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Objectives: We examined the factors influencing delay in seeking abortion and the outcomes for women denied abortion care because of gestational age limits at abortion facilities., Methods: We compared women who presented for abortion care who were under the facilities' gestational age limits and received an abortion (n = 452) with those who were just over the gestational age limits and were denied an abortion (n = 231) at 30 US facilities. We described reasons for delay in seeking services. We examined the determinants of obtaining an abortion elsewhere after being denied one because of facility gestational age limits. We then estimated the national incidence of being denied an abortion because of facility gestational age limits., Results: Adolescents and women who did not recognize their pregnancies early were most likely to delay seeking care. The most common reason for delay was having to raise money for travel and procedure costs. We estimated that each year more than 4000 US women are denied an abortion because of facility gestational limits and must carry unwanted pregnancies to term., Conclusions: Many state laws restrict abortions based on gestational age, and new laws are lowering limits further. The incidence of being denied abortion will likely increase, disproportionately affecting young and poor women.

Women's empowerment has become a focal point for development efforts worldwide and there is a need for an updated, critical assessment of the existing evidence on women's empowerment and fertility. We conducted a literature review on studies examining the relationships between women's empowerment and several fertility-related topics. Among the 60 studies identified for this review, the majority were conducted in South Asia (n = 35) and used household decision-making as a measure of empowerment (n = 37). Overall, the vast majority of studies found some positive associations between women's empowerment and lower fertility, longer birth intervals, and lower rates of unintended pregnancy, but there was some variation in results. In many studies, results differed based on the measure of empowerment used, sociopolitical or gender environment, or sub-population studied. This article is one of the first evaluations of the literature assessing the relationships between women's empowerment and fertility. We identify several key issues that merit further investigation., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

No validated measures are currently available to assess women's ability to achieve their reproductive intentions, also referred to as "reproductive autonomy." We developed and validated a multidimensional instrument that can measure reproductive autonomy. We generated a pool of 26 items and included them in a survey that was conducted among 1,892 women at 13 family planning and 6 abortion facilities in the United States. Fourteen items were selected through factor analysis and grouped into 3 subscales to form a Reproductive Autonomy Scale: freedom from coercion; communication; and decision-making. Construct validity was demonstrated by a mixed-effects model in which the freedom from coercion subscale and the communication subscale were inversely associated with unprotected sex in the past three months. This new Reproductive Autonomy Scale offers researchers a reliable instrument with which to assess a woman's power to control matters regarding contraceptive use, pregnancy, and childbearing, and to evaluate interventions to increase women's autonomy domestically and globally., (© 2014 The Population Council, Inc.)

Objective: Ultrasound scanning is a routine part of preprocedure abortion care, and many health care providers offer patients the opportunity to view their ultrasound images. It has been speculated that ultrasound viewing will dissuade women from having an abortion. We examine whether viewing the image is associated with choosing to continue the pregnancy., Methods: Data from medical records for 15,575 visits by women seeking abortion care at a large, urban abortion provider in 2011 were analyzed for factors associated with choosing to continue the pregnancy. All patients received a preprocedure ultrasound scan and were offered the opportunity to view the image., Results: Patients opted to view the ultrasound image 42.5% of the time. Nearly all pregnancies (98.8%) were terminated: 98.4% of pregnancies among women who viewed their ultrasound images and 99.0% of pregnancies among the patients who did not. Among women with high decision certainty, viewing was not associated with deciding to continue the pregnancy. Viewing was significantly associated with deciding to continue the pregnancy only among the 7.4% of women who reported medium or low decision certainty about having an abortion (adjusted odds ratio 3.21, 95% confidence interval 1.18-8.73)., Conclusion: Voluntarily viewing the ultrasound image may contribute to a small proportion of women with medium or low decision certainty deciding to continue the pregnancy; such viewing does not alter decisions of the large majority of women who are certain that abortion is the right decision., Level of Evidence: II.

