As a standard part of first-trimester antenatal care (ANC) in India, ANC clinics screen pregnant women for SCD using the sickle cell solubility test and confirm a positive result as either SCA or SCT based on the electrophoresis test. A positive solubility test suggests the presence of at least one copy of HbS, which is indicative of the presence of SCA or SCT. Meanwhile, ANC mandates partner disclosure of a positive solubility test to facilitate paternal screening to determine the risk of the child being born with SCA. Paternal screening is critical in the case of maternal positive solubility test, as pregnant women with SCT or SCA can have children with SCA, depending on whether their male partners have SCT or SCA (see Figure 1). Children born with SCA will inherit two hemoglobin “S” (HbS) genes, one from each parent. Children born with SCT will inherit a HbS gene from one parent and a normal gene from the other parent. Pregnant women with a negative result do not have a risk of giving birth to a child with SCA.

Following the socioecological model (22–24), we maintain that SCD stigma occurs at multiple levels of influence, which makes mandatory partner disclosure of SCD screening results a risk factor for IPV among pregnant women. Manifested in micro-interactions (e.g., couple interactions) of the negative beliefs (e.g., possession of undesirable attributes), attitudes (e.g., unworthy of equal status and treatment), and practices (e.g., social exclusion) associated with SCD existing in multiple levels of influence (i.e., society, communities, and institutions), stigma is intended to discriminate or mistreat people (5, 25) including those with SCD (26).

Following the stress process framework (27, 28), we propose ways for how a positive solubility test can trigger a violent response among men in contexts that stigmatize SCD. Lacking knowledge about SCD (29), men may misunderstand a positive solubility test as a confirmation that women have SCA, which is a stigmatizing disease (26). Anticipating having to spend a life with a wife with SCA, men may experience psychological distress as a result. Furthermore, men may worry about the future of the unborn child now having to live with poor health due to SCA or with poor quality of life rife with the experience of discrimination due to prevailing SCA stigma in society (21, 30, 31), leading them to experience psychological distress, and fear of status loss, discrimination, or negative social relations. Consequently, by way of coping with psychological distress (32), men may associate women with a positive solubility test with SCA stereotypes as “damaged” or “no good for childbearing”; accuse women of deceit, when women intentionally hide their SCA result until the current pregnancy; or use other forms of violence, especially if they used IPV in the past, grew up seeing IPV, or currently seeing IPV being perpetrated against women by their male neighbors, friends, or relatives (33–35).

We conducted this study in Nagpur, serving scheduled tribe populations living in the sickle cell belt region of India including in Maharashtra and neighboring states. A total of 20 urban primary health centers (UPHCs) served as data collection sites.

We conducted a cohort study involving pregnant women seeking ANC care in UPHCs in Nagpur in 2019–2020 as the study population. Using interviewer-administered questionnaires, we surveyed 91 pregnant women with a positive solubility test and 91 with a negative solubility test within 3 months of receiving their sickle cell solubility test result about their experiences of IPV 6 months prior to the survey (baseline). A follow-up survey was conducted within 3–4 months after childbirth (endline), where we obtained information on their experiences of IPV since the baseline survey. We implemented this study design to accommodate the participant's availability for this research. Originally, we planned to survey 91 pregnant women with a positive test result and 91 with a negative test result about their experience of IPV 6 months before receiving their sickle cell solubility test results (baseline, prior to partner disclosure) and 6 months after participating in the baseline survey (endline, after partner disclosure). Our study followed the ethics in IPV research, which is to accommodate women's wishes.

Women testing positive participated in the baseline survey within a mean of 1.1 months after receipt of the sickle cell solubility test result, with 95% participating within 3 months, whereas women testing negative did so within a mean of 0.8 months after test results, with 95% participating within 2 months (p = 0.003). Women testing positive participated in the endline survey within a mean of 1.5 months after delivery, with 95% participating within 3 months, whereas women testing negative did so within a mean of 2.1 months, with nine women participating in the endline survey after 4 months of delivery inflating the average (p = 0.001). Overall attrition between the baseline and endline surveys was 14%, which was higher among women testing positive than that among women testing negative (19.8% vs. 8.8%, respectively; p = 0.034). However, within each cohort (women testing positive vs. negative), women who retained in the study and those who dropped out did not differ on baseline IPV or characteristics (results are available upon request).

With 91 women per group, we had the power to detect at least a difference of 20 percentage points between two groups in endline IPV rates, assuming a 20% baseline IPV rate among women with a negative test result and a 95% confidence interval. We chose to use a 20% IPV rate, as this was the 12-month prevalence of IPV among a nationally represented sample of Indian women of reproductive age, and to capture the higher rate of IPV experienced pre-pregnancy rather than using the 4% prevalence rate for physical IPV during pregnancy, as using the latter would require a larger sample size (1, 36).

