Realistic Pregnancy Overhaul Sims 4 (March 2026) Complete Guide

Updated by Soumya Thakur
November 2, 2025
GamingThe Sims 4

Realistic Pregnancy Overhaul (RPO) is one of the most immersive gameplay mods for The Sims 4 that completely transforms the pregnancy experience, making it more realistic, challenging, and engaging. This comprehensive mod introduces a range of new features including menstrual cycles, fertility windows, pregnancy symptoms, complications, and much more. Whether you’re a storyteller looking for more depth in your Sims’ family narratives or a gameplay enthusiast seeking additional challenges, RPO

In this definitive guide, we’ll cover everything you need to know about Realistic Pregnancy Overhaul for Sims 4, from installation and configuration to troubleshooting and compatibility with other mods. We’ll explore every feature in detail, provide tips for gameplay, and answer all your questions about this transformative mod. Updated for the latest Sims 4 patch, this guide will help you master the most realistic pregnancy experience available in the game.

What is Realistic Pregnancy Overhaul (RPO)?

Realistic Pregnancy Overhaul (RPO) is a comprehensive gameplay modification for The Sims 4 created by popular modder PolarBearSims. This mod completely reworks the pregnancy system in the game to make it more realistic and immersive. Unlike the base game’s simplified pregnancy mechanics, RPO introduces a complex system that mirrors real-life pregnancy experiences, including menstrual cycles, fertility tracking, pregnancy symptoms, complications, and postpartum changes.

The mod is designed for players who want more depth and realism in their Sims’ reproductive lives, adding new layers of gameplay that affect relationships, careers, and daily activities. With RPO, pregnancy becomes a significant life event rather than just a temporary state with minimal impact on gameplay.

Key Features of RPO

Realistic Pregnancy Overhaul comes with an extensive list of features that transform the pregnancy experience in Sims 4:

Menstrual Cycle System

Realistic menstrual cycles for female Sims
Variable cycle lengths (typically 24-32 days)
Different flow intensities (light, medium, heavy)
PMS symptoms affecting mood and needs
Menstrual products (pads, tampons, menstrual cups)
Cycle tracking with calendar notifications

Fertility System

Ovulation and fertile windows
Fertility awareness methods
Natural family planning options
Birth control methods (condoms, pills, IUDs)
Fertility testing kits
Fertility treatments for struggling couples

Pregnancy Symptoms

First trimester morning sickness
Food cravings and aversions
Fatigue and energy changes
Mood swings and emotional changes
Physical changes (bloating, breast tenderness)
Pregnancy-specific whims

Pregnancy Complications

Miscarriage risk factors
Ectopic pregnancy possibilities
Gestational diabetes
Preeclampsia
Preterm labor risks
Multiple pregnancy complications

Medical Care System

Pregnancy tests (home and clinical)
Ultrasound appointments
Prenatal care visits
Genetic testing options
Hospital birth options
Postpartum care

Postpartum Features

Postpartum depression
Breastfeeding challenges
Physical recovery period
Hormonal changes
Relationship dynamics adjustments

System Requirements and Compatibility

Before installing Realistic Pregnancy Overhaul, ensure your system meets the following requirements:

Base Game Requirements

The Sims 4 base game (latest version)
All game updates installed
At least 2GB of additional storage space

Expansion Pack Compatibility

Compatible with all expansion packs
Enhanced features with:
Get to Work (hospital births)
City Living (apartment living adjustments)
Seasons (seasonal pregnancy considerations)
Parenthood (parenting skill integration)
Discover University (pregnancy and education)

Mod Compatibility

Works with most popular gameplay mods
Known conflicts with other pregnancy overhaul mods
Compatible with:
MC Command Center
WickedWhims (with proper configuration)
UI Cheats Extension
Slice of Life
Basemental Drugs (with settings adjustments)

Installation Guide

Step 1: Downloading RPO

Visit the official download page: PolarBearSims’ Patreon
Navigate to the RPO mod section
Download the latest version compatible with your game patch
Save the ZIP file to a temporary location on your computer

Step 2: Extracting the Files

Right-click on the downloaded ZIP file
Select “Extract All” or use a program like WinRAR or 7-Zip
Extract the contents to a new folder

