The effectiveness of antepartum surveillance in reducing the risk of stillbirth in patients with advanced maternal age

Characteristics associated with antenatally unidentified small-for-gestational-age fetuses: prospective cohort study nested within DESiGN randomized controlled trial

OBJECTIVE

To identify the clinical characteristics and patterns of ultrasound use amongst pregnancies with an antenatally unidentified small-for-gestational-age (SGA) fetus, compared with those in which SGA is identified, to understand how to design interventions that improve antenatal SGA identification.

METHODS

This was a prospective cohort study of singleton, non-anomalous SGA (birth weight < 10th centile) neonates born after 24 + 0 gestational weeks at 13 UK sites, recruited for the baseline period and control arm of the DESiGN trial. Pregnancy with antenatally unidentified SGA was defined if there was no scan or if the final scan showed estimated fetal weight (EFW) at the 10th centile or above. Identified SGA was defined if EFW was below the 10th centile at the last scan. Maternal and fetal sociodemographic and clinical characteristics were studied for associations with unidentified SGA using unadjusted and adjusted logistic regression models. Ultrasound parameters (gestational age at first growth scan, number and frequency of ultrasound scans) were described, stratified by presence of indication for serial ultrasound. Associations of unidentified SGA with absolute centile and percentage weight difference between the last scan and birth were also studied on unadjusted and adjusted logistic regression, according to time between the last scan and birth.

RESULTS

Of the 15 784 SGA babies included, SGA was not identified antenatally in 78.7% of cases. Of pregnancies with unidentified SGA, 47.1% had no recorded growth scan. Amongst 9410 pregnancies with complete data on key maternal comorbidities and antenatal complications, the risk of unidentified SGA was lower for women with any indication for serial scans (adjusted odds ratio (aOR), 0.56 (95% CI, 0.49-0.64)), for Asian compared with white women (aOR, 0.80 (95% CI, 0.69-0.93)) and for those with non-cephalic presentation at birth (aOR, 0.58 (95% CI, 0.46-0.73)). The risk of unidentified SGA was highest among women with a body mass index (BMI) of 25.0-29.9 kg/m2 (aOR, 1.15 (95% CI, 1.01-1.32)) and lowest in those with underweight BMI (aOR, 0.61 (95% CI, 0.48-0.76)) compared to women with BMI of 18.5-24.9 kg/m2 . Compared to women with identified SGA, those with unidentified SGA had fetuses of higher SGA birth-weight centile (adjusted odds for unidentified SGA increased by 1.21 (95% CI, 1.18-1.23) per one-centile increase between the 0th and 10th centiles). Duration between the last scan and birth increased with advancing gestation in pregnancies with unidentified SGA. SGA babies born within a week of the last growth scan had a mean difference between EFW and birth-weight centiles of 19.5 (SD, 13.8) centiles for the unidentified-SGA group and 0.2 (SD, 3.3) centiles for the identified-SGA group (adjusted mean difference between groups, 19.0 (95% CI, 17.8-20.1) centiles).

CONCLUSIONS

Unidentified SGA was more common amongst women without an indication for serial ultrasound, and in those with cephalic presentation at birth, BMI of 25.0-29.9 kg/m2 and less severe SGA. Ultrasound EFW was overestimated in women with unidentified SGA. This demonstrates the importance of improving the accuracy of SGA screening strategies in low-risk populations and continuing performance of ultrasound scans for term pregnancies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Obstetric Care Consensus #11, Pregnancy at age 35 years or older

Centers for Disease Control and Prevention data from 2020 demonstrate the continued upward trend in the mean age of pregnant individuals in the United States. Observational studies demonstrate that pregnancy in older individuals is associated with increased risks of adverse pregnancy outcomes-for both the pregnant patient and the fetus-that might differ from those found in younger pregnant populations, even in healthy individuals with no other comorbidities. There are several studies that suggest that advancing age at the time of pregnancy is associated with greater disparities in severe maternal morbidity and mortality. This document seeks to provide evidence-based clinical recommendations for minimizing adverse outcomes associated with pregnancy with anticipated delivery at an advanced maternal age. The importance and benefits of accessible health care from prepregnancy through postpartum care for all pregnant individuals cannot be overstated. However, this document focuses on and addresses the unique differences in pregnancy-related care for women and all those seeking obstetrical care with anticipated delivery at the age of 35 years or older within the framework of routine pregnancy care. This Obstetric Care Consensus document was developed using an a priori protocol in conjunction with the authors listed above.