We recruited the first 91 pregnant women with a positive solubility test and 91 with a negative solubility test, from the pregnant women presenting to 1 of 20 UPHCs since the study start date. Information on positive/negative solubility tests was obtained from a UPHC-affiliated laboratory. Women were eligible for this study if they were planning to remain in the study area during pregnancy, labor, and delivery; never attempted or had thoughts of self-harm; had never been treated for mental health issues; were not seeking in-patient care at a medical facility; and had no prior knowledge of their sickle cell status before the current pregnancy.

At the baseline, we collected data on common sociodemographic correlates of IPV for the mother (age, age of first marriage, previously married, consanguinity, education, gestational age, religion, caste membership, food insecurity) and the father (age, age at first marriage, education). At the endline, we collected data on partner disclosure and husbands' SCD screening dates and results.

IPV at the baseline and endline. We used the 49-item Indian Family Violence and Control Scale (FVCS) (α = 0.88) to collect baseline data on experience of physical, sexual, and psychological IPV in the last 6 months prior to the survey and, for endline data, on experience of these types of IPV since participation in the baseline survey.

Survey administration. During clinic visits, trained interviewers administered the surveys face-to-face reading out loud questions in Marathi.

IPV. We considered women to have experienced physical IPV if she responded experiencing any one of the following at least once in the last 6 months: husband slapped her or threw something at her that could hurt her; pushed or shoved her; hit her with a fist or with something else that could hurt her; kicked, dragged, beaten, choked, or burned her; or threatened to use or actually used a gun, knife, or other weapon against her. We used the same method to assess women's experience of sexual IPV (husband forced her to have sexual intercourse against her will; husband forced to do something sexual that she found degrading or humiliating) and emotional IPV (husband insulted her or deliberately made her feel bad about herself; belittled or humiliated her in front of other people; done things to scare or intimidate her on purpose; threatened to hurt her; hurt people she cares about as a way of hurting her; or damaged things that are important to her).

Positive/negative solubility test. We coded women testing positive as 1 and those testing negative as 0.

Aided by our study design, we compared women testing positive with those testing negative for balance on a total of 17 sociodemographic variables using the t-test, χ² test, or Wilcoxon Mann–Whitney sum test, informing our selection of confounders to adjust in regression models. We found the level of education and caste membership to be different between two groups of women. Religion and father's education were also different, which we ignored in model fitting, since they had no association with IPV in our sample of women (results available upon request). We ran separate binomial logistic regression models to estimate the association between a positive solubility test and risk of any IPV (i.e., physical, sexual, or psychological IPV) at baseline and endline, adjusting for level of education and caste at each time point. We used any IPV to ensure that the outcome variable had enough yes vs. no events (i.e., IPV occurrences vs. non-occurrences) for model fitting and to avoid overparameterization (i.e., including too many explanatory variables for an outcome with too few events). Endline regression models included baseline IPV as a control with errors corrected for repeated measures using GLM modeling approaches. We fitted models using physical, sexual, and psychological IPV as an outcome, for exploratory purposes (results available upon request).

We obtained ethical approval from the Boston Medical Center/Boston University Medical Campus Institutional Review Board in the United States and the Lata Medical Research Foundation in India prior to the study. Women provided signed consent prior to participation.

Women. The two groups of women (positive and negative solubility tests) were comparable on 7 of 10 characteristics, including age (26.6 years vs. 25.5 years), age at first/current marriage (22.5 years vs. 22.7 years), first-time married (98.9% vs. 96.7%), husband related by blood (14.3% vs. 11.0%), school attendance (97.8% vs. 98.9%), gestation age at SCD screening (19.9 weeks vs. 20.1 weeks), and no food insecurity (96.7% vs. 98.9%). However, the two groups differed on the highest level of education completed, with twice as many women with a negative solubility test as those with positive having completed at least the secondary level of education (90% vs. 42%, p < 0.0001). Furthermore, more women with a positive solubility test practiced Buddhism/Neo-Buddhism and were from a scheduled caste or scheduled tribe, compared with those who tested negative (57% vs. 32%, respectively; p = 0.04; and 69% vs. 49%, respectively; p = 0.01). Most women underwent SCD screening in the second trimester, with 77% of women testing positive undergoing SCD screening at 24 weeks of gestation, compared with 71% of women testing negative (Table 1).

Men. In the two groups (men married to women testing positive vs. negative), characteristics of fathers were comparable on three of four characteristics, including age (31.5 years vs. 30.2 years), age at first/current marriage (28.1 years vs. 28.3), and school attendance (95.6% vs. 98.9%). Similar to women, men married to women testing positive or negative completed different levels of education, with male partners of women with a negative solubility test tending to be more educated than those with a positive solubility test (secondary level completed 79% vs. 44%, respectively, p < 0.0001).