Step 3: Installing the Mod

Open your Sims 4 documents folder (usually found at Documents/Electronic Arts/The Sims 4)
Navigate to the Mods folder
Create a new folder named “RPO” inside your Mods folder
Copy all extracted files into the RPO folder
Ensure the folder structure is correct: Mods/RPO/[all mod files]

Step 4: Enabling Mods in Game

Launch The Sims 4
Go to Game Options > Other
Check “Enable Custom Content and Mods”
Check “Script Mods Allowed”
Restart the game

Step 5: Verifying Installation

Start a new game or load an existing save
Check if a notification appears confirming RPO is loaded
Test basic features by clicking on a Sim and looking for RPO options

Configuration Options

Realistic Pregnancy Overhaul comes with extensive configuration options that allow you to customize the experience to your preferences:

General Settings

Pregnancy length (default: 9 days, adjustable: 3-21 days)
Miscarriage chances (default: 15%, adjustable: 0-50%)
Twins/triplets likelihood
Gender selection options
Pregnancy symptom intensity

Menstrual Cycle Settings

Cycle length (default: 28 days, adjustable: 21-35 days)
Period length (default: 5 days, adjustable: 2-8 days)
Fertility window duration
PMS symptom intensity
Menopause age settings

Medical Settings

Hospital birth requirements
Ultrasound availability
Genetic testing options
Prenatal care frequency
Postpartum care duration

Notification Settings

Cycle reminders
Fertility window alerts
Doctor appointment notifications
Pregnancy milestone alerts
Symptom notifications

To access these settings:

Click on any Sim
Navigate to “RPO Settings”
Adjust each category according to your preferences
Save changes

Detailed Feature Breakdown

Menstrual Cycle System

The menstrual cycle in RPO is designed to mimic real-life cycles with accuracy and detail:

Cycle Phases

Menstrual Phase (Days 1-5): Bleeding occurs, with options for light, medium, or heavy flow. Sims may experience cramps, fatigue, and mood changes.
Follicular Phase (Days 6-13): Energy levels increase, mood improves. This is the pre-ovulation phase.
Ovulation Phase (Day 14): Fertility peaks. Sims have increased chance of conception. May experience mild ovulation pain.
Luteal Phase (Days 15-28): If conception doesn’t occur, PMS symptoms begin in the final days of this phase.

Cycle Management

Sims can track their cycles using a calendar app on their phones
Menstrual products can be purchased from the pharmacy or online
Cycle irregularities can occur due to stress, health conditions, or age
Perimenopause and menopause are implemented for older Sims

Fertility System

The fertility system in RPO adds depth to family planning:

Fertility Tracking

Basal body temperature charting
Cervical mucus monitoring
Ovulation predictor kits
Fertility apps for tracking cycles

Contraception Options

Male condoms (reduces pregnancy chance by 85%)
Birth control pills (reduces pregnancy chance by 91% with perfect use)
IUDs (reduces pregnancy chance by 99%)
Natural family planning methods
Emergency contraception available after unprotected sex

Fertility Challenges

Age-related fertility decline
PCOS and other fertility conditions
Male factor infertility
Fertility treatments available (IVF, IUI)

Pregnancy Symptoms

RPO implements a comprehensive symptom system that evolves throughout pregnancy:

First Trimester (Days 1-3)

Morning sickness (nausea, vomiting)
Extreme fatigue
Food aversions and cravings
Breast tenderness
Frequent urination
Mood swings
Heightened sense of smell

Second Trimester (Days 4-6)

Increased energy levels
“Pregnancy glow” moodlet
Round ligament pain
Backaches
Dizziness
Nasal congestion
Skin changes

Third Trimester (Days 7-9)

Braxton Hicks contractions
Shortness of breath
Heartburn
Swelling (edema)
Insomnia
Nesting instinct
Anxiety about birth

Pregnancy Complications

RPO introduces realistic pregnancy complications that add challenge to gameplay:

Common Complications

Hyperemesis Gravidarum: Severe morning sickness requiring medical intervention
Gestational Diabetes: Requires dietary changes and monitoring
Anemia: Causes fatigue and requires iron supplements
UTIs: More common during pregnancy, require treatment

