even when accounting for confounders (aOR = 1.78, 95% CI: 1.10-2.87). Conclusion  The presence of an US-EFW among nulliparous obese women was associated with undergoing intrapartum cesarean delivery.

Influence of maternal obesity on the accuracy of ultrasonography birth weight prediction

Objective: The aim of the study was to investigate whether the accuracy of ultrasound estimates of fetal weight (EFW) was dependent on maternal obesity.Study design: A prospective cross-sectional study of 1064 singleton pregnant women classified according to body mass index (BMI) into two categories: normal (BMI < 25 kg/m², n = 863) and obese (BMI ≥ 35 kg/m², n = 201) was conducted. EFW were calculated using Hadlock's formula, and the difference between EFW and the actual birthweight (absolute percent error) was analyzed in both groups. Spearman's correlation was used to assess the relationship between ultrasound performance (absolute error), maternal BMI, and actual birth weight.Results: Median absolute error of sonographic EFW was 5.90 and 6.47% for the normal and obese groups, respectively (p .38). A correlation between EFW and birth weight (BW) was found in both groups, r = 0.755 (p < .001) and r = 0.753 (p < .001), respectively. The correlation between absolute error, maternal BMI, and fetal birth weight was poor.Conclusions: Maternal obesity is unrelated to the accuracy of sonographic EFW, and regardless of maternal or fetal size, ultrasound is currently an accurate method of prediction for both obese and normal weight pregnant women.

Can we improve the gestation-adjusted projection (GAP) method for prediction of birth weight in morbidly obese women?. J Matern Fetal Neonatal Med 2018;32:3600-3605. [PMID: 29681190 DOI: 10.1080/14767058.2018.1468882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Objective: The gestation-adjusted projection (GAP) is a method to predict birthweight using population birth data and third trimester ultrasound fetal weight. This method usually utilizes population birth weight data from almost 40 years ago. In 2011, a large cohort of racially diverse infants across the US was included to validate updated birth curves. Our objective was to determine if the updated data would improve the accuracy of the GAP method during the third trimester among obese women. Methods: This secondary analysis of a cohort study included singleton pregnancies of obese women who had fetal growth assessment(s) in the third trimester. The first subgroup (N = 235) included women with a BMI >40 kg/m² who had ultrasounds during 30 + 0-35 + 0 weeks (EARLY) and greater than 35 + 0 weeks (LATE). The second subgroup (N = 431) included women with a BMI 30-35, 40-50, or >50 kg/m² who had an ultrasound during 34 + 0-36 + 6 weeks. Mean absolute percent error was calculated for all GAP methods and compared using paired t-tests. Sensitivity, specificity, and area under the curve for diagnosis of birth weight >4000 grams were also estimated for each GAP method. Results: The mean absolute percent error for the first subgroup (N = 235) using historical population birth weights was 7.4-7.9%. After using updated population birth weight curves using all neonates, the mean absolute percent error for the first subgroup ranged between 7.6 and 9.4%. GAP predictions using all neonates, as well as male and female-specific birth data compared to the historical population data during both the EARLY and LATE periods were significantly worse (p < .01). The mean absolute percent error for the second subgroup (N = 431) using historical population birth weights ranged from 7.2 to 7.9%. The absolute percent error using gender-specific compared to historical data was significant in the BMI 30-35 group (male 8.1% versus historical 7.6%, p < .01, female 8.1% versus historical 7.6%, p < .01). The differences in absolute percent error between historical and updated population data became less evident in the BMI 40-50 and >50-kg/m² groups (p = .05 and p = .15, respectively) though still overall performed worse with the updated data. Conclusions: Prediction of birth weight using the GAP method does not seem to be improved among obese women after using updated population data. Alternatively, modeling techniques may need to be applied to improve the accuracy of the GAP method.

Does Maternal Body Mass Index Have an Effect on the Accuracy of Ultrasound-Derived Estimated Birth Weight?: A Retrospective Study

OBJECTIVES

The purpose of this study was to investigate the relationship between the maternal body mass index (BMI) and the accuracy of ultrasound-derived birth weight.