Antepartum and intrapartum stillbirth rates across gestation: a cross-sectional study using the revised foetal death reporting system in the U.S

BACKGROUND

There is a renewed call to address preventable foetal deaths in high-income countries, especially where progress has been slow. The Centers for Disease Control and Prevention released publicly, for the first time, the initiating cause and estimated timing of foetal deaths in 2014. The objective of this study is to describe risk and characteristics of antepartum versus intrapartum stillbirths in the U.S., and frequency of pathological examination to determine cause.

METHODS

We conducted a cross-sectional study of singleton births (24-43 weeks) using 2014 U.S. Fetal Death and Natality data available from the National Center for Health Statistics. The primary outcome was timing of death (antepartum (n = 6200), intrapartum (n = 453), and unknown (n = 5403)). Risk factors of interest included maternal sociodemographic, behavioural, medical and obstetric factors, along with foetal sex. We estimated gestational week-specific stillbirth hazard, risk factors for intrapartum versus antepartum stillbirth using multivariable log-binomial regression models, conditional probabilities of intrapartum and antepartum stillbirth at each gestational week, and frequency of pathological examination by timing of death.

RESULTS

The gestational age-specific stillbirth hazard was approximately 2 per 10,000 foetus-weeks among preterm gestations and > 3 per 10,000 foetus-weeks among term gestations. Both antepartum and intrapartum stillbirth risk increased in late-term and post-term gestations. The risk of intrapartum versus antepartum stillbirth was higher among those without a prior live birth, relative to those with at least one prior live birth (RR 1.32; 95% CI 1.08-1.61) and those with gestational hypertension, relative to those with no report of gestational hypertension (RR 1.47; 95% CI 1.09-1.96), and lower among Black, relative to white, individuals (RR 0.70; 95% CI 0.55-0.89). Pathological examination was not performed/planned in 25% of known antepartum stillbirths and 29% of known intrapartum stillbirths.

CONCLUSION

These findings suggest greater stillbirth risk in the late-term and post-term periods. Primiparous mothers had greater risk of intrapartum than antepartum still birth, suggesting the need for intrapartum interventions for primiparous mothers in this phase of pregnancy to prevent some intrapartum foetal deaths. Efforts are needed to improve understanding, prevention and investigation of foetal deaths as well as improve stillbirth data quality and completeness in the United States.

Pregnancy at Age 35 Years or Older

SUMMARY

Centers for Disease Control and Prevention data from 2020 demonstrate the continued upward trend in the mean age of pregnant individuals in the United States. Observational studies demonstrate that pregnancy in older individuals is associated with increased risks of adverse pregnancy outcomes-for both the pregnant patient and the fetus-that might differ from those in a younger pregnant population, even in healthy individuals with no other comorbidities. There are several studies that suggest advancing age at the time of pregnancy is associated with greater disparities in severe maternal morbidity and mortality. This document seeks to provide evidence-based clinical recommendations for minimizing adverse outcomes associated with pregnancy with anticipated delivery at an advanced maternal age. The importance and benefits of accessible health care from prepregnancy through postpartum care for all pregnant individuals cannot be overstated. However, this document focuses on and addresses the unique differences in pregnancy-related care for women and all those seeking obstetric care with anticipated delivery at age 35 years or older within the framework of routine pregnancy care. This Obstetric Care Consensus document was developed using an a priori protocol in conjunction with the authors listed above.