Serious Complications

Preeclampsia: High blood pressure requiring bed rest or early delivery
Placenta Previa: May require C-section delivery
Preterm Labor: Can be stopped with medication if caught early
Miscarriage: Risk factors include age, health, and certain behaviors

Managing Complications

Regular doctor visits can detect issues early
Following medical advice improves outcomes
Hospitalization may be required for severe cases
Some complications may require early delivery

Medical Care System

The medical care system in RPO provides comprehensive healthcare options:

Prenatal Care

Initial pregnancy confirmation at clinic
Regular check-ups (monthly, then bi-weekly, then weekly)
Ultrasound appointments at key milestones
Genetic testing options
Nutrition counseling
Exercise recommendations

Birth Options

Hospital birth (with Get to Work expansion)
Home birth with midwife
Birth center option
Water birth possibility
Natural birth vs. medicated options
C-section for medical necessity

Postpartum Care

Six-week postpartum checkup
Mental health screening for PPD
Lactation consulting
Birth control counseling
Physical recovery monitoring

Gameplay Integration

Realistic Pregnancy Overhaul integrates with various aspects of Sims 4 gameplay:

Career Impacts

Pregnancy may affect job performance
Maternity/paternity leave options
Career advancement considerations
Work-from-home accommodations
Physical job limitations

Relationship Dynamics

Partner involvement in pregnancy journey
Relationship strain during difficult pregnancies
Intimacy changes throughout pregnancy and postpartum
Co-parenting challenges and rewards
Extended family involvement

Skill Development

Parenting skill development during pregnancy
Research skill for pregnancy information
Cooking skill for pregnancy nutrition
Fitness skill modifications during pregnancy
Wellness skill for stress management

Social Interactions

Pregnancy announcement options
Baby shower planning
Support group attendance
Doctor-patient interactions
Pregnancy-related social media posts

Troubleshooting Common Issues

Installation Problems

Mod Not Showing Up

Verify Script Mods is enabled in Game Options
Check that the mod is no more than one folder deep in Mods folder
Ensure you have the latest version of the mod
Delete localthumbcache.package file in Documents/EA/The Sims 4
Repair game through Origin/EA app

Game Crashes

Check for conflicting mods (other pregnancy mods)
Update to the latest version of RPO
Remove and reinstall the mod
Test on a new save file
Check for outdated script mods

Gameplay Issues

Pregnancy Not Progressing

Check if pregnancy length is set too high in settings
Verify Sim isn’t stuck in a travel state
Reset the Sim using testingcheats
Check for mod conflicts
Report the issue to the creator if persistent

Menstrual Cycle Not Working

Ensure the mod is properly installed
Check if you’ve disabled cycles in settings
Verify Sim is of appropriate age
Check for medical conditions affecting cycle
Reset cycle in RPO settings

Performance Issues

Lag After Installation

Reduce notification frequency in settings
Disable features you don’t use
Check if your computer meets minimum requirements
Remove other resource-intensive mods
Lower game graphics settings

Advanced Tips and Strategies

Family Planning Strategies

Track multiple Sims’ cycles simultaneously
Plan pregnancies around career goals
Consider seasonal timing for births
Use fertility awareness method for natural family planning
Save before trying to conceive if you want specific gender

Managing Difficult Pregnancies

Build a strong relationship with healthcare provider
Maintain a healthy lifestyle during pregnancy
Plan for maternity/paternity leave
Prepare home for baby’s arrival
Arrange for support during postpartum period

Storytelling Opportunities

Document pregnancy journey with screenshots
Create pregnancy journals
Plan gender reveal parties
Prepare nursery with themed decor
Plan birth announcement photos

Challenge Ideas

100 Baby Challenge with RPO complications
Legacy Challenge with realistic genetics
No Mods Challenge (using only RPO)
Single Parent Challenge
Career Family Challenge

Compatibility with Other Mods

Fully Compatible Mods

MC Command Center
UI Cheats Extension
Slice of Life
Wonderful Whims
Basemental Drugs (with configuration)
Have Some Personality Please
Meaningful Stories
Private Practice
SimRealist mods

Partially Compatible Mods

WickedWhims (requires configuration)
Extreme Violence (may conflict with pregnancy protection)
Passionate Romance (may need settings adjustment)
Turbo Careers (may affect maternity leave)

