these programs seek to mitigate 1 ) barriers to healthcare , ( 2 ) behavioral risk factors , and ( 3 ) psychosocial stressors . despite several promising studies , a recent meta - analysis suggests that on average , home visiting is not effective in changing birth outcomes . a key limitation is that most pregnant women who enroll in home visiting do so relatively late in pregnancy , minimizing the opportunity to address modifiable risk factors . for home visiting programs , a growing body of literature has demonstrated the importance of adequate pregnancy spacing to reduce risk of preterm birth , particularly among high - risk women . pregnancy spacing may also have important consequences for maternal educational attainment and economic self - sufficiency , underscoring the long - range impact of this outcome for the maternal life course . home visitors have an opportunity to impact pregnancy spacing through emphasis on self - efficacy and connection with family planning services . prior literature describing home visiting effects on pregnancy spacing has been inconsistent . with recent and ongoing expansion of home visiting programs across the u.s . , evaluation of subsequent pregnancies is critical to assessing long - term programmatic benefits . the goal of this study was to evaluate the association of pregnancy spacing with home visiting enrollment among high - risk first - time mothers . we hypothesized that participants would be more likely to delay subsequent pregnancy compared with eligible , non - enrolled women . we also sought to determine the effects of varying participation in this voluntary program by enrolled women . for home visiting programs , which often struggle to engage families in consistent visit schedules and to retain families in services over time , the issue of attrition and loss to follow up has important implications for interpretation and evaluation of program outcomes . we hypothesized that among enrolled participants , greater program participation after birth of the first infant would be associated with improved pregnancy spacing . this retrospective cohort study evaluated a population of high - risk , first time mothers enrolled from 20072009 in a well - established , regional home visiting program serving 7 counties throughout greater cincinnati . this program contracts with 10 home visiting agencies in ohio which adhere to program , training and evaluation standards established by cincinnati children s hospital medical center ( cchmc ) , employing a core curriculum based on one of two national model of healthy families america ( hfa , 9 sites ) and nurse - family partnership ( nfp , 1 site ) . overall program goals are to : 1 ) provide pregnancy education and care coordination , 2 ) promote a nurturing home environment , 3 ) optimize child development , 4 ) link families to health services , and 5 ) promote economic self - sufficiency . eligible participants must be first - time mothers with at least 1 of 4 characteristics : unmarried , low income ( up to 300% of poverty level , receipt of medicaid , or reported financial concerns ) , < 18 years of age , or suboptimal prenatal care ( broadly defined with no specific gestational age cutoff ) . of these 4 criteria , suboptimal prenatal care is the least commonly used with < 5% of participants enrolled based on this alone . home visitors hold bachelor s degrees with training in child development and related disciplines ( hfa ) , or are licensed nurses ( nfp ) . to address pregnancy spacing , the program uses both formal approaches , such as handouts and tools to promote maternal health , life course planning , and connection to postpartum care , as well as informal approaches , e.g. motivation and confidence building for mothers to achieve their goals . the schedule of visits starts with weekly home visits , tapering to fewer visits as the child ages , with completion at 3 years of age . for each participant , home visiting data were abstracted from a web - based data entry system used to document service provision data and for billing . to derive information for the index pregnancy , program records were linked to ohio vital statistics and birth - related hospital discharge of both mother and infant . record linkage was accomplished using links ( university of manitoba ) , a sas - based probabilistic and deterministic matching program . similarly , linkage to subsequent live births for these mothers was conducted using ohio vital statistics through 2013 , such that information on subsequent pregnancies was examined within a three - year time frame from birth of the index infant ( i.e. fixed type 1 censoring ) . the ohio department of health and cchmc institutional review boards approved this study , including a waiver of consent based on minimal risk to subjects and feasibility .. interpregnancy interval ( ipi ) was defined as length of time between index birth and date of conception for the second pregnancy , derived by subtracting the second infant s gestational age from her or his birth date and then calculating the interval between the index birth and conception of the second infant . using this method , ipi was assessed as a continuous variable as well as a binary variable ( < or 18 months ) . as in previous analyses , we also evaluated a secondary outcome of very short ipi (  6 months ) to reflect rapid repeat births . among