Dear Editor,

Sleep is essential for both maternal and fetal health, particularly during pregnancy. Hormonal, psychological, and physiological changes increase the vulnerability of women to “poor sleep quality” (PSQ), which in turn is linked to mental distress. PSQ during pregnancy is associated with various complications, including gestational diabetes, pre-eclampsia, increased cesarean sections, obesity, depression, and anxiety. Long-term risks include hypertension, type-2 diabetes (T2D), lung cancer, and cardiometabolic disorders (Fig. 1) [1]. A systematic review by Li et al. [2] revealed that even a 1-hour reduction in sleep increases the risk of coronary heart disease, stroke, and T2D by 3%–11% for short sleepers, whereas a 1-hour increase raises these risks by 7%–17% for long sleepers.

Although PSQ has been studied in the later stages of pregnancy, its impact during the periconceptional period (conception till the first trimester) is underexplored. PSQ in this early stage of pregnancy has been linked to adverse pregnancy outcomes, such as preterm birth, intrauterine growth restriction, stillbirth, low birth weight, neurodevelopmental delays, and chromosomal abnormalities. Prenatal PSQ and daytime sleepiness may also affect sleep patterns in offspring later in life [3].

The impact of PSQ on cardiovascular conditions and syndromic phenotypes is well-documented; however, its effect on birth anomalies during the periconceptional period has been less investigated. To date, only two epidemiological studies have linked PSQ to multifactorial congenital conditions—neural tube defects (NTDs) and congenital heart disease (CHD). Li et al. [4] found that maternal PSQ (≥4 days/week) is associated with an increased risk of NTD in normal and obese Chinese women, with an odds ratio (OR) of 4.1 (95% confidence interval [CI]=1.9–8.8) and 11.8 (95% CI=1.4–97.6), respectively. Zhao et al. [5] showed that periconceptional PSQ is a risk factor for simple CHD (OR=2.49, 95% CI=1.62–3.82) and severe CHD (OR=1.95, 95% CI=1.27–2.30) in the Chinese population. Daytime naps were associated with a reduced risk of simple CHD (OR=0.63, 95% CI=0.44–0.92).

These increased susceptibilities could be a consequence of dysregulation of the endocrine, metabolic, and immune systems, although the mechanisms remain unclear [1,3]. Glucose-related metabolic alterations, including hyperglycemia, hyperinsulinemia, and gestational diabetes, combined with interference in circadian rhythms and melatonin secretion, are recognized risk factors for congenital anomalies [4,5]. Pre-pregnancy sleep deprivation may also impair yolk sac growth, which is vital for fetal nutrition and development. Additionally, PSQ is influenced by lifestyle factors, such as stress, illness, and sedative use, further elevating the risks of birth defects [4].

Addressing PSQ and psychological distress during pregnancy is critical for maternal and fetal health. Yet, sleep disorders remain underdiagnosed, with up to 48% of pregnant women in India experiencing sleep-related distress. This issue aligns with Target 3.4 of the third Sustainable Development Goal, aimed at reducing premature mortality from non-communicable diseases (source: https://www.un.org/sustainabledevelopment/health/).

First-line treatments such as continuous positive airway pressure therapy and cognitive behavioral therapy for insomnia are effective in managing PSQ in pregnant women [3]. A multidisciplinary approach that includes mental health support is essential for improving well-being and preventing long-term complications. Raising awareness and implementing effective treatments can significantly enhance outcomes for both mothers and children, thereby reducing the long-term burden of chronic diseases.