METHODS

A retrospective chart review was performed on women who had an ultrasound examination between 36 and 43 weeks' gestation and had complete delivery data available through electronic medical records. The ultrasound-derived fetal weight was adjusted by 30 g per day of gestation that elapsed between the ultrasound examination and delivery to arrive at the predicted birth weight.

RESULTS

A total of 403 pregnant women met inclusion criteria. Age ranged from 13-44 years (mean ± SD, 28.38 ± 5.97 years). The mean BMI was 32.62 ± 8.59 kg/m² . Most of the women did not have diabetes (n = 300 [74.0%]). The sample was primarily white (n = 165 [40.9%]) and Hispanic (n = 147 [36.5%]). The predicted weight of neonates at delivery (3677.07 ± 540.51 g) was higher than the actual birth weight (3335.92 ± 585.46 g). Based on regression analyses, as the BMI increased, so did the predicted weight (P < .01) and weight at delivery (P < .01). The accuracy of the estimated ultrasound-derived birth weight was not predicted by the maternal BMI (P = .22). Maternal race and diabetes status were not associated with the accuracy of ultrasound in predicting birth weight.

CONCLUSIONS

Both predicted and actual birth weight increased as the BMI increased. However, the BMI did not affect the accuracy of the estimated ultrasound-derived birth weight. Maternal race and diabetes status did not influence the accuracy of the ultrasound-derived predicted birth weight.

Fetal size monitoring and birth-weight prediction: a new population-based approach

OBJECTIVE

To develop a complete, population-based system for ultrasound-based fetal size monitoring and birth-weight prediction for use in the second and third trimesters of pregnancy.

METHODS

Using 31 516 ultrasound examinations from a population-based Norwegian clinical database, we constructed fetal size charts for biparietal diameter, femur length and abdominal circumference from 24 to 42 weeks' gestation. A reference curve of median birth weight for gestational age was estimated using 45 037 birth weights. We determined how individual deviations from the expected ultrasound measures predicted individual percentage deviations from expected birth weight. The predictive quality was assessed by explained variance of birth weight and receiver-operating characteristics curves for prediction of small-for-gestational age. A curve for intrauterine estimated fetal weight was constructed. Charts were smoothed using the gamlss non-linear regression method.

RESULTS

The population-based approach, using bias-free ultrasound gestational age, produces stable estimates of size-for-age and weight-for-age curves in the range 24-42 weeks' gestation. There is a close correspondence between percentage deviations and percentiles of birth weight by gestational age, making it easy to convert between the two. The variance of birth weight that can be 'explained' by ultrasound increases from 8% at 20 weeks up to 67% around term. Intrauterine estimated fetal weight is 0-106 g higher than median birth weight in the preterm period.

CONCLUSIONS

The new population-based birth-weight prediction model provides a simple summary measure, the 'percentage birth-weight deviation', to be used for fetal size monitoring throughout the third trimester. Predictive quality of the model can be measured directly from the population data. The model computes both median observed birth weight and intrauterine estimated fetal weight. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Accuracy of Sonographically Estimated Fetal Weight Near Delivery in Pregnancies Complicated With Diabetes Mellitus

OBJECTIVES

The purpose of this study was to evaluate the accuracy of sonographic estimations of fetal weight (FW) and signed percent error between pregnant patients with and without diabetes mellitus (DM).

METHODS

We conducted a retrospective cohort study of all singleton nonanomalous live births who delivered after 34 weeks and received a sonographic estimation of FW within 2 weeks of delivery at the University of Cincinnati Medical Center between 2008 and 2011. Our primary outcome compared the ΔFW and signed percent error between DM and non-DM pregnancies. Sensitivity and specificity were calculated for the prediction of FW greater than 4000 g in each study group. Linear regression analysis assessed correlation coefficients, R² values, and variance of the ΔFW by live birth weight.

RESULTS

The mean ΔFWs were 62 and 103 g for non-DM and DM pregnancies, respectively (P = .04). However, the signed percent error (mean ± SD, 1.7% ± 9.8% versus 2.6% ± 9.9%; P = .15) was similar between the study groups. Linear regression comparing the ΔFW to the live birth weight revealed a weak correlation in DM (r = 0.34; R²  = 0.11) and non-DM pregnancies, (r = 0.17; R²  = 0.03) pregnancies. Overall sensitivity for the prediction of FW greater than 4000 g was poor (0.41 and 0.62 in non-DM and DM pregnancies). However, the specificity was high (0.97 and 0.99 for both groups).

