Chat Generative Pre-trained Transformer: why we should embrace this technology.

With the advent of artificial intelligence that not only can learn from us but also can communicate with us in plain language, humans are embarking on a brave new future. The interaction between humans and artificial intelligence has never been so widespread. Chat Generative Pre-trained Transformer is an artificial intelligence resource that has potential uses in the practice of medicine. As clinicians, we have the opportunity to help guide and develop new ways to use this powerful tool. Optimal use of any tool requires a certain level of comfort. This is best achieved by appreciating its power and limitations. Being part of the process is crucial in maximizing its use in our field. This clinical opinion demonstrates the potential uses of Chat Generative Pre-trained Transformer for obstetrician-gynecologists and encourages readers to serve as the driving force behind this resource.

Use of cervical elastography at 18 to 22 weeks' gestation in the prediction of spontaneous preterm birth.

BACKGROUND: Accurate identification of the women who will have spontaneous preterm birth continues to be a great challenge. The use of cervical elastography for prediction of preterm birth is promising, but several limitations exist. Newer cervical elastography technology has been developed that may prove useful in evaluation of risk of preterm birth. OBJECTIVE: This study aimed to develop standard cervical elastography nomograms for singleton pregnancies at 18 to 22 weeks' gestation using the E-Cervix ultrasound application, assess intraobserver reliability of the E-Cervix elastography parameters, and determine whether these cervical elastography measurements can be used in the prediction of spontaneous preterm birth. STUDY DESIGN: This was a prospective cohort study of pregnant women undergoing cervical length screening assessment via transvaginal ultrasound examination at 18 to 22 weeks' gestation. A semiautomatic, cervical elastography application (E-Cervix) was used during the transvaginal examination to calculate 5 quantitative parameters (internal os stiffness, external os stiffness, internal -to -external os stiffness ratio, hardness ratio, and elasticity contrast index) and create a standard nomogram for each one of them. The intraobserver reliability was calculated using Shrout-Fleiss reliability. Cervical elastography parameters were compared between those who delivered preterm (<37 weeks) spontaneously and those who delivered full term. A multivariable logistic regression model was performed to determine the ability of the cervical elastography parameters to predict spontaneous preterm birth. RESULTS: A total of 742 women were included, of which 49 (6.6%) had a spontaneous preterm delivery. A standard nomogram was created for each of the cervical elastography parameters from those who had a full-term birth in the index pregnancy (n=693). Intraobserver reliability was good or excellent (intraclass correlation, 0.757-0.887) for each of the cervical elastography parameters except external os stiffness which was poor (intraclass correlation, 0.441). In univariate analysis, none of the cervical elastography parameters were associated with a statistically significant increased risk of spontaneous preterm birth. In a multivariable model adjusting for history of preterm birth, gravidity, ethnicity, cervical cerclage, and vaginal progesterone use, increasing elasticity contrast index was significantly associated with an increased risk of spontaneous preterm birth (odds ratio, 1.15; 95% confidence interval, 1.02-1.30; P=.02). CONCLUSION: Cervical elastography parameters are reliably measured and are stable across 18 to 22 weeks' gestation. Based on our findings, the elasticity contrast index was associated with an increased risk of spontaneous preterm birth and may be a useful parameter for future research.

Experiences of early graduate medical students working in New York hospitals during the COVID-19 pandemic: a mixed methods study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic presented the world with a sudden need for additional medical professionals. Senior medical students were identified as potential workers and many worldwide graduated early to serve as Junior Physicians in hospitals. The authors sought to identify factors that informed the decision to work, describe experiences in this capacity, and elucidate benefits for trainees. METHODS: The investigators conducted a mixed-methods observational cohort study of early medical graduates eligible to work as Junior Physicians at two New York medical centers in April/May 2020 during an initial surge in COVID-19 hospitalizations. Graduates were surveyed, and a sample of Junior Physicians participated in a focus group. Survey responses of those who worked were compared to those who did not. Focus group responses were transcribed, coded, and thematically analyzed. RESULTS: Fifty-nine graduates completed the study methods and 39 worked as Junior Physicians. Primary reasons for working included duty to help (39 [100%]), financial incentive (32 [82%]), desire to learn about pandemic response (25 [64%]), and educational incentive (24 [62%]). All had direct contact with COVID-19 patients, believed working was beneficial to their medical training, and were glad they worked. None contracted a symptomatic infection while working. Compared with non-Junior Physicians, Junior Physicians reported increased comfort levels in completing medical intern-level actions like transitions of care functions, such as writing transfer notes (P < 0.01), writing discharge orders (P = 0.01), and providing verbal sign out (P = 0.05), and they reported more comfort in managing COVID-19 patients. Sixteen themes emerged from the focus group and were placed into four categories: development of skills, patient care, safety, and wellness. CONCLUSIONS: Senior medical students chose to work as Junior Physicians for both personal and educational reasons. Experiences were beneficial to trainees and can inform future innovations in medical education.

