Quality of couple relationship and associated factors in parents of NICU-cared infants during the first year after birth

The study addresses how the transition to parenthood—often stressful and linked to declines in relationship satisfaction, increased strain, and risk of depression—affects couple relationships for parents whose infants required NICU care. Prior research indicates both risks (e.g., psychological distress, depression) and possible benefits (e.g., strengthened bonds through shared emotional experiences) for NICU parents, but few studies have examined couple relationship quality longitudinally after NICU discharge. The aims were to identify factors associated with couple relationship quality 1 year after birth among NICU parents and to compare the trajectory of relationship quality during the first year with parents of term/healthy infants from maternity units. The hypothesis was that NICU parents would experience more strain than MU parents.

Background literature shows relationship satisfaction often declines across the transition to parenthood, with associations to stress and depression. Protective factors include younger age, higher education, income, and social support. Partner support buffers stress and promotes intimacy and health. Inequity in household and parenting tasks relates to poorer health and increased depression. NICU parents commonly experience distress, trauma, and depression; some studies report decreased relationship quality from NICU admission to discharge, while others suggest the NICU experience can also strengthen relationships if emotions are shared. Effects of preterm birth on relationships are mixed, underscoring the need to understand determinants of relationship quality after NICU hospitalization.

Design: Ongoing longitudinal comparative cohort study (PANC) with three survey timepoints over the infant’s first year after discharge (1 month, 6 months, 1 year). An advisory group of NICU-experienced parents contributed to aim, design, recruitment, instrument testing, and interpretation. Ethical approval: Swedish Ethical Review Authority (dnr: 2019-04367). Setting: Six NICUs (levels II–III) and four maternity units (MUs) in Sweden during the COVID-19 pandemic. NICUs allowed 24/7 parental access; most allowed both parents to stay; visitors (siblings/relatives/friends) were restricted. Some MU restrictions limited father/partner stay; all MUs restricted visitors. Recruitment: Parents ≥18 years, speaking Swedish/English/Arabic/Somali, discharged to home, infant not needing palliative care, and no social services involvement. From Mar 2020–Mar 2021, invitations, consent, and first questionnaire were sent 1 month post-discharge. Participation: First questionnaire: 923 parents (NICU 439; MU 484; 22% and 20% response rates). Second: 783 (NICU 365; MU 418; 85% of participants). Third: 687 (NICU 323; MU 364; 74% of participants). Measures: Sociodemographics; pregnancy/birth/NICU stay details; infant characteristics (gestational age, birth weight, length of stay) and health/care needs. Follow-up questionnaires included civil status, occupation, health, household tasks, economy, and parental leave duration. Primary outcome: Quality of Dyadic Relationship (QDR36), 36 items across five dimensions (consensus, cohesion, satisfaction, sensuality, sexuality), each 1–6; total index is sum of dimension means (5.00–30.00), higher scores indicate better quality; validated Swedish/English. Depressive symptoms: Edinburgh Postnatal Depression Scale (EPDS), 10 items scored 0–3 (0–30 total), higher indicates more symptoms; cut-offs: mothers ≥13, fathers ≥10; available in four languages with prior validations (except Somali for women; English validated for men). Social support: MOS Social Support Survey (MOS-SSS), 19 items scored 1–5; index 1.00–5.00; validated in English and Arabic; other languages underwent forward-backward translation. Statistical analysis: Power calculation targeted detection of small effect (d=0.2) at alpha 0.025, power 0.80, requiring 393 parents per group. Descriptive statistics as frequencies/percentages. MCAR test indicated missingness random (QDR36 missing 3.1%; p=0.141); no imputation. Generalized linear model (scale response linear) assessed factors associated with QDR36 at 1 year among NICU parents; reported B (change in mean QDR36), 95% CI, p values. Linear mixed-effects models assessed trajectories of QDR36 index and five dimensions across three timepoints for four groups (NICU mothers/fathers; MU mothers/fathers), adjusted for older children at home, multiple births, and treatment for psychological symptoms during pregnancy; reported estimated marginal means (EMMs) and 95% CIs; only participants who answered the 1-year questionnaire were included; missing 9%; significance p≤0.05. Software: SPSS 28.0 and R 4.3.0.