Association of Prenatal Care Services, Maternal Morbidity, and Perinatal Mortality With the Advanced Maternal Age Cutoff of 35 Years

Importance

Maternal and perinatal mortality remain high in the US despite growing rates of prenatal services and spending, and little rigorous evidence exists regarding the impact of prenatal care intensity on pregnancy outcomes. Patients with an expected date of delivery just after their 35th birthday may receive more intensive care owing to the advanced maternal age (AMA) designation; whether this increase in prenatal care is associated with improvements in outcomes has not been explored.

Objective

To determine the association between the AMA designation and prenatal care services, severe maternal morbidity, and perinatal mortality.

Design Setting and Participants

This cross-sectional study used a regression discontinuity design to compare individuals just above vs just below the 35-year AMA cutoff, using unidentifiable administrative claims data from a large, nationwide commercial insurer. All individuals with a delivery between January 1, 2008, and December 31, 2019, who were aged 35 years within 120 days of their expected date of delivery were included in the study. Analyses were performed from July 1, 2020, to February 1, 2021.

Exposures

Individuals who were aged 35.0 through 35.3 years on the expected date of delivery were designated as AMA.

Main Outcomes and Measures

Outcomes were visits with specialists (obstetrician-gynecologists and maternal-fetal medicine), ultrasound scan use, antepartum fetal surveillance, aneuploidy screening, severe maternal morbidity, preterm birth or low birth weight, and perinatal mortality.

Results

The analysis included 51 290 individuals (mean [SD] age; 34.5 [0.5] years); 26 108 individuals (50.9%) were aged 34.7 to 34.9 years and 25 182 individuals (49.1%) were aged 35.0 to 35.3 years on the expected date of delivery. A total of 2407 pregnant individuals (4.7%) had multiple gestation, 2438 (4.8%) had pregestational diabetes, 2265 (4.4%) had chronic hypertension, and 4963 (9.7%) had obesity. Advanced maternal age was associated with a 4.27 percentage point increase in maternal-fetal medicine visits (95% CI, 2.27-6.26 percentage points; P < .001), a 0.21 unit increase in total ultrasound scans (95% CI, 0.06-0.37; P = .006), a 15.67 percentage point increase in detailed ultrasound scans (95% CI, 13.68-17.66 percentage points; P < .001), and a 4.86 percentage point increase in antepartum surveillance (95% CI, 2.83-6.89 percentage points; P < .001). The AMA designation was associated with a 0.39 percentage point decline in perinatal mortality (95% CI, -0.77 to -0.01 percentage points; P = .04).

Conclusions and Relevance

In this cross-sectional study, the AMA designation at age 35 years was associated with an increase in receipt of prenatal monitoring and a small decrease in perinatal mortality, suggesting that the AMA designation may be associated with clinical decision-making, with individuals just older than 35 years receiving more prenatal monitoring. These results suggest that increases in prenatal care services stemming from the AMA designation may have important benefits for fetal and infant survival for patients in this age range.

Adverse maternal and perinatal pregnancy outcomes related to very advanced maternal age in primigravida and multigravida in the Netherlands: A population-based cohort

INTRODUCTION

The age at which women give birth is rising steadily in the western world. Advanced maternal age has been associated with adverse pregnancy outcomes. We assessed the association between advanced maternal age and the risk of adverse maternal and perinatal outcome in primigravid and multigravid women.

MATERIAL AND METHODS

The study was a population-based cohort study and included women giving birth between January 2000 and December 2018 using data from the Dutch perinatal registration of Perined. Women were divided into age groups. We compared outcomes between women of 40-44, 45-49, and over 50 years old (the study groups) with women of 25-29 years old (reference group), stratified for parity. We employed multivariable regression to correct for possible confounders including methods of conception, multiple pregnancies, ethnicity, and socio-economic status. Our primary outcomes were maternal and perinatal mortality. Secondary outcomes included common maternal and perinatal complications, as well as cesarean section rate.