women with a subsequent pregnancy identified within the study time frame , preterm birth was assessed using the obstetrical estimate of gestational age documented in vital statistics . first , we examined outcome differences between those enrolled in home visiting and those not enrolled . our prior research has shown that among women eligible for home visiting in the region , approximately one third are referred and among those referred approximately half enroll . therefore , using ohio vital statistics from the same years of 20072009 , a matched comparison group of first - time mothers was selected based on program eligibility criteria . to minimize the potential for self - selection bias in the enrolled group , we excluded from the comparison group any women who were referred to home visiting but declined enrollment . we also excluded women with an index neonatal death , because home visiting requires participants to either be pregnant or parenting and therefore they would no longer be eligible for services . similarly , women with a previable gestational age at delivery ( < 23 weeks ) for the index pregnancy were also excluded , as such infants have a low likelihood of survival or eventual discharge by 3 months of age thereby precluding home visiting participation . we then performed a 1:1 matching of potential comparison mothers to home visiting participants using the following matching characteristics : race , maternal age , index year of birth , and residence within a zip code with either higher or lower penetration of the home visiting program ( < or  25% of eligible women in the area enrolled in home visiting ) . exact matching constraints were permitted to vary modestly for maternal age ( 1 year ; approximately 20% standard deviation in age ) and birth year ( 2 years ) to prevent unnecessary exclusion of matched comparisons . we also matched by propensity score , derived using logistic regression for the individual conditional probability of participating in home visiting based on the following baseline characteristics : maternal age , education level , tobacco use , marital status , race , ethnicity , zip code of residence , hypertension before or during the index pregnancy , and diabetes before or during the index pregnancy . these characteristics were selected on the basis of prior research demonstrating their importance in predicting referral and enrollment into home visiting . a 1:1 matching ratio was selected to minimize bias and ensure balance of covariates across enrolled and comparison mothers . matches were constrained by a caliper of 20% of the propensity score standard deviation . a greedy algorithm with weighted euclidean distance balance of covariates across controls and the enrolled participants was assessed using absolute standardized differences in means . for the second phase of the analysis , we evaluated whether level of program participation was associated with outcome differences within the group of women enrolled in home visiting . as above , women with a gestational age < 23 weeks at delivery and those with a neonatal death were excluded . based on empirical evidence from multiple programs that attrition from home visiting is common in the first year , we measured participation as percentage of expected home visits completed over the first year of life for the mother s first infant per the program s curriculum ( complete participation would approximate 32 total home visits ) . we categorized these percentages a priori into levels of participation deemed low ( 025% of expected visits ) , moderate ( 2575% of expected visits ) , high ( 75100% of expected visits ) , and very high ( > 100% ) . our characterization of 75100% of expected visits as high participation aligns closely with previous research on home visiting engagement . characteristics of participants by participation level were analyzed by the pearson chi - squared test or student s t test . for both phases of analysis , cox proportional hazards regression models tested differences in timing to subsequent pregnancy . models were tested for the assumption of proportional hazards using schoenfeld residuals and adjusted for clinical and demographic covariates . for the analysis of program participation , modelling was also stratified by agency to account for site - level differences in the baseline hazard . cumulative hazard function curves were used to display results graphically . finally , for both phases of analysis we used multivariable logistic regression to evaluate the likelihood of preterm birth among those women experiencing a subsequent pregnancy . interpregnancy interval ( ipi ) was defined as length of time between index birth and date of conception for the second pregnancy , derived by subtracting the second infant s gestational age from her or his birth date and then calculating the interval between the index birth and conception of the second infant . using this method , ipi was assessed as a continuous variable as well as a binary variable ( < or 18 months ) . as in previous analyses , we also evaluated a secondary outcome of very short ipi (  6 months ) to reflect rapid repeat births . among women with a subsequent pregnancy identified within the study time frame , preterm birth was assessed using the obstetrical estimate of gestational age documented in vital statistics . first , we examined outcome