Term cesarean delivery in the first pregnancy is not associated with an increased risk for preterm delivery in the subsequent pregnancy.

BACKGROUND: Prior studies have reported an increased risk for preterm delivery following a term cesarean delivery. However, these studies did not adjust for high-risk conditions related to the first cesarean delivery and are known to recur. OBJECTIVE: The objective of the study was to determine whether there is an association between term cesarean delivery in the first pregnancy and subsequent spontaneous or indicated preterm delivery. STUDY DESIGN: This was a retrospective cohort study of women with the first 2 consecutive singleton deliveries (2007-2014) identified through a linked pregnancy database at a single institution. Women with a first pregnancy that resulted in cesarean delivery at term were compared with women whose first pregnancy resulted in a vaginal delivery at term. Exclusion criteria were known to recur medical or obstetrical complications during the first pregnancy. A propensity score analysis was performed by matching women who underwent a cesarean delivery with those who underwent a vaginal delivery in the first pregnancy. The association between cesarean delivery in the first pregnancy and preterm delivery in the second pregnancy in this matched set was examined using conditional logistic regression. The primary outcome was overall preterm delivery <37 weeks in the second pregnancy. Secondary outcomes included type of preterm delivery (spontaneous vs indicated), late preterm delivery (34-36 6/7 weeks), early preterm delivery (<34 weeks), and small-for-gestational-age birth. RESULTS: Of a total of 6456 linked pregnancies, 2284 deliveries were matched; 1142 were preceded by cesarean delivery and 1142 were preceded by vaginal delivery. The main indications for cesarean delivery in the first pregnancy were dystocia in 703 (61.5%), nonreassuring fetal status in 222 (19.4%), breech presentation in 100 (8.8%), and other in 84 (7.4%). The mean (SD) gestational ages at delivery for the second pregnancy was 38.8 (1.8) and 38.9 (1.7) weeks, respectively, for prior cesarean delivery and vaginal delivery. The risks of preterm delivery in the second pregnancy among women with a previous cesarean and vaginal delivery were 6.0% and 5.2%, respectively (adjusted odds ratio, 1.46, 95% confidence interval, [CI] 0.77-2.76). In an analysis stratified by the type of preterm delivery in the second pregnancy, no associations were seen between cesarean delivery in the first pregnancy and spontaneous preterm delivery (4.6% vs 3.9%; adjusted odds ratio, 1.40, 95% confidence interval, 0.59-3.32) or indicated preterm delivery (1.6% vs 1.4%; adjusted odds ratio, 1.21, 95% confidence interval, 0.60-2.46). Similarly, no significant differences were found in late preterm delivery (4.6% vs 4.1%; adjusted odds ratio, 1.13, 95% confidence interval, 0.55-2.29), early preterm delivery (1.6% vs 1.2%; adjusted odds ratio, 1.25, 95% confidence interval, 0.59-2.67), or neonates with birthweight less than the fifth percentile for gestational age (3.6% vs 2.2%; adjusted odds ratio, 1.26, 95% confidence interval, 0.52-3.06). CONCLUSION: After robust adjustment for confounders through a propensity score analysis related to the indication for the first cesarean delivery at term, cesarean delivery is not associated with an increase in preterm delivery, spontaneous or indicated, in the subsequent pregnancy.

The use of cervical sonography to differentiate true from false labor in term patients presenting for labor check.

