Activation of CGRP neurons in the parabrachial nucleus suppresses addictive behavior.

Punishment such as electric shock or physical discipline employs a mixture of physical pain and emotional distress to induce behavior modification. However, a neural circuit that produces behavior modification by selectively focusing the emotional component, while bypassing the pain typically induced by peripheral nociceptor activation, is not well studied. Here, we show that genetically silencing the activity of neurons expressing calcitonin gene-related peptide (CGRP) in the parabrachial nucleus blocks the suppression of addictive-like behavior induced by footshock. Furthermore, activating CGRP neurons suppresses not only addictive behavior induced by self-stimulating dopamine neurons but also behavior resulting from self-administering cocaine, without eliciting nocifensive reactions. Moreover, among multiple downstream targets of CGRP neurons, terminal activation of CGRP in the central amygdala is effective, mimicking the results of cell body stimulation. Our results indicate that unlike conventional electric footshock, stimulation of CGRP neurons does not activate peripheral nociceptors but effectively curb addictive behavior.

The Association between Low Fetal Fraction of Non-Invasive Prenatal Testing and Adverse Pregnancy Outcomes for Placental Compromise.

(1) Background: Non-invasive prenatal testing (NIPT) is a screening test for fetal aneuploidy using cell-free fetal DNA. The fetal fragments (FF) of cell-free DNA (cfDNA) are derived from apoptotic trophoblast of the placenta. The level of fetal cfDNA is known to be influenced by gestational age, multiple pregnancies, maternal weight, and height. (2) Methods: This study is a single-center retrospective observational study which examines the relationship between the fetal fraction (FF) of cell-free DNA in non-invasive prenatal testing (NIPT) and adverse pregnancy outcomes in singleton pregnancies. A total of 1393 samples were collected between 10 weeks and 6 days, and 25 weeks and 3 days of gestation. (3) Results: Hypertensive disease of pregnancy (HDP) occurred more frequently in the low FF group than the normal FF group (5.17% vs. 1.91%, p = 0.001). Although the rates of small for gestational age (SGA) and placental abruption did not significantly differ between groups, the composite outcome was significantly higher in the low FF group (7.76% vs. 3.64%, p = 0.002). Furthermore, women who later experienced complications such as HDP or gestational diabetes mellitus (GDM) had significantly lower plasma FF levels compared to those without complications (p < 0.001). After adjustments, the low FF group exhibited a significantly higher likelihood of placental compromise (adjusted odds ratio: 1.946). (4) Conclusions: Low FF in NIPT during the first and early second trimesters is associated with adverse pregnancy outcomes, particularly HDP, suggesting its potential as a predictive marker for such outcomes.

Heterogenous effect of early adulthood stress on cognitive aging and synaptic function in the dentate gyrus.

Cognitive aging widely varies among individuals due to different stress experiences throughout the lifespan and vulnerability of neurocognitive mechanisms. To understand the heterogeneity of cognitive aging, we investigated the effect of early adulthood stress (EAS) on three different hippocampus-dependent memory tasks: the novel object recognition test (assessing recognition memory: RM), the paired association test (assessing episodic-like memory: EM), and trace fear conditioning (assessing trace memory: TM). Two-month-old rats were exposed to chronic mild stress for 6 weeks and underwent behavioral testing either 2 weeks or 20 months later. The results show that stress and aging impaired different types of memory tasks to varying degrees. RM is affected by combined effect of stress and aging. EM became less precise in EAS animals. TM, especially the contextual memory, showed impairment in aging although EAS attenuated the aging effect, perhaps due to its engagement in emotional memory systems. To further explore the neural underpinnings of these multi-faceted effects, we measured long-term potentiation (LTP), neural density, and synaptic density in the dentate gyrus (DG). Both stress and aging reduced LTP. Additionally, the synaptic density per neuron showed a further reduction in the stress aged group. In summary, EAS modulates different forms of memory functions perhaps due to their substantial or partial dependence on the functional integrity of the hippocampus. The current results suggest that lasting alterations in hippocampal circuits following EAS could potentially generate remote effects on individual variability in cognitive aging, as demonstrated by performance in multiple types of memory.