differences between those enrolled in home visiting and those not enrolled . our prior research has shown that among women eligible for home visiting in the region , approximately one third are referred and among those referred approximately half enroll . therefore , using ohio vital statistics from the same years of 20072009 , a matched comparison group of first - time mothers was selected based on program eligibility criteria . to minimize the potential for self - selection bias in the enrolled group , we excluded from the comparison group any women who were referred to home visiting but declined enrollment . we also excluded women with an index neonatal death , because home visiting requires participants to either be pregnant or parenting and therefore they would no longer be eligible for services . similarly , women with a previable gestational age at delivery ( < 23 weeks ) for the index pregnancy were also excluded , as such infants have a low likelihood of survival or eventual discharge by 3 months of age thereby precluding home visiting participation . we then performed a 1:1 matching of potential comparison mothers to home visiting participants using the following matching characteristics : race , maternal age , index year of birth , and residence within a zip code with either higher or lower penetration of the home visiting program ( < or  25% of eligible women in the area enrolled in home visiting ) . exact matching constraints were permitted to vary modestly for maternal age ( 1 year ; approximately 20% standard deviation in age ) and birth year ( 2 years ) to prevent unnecessary exclusion of matched comparisons . we also matched by propensity score , derived using logistic regression for the individual conditional probability of participating in home visiting based on the following baseline characteristics : maternal age , education level , tobacco use , marital status , race , ethnicity , zip code of residence , hypertension before or during the index pregnancy , and diabetes before or during the index pregnancy . these characteristics were selected on the basis of prior research demonstrating their importance in predicting referral and enrollment into home visiting . a 1:1 matching ratio was selected to minimize bias and ensure balance of covariates across enrolled and comparison mothers . matches were constrained by a caliper of 20% of the propensity score standard deviation . a greedy algorithm with weighted euclidean distance balance of covariates across controls and the enrolled participants was assessed using absolute standardized differences in means . for the second phase of the analysis , we evaluated whether level of program participation was associated with outcome differences within the group of women enrolled in home visiting . as above , women with a gestational age < 23 weeks at delivery and those with a neonatal death were excluded . based on empirical evidence from multiple programs that attrition from home visiting is common in the first year , we measured participation as percentage of expected home visits completed over the first year of life for the mother s first infant per the program s curriculum ( complete participation would approximate 32 total home visits ) . we categorized these percentages a priori into levels of participation deemed low ( 025% of expected visits ) , moderate ( 2575% of expected visits ) , high ( 75100% of expected visits ) , and very high ( > 100% ) . our characterization of 75100% of expected visits as high participation aligns closely with previous research on home visiting engagement . characteristics of participants by participation level were analyzed by the pearson chi - squared test or student s t test . for both phases of analysis , cox proportional hazards regression models tested differences in timing to subsequent pregnancy . models were tested for the assumption of proportional hazards using schoenfeld residuals and adjusted for clinical and demographic covariates . for the analysis of program participation , modelling was also stratified by agency to account for site - level differences in the baseline hazard . cumulative hazard function curves were used to display results graphically . finally , for both phases of analysis we used multivariable logistic regression to evaluate the likelihood of preterm birth among those women experiencing a subsequent pregnancy . to derive the sample for the first phase of the analysis , we identified 1,516 women with an ohio birth certificate between 2007 and 2009 and who were enrolled in home visiting either prenatally or after birth of the infant . after applying matching algorithm constraints , 1,460 participants were matched 1:1 to comparison women who were neither referred to nor enrolled ( total sample 2,920 women ) . based on this sample size we had > 80% power ( at alpha=0.05 ) to detect a 25% reduction in repeat pregnancy by 18 months among enrolled participants using a two - sided test , which is similar to effect sizes shown in prior research . as shown in table 1 , characteristics were balanced across the two matched groups . across this total sample , 485 ( 16.6% ) had an ipi < 18 months ( 17.4% among enrolled vs. 15.8% among comparisons ) , and 4.6% had an ipi < 6 months ( 4.8% among enrolled vs. 4.3% among comparisons ) . as shown in table 2 and figure 1 ( panel a ) , after multivariable adjustment