Physical, psychological, sexual, and any IPV. Significantly more women with a positive result vs. those with a negative result reported experiencing physical IPV (20.9% vs. 6.6%, respectively, p = 0.005; see Table 2), emotional IPV (31.8% vs. 16.5%, respectively; p = 0.015), and any IPV (39.6% vs. 17.6%, respectively; p = 0.001) in the prior 6 months at baseline. However, at endline, we found no difference in the rates of physical IPV, emotional IPV, or any IPV between groups.

Baseline. Compared to women testing negative, those with a positive test result were three times as likely to report having experienced any IPV at baseline (OR: 3.07, p = 0.001) in both the unadjusted and adjusted models (Models 1 and 2, respectively; see Table 3). However, neither women's lower level of education nor scheduled caste membership was associated with their risk of IPV at baseline (Model 2).

Endline. Compared to women with a negative test result, those testing positive were not more at risk for IPV at endline in the unadjusted or adjusted models (Models 3 and 4).

Plausibility analysis. For baseline IPV, the recall period (i.e., 6 months before the baseline survey) includes up to 4 months post-partner disclosure of a positive test result. Ninety-six percent of women testing positive reported partner disclosure, and partner disclosure occurred prior to the baseline survey for 100% of the women for whom such data are available. To elaborate, we know the dates when women underwent the sickle cell solubility tests and when they participated in the baseline survey, and we know when husbands were screened for SCD for nearly 50% of the women for whom such data are available. Based on these dates, we were able to confirm for the women from whom data are available, that 100% of them disclosed their positive solubility test to their husbands prior to the baseline survey.

Robustness checks. Additional analyses were performed to repudiate the idea that the observed association between a positive test result and risk for IPV is a proxy of the association between the lower level of education and IPV or between scheduled-caste membership and IPV. While women testing positive mostly had a primary level of education and were members of a scheduled caste (Model 1; see Table 4), neither the lower level of education nor scheduled-caste membership is a risk factor for baseline or endline IPV for our sample of women (Models 2 and 3, respectively). Therefore, a positive association between a positive test result and risk for IPV in the model adjusted for the lower level of education and scheduled-caste membership is suggestive of a direct effect of a positive test result on IPV, independent of the effects of the lower level of education and schedule-caste membership.

To our knowledge, this is the first study to examine the association between antenatal screening for SCD and IPV, and one of only a handful of studies on IPV among women with SCD, globally. Nonetheless, our findings must be interpreted within the context of the limitations below. First, due to how the study had to be implemented, we ended up not having “true” baseline rates of IPV prior to SCD screening, affecting our ability to draw more conclusive findings on the relationship between disclosure of SCD screening results and IPV. Originally, we designed the study to survey 91 pregnant women with a positive test result and 91 with a negative test result about their experience of IPV 6 months before (baseline) receiving the sickle cell solubility test results (prior to partner disclosure) and since participation in the baseline survey (endline) (after partner disclosure). With this design implemented, we would have been able to attribute endline differences in IPV between women testing positive and negative to partner disclosure of a positive result, all else being equal at baseline including IPV. However, during study implementation, we had to deviate from the original study design to accommodate women's wishes regarding the timing of their participation in the surveys as per the ethical conduct of IPV research. In theory, to obtain true baseline IPV rates, we could have recruited only those women agreeing to participate in the baseline survey on the same day that they received a test result; however, doing so would have elongated the time of sample recruitment, which could not be supported by the study budget. Second, we relied on women's self-report for data on women's experience of IPV over some time in the past, which can be affected by underreporting due to IPV stigma or recall bias (47). Furthermore, women may be reluctant to disclose IPV in face-to-face interviews due to shame or reluctance to disclose family matters to strangers, leading to underreporting of IPV events. Third, self-selection is a potential source of bias in cohort studies and may lead to over- or underestimation of effects. However, in our study, self-selection is a bias if pregnant women who tested positive had a different set of motivations for study participation compared with those testing negative. Since we did not collect data on motivations informing study participation, we are limited in our ability to confirm or refute if self-selection is indeed a bias of this study. Fourth, we do not know whether and to what extent participants ended up not consenting to participate in the study even when they were deemed eligible. Fifth, since we designed the study for hypothesis testing, we were not able to explore the extent to which the observed association followed the pathways and the contexts articulated in our conceptual framework (see Conceptual framework section). Sixth, we lack data on prior disabilities, which is a risk factor for IPV and, on prior knowledge about SCD, a protective factor. Finally, our study was underpowered to detect a significant difference in IPV rates between women testing positive vs. negative due to our use of 20% for baseline physical IPV during pregnancy, as opposed to the 4% prevailing in India. Using a 4% rate would require too large a sample for a pioneering study such as ours.

Nonetheless, our present evidence of a positive association between a positive test result and risk for IPV, potentially via partner disclosure, remains intact even when we adjust for an array of confounders including the lower level of education and scheduled-caste membership. Future studies should examine potential mechanisms using a mixed-methods design, as well as sources of variation in the risk for IPV among women who test positive on the sickle cell solubility test.