Transcranial focused ultrasound stimulation in the infralimbic cortex facilitates extinction of conditioned fear in rats.

Transcranial focused ultrasound (tFUS) neuromodulation emerges as a promising non-invasive approach for improving neurological conditions. Extinction of conditioned fear has served as a prime model for exposure-based therapies for anxiety disorders. We investigated whether tFUS stimulation to a critical brain area, the infralimbic subdivision of the prefrontal cortex (IL), could facilitate fear extinction using rats. In a series of experiments, tFUS was delivered to the IL of a freely-moving rat and compared to sham stimulation (tFUS vs. SHAM). Initially, Fos expression in the IL was measured shortly after the stimulation. The results show that Fos expression was significantly increased in the IL but not in the neighboring regions compared to SHAM. Subsequently, two groups of rats were subjected to fear conditioning, extinction, and retention while receiving stimulation during the extinction. Rats in the tFUS group froze significantly less than SHAM during both extinction and retention tests. Importantly, the reduced freezing in the tFUS group was not attributable to non-specific effect such as auditory noise, as both groups demonstrated a similar level of locomotive activity in an open field regardless of the stimulation condition. Finally, we replicated the procedure with a shortened conditioning-to-extinction interval (15 min) to induce immediate extinction deficit. The tFUS group showed a facilitated reduction in freezing during the extinction, which persisted in the subsequent retention session compared to SHAM. In summary, the current findings suggest that tFUS stimulation in the IL facilitates fear extinction, offering a potential therapeutic regimen for fear-related psychiatric disorders.

Conditioned flight response in female rats to naturalistic threat is estrous-cycle dependent.

Despite the prevalent expression of freezing behavior following Pavlovian fear conditioning, a growing body of literature suggests potential sex differences in defensive responses. Our study investigated how female defensive behaviors are expressed in different threat situations and modulated by the estrous cycle. We aimed to compare freezing and flight-like responses during the acquisition and retrieval of fear conditioning using two distinct unconditioned stimuli (US) in two different spatial configurations: (1) electrical footshock (FUS) in a small, conventional enclosure with a grid floor, and (2) a predator-like robot (PUS) in a spacious, open arena. Fear conditioning with FUS showed no substantial differences between male and female rats of two different estrous cycles (proestrus and diestrus) in the levels of freezing and flight. However, when PUS was employed, proestrus female rats showed significantly more flight responses to the CS during both acquisition and the retrieval compared to the male and diestrus female rats. Taken together, our findings suggest that hormonal influences on the choice of defensive strategies in threat situations are significantly modulated by both the type of US and the spatial configuration of the environment.

The central amygdala modulates distinctive conflict-like behaviors in a naturalistic foraging task.

Conflict situations elicit a diverse range of behaviors that extend beyond the simplistic approach or avoidance dichotomy. However, many conflict-related studies have primarily focused on approach suppression, neglecting the complexity of these behaviors. In our study, we exposed rats to a semi-naturalistic foraging task, presenting them with a trade-off between a food reward and a predatory threat posed by a robotic agent. We observed that rats displayed two conflict-like behaviors (CLBs)-diagonal approach and stretched posture-when facing a robotic predator guarding a food pellet. After electrolytic lesions to the central amygdala (CeA), both conflict behaviors were significantly reduced, accompanied by a decrease in avoidance behavior (hiding) and an increase in approach behavior (frequency of interactions with the robot). A significant negative correlation between avoidance and approach behaviors emerged after the CeA lesion; however, our data suggest that CLBs are not tightly coupled with either approach or avoidance behaviors, showing no significant correlation to those behaviors. Our findings indicate that the CeA plays a crucial role in modulating conflict behaviors, competing with approach suppression in risky situations.