CONCLUSIONS

Although DM alters the biometric measurements of the fetus with increasing thoracoabdominal size, there are no clinically significant alterations in the accuracy of sonography for FW prediction when performed near delivery. Sonography is highly specific for birth weight greater than 4000 g, which is helpful for delivery planning and management.

Implications of maternal obesity on fetal growth and the role of ultrasound

Over fifty percent of women entering pregnancy are overweight or obese. This has a significant impact on short and long term maternal and infant health outcomes, and the intergenerational effects of obesity are now a major public health problem globally. Areas covered: There are two major pathways contributing to fetal growth. Glucose and insulin directly affect growth, while other substrates such as leptin, adiponectin and insulin-like growth factors indirectly influence growth through structural and morphological effects on the placenta, uteroplacental blood flow, and regulation of placental transporters. Advances in ultrasonography over the past decade have led to interest in the prediction of the fetus at risk of overgrowth and adiposity utilizing both standard ultrasound biometry and fetal body composition measurements. However, to date there is no consensus regarding the definition of fetal overgrowth, its reporting, and clinical management. Expert commentary: Maternal dietary intervention targeting the antenatal period appear to be too late to sufficiently affect fetal growth. The peri-conceptual period and early pregnancy are being evaluated to determine if the intergenerational effects of maternal obesity can be altered to improve newborn, infant and child health.

Estimation of fetal weight in pregnancies past term

INTRODUCTION

The aim of the study was to investigate the accuracy of estimating fetal weight with ultrasound in pregnancies past term, using the eSnurra algorithm.

MATERIAL AND METHODS

In all, 419 women with pregnancy length of 290 days, attending a specialist consultation at Stavanger University Hospital, Norway, were included in a prospective observational study. Fetal weight was estimated using biparietal diameter (BPD) and abdominal circumference (AC). The algorithm implemented in an electronic calculation (eSnurra) was used to compute estimated fetal weight (EFW). Results were compared with birthweight (BW).

RESULTS

The mean interval between the ultrasound examination and birth was 2 days (SD 1.4). The median difference between BW and EFW was -6 g (CI -40 to +25 g) and the median percentage error was -0.1% (95% CI -1.0 to 0.6%). The median absolute difference was 190 g (95% CI 170-207 g). The BW was within 10% of EFW in 83% (95% CI 79-87%) of cases and within 15% of EFW in 94% (95% CI 92-96%) of cases. Limits of agreement (95%) were from -553 g to +556 g. Using 5% false-positive rates, the sensitivity in detecting macrosomic and small for gestational age fetuses was 54% (95% CI 35-72%) and 49% (95% CI 35-63%), respectively.

CONCLUSION

The accuracy of fetal weight estimation was good. Clinicians should be aware of limitations related to prediction at the upper and lower end, and the importance of choosing appropriate cut-off levels.

Obesity and the Critical Care Pregnant Patient

The rise of obesity among gravid women has been tracked and documented in many first-world countries, but a dramatic rise has been noted over the last 15 years. Definitions of "normal-weight, overweight and obese" have been defined; however, new terms are used to describe more severe degrees of obesity. Obesity in any form or degree increases morbidities in mothers. The unique physiologic characteristics of the obese gravida set up unique challenges in her management, especially in an acute setting such as labor. The definitions, trends, and management decisions pertaining to the obese parturient will be described in this review.

Antenatal dietary and lifestyle advice for women who are overweight or obese and the effect on fetal growth and adiposity: the LIMIT randomised trial

OBJECTIVE

To report the influence of maternal overweight and obesity on fetal growth and adiposity and effects of an antenatal dietary and lifestyle intervention among these women on measures of fetal growth and adiposity as secondary outcomes of the LIMIT Trial.

DESIGN

Randomised controlled trial.

SETTING

Public maternity hospitals in metropolitan Adelaide, South Australia.

POPULATION

Pregnant women with a body mass index ≥ 25 kg/m(2), and singleton gestation between 10(+0) and 20(+0) weeks.