Background: Little research has investigated women's interest in and factors associated with viewing their ultrasound image in abortion care., Study Design: Using medical records for all abortion care visits in 2011 (n = 15,575) at an urban abortion provider, we determined the proportion of women who chose to view by sociodemographic and pregnancy-related characteristics. We used bivariate and multivariable mixed-effects logistic regression models to examine associations between individual-level factors and the decision to view., Results: A total of 42.6% of women chose to view. Identifying as nonwhite, being under age 25, being at or below the federal poverty level, and having medium or low decision certainty about the abortion were associated with increased odds of viewing. Being age 30 and over, having previously been pregnant and being more than 9 weeks gestation were associated with decreased odds of viewing., Conclusions: Many women seeking abortion care want to view their ultrasound image when offered the opportunity., (© 2013.)

Context: Although abortion is common in the United States, women who have abortions report significant social stigma. Currently, there is no standard measure for individual-level abortion stigma, and little is known about the social and demographic characteristics associated with it., Methods: To create a measure of abortion stigma, an initial item pool was generated using abortion story content analysis and refined using cognitive interviews. In 2011, the final item pool was used to assess individual-level abortion stigma among 627 women at 13 U.S. Planned Parenthood health centers who reported a previous abortion. Factor analysis was conducted on the survey responses to reduce the number of items and to establish scale validity and reliability. Differences in level of reported abortion stigma were examined with multivariable linear regression., Results: Factor analysis revealed a four-factor model for individual-level abortion stigma: worries about judgment, isolation, self-judgment and community condemnation (Cronbach's alphas, 0.8-0.9). Catholic and Protestant women experienced higher levels of stigma than nonreligious women (coefficients, 0.23 and 0.18, respectively). On the subscales, women with the strongest religious beliefs had higher levels of self-judgment and greater perception of community condemnation than only somewhat religious women. Additional differences were found by race, age, education, religiosity and motherhood status on the subscales., Conclusion: This valid and reliable scale can be used in research examining abortion stigma and related outcomes (e.g., women's health, relationships and behavior). The scale can also be used to evaluate programs and interventions that aim to reduce the stigma experienced by women who have abortions., (Copyright © 2013 by the Guttmacher Institute.)

Background: Most U.S. abortion patients are poor or low-income, yet most pay several hundred dollars out of pocket for these services. This study explores how women procure these funds., Methods: iPad-administered surveys were implemented among 639 women obtaining abortions at six geographically diverse healthcare facilities. Women provided information about insurance coverage, payment for service, acquisition of funds, and ancillary costs incurred., Findings: Only 36% of the sample lacked health insurance, but at least 69% were paying out of pocket for abortion care. Women were twice as likely to pay using Medicaid (16% of abortions) than private health insurance (7%). The most common reason women were not using private insurance was because it did not cover the procedure (46%), or they were unsure if it was covered (29%). Among women who did not use insurance for their abortion, 52% found it difficult to pay for the procedure. One half of patients relied on someone else to help cover costs, most commonly the man involved in the pregnancy. Most women incurred ancillary expenses in the form of transportation (mean, $44), and a minority also reported lost wages (mean, $198), childcare expenses (mean, $57) and other travel-related costs (mean, $140). Substantial minorities also delayed or did not pay bills such as rent (14%), food (16%), or utilities and other bills (30%) to pay for the abortion., Conclusions: Public and private health insurance plan coverage of abortion care services could ease the financial strain experienced by abortion patients, many of whom are low income., (Copyright © 2013 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.)

Objectives: We examined the impact on patient safety if nurse practitioners (NPs), certified nurse midwives (CNMs), and physician assistants (PAs) were permitted to provide aspiration abortions in California., Methods: In a prospective, observational study, we evaluated the outcomes of 11 487 early aspiration abortions completed by physicians (n = 5812) and newly trained NPs, CNMs, and PAs (n = 5675) from 4 Planned Parenthood affiliates and Kaiser Permanente of Northern California, by using a noninferiority design with a predetermined acceptable risk difference of 2%. All complications up to 4 weeks after the abortion were included., Results: Of the 11 487 aspiration abortions analyzed, 1.3% (n = 152) resulted in a complication: 1.8% for NP-, CNM-, and PA-performed aspirations and 0.9% for physician-performed aspirations. The unadjusted risk difference for total complications between NP-CNM-PA and physician groups was 0.87 (95% confidence interval [CI] = 0.45, 1.29) and 0.83 (95% CI = 0.33, 1.33) in a propensity score-matched sample., Conclusions: Abortion complications were clinically equivalent between newly trained NPs, CNMs, and PAs and physicians, supporting the adoption of policies to allow these providers to perform early aspirations to expand access to abortion care.