Value-driven attention and associative learning models: a computational simulation analysis.

Value-driven attentional capture (VDAC) refers to a phenomenon by which stimulus features associated with greater reward value attract more attention than those associated with smaller reward value. To date, the majority of VDAC research has revealed that the relationship between reward history and attentional allocation follows associative learning rules. Accordingly, a mathematical implementation of associative learning models and multiple comparison between them can elucidate the underlying process and properties of VDAC. In this study, we implemented the Rescorla-Wagner, Mackintosh (Mac), Schumajuk-Pearce-Hall (SPH), and Esber-Haselgrove (EH) models to determine whether different models predict different outcomes when critical parameters in VDAC were adjusted. Simulation results were compared with experimental data from a series of VDAC studies by fitting two key model parameters, associative strength (V) and associability (α), using the Bayesian information criterion as a loss function. The results showed that SPH-V and EH- α outperformed other implementations of phenomena related to VDAC, such as expected value, training session, switching (or inertia), and uncertainty. Although V of models were sufficient to simulate VDAC when the expected value was the main manipulation of the experiment, α of models could predict additional aspects of VDAC, including uncertainty and resistance to extinction. In summary, associative learning models concur with the crucial aspects of behavioral data from VDAC experiments and elucidate underlying dynamics including novel predictions that need to be verified.

Differential Encoding of Trace and Delay Fear Memory in the Entorhinal Cortex.

Trace fear conditioning is characterized by a stimulus-free trace interval (TI) between the conditioned stimulus (CS) and the unconditioned stimulus (US), which requires an array of brain structures to support the formation and storage of associative memory. The entorhinal cortex (EC) has been proposed to provide essential neural code for resolving temporal discontinuity in conjunction with the hippocampus. However, how the CS and TI are encoded at the neuronal level in the EC is not clear. In Exp. 1, we tested the effect of bilateral pre-training electrolytic lesions of EC on trace vs. delay fear conditioning using rats as subjects. We found that the lesions impaired the acquisition of trace but not delay fear conditioning confirming that EC is a critical brain area for trace fear memory formation. In Exp. 2, single-unit activities from EC were recorded during the pre-training baseline and post-training retention sessions following trace or delay conditioning. The recording results showed that a significant proportion of the EC neurons modulated their firing during TI after the trace conditioning, but not after the delay fear conditioning. Further analysis revealed that the majority of modulated units decreased the firing rate during the TI or the CS. Taken together, these results suggest that EC critically contributes to trace fear conditioning by modulating neuronal activity during the TI to facilitate the association between the CS and US across a temporal gap.

Corrigendum: Pregnancy and Neonatal Outcomes After Exposure to Alprazolam in Pregnancy.

[This corrects the article DOI: 10.3389/fphar.2022.854562.].

N-Methyl-D-Aspartate (NMDA) Receptors in the Prelimbic Cortex Are Required for Short- and Long-Term Memory Formation in Trace Fear Conditioning.

Accumulating evidence suggests that the medial prefrontal cortex (mPFC) has been implicated in the acquisition of fear memory during trace fear conditioning in which a conditional stimulus (CS) is paired with an aversive unconditional stimulus (UCS) separated by a temporal gap (trace interval, TI). However, little is known about the role of the prefrontal cortex for short- and long-term trace fear memory formation. Thus, we investigated how the prelimbic (PL) subregion within mPFC in rats contributes to short- and long-term trace fear memory formation using electrolytic lesions and d,l,-2-amino-5-phosphonovaleric acid (APV), an N-methyl-D-aspartate receptor (NMDAR) antagonist infusions into PL. In experiment 1, pre-conditioning lesions of PL impaired freezing to the CS as well as TI during the acquisition and retrieval sessions, indicating that PL is critically involved in trace fear memory formation. In experiment 2, temporary blockade of NMDA receptors in PL impaired the acquisition, but not the expression of short- and long-term trace fear memory. In addition, the inactivation of NMDAR in PL had little effect on locomotor activity, pre-pulse inhibition (PPI), or shock sensitivity. Taken together, these results suggest that NMDA receptor-mediated neurotransmission in PL is required for the acquisition of trace fear memory.