METHODS

Women were randomised to Lifestyle Advice or continued Standard Care and offered two research ultrasound scans at 28 and 36 weeks of gestation.

MAIN OUTCOME MEASURES

Ultrasound measures of fetal growth and adiposity.

RESULTS

For each fetal body composition parameter, mean Z-scores were substantially higher when compared with population standards. Fetuses of women receiving Lifestyle Advice demonstrated significantly greater mean mid-thigh fat mass, when compared with fetuses of women receiving Standard Care (adjusted difference in means 0.17; 95% CI 0.02-0.32; P = 0.0245). While subscapular fat mass increased between 28 and 36 weeks of gestation in fetuses in both treatment groups, the rate of adipose tissue deposition slowed among fetuses of women receiving Lifestyle Advice, when compared with fetuses of women receiving Standard Care (P = 0.0160). No other significant differences were observed.

CONCLUSIONS

These findings provide the first evidence of changes to fetal growth following an antenatal dietary and lifestyle intervention among women who are overweight or obese.

Sonographic fetal weight estimation in normal and overweight/obese healthy term pregnant women by gestation-adjusted projection (GAP) method

PURPOSE

The objective of this study is to assess the ultrasound accuracy in fetal weight estimation related to the time distance between the actual weight recorded at delivery and the period of sonography among normal and overweight/obese pregnant women within 3 weeks prior birth at term.

METHODS

Four-hundred and ninety patients with healthy pregnancy were studied in a cohort study. The absolute percent error in estimation was achieved by gestation-adjusted projection method from Hadlock model for weight calculation as measure of accuracy. The mean percentage error variation over the weeks was correlated to maternal body mass index (BMI, Kg/m(2)) at ultrasound. The relationship between BMI and ultrasound performance was assessed by linear regression.

RESULTS

The overall proportion of supposed sonographic estimated fetal weight at birth within ±10 % of the birth weight significantly declines over the weeks (P = .016). The trend toward a progressive deterioration in ultrasound accuracy is not statistically significant for normal weight women (P = .272) but it is for over-weight/obese (P = .044). On univariate analysis, the absolute percent error and absolute error are positively related to BMI.

CONCLUSIONS

Accuracy is related to the week at ultrasound scan with a gradual deterioration over the time and it worsens with increasing distance in days between the date of ultrasounds and delivery. The deterioration is greater for BMI ≥ 25.

Fetal weight estimation in diabetic pregnancies using the gestation-adjusted projection method: comparison of two timing strategies for third-trimester sonography

OBJECTIVES

The gestation-adjusted projection method extrapolates birth weight using third-trimester sonography. This technique is shown to be more accurate for sonographic examinations from 34 weeks to 36 weeks 6 days than 37 weeks to 38 weeks 6 days. Our objective was to determine whether even earlier sonographic examinations (31 weeks-33 weeks 6 days) further improves birth weight prediction in patients with diabetes.

METHODS

We conducted a retrospective cohort analysis of 388 pregnant women with pregestational or gestational diabetes who delivered at 37 weeks or later and had a sonographic examination performed between 31 weeks and 36 weeks 6 days. Sonographic examinations were categorized as "early" if performed at 31 weeks to 33 weeks 6 days or "late" if performed at 34 weeks to 36 weeks 6 days. We estimated birth weight using the gestation-adjusted projection method, compared errors in prediction of birth weight using the t test and Mann-Whitney U test, and performed a 2-sample test of proportions to compare prediction of macrosomia (birth weight >4000 g).

RESULTS

The early and late groups had similar mean gestational ages at birth (38 weeks 4 days versus 38 weeks 5 days; P = .13) and rates of macrosomia (10.7% versus 12.4%; P = .63). The early group had a greater mean absolute error (336 versus 297 g; P = .03) and percent error (9.9% versus 7.9%; P = .01) in birth weight prediction but a lower mean birth weight (3303 versus 3426 g; P = .02). Sensitivity for prediction of macrosomia was 19% in the early group versus 45% in the late group (P = .07), whereas specificity was similar (98% versus 96%; P = .27).

CONCLUSIONS

Using the gestation-adjusted projection method in our patients with diabetes, we found that sonographic examinations performed at 34 weeks to 36 weeks 6 days better predicted birth weight than those performed at 31 weeks to 33 weeks 6 days.