BACKGROUND: Cervical length by transvaginal ultrasound to predict preterm labor is widely used in clinical practice. Virtually no data exist on cervical length measurement to differentiate true from false labor in term patients who present for labor check. False-positive diagnosis of true labor at term may lead to unnecessary hospital admissions, obstetrical interventions, resource utilization, and cost. OBJECTIVE: We sought to determine if cervical length by transvaginal ultrasound can differentiate true from false labor in term patients presenting for labor check. STUDY DESIGN: This is a prospective observational study of women presenting to labor and delivery with labor symptoms at 37-42 weeks, singleton cephalic gestation, regular uterine contractions (≥4/20 min), intact membranes, and cervix ≤4 cm dilated and ≤80% effaced. Those patients with placenta previa and indications for immediate delivery were excluded. The shortest best cervical length of 3 collected images was used for analysis. Providers managing labor were blinded to the cervical length. True labor was defined as spontaneous rupture of membranes or spontaneous cervical dilation ≥4 cm and ≥80% effaced within 24 hours of cervical length measurement. In the absence of these outcomes, labor status was determined as false labor. Receiver operating characteristic curves were generated to assess the predictive ability of cervical length to differentiate true from false labor and were analyzed separately for primiparous and multiparous patients. The diagnostic accuracies of various cervical length cutoffs were determined. The relationship of cervical length and time to delivery was also analyzed including both use and nonuse of oxytocin. RESULTS: In all, 77 patients were included in the study; the prevalence of true labor was 58.4% (45/77). Patients who were in true labor had shorter cervical length as compared to those in false labor: median 1.3 cm (range 0.5-4.1) vs 2.4 cm (range 1.0-5.0), respectively (P < .001). The area under the receiver operating characteristic curve for primiparous patients was 0.88 (P < .001) and for multiparous patients was 0.76 (P < .01), both demonstrating good correlation. The area under the receiver operating characteristic curves were not significantly different between primiparous and multiparous (P = .23). The area under the receiver operating characteristic curve for primiparous and multiparous patients combined was 0.8 (P < .0001), indicating a good overall correlation between cervical length and its ability to differentiate true from false labor. Overall, a cervical length cutoff of ≤1.5 cm to predict true labor had the highest specificity (81%), positive predictive value (83%), and positive likelihood ratio (4.2). There were no differences in cervical length prediction between primiparous and multiparous patients. Cervical length was positively correlated with time to delivery, regardless of the use of oxytocin. CONCLUSION: In differentiating true from false labor in term patients who present for labor check, a cervical length of ≤1.5 cm was the most clinically optimal cutoff with the lowest false positive rate-due to its highest specificity-and highest positive predictive value and positive likelihood ratios. Its use to decide admission in patients at term with labor symptoms may prevent unnecessary admissions, obstetrical interventions, resource utilization, and cost.

Does educational intervention affect resident competence in sonographic cervical length measurement?

OBJECTIVE: To determine if a structured teaching module improves resident competency in transvaginal sonographic cervical length measurements. METHODS: This was a prospective cohort study involving obstetrics and gynecology residents at a single institution. Residents collected 10 transvaginal cervical images from patients with threatened preterm labor presenting to Labor and Delivery. After initial image acquisition, residents participated in a lecture-based teaching module involving a pre- and post-intervention assessment. Following the didactic session, they collected 10 additional images. All the images were scored independently by two Maternal-Fetal Medicine attending physicians based on the quality and accuracy of the measured cervical length. Pre-and post- intervention test results were compared, as well as pre- and post- intervention image scores. Parametric and nonparametric tests were used as appropriate with p < 0.05 considered significant. RESULTS: Ninety-three percent of the residents (14/15) improved their scores from pre-test to post-test or maintained an already perfect score (p < 0.01). Improvement was most significant with the junior residents. Seventy-nine percent of the residents (11/14) improved their cervical image scores after the educational session. Mean score for total residents was 73.7 + 12.6 pre-intervention and 90.2 + 9.9 post-intervention (p < 0.01) out of a total of 120. CONCLUSIONS: There is an improvement in the competence of resident measured cervical lengths via transvaginal ultrasound when a structured educational module is implemented for resident education.

The timing of administration of antenatal corticosteroids in women with indicated preterm birth.