enrollment was not associated with a significant difference in timing to repeat pregnancy over an 18 month timeframe ( hr 1.13 , 95% ci 0.94 , 1.37 ) . tests for interaction with key covariates ( race , maternal age , and education level ) were not statistically significant . covariates that were associated with significant risk differences were obesity ( hr 1.26 , 95% ci 1.01 , 1.57 ) , college education ( hr 0.68 , 95% ci 0.50 , 0.92 ) , hispanic ethnicity ( hr 0.46 , 95% ci 0.24 , 0.89 ) and index cesarean delivery ( hr 0.59 , 95% ci 0.47 , 0.75 ) . among this sample of enrolled and non - enrolled women , 854 ( 29.3% ) had a repeat pregnancy over a 3 year timeframe ; the preterm birth rate for these second pregnancies was 12.3% ( 12.1% among enrolled vs. 12.5% among comparisons ) . in multivariable logistic regression shown in table 2 , enrollment was not associated with a significant reduction in odds of preterm birth for the subsequent pregnancy ( adjusted odds ratio ( aor ) 0.78 , 95% ci 0.49 , 1.24 ) . however , prior preterm birth and ipi < 6 months were both significant predictors of subsequent preterm birth . approximately 37% were classified as low participation , 50% as medium participation , and 10% as high participants . finally , a small number ( 3% ) received > 100% of the expected intervention . because we observed significant differences in risk characteristics of participants with this very high level of home visiting service , these were categorized separately ( see table 3 ) . among all enrolled participants , 19% had a repeat pregnancy within 18 months of first birth , and 5% had a repeat pregnancy within 6 months . compared to low program participation , moderate participation was associated with reduced risk of repeat pregnancy over 18 months ( hr 0.67 , 95% ci 0.52 , 0.87 ) . high participation was also associated with a reduced risk ( hr 0.55 , 95% ci 0.33 , 0.91 ) . however , those with the highest number of visits did not demonstrate a significant difference in repeat pregnancies compared with low participants ( hr 1.39 , 95% ci 0.78 , 2.50 ) ( see figure 1 , panel b ) . tests for interaction effects with key covariates ( race , maternal age , and education level ) were not statistically significant . we did not observe significant differences in timing to repeat based on home visiting model ( approximately 5% served by an nfp agency ) or on prenatal vs. postnatal enrollment ( after birth of the index child ) . however , covariates that were associated with significant risk differences were maternal smoking ( hr 1.19 , 95% ci 0.91 , 1.57 ) , obesity ( hr 1.44 , 95% ci 1.08 , 1.91 ) , college education ( hr 0.63 , 95% ci 0.44 , 0.91 ) , and index cesarean delivery ( hr 0.64 , 95% ci 0.48 , 0.86 ) . as a sensitivity analysis , we omitted 87 participants who based on program records were discharged from home visiting due to a move outside of the service area ; results for all predictors were substantially unchanged . for the 498 enrolled in home visiting with a repeat pregnancy over 3 years , the preterm birth rate for the second pregnancy was 12.3% . we evaluated for possible mediation by modeling the analysis of preterm birth with and without ipi as a covariate . in multivariable logistic regression , high home visiting participation demonstrated a trend towards reduced odds of subsequent preterm birth , but the effect was not statistically significant ( aor 0.45 , 95% ci 0.10 , 2.06 ) . when ipi < 6 months was added to the model of preterm birth ( table 4 ) , the effect of high home visiting participation was not substantially different , while ipi itself was a significant predictor of preterm birth ( aor 4.30 , 95% ci 2.21 , 8.38 ) . to derive the sample for the first phase of the analysis , we identified 1,516 women with an ohio birth certificate between 2007 and 2009 and who were enrolled in home visiting either prenatally or after birth of the infant . after applying matching algorithm constraints , 1,460 participants were matched 1:1 to comparison women who were neither referred to nor enrolled ( total sample 2,920 women ) . based on this sample size we had > 80% power ( at alpha=0.05 ) to detect a 25% reduction in repeat pregnancy by 18 months among enrolled participants using a two - sided test , which is similar to effect sizes shown in prior research . as shown in table 1 , characteristics were balanced across the two matched groups . across this total sample , 485 ( 16.6% ) had an ipi < 18 months ( 17.4% among enrolled vs. 15.8% among comparisons ) , and 4.6% had an ipi < 6 months ( 4.8% among enrolled vs. 4.3% among comparisons ) . as shown in table 2 and figure 1 ( panel a ) , after multivariable adjustment enrollment was not associated with a significant difference in timing to repeat pregnancy over an 18 month timeframe ( hr 1.13 , 95% ci 0.94 , 1.37 ) . tests for interaction with key covariates ( race , maternal age , and education level ) were not statistically significant . covariates that were associated with significant risk differences were obesity ( hr 1.26 , 95% ci 1.01 , 1.57 ) , college education ( hr 0.68 , 95% ci 0.50 , 0.92 ) , hispanic ethnicity ( hr 0.46 , 95% ci 0.24 , 0.89 ) and index cesarean delivery ( hr 0.59 , 95% ci 0.47 , 0.75 ) . among this sample of enrolled and non - enrolled women , 854 ( 29.3% ) had a repeat pregnancy over a 3 year timeframe ; the preterm birth rate for these second pregnancies was 12.3% ( 12.1% among enrolled vs. 12.5% among comparisons ) . in multivariable logistic regression shown in table 2 , enrollment was not associated with a significant reduction in odds of preterm birth for the subsequent pregnancy ( adjusted odds ratio ( aor ) 0.78 , 95% ci 0.49 , 1.24 ) . however , prior preterm birth and ipi < 6 months were both significant predictors of subsequent preterm birth . approximately 37% were classified as low participation , 50% as medium participation , and 10% as high participants . finally , a small number ( 3% ) received > 100% of the expected intervention . because we observed significant differences in risk characteristics of participants with this very high level of home visiting service , these were categorized separately ( see table 3 ) . among all enrolled participants , 19% had a repeat pregnancy within 18 months of first birth , and 5% had a repeat pregnancy within 6 months . compared to low program participation , moderate participation was associated with reduced risk of repeat pregnancy over 18 months ( hr 0.67 , 95% ci 0.52 , 0.87 ) . high participation was also associated with a reduced risk ( hr 0.55 , 95% ci 0.33 , 0.91 ) . however , those with the highest number of visits did not demonstrate a significant difference in repeat pregnancies compared with low participants ( hr 1.39 , 95% ci 0.78 , 2.50 ) ( see figure 1 , panel b ) . tests for interaction effects with key covariates ( race , maternal age , and education level ) were not statistically significant . we did not observe significant differences in timing to repeat based on home visiting model ( approximately 5% served by an nfp agency ) or on prenatal vs. postnatal enrollment ( after birth of the index child ) . however , covariates that were associated with significant risk differences were maternal smoking ( hr 1.19 , 95% ci 0.91 , 1.57 ) , obesity ( hr 1.44 , 95% ci 1.08 , 1.91 ) , college education ( hr 0.63 , 95% ci 0.44 , 0.91 ) , and index cesarean delivery ( hr 0.64 , 95% ci 0.48 , 0.86 ) . as a sensitivity analysis , we omitted 87 participants who based on program records were discharged from home visiting due to a move outside of the service area ; results for all predictors were substantially unchanged . for the 498 enrolled in home visiting with a repeat pregnancy over 3 years , the preterm birth rate for the second pregnancy was 12.3% . we evaluated for possible mediation by modeling the analysis of preterm birth with and without ipi as a covariate . in multivariable logistic regression , high home visiting participation demonstrated a trend towards reduced odds of subsequent preterm birth , but the effect was not statistically significant ( aor 0.45 , 95% ci 0.10 , 2.06 ) . when ipi < 6 months was added to the model of preterm birth ( table 4 ) , the effect of high home visiting participation was not substantially different , while ipi itself was a significant predictor of preterm birth ( aor 4.30 , 95% ci 2.21 , 8.38 ) . several aspects of real world programmatic implementation likely contribute to the inconsistency of published findings on home visiting and birth outcomes , including referral bias towards women with more complicated pregnancies , as well as an inability of home visiting programs to reach most participants until they are late in pregnancy . given these limitations , the question of whether home visiting influences subsequent birth outcomes has significant public health implications . in this study of high - risk first - time mothers , we observed no difference in pregnancy spacing or subsequent preterm birth between those enrolled and not enrolled in home visiting , which suggests limited overall impact of this intervention . these findings may be related to lack of sustained engagement among participants in this intensive , voluntary program , of whom roughly one quarter had fewer than 5 home visits after delivery of their first infant . importantly , we observed that among enrolled participants , those with at least moderate program participation did have increased time to subsequent pregnancy compared with those who had very few home visits . while we observed no significant effect of participation level on subsequent preterm birth , our ability to detect differences in preterm birth was likely affected by the limited number of subsequent pregnancies , particularly among those women with moderate and high program participation . shorter ipi was a significant risk factor for preterm birth within this cohort , indicating that pregnancy spacing is important for home visiting programs to achieve long term benefits for participants . prior studies on home visiting and pregnancy spacing have yielded mixed results . a recent cohort study comparing women enrolled and not enrolled in nfp home visiting in pennsylvania demonstrated positive effects on pregnancy spacing , particularly for young women and those living in rural locations . conversely , evaluation of hfa home visiting in hawaii has demonstrated no improvement in pregnancy spacing among enrolled participants compared with those not enrolled . we do not suspect our null findings are due to insufficient power to detect small but meaningful differences , as the trend for enrolled women actually appeared slightly worse than comparisons . lack of effect has previously