RESULTS

A cohort of 3 700 326 women gave birth during the study period. Of these women, 3.2% were above 40 years of age. Maternal mortality was rare in all groups, but significantly higher in multigravid women over 50 years old. Perinatal mortality was significantly higher in all pregnancies of women over 40 years old, but not for primigravida over 50 years old. The most notable results with the steepest increase were in maternal complications. Both primigravida and multigravida over 40 years old were at a two times higher risk of perinatal mortality, cesarean section, gestational diabetes, hypertensive disorders, and a low Apgar score after 5 minutes. The risk for women over 45 was almost tripled for perinatal mortality and gestational diabetes and six times higher for cesarean section. Women over 50 years old had a seven times higher risk of cesarean section, a four times higher risk of gestational diabetes, postpartum hemorrhage, and neonatal intensive care unit admission, and a 10 times higher risk of hypertensive disorders.

CONCLUSIONS

The risk of adverse maternal and perinatal outcomes for women over 40 years old surges as age increases. A novel aspect was the consistent increased risks not only for primigravid women but also for multigravida.

Antenatal Testing for Women With Preexisting Medical Conditions Using Only the Ultrasonographic Portion of the Biophysical Profile

OBJECTIVE

To report the utility of the ultrasonographic biophysical profile, which includes all the components of a biophysical profile minus the nonstress test, in women with maternal indications for antepartum surveillance.

METHODS

We conducted a case series reviewing the records of all women at 32 weeks of gestation or greater with at least one indication for antenatal testing (per the American College of Obstetricians and Gynecologists) delivered by a single maternal-fetal medicine practice between 2006 and 2018. Indications included diabetes, hypertension, lupus, antiphospholipid syndrome, sickle cell disease, renal disease, heart disease, hyperthyroidism, isoimmunization, inherited thrombophilia, and prior intrauterine fetal demise. Weekly ultrasonographic biophysical profiles were initiated at 32 weeks of gestation. We calculated the test-positive rate, the percentage of women delivered for an abnormal ultrasonography biophysical profile, and the intrauterine fetal demise rate (false-negative rate).

RESULTS

Nine hundred eighty-five women underwent 3,981 ultrasonographic biophysical profiles (four per woman; range 1-11). Sixteen women had an abnormal ultrasonographic biophysical profile, for a test positive rate of 1.6% (95% CI 1.0-2.6%) per woman, or 0.4% (95% CI 0.3-0.7%) per ultrasonographic biophysical profile. Of the 16 women with abnormal ultrasonographic biophysical profiles, 13 were delivered with good outcomes and three women had normal follow-up testing and uncomplicated deliveries at a later date. There were three women with intrauterine fetal demise (false-negative rate of 0.3%, 95% CI 0.1-0.9%). One woman with intrauterine fetal demise had a factor V Leiden mutation, fetal ventriculomegaly, and fetal growth restriction. The second woman with intrauterine fetal demise had advanced maternal age, a factor V Leiden mutation, and fetal growth restriction. The third woman with intrauterine fetal demise had class B diabetes. All three intrauterine fetal demises were diagnosed antepartum with an interval from normal ultrasonographic biophysical profile to intrauterine fetal demise of 7, 7, and 6 days, respectively.

CONCLUSION

The use of ultrasonographic biophysical profile in a high-risk cohort is associated with a very low test-positive rate and a very low incidence of intrauterine fetal demise. In women with preexisting medical conditions that place them at higher risk for intrauterine fetal demise, ultrasonographic biophysical profile can be used for antenatal testing.

Obstetric and perinatal outcomes in women ≥40years of age: Associations with fetal growth disorders

BACKGROUND

Evidence indicates that advanced maternal age is associated with adverse obstetric and perinatal outcomes. The purpose of this study was to evaluate pregnancy outcomes in women of advanced maternal age (≥40years).

METHODS

Using a prospective study design, data were collected by the Department of Obstetrics at the San Joan de Deu Hospital of Barcelona during the 1 June 2009 to 31 May 2012 period. The results were compared across three maternal age groups (≥40 [n=654], 35-39 [n=2781], and <35 [n=7893] years).