Purpose: To describe women's condom use patterns over time and assess predictors of dual method use 12 months after initiating hormonal contraceptives., Methods: We conducted a prospective cohort study among women aged 15-24 years initiating oral contraceptive pills, patch, ring, or depot medroxyprogesterone and attending public family planning clinics. Participants completed questionnaires at baseline and 3, 6, and 12 months after enrollment. We used multivariable logistic regression to assess baseline factors associated with dual method use at 12 months among 1,194 women who were sexually active in the past 30 days., Results: At baseline, 36% were condom users, and only 5% were dual method users. After initiation of a hormonal method, condom use decreased to 27% and remained relatively unchanged thereafter. Dual method use increased to a peak of 20% at 3 months but decreased over time. Women who were condom users at baseline had nearly twice the odds of being a dual method user at 12 months compared with nonusers (adjusted odds ratio [AOR] = 2.01, 95% CI: 1.28-3.14). Women who believed their main partner thought condoms were "very important," regardless of perceived sexually transmitted infection risk or participant's own views of condoms, had higher odds of dual method use (AOR = 2.89, 95% CI: 1.47-5.71)., Conclusions: These results highlight a potential missed opportunity for family planning providers. Providers focus on helping women initiate hormonal methods, however, they may improve outcomes by giving greater attention to method continuation and contingency planning in the event of method discontinuation and to the role of the partner in family planning., (Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Context: The Demographic and Health Survey (DHS) program collects data on women's empowerment, but little is known about how these measures perform in Sub-Saharan African countries. It is important to understand whether women's empowerment is associated with their ideal number of children and ability to limit fertility to that ideal number in the Sub-Saharan African context., Methods: The analysis used couples data from DHS surveys in four Sub-Saharan African countries: Guinea, Mali, Namibia and Zambia. Women's empowerment was measured by participation in household decision making, attitudes toward wife beating and attitudes toward refusing sex with one's husband. Multivariable linear regression was used to model women's ideal number of children, and multivariable logistic regression was used to model women's odds of having more children than their ideal., Results: In Guinea and Zambia, negative attitudes toward wife beating were associated with having a smaller ideal number of children (beta coefficients, -0.5 and -0.3, respectively). Greater household decision making was associated with a smaller ideal number of children only in Guinea (beta coefficient, -0.3). Additionally, household decision making and positive attitudes toward women's right to refuse sex were associated with elevated odds of having more children than desired in Namibia and Zambia, respectively (odds ratios, 2.3 and 1.4); negative attitudes toward wife beating were associated with reduced odds of the outcome in Mali (0.4)., Conclusions: Women's empowerment--as assessed using currently available measures--is not consistently associated with a desire for smaller families or the ability to achieve desired fertility in these Sub-Saharan African countries. Further research is needed to determine what measures are most applicable for these contexts.

Background: We examined 12-month hormonal contraceptive continuation and pregnancy rates by abortion history., Study Design: Women who wanted to avoid pregnancy for at least 1 year were recruited at four San Francisco Bay area family planning clinics on regular service days and on abortion care days. Participants completed baseline and follow-up questionnaires. Multivariable Cox models assessed the factors associated with method discontinuation and pregnancy., Results: Women who were enrolled into the study on the day of their abortion were 20% more likely to discontinue their contraceptive method than women who never had an abortion [adjusted hazard ratio (AHR)=1.21, 95% confidence interval (CI)=1.03-1.42]. Women who had a recent abortion or previous abortion were 60% more likely to have a pregnancy during follow-up than women who never had an abortion (AHR=1.63, 95% CI =1.21-2.20, and AHR=1.66, 95% CI=1.18-2.33, respectively)., Conclusion: The experience of having an unintended pregnancy and abortion does not lead to behavioral changes that protect against another unintended pregnancy., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Objective: To assess contraceptive discontinuation, switching, factors associated with method discontinuation, and pregnancy among women initiating hormonal contraceptives., Methods: This was a 12-month longitudinal cohort study of adolescent girls and women (n=1,387) aged 15 to 24 years attending public family planning clinics who did not desire pregnancy for at least 1 year and selected to initiate the patch, ring, depot medroxyprogesterone acetate, or pills. Participants completed follow-up assessments at 3, 6, and 12 months after baseline. Life table analysis was used to estimate survival rates for contraceptive continuation. Cox proportional hazards models were used to estimate factors associated with method discontinuation., Results: The continuation rate (per 100 person-years) at 12 months was low for all methods; however, it was lowest for patch and depot medroxyprogesterone acetate initiators, 10.9 and 12.1 per 100 person years, respectively (P≤.003); continuation among ring initiators was comparable to pill initiators, 29.4 and 32.7 per 100 person-years, respectively (P=.06). Discontinuation was independently associated with method initiated and younger age. The only factors associated with lower risk of discontinuation were greater intent to use the method and being in school or working. The pregnancy rate (per 100 person-years) was highest for patch and ring initiators (30.1 and 30.5) and comparable for pill and depot medroxyprogesterone acetate initiators (16.5 and 16.1; P<.001)., Conclusion: The patch and the ring may not be better options than the pill or depot medroxyprogesterone acetate for women at high risk for unintended pregnancy. This study highlights the need for counseling interventions to improve contraceptive continuation, education about longer-acting methods, and developing new contraceptives that women may be more likely to continue., Level of Evidence: II.