Pregnancy and Neonatal Outcomes After Exposure to Alprazolam in Pregnancy.

Alprazolam is a commonly prescribed benzodiazepine for anxiety or panic disorder, even in pregnant women. Information on the safety of alprazolam during pregnancy is insufficient. We aimed to evaluate pregnancy and neonatal outcomes after exposure to alprazolam during pregnancy. A prospective study was conducted on 725 pregnancies from January 2000 to December 2019. Participants were recruited through the Korean Mother-Safe Program, a service providing information on drug-induced teratogenic risk during pregnancy and breastfeeding. Exposed (N = 96) and non-exposed (N = 629) women to alprazolam during pregnancy were selected and followed-up until delivery. Pregnancy outcomes, including spontaneous abortion, still birth, low birth weight (LBW), preterm birth, Apgar score (at 1 and 5 min), and malformations were measured and compared. Multivariable logistic regression was performed to examine the association between alprazolam exposure and outcomes. The mean age was 32.9 (SD 4.0) years in the alprazolam-exposed group and 31.8 (SD 3.8) years in the unexposed group (p = 0.008). The alprazolam exposure group demonstrated a significantly higher likelihood of pregnancy and neonatal outcomes: spontaneous abortion (OR = 2.38; 95% CI 1.20-4.69), LBW (OR = 3.65; 95% CI 1.22-11.00), and Apgar score at 1 min ≤ 7 (OR = 2.19; 95% CI 1.02-4.67). There was no significant difference in congenital abnormalities between the exposure and non-exposure groups. Our findings confirmed that alprazolam exposure during pregnancy was significantly associated with adverse pregnancy and neonatal outcomes, including spontaneous abortion, low birth weight, and Apgar score at 1 min ≤ 7. Alprazolam during pregnancy should be appropriately regulated and monitored.

Pregnancy and neonatal outcomes after periconceptional exposure to isotretinoin in Koreans.

OBJECTIVE: Isotretinoin should not be used during pregnancy because of the risk of birth defects. Most pregnant women exposed to isotretinoin choose voluntary pregnancy termination due to concerns about birth defects. However, birth outcome data supporting the termination of pregnancy are lacking. This study aimed to evaluate pregnancy and neonatal outcomes after periconception exposure to isotretinoin. METHODS: This was a prospective cohort study. We evaluated pregnancy and neonatal outcomes after exposure to isotretinoin in 151 pregnant women. Among 1,026 callers at the Korean Teratology Information Service from 2001 to 2017 exposed to isotretinoin during the periconception period, 151 pregnant women who received counseling on teratogenic risk after visiting the clinic were included. RESULTS: Among the 151 participants who visited the clinic, only 42 were evaluated using ultrasonography until approximately 20 weeks of gestation. Ultimately, 23 patients were included in the study. The average gestation period during the last exposure to the drug was 2 weeks, and the average daily exposure dose was 12 mg. There were two cases of major birth defects in the exposure group. Spontaneous abortion rates were 17.7% and 8.7% in the exposure and nonexposure groups, respectively (P=0.035). There was no significant difference between the exposure and non-exposure groups in terms of pregnancy and neonatal outcomes. CONCLUSION: There was no significant difference in pregnancy and neonatal outcomes, including birth defects, between the exposure and non-exposure groups. Further studies with larger sample sizes are required to validate our findings.

Evaluation of fetal and neonatal outcomes after ingestion of Cnidium root (Cnidium officinale Makino) during pregnancy.