RESULTS

Of the 11328 births recorded during the study period, pregnancy-related complications were more common in women ≥40years of age. The most common disorder was diabetes (8.5% in the ≥40, 5.3% in the 35-39, and 3.0% in the <35years age groups). The women ≥40years of age also had significantly more premature births (p=0.001) and cesarean sections (17% in the ≥40, 12.5% in the 35-39, and 7.9% in the <35-year age groups; p=0.001). Intrauterine growth retardation was significantly more frequent in women aged ≥40years (17.4% in the ≥40, 15% in the 35-39, and 14.0% in the <35-year age groups; p=0.03). Fetal macrosomia was significantly more common in women ≥40years (15.4% in the ≥40, 12.6% in the 35-39, and 12% in the <35-year age groups; p=0.03).

CONCLUSION

Maternal age ≥40years was associated with poorer obstetric and perinatal outcomes and increased the risks of cesarean section, intrauterine growth retardation, and fetal macrosomia.

Evaluating the Obstetrical Implications of Antenatal Testing for Women with Morbid Obesity: Maternal and Fetal Outcomes of Increased Surveillance

Objectives Despite limited data, antenatal testing has been initiated in many institutions for women with morbid obesity given their increased risk of stillbirth. Therefore, our objective was to evaluate the obstetrical implications of antenatal testing in the morbidly obese population. Study Design We performed a retrospective cohort study of women undergoing antenatal testing from January 2011 through December 2012 who delivered at our institution. The exposed group was women undergoing antenatal testing with morbid obesity (body mass index [BMI] ≥ 40 kg/m(2)). This group was subdivided into two groups: group 1, which included women undergoing testing for morbid obesity alone, and group 2, which included women undergoing testing for morbid obesity with an additional medical comorbidity. The unexposed group (group 3) comprised nonmorbidly obese women (BMI < 35 kg/m(2)) undergoing antenatal testing for similar medical comorbidities. Our primary outcomes were induction of labor and gestational age at delivery. Results A total of 512 women met inclusion criteria. Group 1 had a lower induction rate as compared with groups 2 and 3 (22.2, 32.5, and 37.6%, respectively; p = 0.003). Additionally, women delivered at a later gestational age in group 1 (39.3 weeks [38.4-40.2]) compared with groups 2 (38.5 weeks [36.1-40.3]) or 3 (37.1 weeks [37.0-38.2]), p = 0.04. There were no significant differences in our secondary outcomes including rate of cesarean delivery (p = 0.11) or rate of nonreactive nonstress test (p = 0.4). Conclusions While it remains unknown whether antenatal testing decreases the stillbirth risk in morbidly obese women, this population does not appear to be at increased risk of induction of labor or delivery prior to 39 weeks secondary to testing. Future studies should evaluate neonatal implications and cost-effectiveness of antenatal testing in this group.

The impact of antenatal testing for advanced maternal age on cesarean delivery rate at an urban institution

OBJECTIVE

Antenatal testing has been implemented for advanced maternal age (AMA) women given their increased stillbirth risk. Our objective was to evaluate cesarean delivery and induction rates after the start of antenatal testing at our institution.

STUDY DESIGN

A retrospective cohort study of AMA women (≥ 40 years) who delivered at our institution was performed. Testing for AMA began in 2005. AMA women who delivered before (unexposed) and after (exposed) the implementation were compared. Our primary outcome was cesarean delivery and secondary outcome was induction. Chi-square compared categorical variables and multivariable logistic regression calculated odds ratio (OR) and controlled for confounders.

RESULTS

A total of 276 women were included (147 unexposed and 129 exposed). The cesarean rate was higher in the exposed group (53 vs. 39%, OR 1.76 [1.09-2.84]). The increased risk of cesarean remained after adjusting for race, previous cesarean, multiple gestations, and parity (adjusted OR 1.85 [1.05-3.28]). When excluding those with previous cesareans, the risk of primary cesarean was not significant (OR 1.57 [0.89-2.76]). The induction rate was not different (38 vs. 33%, p = 0.4).

CONCLUSIONS

While overall cesareans increased, there was no difference in primary cesarean and induction rates for AMA women after implementation of antenatal testing for AMA.