Objective: Emotional care is an important component of abortion services. Evidence-based counseling for other stigmatized and sensitive health issues may be informative for the improvement of abortion counseling., Methods: We searched the literature for practices used in emotional care for stigmatized and sensitive health issues. We made analytic choices for the selection of articles using the "constant comparative method," a grounded theory technique. We selected practices that were effective in supporting coping and improving psychosocial adjustment. Findings were synthesized and analyzed to draw evidence-based implications for abortion counseling., Results: We uncovered nine practices used in emotional care for stigmatized and sensitive health issues that have been shown to support coping or improve psychological adjustment. The techniques and interventions identified were: self-awareness assessments, peer counseling, decision aids, encouraging active client participation, supporting decision satisfaction, support groups, Internet-based support, ongoing telephone counseling, and public artistic expression., Conclusion: A variety of patient-centered, evidence-based interventions used for other health issues are applicable in emotional care for abortion. Evaluation of these practices in the abortion counseling setting can determine their appropriateness and effectiveness., Practice Implications: Abortion care providers may be able to integrate additional patient-centered practices to support coping or improve psychological adjustment after abortion., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Introduction: Low-density lipoprotein (LDL) cholesterol is a major contributor to coronary heart disease and the primary target of cholesterol-lowering therapy. Substantial disparities in cholesterol control exist nationally, but it is unclear how these patterns vary locally., Methods: We estimated the prevalence, awareness, treatment, and control of high LDL cholesterol using data from a unique local survey of New York City's diverse population. The New York City Health and Nutrition Examination Survey 2004 was administered to a probability sample of New York City adults. The National Health and Nutrition Examination Survey 2003-2004 was used for comparison. High LDL cholesterol and coronary heart disease risk were defined using National Cholesterol Education Program Adult Treatment Panel III (ATP III) guidelines., Results: Mean LDL cholesterol levels in New York City and nationally were similar. In New York City, 28% of adults had high LDL cholesterol, 71% of whom were aware of their condition. Most aware adults reported modifying their diet or activity level (88%), 64% took medication, and 44% had their condition under control. More aware adults in the low ATP III risk group than those in higher risk groups had controlled LDL cholesterol (71% vs 33%-42%); more whites than blacks and Hispanics had controlled LDL cholesterol (53% vs 31% and 32%, respectively)., Conclusion: High prevalence of high LDL cholesterol and inadequate treatment and control contribute to preventable illness and death, especially among those at highest risk. Population approaches - such as making the food environment more heart-healthy - and aggressive clinical management of cholesterol levels are needed.