Cnidium officinale Makino is a perennial plant, a member of the Umbelliferae family. Cnidium root has traditionally been used as a medicinal herb. It has analgesic, antiinflammatory, antipyretic, antibacterial, antispasmodic, vasodilatory, hypertensive, and sedative effects. However, there are no studies of reproductive toxicity in humans. Therefore, this study aimed to prospectively evaluate the fetal and neonatal outcomes in the children of women who inadvertently used Cnidium root during pregnancy. In a prospective cohort study design, 111 singleton pregnant women taking Cnidium root for various reasons, and 219 age-matched singleton pregnant women unexposed to any herbal agent (unexposed group), were followed up until delivery. In the exposed group, Cnidium root was indicated as controlling cough and cold in 54.1% of patients, at the maximal dose of 12,000 mg/day between 1 day to 12.4 weeks of gestation. Fetal outcomes, including birth weight and 1- and 5-min Apgar score, were similar for the two groups. There were four babies born with major malformations in the exposed group vs. 14 in the unexposed group (OR = 0.5; 95% CI 0.2-1.6; p = 0.190). The gestational age, length, and head circumference were relatively shorter among babies born in the exposed group. Even after adjusting for gender, there was a tenfold increase in the frequency of shorter newborns (<2SD) in the exposed group (OR = 10.1; 95% CI 1.2-87.6; p = 0.019). Our study suggests that Cnidium root is not a major human teratogen. Whether lesser gestational ages at birth and shorter birth lengths are clinically relevant after exposure to Cnidium remains to be elucidated in further studies.

Evaluation of the Effects of Developmental Trauma on Neurotransmitter Systems Using Functional Molecular Imaging.

Early life stress (ELS) is strongly associated with psychiatric disorders such as anxiety, depression, and schizophrenia in adulthood. To date, biological, behavioral, and structural aspects of ELS have been studied extensively, but their functional effects remain unclear. Here, we examined NeuroPET studies of dopaminergic, glutamatergic, and serotonergic systems in ELS animal models. Maternal separation and restraint stress were used to generate single or complex developmental trauma. Body weights of animals exposed to single trauma were similar to those of control animals; however, animals exposed to complex trauma exhibited loss of body weight when compared to controls. In behavioral tests, the complex developmental trauma group exhibited a decrease in time spent in the open arm of the elevated plus-maze and an increase in immobility time in the forced swim test when compared to control animals. In NeuroPET studies, the complex trauma group displayed a reduction in brain uptake values when compared to single trauma and control groups. Of neurotransmitter systems analyzed, the rate of decrease in brain uptake was the highest in the serotonergic group. Collectively, our results indicate that developmental trauma events induce behavioral deficits, including anxiety- and depressive-like phenotypes and dysfunction in neurotransmitter systems.

Maladaptive Alterations of Defensive Response Following Developmental Complex Stress in Rats.

OBJECTIVE: Despite the etiological significance of complex developmental trauma in adult personality disorders and treatment-resistant depression, neurobiological studies have been rare due to the lack of useful animal models. As a first step, we devised an animal model to investigate the effects of multiple trauma-like stress during different developmental periods. METHODS: Twenty-one male Sprague-Dawley rats were classified into 3 groups based on the stress protocol: fear conditioning control (FCC, n = 6), complex stress (ComS, n = 9), and control (n = 6). While the ComS experienced three types of stress (maternal separation, juvenile isolation, electric foot shock), the FCC only experienced an electric foot shock stress and the control never experienced any. We compared fear responses at postnatal day (PND) 29 and PND 56 through freezing time per episode (FTpE), total freezing time (TFT), total freezing episodes (TFE), and ultrasonic vocalization (USV). RESULTS: ComS showed the longest FTpE in the conditioned fear response test. ComS and FCC exhibited the longer TFT and these two groups only displayed USV. ComS show difference TFE between PND 29 and PND 56. CONCLUSION: The results of this investigation show that complex stress may affect not quantity of fear response but characteristics of fear response. Longer FTpE may be associated with tonic immobility which could be considered as a failed self-protective reaction and might be analogous to a sign of inappropriate coping strategy and self-dysregulation in complex trauma patients.