been attributed to several factors , including program attrition and lack of program specificity with regards to family planning interventions . across home visiting programs nationally , heterogeneity of services is well documented , with most participants not receiving the recommended number of visits . our current findings provide further insight into the impact of variable dose of the intended intervention on this important outcome . results suggest not only the need for specific content on pregnancy spacing , but also to maximize delivery of this content to all participants , including those only enrolled briefly . finally , we found that very high program utilization was associated with increased maternal risk , including hypertension , diabetes , obesity , and smoking . for this subgroup , pregnancy outcomes were not statistically different from those of very low program utilizers ( and suggestive of a trend towards worse outcomes ) . this is consistent with prior findings that very high prenatal care utilization is associated with greater maternal pregnancy risk , as well as recent findings from holland et al . that increasing use of home visiting over time is predictive of poor outcomes this non - linear association between maternal risk and dosage of preventive services likely reflects the dynamic process of evaluation by both providers and participants , such that higher needs can be a driver of more frequent visits . within home visiting , recommended visit schedules are not empirically based but rather derived a priori ; although general wisdom suggests  more is better ,  our findings suggest that the extent of a home visiting dose - effect relationship may depend on maternal characteristics and on the outcome being evaluated . further research is needed not only on approaches to strengthen maternal motivation to participate and adhere to recommended visits , but also to optimize program dose based on their risk characteristics and outcomes . strengths include a large regional cohort with 3 years of follow up data and details of service use for this community - based program . we have attempted to minimize selection bias associated with referral and decision to enroll , which may be considerable among the eligible population . there may be unmeasured , systematic differences between women who received high and low levels of service . bias toward overstating the results would occur if , for example , women with subsequent pregnancies were less able to adhere to the home visiting schedule , or if those with adequate participation were especially motivated with regards to family planning . alternatively , prior data from our program suggests there may be bias in retention such that participants with higher acute needs are more likely to remain engaged in home visiting . furthermore , given limitations of the data we could not quantify either time spent on pregnancy spacing counselling , the quality of such information , or the percentage of women who initiated postpartum contraception . ascertainment bias should also be considered , because miscarriages , therapeutic abortions , and births outside of ohio were not counted as events . we have no reason to believe that miscarriages and abortion might be systematically different between women with lower and higher program participation . however , it is possible that women exiting the program earlier were also more likely to move out of the state and therefore be less likely to have a record of subsequent pregnancy , biasing our estimates towards the null . finally , generalizability may also be concern , given our analysis was confined to one regional program . however , rates of subsequent pregnancy for women in our sample were consistent with rates among an eligible , at - risk population in ohio . among women enrolled in home visiting , short ipi is a risk factor for preterm birth . programmatic effects on pregnancy spacing are demonstrated among those with at least moderate program participation . although findings suggest that increasing delivery of recommended home visits may increase observable program benefits , future efforts to develop and implement empirically - based visit schedules should take into account maternal risk characteristics as well as outcomes of interest .
objectivedetermine association of home visiting with subsequent pregnancy outcomesstudy designretrospective study of ohio mothers delivering their first infant from 20072009 . 
 first , we compared mothers enrolled in home visiting to a matched eligible group . 
 second , we compared outcomes within home visiting based on program participation ( low < 25% of recommended home visits , moderate 2575% , high 75100% and very high > 100% ) . 
 time to subsequent pregnancy within 18 months was evaluated using cox proportional hazards regression ; logistic regression tested the likelihood of subsequent preterm birth.resultof 1,516 participants , 1,460 were matched 1:1 to a comparison mother ( n=2,920 ) . 
 after multivariable adjustment , enrollment was associated with no difference in pregnancy spacing or subsequent preterm birth . among those enrolled , moderate vs. low participants had reduced risk of repeat pregnancy over 18 months ( hazard ratio 0.68 , 
 p=0.003).conclusionincreased pregnancy spacing is observed among women with at least moderate home visiting participation .