Objective: To determine the prevalence of diabetes and impaired fasting glucose (IFG) and to assess clinical management indicators among adults with diabetes in a representative sample of New York City adults., Research Design and Methods: In 2004, New York City implemented the first community-level Health and Nutrition Examination Survey (NYC HANES), modeled after the National Health and Nutrition Examination Survey (NHANES). We used an interview to determine previously diagnosed diabetes and measured fasting plasma glucose to determine undiagnosed diabetes and IFG in a probability sample of 1,336 New York City adults. We assessed glycemic control and other clinical indicators using standardized NHANES protocols., Results: The prevalence of diabetes among New York City adults was 12.5% (95% CI 10.3-15.1): 8.7% diagnosed and 3.8% undiagnosed. Nearly one-fourth (23.5%) of adults had IFG. Asians had the highest prevalence of impaired glucose metabolism (diabetes 16.1%, IFG 32.4%) but were significantly less likely to be obese. Among adults with diagnosed diabetes, less than one-half (45%) had A1C levels <7%; one-half (50%) had elevated blood pressure measures at interview, 43% of whom were not on antihypertensive medications; nearly two-thirds (66%) had elevated LDL levels, and only 10% had their glucose, blood pressure, and cholesterol all at or below recommended levels. Most adults (84%) with diagnosed diabetes were on medication, but only 12% were receiving insulin., Conclusions: In New York City, diabetes and IFG are widespread. Policies and structural interventions to promote physical activity and healthy eating should be prioritized. Improved disease management systems are needed for people with diabetes.

This study examines the intergenerational effects of parents' marital relationship and the status of women on children's age at first sexual intercourse in Cebu, Philippines. Matched longitudinal data for 1,661 mothers and their children are analyzed. The mothers were interviewed in 1994, when their children were aged 9 to 11, about sociodemographic characteristics, their marital relationships, and women's status. Cox proportional hazards models are used to assess unmarried children's age at first sex as reported by the children in 2005 at ages 20 to 22. After multivariate adjustment, the analysis indicates that when parents make household decisions jointly, sons report delaying first sex. In households in which mothers have higher status, daughters report delayed first sex. The results demonstrate that long-term positive effects on children, particularly delaying first sex, occur in families in which parental decisionmaking is cooperative and in which women have high status.

Context: Early age at first sex has been identified as a risk factor for unplanned pregnancy and HIV infection. However, the emotional relationships and physical behaviors that precede first intercourse, and how they differ by sex, also may provide important cues about how to prevent sexual risk behavior., Methods: The precoital activities of 2,051 adolescents aged 17-19 in Cebu, Philippines, are examined using 1998-2000 and 2002 data from the Cebu Longitudinal Health and Nutrition Survey. The timing and tempo of emotional relationships and physical behaviors for males and females are described. Cox proportional hazards models are used to identify the characteristics associated with age at first sex., Results: Males engage in precoital physical behaviors and first sex at younger ages than females. Although the standard order in which the two sexes engage in emotional relationships for the first time is the same, males progress through the sequence more quickly than females. After adolescents have progressed through the sequence of emotional relationships, there is a gap of a least a year before they begin to have sex. In the multivariate analysis, rapid progression through the sequence of emotional relationships was associated with initiating sex at a younger age for females (hazard ratio, 1.5), but not for males., Conclusion: The period between first date and first sex experienced by both males and females provides an opportunity to ensure that adolescents have access to the information and services that will allow them to make informed choices about sexual behavior.

We look at whether women's status and autonomy affect birth-to-conception intervals using data from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines. We followed 1123 married, fecund women, aged 25-49, for up to 5 years. In a 1994-1995 survey, women were asked about the timing of their last birth. In 1998-2000, women were asked about any pregnancies since the 1994-1995 survey. Using these two surveys, we calculated birth to conception intervals. Women were censored if they reached their 50th birthday during follow-up. We measure autonomy based on whether the wife has the final say in 10 household decisions as measured in the 1994-1995 survey. Using Cox proportional hazards models we find that women with more decision-making autonomy have significantly longer birth-to-conception intervals in unadjusted models. After adjustment for age, wealth, education, other socio-economic variables, and women's status, decision-making autonomy remained a significant predictor in all models. This effect remains even after adjusting for contraceptive use, implying that autonomy influences birth-to-conception intervals through other mechanisms above and beyond increased contraceptive use. Additionally, few of the women's status variables were significantly associated with time to next conception. Women who had their first birth later in life were more likely to conceive during the observation period suggesting that they may be having shorter birth intervals in order to "catch up" with their peers. Maternal and child health-care efforts can help women achieve their desired spacing goals by supporting women's autonomy-in addition to ensuring they have accurate information and a range of contraceptive options.