OBJECTIVE: We sought to determine the timing of administration of antenatal corticosteroids (AS) for indicated preterm births and to identify which indications are associated with the most optimal timing of administration. STUDY DESIGN: This was a retrospective cohort of patients who received AS in anticipation of indicated preterm birth from 2009 through 2012 at Winthrop University Hospital, Mineola, NY. Medical records of patients who received AS, as identified through the hospital pharmacy database, were reviewed. Patients were included if they had a singleton or twin gestation and they received AS for maternal or fetal indications. Women were excluded if they received AS for spontaneous preterm labor or preterm rupture of membranes. Maternal demographic and obstetrical characteristics were compared between those who received AS≤7 days vs >7 days from delivery using parametric and nonparametric tests with relative risks and 95% confidence intervals. P<.05 was considered significant. RESULTS: In all, 193 patients were included in this study. Median latency from AS administration to delivery was 9 days (range, 0-83); 93 patients (48%) received AS within 7 days of delivery. There were no significant differences between the 2 groups with regards to baseline maternal characteristics. Those delivering within 7 days of AS administration were more likely to have maternal vs fetal indications (84% vs 16%). CONCLUSION: Only 48% of patients with an indication for preterm birth received AS within 7 days of its administration. AS appear to be more optimally timed in the presence of maternal rather than fetal indications.

Practice patterns in the timing of antenatal corticosteroids for fetal lung maturity.

OBJECTIVE: To determine the practice patterns of antenatal corticosteroid (AS) administration in women with threatened preterm labor. METHODS: This was a retrospective cohort of patients who received betamethasone between 2009 and 2010, identified through a pharmacy database. Patients with high order multiples; incomplete records and indicated preterm delivery were excluded. Demographic and obstetrical factors were compared between women with an AS to delivery latency of ≤7 days versus >7 days. Parametric and non-parametric tests were used as appropriate. p < 0.05 denotes statistical significance; relative risks with 95% confidence intervals were calculated. RESULTS: Three-hundred forty-five patients were included. Sixty-eight patients (20%) received AS within 7 days of delivery. Women who received AS ≤7 days before delivery (optimal timing) were more likely to have a transvaginal cervical length ≤2 cm (RR:2.53, CI: 1.2-5.6), cervical dilation ≥2 cm (RR: 3.86, CI: 2.7-5.6) and positive fFN (RR: 2.59, CI: 1.1-6.3). Preterm premature ruptured membranes were also associated with optimal timing of AS (RR: 4.86, CI: 3.4-6.8). CONCLUSIONS: Eighty percent of patients receive suboptimal timing of AS administration. Factors associated with suboptimal timing are: cervical length >2 cm, cervical dilation <2 cm and negative fFN. Cervical assessment should be a key factor in the decision for AS administration. More research is needed for accurate timing of AS in women with threatened preterm labor.

Long-term maternal morbidity and mortality associated with ischemic placental disease.

Ischemic placental disease can have long-term maternal health implications. In this article, we discuss the three conditions of ischemic placental disease (preeclampsia, fetal growth restriction, and abruption placenta) and its associated long-term maternal morbidity. Retrospective observational studies comparing pregnancies complicated by ischemic placental disease to uncomplicated pregnancies suggest an increased long-term risk of hypertension, cardiovascular death, metabolic syndrome, and cerebrovascular disease. This association is much stronger in women who had an indicated-preterm delivery due to ischemic placental disease. It is important to adequately counsel women who are diagnosed with these conditions about their future health risks. Increased awareness of the potential health risks and multidisciplinary collaboration remains paramount to instituting the appropriate screening and preventative strategies (i.e., behavior modification) for affected women.

Patient acceptance of non-invasive testing for fetal aneuploidy via cell-free fetal DNA.

OBJECTIVE: To evaluate factors associated with patient acceptance of noninvasive prenatal testing for trisomy 21, 18 and 13 via cell-free fetal DNA. METHODS: This was a retrospective study of all patients who were offered noninvasive prenatal testing at a single institution from 1 March 2012 to 2 July 2012. Patients were identified through our perinatal ultrasound database; demographic information, testing indication and insurance coverage were compared between patients who accepted the test and those who declined. Parametric and nonparametric tests were used as appropriate. Significant variables were assessed using multivariate logistic regression. The value p < 0.05 was considered significant. RESULTS: Two hundred thirty-five patients were offered noninvasive prenatal testing. Ninety-three patients (40%) accepted testing and 142 (60%) declined. Women who accepted noninvasive prenatal testing were more commonly white, had private insurance and had more than one testing indication. There was no statistical difference in the number or the type of testing indications. Multivariable logistic regression analysis was then used to assess individual variables. After controlling for race, patients with public insurance were 83% less likely to accept noninvasive prenatal testing than those with private insurance (3% vs. 97%, adjusted RR 0.17, 95% CI 0.05-0.62). CONCLUSION: In our population, having public insurance was the factor most strongly associated with declining noninvasive prenatal testing.