DRG2 Deficient Mice Exhibit Impaired Motor Behaviors with Reduced Striatal Dopamine Release.

Developmentally regulated GTP-binding protein 2 (DRG2) was first identified in the central nervous system of mice. However, the physiological function of DRG2 in the brain remains largely unknown. Here, we demonstrated that knocking out DRG2 impairs the function of dopamine neurons in mice. DRG2 was strongly expressed in the neurons of the dopaminergic system such as those in the striatum (Str), ventral tegmental area (VTA), and substantia nigra (SN), and on neuronal cell bodies in high-density regions such as the hippocampus (HIP), cerebellum, and cerebral cortex in the mouse brain. DRG2 knockout (KO) mice displayed defects in motor function in motor coordination and rotarod tests and increased anxiety. However, unexpectedly, DRG2 depletion did not affect the dopamine (DA) neuron population in the SN, Str, or VTA region or dopamine synthesis in the Str region. We further demonstrated that dopamine release was significantly diminished in the Str region of DRG2 KO mice and that treatment of DRG2 KO mice with l-3,4-dihydroxyphenylalanine (L-DOPA), a dopamine precursor, rescued the behavioral motor deficiency in DRG2 KO mice as observed with the rotarod test. This is the first report to identify DRG2 as a key regulator of dopamine release from dopamine neurons in the mouse brain.

Isotretinoin exposure in pregnant women in Korea.

OBJECTIVE: Isotretinoin is a notorious teratogen otherwise used for the treatment of acne vulgaris. Some countries, including those in North America and the European Union, implemented the pregnancy prevention program (PPP); however, no PPP has yet been established in South Korea. So the aim of this study was to evaluate the rate of pregnant women exposed to isotretinoin among the callers of the Korean Mother Safe Counseling Center. METHODS: This is a prospective cohort study. We evaluated the demographic characteristics, obstetric history, and isotretinoin exposure of pregnant women based on the mother safe registry from April 2010 to July 2016. RESULTS: Among 22,374 callers, 650 (2.9%) pregnant women were exposed to isotretinoin. The mean age was 29.0±4.4 years in the isotretinoin-exposed group and 32.0±4.2 years in the unexposed group (P<0.001). Moreover, the incidence of pregnancies within 30 days after isotretinoin discontinuation or during isotretinoin intake was 78.9% (513/650). The median duration of isotretinoin exposure was 18 (1-4,231) days. Furthermore, from 2011 to 2015, the incidence of isotretinoin exposure was 2.9±1.2 pregnancies per 10,000 births in South Korea. CONCLUSION: Approximately 80% of pregnant women are exposed to isotretinoin within the recommended 30 days of contraception or during pregnancy. Therefore, the PPP has to be established in South Korea.

Dopamine D2 receptor-mediated circuit from the central amygdala to the bed nucleus of the stria terminalis regulates impulsive behavior.

Impulsivity is closely associated with addictive disorders, and changes in the brain dopamine system have been proposed to affect impulse control in reward-related behaviors. However, the central neural pathways through which the dopamine system controls impulsive behavior are still unclear. We found that the absence of the D2 dopamine receptor (D2R) increased impulsive behavior in mice, whereas restoration of D2R expression specifically in the central amygdala (CeA) of D2R knockout mice (Drd2-/-) normalized their enhanced impulsivity. Inhibitory synaptic output from D2R-expressing neurons in the CeA underlies modulation of impulsive behavior because optogenetic activation of D2R-positive inhibitory neurons that project from the CeA to the bed nucleus of the stria terminalis (BNST) attenuate such behavior. Our identification of the key contribution of D2R-expressing neurons in the CeA → BNST circuit to the control of impulsive behavior reveals a pathway that could serve as a target for approaches to the management of neuropsychiatric disorders associated with impulsivity.