Family planning users and providers have been calling for more choices. They want contraceptive methods that provide highly effective protection and at the same time cause fewer side effects, cost less, and are easier to use. In response, researchers are improving existing contraceptives and developing new ways to deliver hormones. Offering a wide range of safe, effective, and convenient family planning methods encourages more people to use contraception. Having more choices helps ensure that users are satisfied with their family planning method. Most new methods reaching the market today result from investments made years ago. Virtually all methods undergo a long process of research and rigorous testing for safety and effectiveness and must obtain regulatory approvals before becoming available.

Objectives: Systemic retinoic acid (RA) treatment for chemoprevention of squamous cell carcinoma of the head and neck (HNSCC) is limited by RA's toxic side effects at therapeutic doses. The pulsed-dye laser (PDL), through a mechanism of selective vascular targeting, may allow reduction of the RA dose to one that is better tolerated when these treatments are used in combination. This study tests our hypothesis that combination therapy of PDL irradiation and low-dose systemic RA is as effective as high-dose RA therapy alone in the chemoprevention of HNSCC., Study Design: Randomized, prospective study in a hamster model., Methods: Dysplastic lesions were induced in the cheek pouches of 48 hamsters by painting with topical 9,10-dimethl-1,2-benzanthrancene (DMBA). The hamsters were randomly divided into four treatment groups: 1) control (no treatment); 2) PDL irradiation only; 3) 5.0 mg RA (all-trans retinoid, 5.0 mg/kg per day, intraperitoneally [IP]); and (4) PDL + 0.5 mg RA (0.5 mg/kg per day, IP). The PDL irradiation was conducted at day 0 and 15, whereas the RA treatment was continued for 27 days. Tumor burden was measured over time., Results: The lesions in all of three treatment groups grow more slowly than the untreated controls. The combination treatment of PDL and RA had the greatest inhibitory effect on tumors., Conclusion: This study suggests that combination treatment of PDL and low-dose RA is more effective than high-dose RA alone in the chemoprevention of HNSCC in a hamster cheek-pouch model, so that it should allow greatly improved tolerance of this regimen.

Olfactory loss can occur through accidental exposure, poor industrial hygiene, or exposure to low levels of toxins in the ambient air over long periods. This loss can lead to transient olfactory disorders, irreversible anosmia, temporary olfactory fatigue, or industrial anosmia. Inevitably, a practicing otolaryngologist will encounter a patient with complaints of decreased smell and taste that initially may be difficult to diagnose and treat. Much of the challenge in evaluating a patient with disturbances of olfaction is in obtaining adequate quantitative measurements of sensory dysfunction and identifying a source for the olfactory loss. Although there is no particular test for environmental toxins as a source of olfactory loss, an accurate cause can be determined by obtaining a careful, detailed history. A significant exposure history and lack of more common causes of olfactory loss strengthens an argument for environmental toxins as an etiology. Unfortunately, no available treatments can reverse permanent damage caused by toxic exposure, but removal from the source of toxins may allow for repair of the olfactory system and return of normal function, especially in acute exposures. Despite the increasing number of studies investigating toxic exposure on olfactory function, these effects are understood poorly. With continued study of human exposure to these substances and the use of animal models, the mechanisms by which damage occurs will be understood better and new approaches for diagnosis and treatment will be developed. Furthermore, with increasing regulations of occupational environments and stricter policies on industrial air pollution, olfactory dysfunction secondary to toxicity should become less prevalent.

Self-movement creates the patterned visual motion of optic flow with a focus of expansion (FOE) that indicates heading direction. During pursuit eye movements, depth cues create a retinal flow field that contains multiple FOEs, potentially complicating heading perception. Paradoxically, human heading perception during pursuit is improved by depth cues. We have studied medial superior temporal (MST) neurons to see whether their heading selectivity is also improved under these conditions. The responses of 134 MST neurons were recorded during the presentation of optic flow stimuli containing one or three speed-defined depth planes. During pursuit, multiple depth-plane stimuli evoked larger responses (71% of neurons) and stronger heading selectivity (70% of neurons). Responses to the three speed-defined depth-planes presented separately showed that most neurons (54%) preferred one of the planes. Responses to multiple depth-plane stimuli were larger than the averaged responses to the three component planes, suggesting enhancing interactions between depth-planes. Thus speed preferences create selective responses to one of many depth-planes in the retinal flow field. The presence of multiple depth-planes enhances those responses. These properties might improve heading perception during pursuit and contribute to relative depth perception.