Prediction of birthweight from third-trimester ultrasound in morbidly obese women

OBJECTIVE

The gestation-adjusted projection method (GAP method) uses third trimester ultrasound fetal weight to predict birthweight. Our study sought to assess if the accuracy of the GAP method in morbidly obese women depended on (1) ultrasound timing or (2) extreme elevations in maternal body mass index (BMI).

STUDY DESIGN

We conducted a diagnostic accuracy study from 2007 to 2012 of all singleton pregnancies with BMI >40 kg/m(2) at the time of delivery that had fetal growth assessment between 30+0 and 35+0 weeks (EARLY) and greater than 35+0 weeks (LATE). Next, a 'reference' BMI group (30-35) was compared with subcategories of women with BMI ≥40. Paired t tests, χ(2) tests and analysis of variance were used to determine significance.

RESULTS

A total of 235 pregnancies for the first objective and 430 for the second objective were included. The mean absolute percent error was comparable between the 2 periods (EARLY 7.9 ± 6.7%, LATE 7.4 ± 5.6%; P = .33) and across BMI categories (30-35: 7.6 ± 6.3%, 40-50: 7.2 ± 5.7%, >50: 7.8 ± 6.0%; P = .79). The sensitivity and specificity of the GAP method to predict macrosomia during the EARLY time period was 46% (95% confidence interval 28-66) and 97% (94-99) and in the 40-50 BMI subcategory was 72% (47-90) and 96% (90-99), respectively.

CONCLUSION

Prediction of birthweight using the GAP method in obese women does not appear to be influenced by timing of ultrasound or extreme BMI. In a population where clinical estimated fetal weight is difficult, the GAP method may aid in delivery planning.

Fetal weight estimation in gestational diabetic pregnancies: comparison between conventional and three-dimensional fractional thigh volume methods using gestation-adjusted projection

OBJECTIVES

To evaluate the accuracy of gestation-adjusted birth-weight estimation using a three-dimensional (3D) fractional thigh volume (TVol) method in pregnant women with gestational diabetes mellitus (GDM), and to compare it with the conventional two-dimensional method of Hadlock et al.

METHODS

Pregnant women with GDM were referred at 34 to 36 + 6 weeks' gestation for ultrasound examination. Estimated fetal weight (EFW) was obtained using both the Hadlock and the TVol methods. Using a gestation-adjusted projection method, predicted birth weight was compared to actual birth weight at delivery.

RESULTS

Based on 125 pregnancies, the TVol method with gestation-adjusted projection had a mean (± SD) percentage error in estimating birth weight of -0.01 ± 5.0 (95% CI, -0.96 to 0.98)% while the method of Hadlock with gestation-adjusted projection had an error of 1.28 ± 9.1 (95% CI, -0.33 to 2.87)%. The mean percentage error of the two methods was significantly different (P = 0.039), while the random error was not (P = 1.0). For the prediction of macrosomia (birth weight ≥ 4000 g, n = 19), sensitivity was 84 and 63% for the TVol and Hadlock methods, respectively (95% CI for difference -2 to 44%, P = 0.22) and specificity was 96 and 89% for the TVol and Hadlock methods, respectively (95% CI for difference 5-9%, P = 0.01).

CONCLUSIONS

In women with GDM, a new method of estimating birth weight based on 3D-TVol measurements performed at 34 + 0 to 36 + 6 weeks' gestation and gestation-adjusted projection of estimated fetal weight, is more accurate than the standard method based on Hadlock's formula in predicting birth weight. The TVol method has comparable sensitivity but higher specificity than the Hadlock method in predicting neonatal macrosomia.

Antepartum obstetrical complications associated with obesity

Obesity is a major risk factor for many obstetrical complications, including pre-eclampsia, gestational diabetes, indicated preterm birth, macrosomia, and stillbirth. Clinicians should be aware of the unique obstetrical management considerations related to obesity, including recommendations for alterations in prenatal care. In addition, obese gravidas commonly have underlying medical conditions that can impact pregnancy and must be appreciated to optimize care. Obese women should be educated about these risks, ideally before pregnancy. Awareness of the complications that can arise for these women and potential changes in management offer opportunities to improve both prenatal and lifelong health.