Incompatible Mods

Other pregnancy overhaul mods
Menstrual cycle mods
Fertility mods that override RPO systems
Pregnancy duration mods

Updates and Version History

Recent Updates (as of March 2026)

Improved hospital birth integration with Get to Work
Enhanced postpartum depression system
New fertility treatment options
Improved menstrual product management
Better compatibility with latest game patch
Bug fixes for rare pregnancy complications

Version History

v3.5: Added postpartum care system
v3.0: Complete rewrite for improved performance
v2.5: Introduced menstrual cycle system
v2.0: Added pregnancy complications
v1.5: Initial release with basic pregnancy features

Community Resources

Official Support

Creator’s Patreon for direct support
Discord server for community help
Tumblr blog for updates and tutorials
YouTube channel for visual guides

Community Creations

Custom pregnancy clothes compatible with RPO
Pregnancy pose packs
Nursery CC collections
Pregnancy story series
RPO challenge saves

Forums and Discussion

ModThe Sims forum thread
Reddit community (r/sims4mods)
Sims Community discussion boards
Carl’s Sims 4 Guide forum

Frequently Asked Questions

Is Realistic Pregnancy Overhaul safe to use?

Yes, RPO is completely safe when downloaded from the creator’s official page. It’s a script-based mod that doesn’t alter core game files and can be removed anytime without permanent effects. Still, it’s good practice to back up your saves before installing any major mod.

Does RPO work with the latest Sims 4 patch?

The creator updates RPO frequently to ensure compatibility with new Sims 4 patches. Always check for the latest version before launching the game after an update. If you rely heavily on the mod, consider disabling automatic game updates until RPO’s newest version is confirmed stable.

Can I use RPO with other pregnancy mods?

No, RPO isn’t compatible with other pregnancy or menstrual cycle mods, as they modify similar game systems. However, it works seamlessly with MC Command Center (MCCC), Slice of Life, and other general gameplay enhancement mods.

Does RPO work on Mac computers?

Yes! The mod is fully compatible with both Mac and Windows versions of The Sims 4. The installation process is identical for both platforms—just drop the files into your Mods folder and enable script mods in the game settings.

Can I adjust the difficulty of RPO?

Absolutely. RPO is highly customizable, letting you tweak pregnancy duration, complication risks, fertility chances, and more. Whether you want a realistic simulation or a lighter, story-driven experience, the mod offers flexible options to match your playstyle.

Will RPO cause my game to run slower?

RPO is relatively lightweight, but it does introduce additional scripts that simulate complex pregnancy systems. Most modern PCs and Macs handle it fine. If you’re on a lower-end computer, consider disabling extra features or reducing notification frequency for smoother performance.

Can teen Sims use RPO?

By default, only Young Adult, Adult, and Elder Sims can experience pregnancy through RPO. However, there are optional settings that allow certain features for teen Sims—though the creator does not recommend enabling them for all players.

How do I uninstall RPO?

To safely remove RPO, simply delete the mod files from your Mods folder. If you have pregnant Sims in your save, it’s best to let them give birth first to prevent data or progress issues during uninstallation.

Does RPO work with console versions of Sims 4?

Unfortunately, no. Console versions of The Sims 4 (PlayStation and Xbox) do not support custom content or script mods, meaning RPO can only be installed on PC or Mac.

Can I translate RPO to my language?

Yes! RPO includes multi-language support, and community translations are often available on the mod’s official download page. The creator also provides instructions for adding or editing translations if you want to create your own.

Conclusion

Realistic Pregnancy Overhaul transforms The Sims 4’s pregnancy system into a deeply immersive, realistic experience that adds new layers of challenge and storytelling potential to your game. With its comprehensive menstrual cycle system, detailed pregnancy symptoms, medical care options, and postpartum features, RPO offers unparalleled depth for players seeking more realism in their Sims’ reproductive lives.

Whether you’re a family-oriented player looking to enhance your legacy gameplay, a storyteller seeking more narrative depth, or simply someone who wants a more challenging and realistic pregnancy experience, RPO provides the tools and features to transform your game. With proper installation and configuration, this mod will revolutionize how you experience pregnancy in The Sims 4.

Remember to keep your mod updated, back up your saves regularly, and engage with the community for the best experience with Realistic Pregnancy Overhaul. Happy simming!