Use of ultrasound in the labor and delivery.

Ultrasound machines are nowadays part of the armamentarium of all modern Labor and Delivery Suites. Due to their portability, these machines are ideal for use in emergencies which can occur at any of the labor and delivery rooms. Many of the emergencies in Labor and Delivery can be life threatening; thus, maternal and fetal safety requires efficient and timely ultrasound evaluation. The purpose of this article is to provide guidelines for quick and efficient use of ultrasound based on both the authors' experience and the published literature.

The effect of maternal thrombophilia on placental abruption: Histologic correlates.

OBJECTIVE: To determine if the histology of placental abruption differs by maternal thrombophilia status. STUDY DESIGN: This was a multicentre, case-control study of women with abruption and delivering at >or=20 weeks' gestation, collected as part of the ongoing New Jersey-placental abruption study. Women were identified by clinical criteria of abruption. Maternal blood was collected postpartum and tested for anticardiolipin antibodies, and mutations in the Factor V Leiden and prothrombin genes. Cases were comprised of women with an abruption and a positive thrombophilia screen. Controls were comprised of women with an abruption and a negative thrombophilia screen. All placental histology was systematically reviewed by two perinatal pathologists, blinded to the abruption status. RESULTS: A total of 135 women with placental abruption were identified, of which 63.0% (n = 85) had at least one diagnosed maternal thrombophilia. There were increases in the rates of meconium-stained membranes (7.9%vs. 2.1%, p = 0.015) and decidual necrosis (4.5%vs. 2.1%, p = 0.023) when a maternal thrombophilia was diagnosed. Although there was no difference in the overall presence of infarcts between the two groups (27.0%vs. 38.3%, p = 0.064), the presence of an old infarct was more common among women with a positive thrombophilia screen (83.3%vs. 44.4%, p = 0.003). CONCLUSION: Placental abruption with a positive maternal thrombophilia screen is associated with higher rates of old placental infarcts and decidual necrosis compared with abruption when thrombophilia is not diagnosed. These lesions suggest a chronic etiology of placental abruption in the presence of a maternal thrombophilia.

Effect of sulfasalazine on basal and bacteria-stimulated interleukin-8 production by endocervical epithelial cells.

PROBLEM: Sulfasalazine (SASP) inhibits lipopolysaccharide-induced nuclear-factor kappa B activation and interleukin-8 (IL-8) production by cultured explants of placenta, amnion and choriodecidua. Bacteria-induced IL-8 production in the cervix is a potential mechanism for premature cervical ripening that may lead to preterm birth. Our objective was to determine if SASP inhibits IL-8 production by endocervical cells stimulated with bacterial pathogens associated with preterm birth. METHOD OF STUDY: Human endocervical cells were incubated with 0-1.6 mm SASP and then stimulated with Ureaplasma parvum, Escherichia coli, or Gardnerella vaginalis. Conditioned medium was then harvested and production of IL-8 was quantified by ELISA. Viability of the cells was ascertained at the end of the experiment with the MTT-assay. RESULTS: At the highest concentration tested (1.6 mm), SASP significantly inhibited IL-8 production by cultures stimulated with E. coli (P < 0.001), U. parvum (P < 0.001), and G. vaginalis (P < 0.001). Viability of the cells, however, was significantly reduced by SASP at 0.8 and 1.6 mm in both the presence and absence of bacteria for all experiments. CONCLUSION: Although high concentrations of SASP inhibit IL-8 production by cultures of endocervical cells stimulated with pathogens associated with preterm birth, this effect may be because of toxicity of the antibiotic on the cells.

Reduced folate carrier 80A-->G polymorphism, plasma folate, and risk of placental abruption.