Observational threat conditioning is induced by circa-strike activity burst but not freezing and requires visual attention.

Social transmission refers to a process in which an observer (OB) acquires new information about the environment including threat situations, through the action of familiar conspecifics. Recently, a number of studies employing observational threat conditioning (OTC) in which OB mice expressed defensive responses following indirect exposure to pair-housed partner mice (demonstrator: DE) which were receiving repeated footshocks, have produced interesting insights into the social mechanisms of emotional transfer. However, the nature of the transmitted information or the critical cognitive processes involved in OTC is not clear. In a series of experiments, we investigated the key elements involves in triggering socially-induced defensive responses. In Exp.1, we compared the effectiveness in conveying a threat of two different types of defensive reactions of DEs: the circa-strike activity burst (CSAB) vs. freezing. The results show that the CSAB is more effective than freezing in inducing defensive freezing in an OB. In Exp. 2, we investigated different types of the OBs' defensive responses by measuring their change in head orientation or their "gazing" at the DEs, and their temporal synchrony with the DEs' defensive reactions in the form of their CSAB. The results show that OBs' gazing was significantly correlated with the DEs' CSAB, especially the DEs' jumping behavior, but not with the freezing of the DEs, indicating that jumping is a more effective trigger stimulus in inducing attentional capture in conspecific partner animals. In Exp. 3, the role of visual information was tested. The result shows that the OBs' level of freezing was significantly reduced when visual information was blocked by an opaque partition. In Exp. 4, to confirm the critical role of visual attention, we introduced distracting flashing lights, which were switched on and off at random intervals during the conditioning process. With all other conditions being maintained unaltered, the OBs in the distractor condition displayed a significantly decreased level of freezing, indicating that the visual attention paid to the DEs by the OBs during the conditioning process was critical for the social transmission of threat. Taken together, the results of the current study strongly suggest that socially transmitted defensive behavior is dependent on the specific behavioral elements of a DE's defensive behavior, and moreover, that a visual attentional process is required during the OTC.

Change in rates of prenatal tests for chromosomal abnormality over a 12-year period in women of advanced maternal age.

OBJECTIVE: In 2007, the American College of Obstetricians and Gynecologists (ACOG) recommended that all pregnant women be offered screening or diagnostic tests for chromosomal abnormalities regardless of their age. Noninvasive prenatal testing (NIPT) for common chromosomal aneuploidies was introduced as a screening test in case of high-risk pregnancies. We assessed the rates of prenatal tests in women aged 35 years and older. METHODS: A retrospective study was conducted to compare the rates of amniocentesis, chorionic villus sampling (CVS), serum screening, and NIPT from January 2005 through March 2017 in women aged 35 years and older. We divided the initial 12 months after NIPT introduction into 4-month intervals, beginning in April 2016 through March 2017. RESULTS: The rates of amniocentesis were 56% before the ACOG statement, 38% between the ACOG statement and NIPT introduction, and 10% after NIPT introduction (P=0.001). The rates of CVS during the same periods were 0.5%, 2.1%, and 4.3% (P=0.016), respectively. The rates of serum screening were 44.2%, 61.3%, and 55.1% (P=0.049), respectively. During the 3 quarters after NIPT introduction, the rates of amniocentesis were 16.2%, 12.3%, and 7.3% (P=0.002), respectively; the rates of serum screening were 62%, 54%, and 46% (P=0.03), respectively; and the rates of NIPT were 19.9%, 30.3%, and 39.5% (P=0.007), respectively. The rates of CVS over the same periods were not significantly different. CONCLUSION: The ACOG statement and NIPT introduction significantly decreased the rate of amniocentesis in women of advanced maternal age. NIPT also reduced the rate of serum screening.