Redefining “Eating for Two”—The Role of Both Partners in Pregnancy

Understanding the Impact of Both Parents

Pregnancy prep often zooms in on the mom: her supplements, her sleep, her stress. But what if we told you the father’s biology could shape the baby’s placenta, influence the risk of miscarriage, and even pre-program how that child responds to stress, metabolism, and brain development?

Emerging science from fields like epigenetics and placental biology is rewriting the rules of prenatal care. It’s no longer just about sperm meeting egg. It’s about the whole story that sperm carries—stories written by nutrition, stress, sleep, and even gym attendance in the months (and years) before conception.

This matters if you’re:

• A couple trying to conceive in a sympathetically dominant region like Jersey City or NYC

• A pregnant mom wondering why fitness advice includes both of you

• A trainer, doula, or coach looking to guide parents with evidence-backed support

  
  

In this post, we’ll break down what recent research says about how a father’s health affects pregnancy—from placenta structure and diastasis recti risk to the surprising legacy of paternal stress and diet. You’ll walk away with actionable steps, clear visuals, and a new appreciation for co-parenting from day one.

Let’s dive into what the science says—without making your head spin.

The Placenta—Built by Both Parents

The placenta isn’t just “mom’s job.” Research shows it’s deeply influenced by the father’s genes, especially those controlling its shape, nutrient flow, and ability to protect against complications like preeclampsia (Perez-Garcia et al.). These aren’t trivial changes—the placenta determines how much oxygen and nutrition a baby receives throughout pregnancy.

In fact, specific paternal genes regulate how far into the uterine wall the placenta can embed—a critical factor for avoiding pregnancy-threatening issues like poor fetal growth or early delivery (Knöfler et al.).

Father’s Diet Shapes the Baby’s Metabolism

The POHaD hypothesis (Paternal Origins of Health and Disease) reveals a powerful truth: what a father eats before conception affects their child’s future risk for obesity, insulin resistance, and cardiovascular disease (Soubry).

In one landmark study, obese male mice produced offspring with altered metabolic regulation—and those effects extended two generations (Fullston et al.). The mechanism? Epigenetic changes in sperm, triggered by poor nutrition and excess weight.

Dad’s Stress Can Rewire Baby’s Brain

We’ve long known maternal stress matters—but we’re only beginning to understand the father’s role in early neurological programming.

Chronic stress in male mice—before conception—was shown to alter how offspring brains process anxiety and regulate stress hormones (Chan et al.). Another study found that paternal stress changed sperm in ways that affected how offspring metabolized glucose (Zhao et al.).

Big Babies, Bigger Strain

When fathers carry more body fat or poor metabolic health, they may pass on genetic signals that result in heavier babies and larger placentas (Binder et al.). That sounds innocent—until you consider the extra intra-abdominal pressure this places on the birthing parent.

Heavier babies can increase the risk for diastasis recti—a separation of the abdominal wall that affects posture, core function, and postpartum recovery.

Rewriting the Fatherhood Script

For decades, prenatal advice has focused squarely on mom—and while she’s certainly the MVP of the journey, science is showing us it’s a team sport. From placental function to mental health outcomes, a father’s diet, stress, and genetic expression shape the womb environment and the child’s lifelong wellbeing.

This doesn’t mean perfection—it means partnership. It means that breathwork before bed, upgrading your snacks, and showing up to that gym session together isn’t just about fitness—it’s about legacy.

You’re not just planning a baby. You’re laying the biological foundation for generations.

Homework Assignment

Talk with your partner about one lifestyle change you’re each willing to make in the next 30 days—whether that’s reducing processed foods, doing breathwork before bed, or adding one weekly strength session together.

Write it down. Keep it visible. Make it a shared commitment to future parenting.

Works Cited

• Binder, Natalie K., et al. “Paternal Diet-Induced Obesity Programs Embryo and Placental Development.” Biology of Reproduction, vol. 93, no. 6, 2015, pp. 1–13. Oxford Academic, https://doi.org/10.1095/biolreprod.115.132597.

• Chan, Jeffrey C. Y., et al. “Paternal Stress before Conception Alters Offspring Brain Development.” Biological Psychiatry, vol. 85, no. 11, 2019, pp. 940–950. Elsevier, https://doi.org/10.1016/j.biopsych.2018.12.021.

• Fullston, Tod, et al. “Paternal Obesity Initiates Metabolic Disturbances in Two Generations of Mice with Incomplete Penetrance to the F2 Generation and Alters the Transcriptional Profile of Testis and Sperm microRNA Content.” The FASEB Journal, vol. 27, no. 10, 2013, pp. 4226–4243. Wiley, https://doi.org/10.1096/fj.12-224048.

• Knöfler, Martin, et al. “Human Placenta and Trophoblast Development: Key Molecular Mechanisms and Model Systems.” Cellular and Molecular Life Sciences, vol. 76, no. 18, 2019, pp. 3479–3496. Springer, https://doi.org/10.1007/s00018-019-03104-6.

• Lambrot, Romain, et al. “Paternal Diet Affects Offspring Health through Sperm Epigenome.” Nature Reviews Urology, vol. 10, no. 11, 2013, pp. 705–712. Nature Publishing Group, https://doi.org/10.1038/nrurol.2013.256.

• Li, Minghua, et al. “The Male Reproductive System: Epigenetic Susceptibility and Transgenerational Effects of Obesity.” Molecular and Cellular Endocrinology, vol. 468, 2018, pp. 139–149. Elsevier, https://doi.org/10.1016/j.mce.2017.10.011.

• Perez-Garcia, Victor, et al. “Paternal Influence on the Human Placenta.” Nature Reviews Endocrinology, vol. 18, no. 4, 2022, pp. 223–234. Nature Publishing Group, https://doi.org/10.1038/s41574-022-00597-w.

• Soubry, Adelheid. “POHaD: Why We Should Study Future Fathers.” Environmental Epigenetics, vol. 4, no. 2, 2018, dvy007. Oxford Academic, https://doi.org/10.1093/eep/dvy007.

• Zhao, Xiaoxiao, et al. “Paternal Psychological Stress Reprograms Hepatic Gluconeogenesis in Offspring.” Cell Metabolism, vol. 23, no. 4, 2016, pp. 735–743. Elsevier, https://doi.org/10.1016/j.cmet.2016.03.006.

  
  

Ready to start your journey with expert support?

We offer evidence-backed preconception training, prenatal fitness, and partner-based coaching designed to support you both—physically and emotionally—through every trimester and beyond.

Serving Jersey City, Hoboken, and NYC (Manhattan + virtual options)

Specializing in: prenatal strength training, diastasis recti prevention, pelvic floor health, and mindset coaching

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Helpful First Trimester Resources

1. March of Dimes: Healthy Pregnancy Steps https://www.marchofdimes.org/find-support/topics/pregnancy

2. Evidence Based Birth: Partner’s Role in Birth Preparation https://evidencebasedbirth.com/

3. Espire Wellness Preconception Checklist https://drive.google.com/file/d/1Dt56Oa0EeTHSk3Ny9xrOSVmK4UOmGiA7/view?usp=sharing