Folate deficiency and maternal smoking are strong risk factors for placental abruption. We assessed whether the reduced folate carrier [NM_194255.1: c.80A-->G (i.e., p.His27Arg)] (RFC-1) polymorphism was associated with placental abruption, and evaluated if maternal smoking modified the association between plasma folate and abruption. Data were derived from the New Jersey-Placental Abruption Study--a multicenter, case-control study of placental abruption (2002-2007). Maternal DNA was assayed for the RFC-1 c.80A-->G polymorphism using a PCR-dependent diagnostic test. Maternal folate (nmol/l) was assessed from maternal plasma, collected immediately following delivery. Due to assay limitations, folate levels at > or =60 nmol/l were truncated at 60 nmol/l. Therefore, case-control differences in folate were assessed from censored log-normal regression models following adjustment for potential confounders. Distribution of the mutant allele (G) of the RFC-1 c.80A-->G polymorphism was similar between cases (52.3%; n = 196) and controls (50.5%; n = 191), as was the homozygous mutant (G/G) genotype (OR 1.1, 95% CI 0.6-2.2). In a sub-sample of 136 cases and 140 controls, maternal plasma folate levels (mean +/- standard error) corrected for assay detection limits were similar between placental abruption cases (63.6 +/- 5.1 nmol/l) and controls (58.3 +/- 4.7 nmol/l; P = 0.270), and maternal smoking did not modify this relationship (interaction P = 0.169). We did not detect any association between the RFC-1 c.80A-->G polymorphism and placental abruption, nor was an association between plasma folate and abruption risk evident. These findings may be the consequence of high prevalence of prenatal multivitamin and folate supplementation in this population (over 80%). It is therefore not surprising that folate deficiency may be rare and that the RFC-1 c.80A-->G polymorphism is less biologically significant for placental abruption.

Fetal growth restriction: a modern approach.

PURPOSE OF REVIEW: Fetal growth restriction is a complicated perinatal condition, with multiple causes. It shares common pathophysiologies with other important disorders, such as preeclampsia and abruption. As a group, these conditions associated with ischemic placental disease are responsible for a large percentage of indicated preterm births. The ability to accurately predict, diagnose and manage these pregnancies has significant and far-reaching implications, including potential effects on long-term adult health. RECENT FINDINGS: Placental ischemia is the most common cause of fetal growth restriction. Alterations in placental development are being linked to various angiogenic mediators, which may be of future use in early risk-determination. Until then, the use of ultrasound to accurately diagnose fetal growth restriction and time delivery is the mainstay of management. Research in this area has revealed some commonalities in the deterioration of the growth restricted fetus, but has also indicated that not every affected fetus will follow the same progression in Doppler and other wellbeing parameters. Most importantly, gestational age at delivery is consistently being documented as a critical factor in perinatal morbidity and mortality. SUMMARY: Fetal growth restriction is a late manifestation of early abnormal placental development. Once abnormal Doppler velocimetry is present, surveillance and timing of delivery should be based on the antepartum test results and on the gestational age.

Chronic hypertension and risk of placental abruption: is the association modified by ischemic placental disease?

OBJECTIVE: The purpose of this study was to evaluate whether the increased risk of placental abruption among women with chronic hypertension is modified by ischemic placental disease, specifically pregnancy-induced hypertension (PIH) and fetal growth restriction (FGR). STUDY DESIGN: We used the US linked natality and fetal death data files (1995-2002) and restricted the analysis to women who had a singleton birth at > or = 22 weeks of gestation and to fetuses who weighed > or = 500 g (n = 30,189,949). Fetal growth was defined both on a continuum (<1, 1-2, 3-4, 5-9, 10-19, ..., > or = 90) and as birthweight of < 10th percentile for gestational age (FGR) or birthweight of > 90th percentile (large for gestational age [LGA]). All analyses were adjusted for potential confounding factors through multivariable logistic regression. RESULTS: Rates of abruption among women with and without chronic hypertension were 15.6 and 5.8 per 1000 pregnancies, respectively (relative risk [RR], 2.4; 95% CI, 2.3, 2.5). In comparison with normotensive women with appropriately grown babies (ie, 10th-90th percentile), the association between chronic hypertension and abruption was modified in the presence of FGR (RR, 3.8; 95% CI, 3.6, 4.1) and PIH (RR, 7.7; 95% CI, 6.6, 8.9). However, the highest risk was seen among women with chronic hypertension, PIH, and LGA (RR, 9.0; 95% CI, 7.2, 11.3). A dose-response relationship was observed between the risk of abruption and fetal growth (assessed on a continuum), with the risk being lowest among LGA babies. CONCLUSION: The association between chronic hypertension and abruption is strong; ischemic placental disease (PIH and FGR) modified this relationship. These findings suggest an etiologic relationship between abruption and chronic placental disease. Chronic hypertension, if associated with LGA, is not associated with abruption; however, chronic hypertension with superimposed PIH accompanied by LGA is associated with significantly increased risk.