- Sample and context: Among NICU parents who completed the 1-year questionnaire (n=323; 178 mothers, 145 fathers), many infants were term (54%), with hospital stays ranging 1–150 days. NICU parents were more likely to be first-time parents, have multiple births, lower gestational age, longer hospital stays, and infants with illness/impairment than MU parents (p<0.001). About 63% of NICU mothers and 69% of NICU fathers reported sleeping/staying together with partner and infant for all or part of the hospitalization. - Factors associated with QDR36 at 1 year (NICU parents): • Mothers (n=160): - Younger age associated with higher QDR36: 21–28 years B=1.64 (95% CI 0.56 to 2.72; p=0.003); 29–34 years B=0.76 (−0.18 to 1.70; p=0.11) vs 35–42 ref. - Born outside Sweden: B=1.77 (0.28 to 3.25; p=0.02). - Social support (MOS-SSS index): B=0.56 (0.11 to 1.01; p=0.01). - Length of hospital stay 7–14 days vs 1–6 days: B=0.91 (0.05 to 1.78; p=0.04). - Not sleeping together with partner and infant during hospitalization: B=−0.82 (−1.61 to −0.03; p=0.04). - Doing household duties often/always vs half the time: B=−1.58 (−2.38 to −0.78; p<0.001). - EPDS≥13 not significantly associated: B=−0.98 (−2.54 to 0.58; p=0.22). • Fathers (n=123): - Younger age associated with higher QDR36: 21–28 years B=2.06 (0.57 to 3.55; p=0.007); 29–34 years B=1.09 (0.15 to 2.04; p=0.023) vs 35–42 ref. - EPDS≥10: B=−3.52 (−4.91 to −2.13; p<0.001). - Multiple births: B=−1.49 (−3.00 to 0.15; p=0.05). - Other factors (education, hospital stay categories, sleeping together, household duties, social support) not statistically significant. - Trajectory analyses (Linear mixed-effects models): • No significant differences in QDR36 trajectories between NICU and MU groups for mothers or fathers at any timepoint (all p>0.26 for averaged comparisons; specific timepoints p≥0.47 for index; see Table 3). • QDR36 EMMs were similar across groups and declined slightly over the first year: - NICU mothers: 24.2 (1 month) → 23.4 (1 year), decline ≈0.8. - NICU fathers: 23.9 → 23.2, decline ≈0.7. - MU mothers: 24.2 → 23.3, decline ≈0.9. - MU fathers: 24.1 → 23.2, decline ≈0.9. • Dimensions: Cohesion and sensuality showed the greatest declines across all groups. Mothers rated sexuality higher than fathers; MU mothers rated consensus lower than MU fathers. Overall averaged EMMs for QDR36 index: NICU mothers 23.7 (95% CI 23.4–24.1), MU mothers 23.7 (23.4–24.1), p=0.94; NICU fathers 23.6 (23.2–23.9), MU fathers 23.7 (23.3–24.0), p=0.79.

Findings indicate that, contrary to the initial hypothesis, parents of NICU-cared infants did not experience greater deterioration in couple relationship quality during the first postpartum year compared with parents of term/healthy infants. Relationship quality was generally high and declined only slightly across groups. Among NICU mothers, better perceived social support, a moderate-length hospital stay (7–14 days), and the opportunity to sleep/stay together with partner and infant were associated with better relationship outcomes, while taking on household duties most of the time related to lower relationship quality. Among NICU fathers, depressive symptoms and multiple births were associated with lower relationship quality, and younger age was associated with better quality for both mothers and fathers. Interpreted through Bowen Family Systems Theory, the role of the extended family and togetherness within the nuclear family may stabilize and enhance couple functioning, suggesting that facilitating involvement of family/friends and enabling parental togetherness during hospitalization can support relationship quality. The strong negative association of paternal depressive symptoms with relationship quality reinforces the importance of screening and supporting both parents’ mental health after discharge.

There were no differences in the trajectory of couple relationship quality during the first year after birth between NICU and MU parents. For NICU parents, several modifiable factors were associated with better long-term couple relationship quality: greater social support from family and friends, NICU stays of 7–14 days, and the ability for both parents to stay/sleep together with the infant during hospitalization; depressive symptoms, especially in fathers, and unequal household task distribution were associated with poorer outcomes. Clinical and organizational implications include enhancing social support pathways, providing time and space for partner togetherness during hospitalization, and screening/supporting parental mental health. Future research should conduct longer-term follow-ups of family relationships, support needs, and parenting after NICU discharge, including diverse settings with varying policies on parental presence.

- Low initial participation rate (20–22% of eligible parents), raising concerns about representativeness and generalizability; lack of data on nonparticipants precludes assessment of selection bias. - Possible higher education level among participants than the general population, which may be associated with better relationship outcomes. - Conducted during the first year of the COVID-19 pandemic; visiting restrictions and contextual stressors may have influenced experiences differently across NICUs and MUs. - Swedish context with generous parental leave and widespread capacity for both parents to stay in NICU may limit generalizability to settings with different social support systems and hospital policies. - Some instruments were translated for this study (e.g., Somali not previously validated for EPDS in women), which might affect measurement equivalence. - Only parents who completed the 1-year questionnaire were included in trajectory analyses; although missingness was MCAR and modest, this may still influence longitudinal estimates. - Datasets not publicly available at present, limiting external verification.