Track Timed Pregnancies with Plug Event Tracking in Moustra

If your lab runs timed pregnancies, you know the drill: check for vaginal plugs every morning, scribble the date on a cage card, do mental math to figure out the embryonic day, and hope nobody forgets when the harvest or delivery window is. One missed day can mean a ruined experiment.

Moustra's plug event tracking takes the guesswork out of timed matings. It's built directly into the platform — web and mobile — so your entire team stays aligned on every pregnancy from plug detection to outcome.

What Is Plug Event Tracking?

A plug event in Moustra represents a confirmed vaginal plug observation. When you record one, the system captures everything you need:

Female and male animals linked to the event
Mating pair association (auto-links the male if you select the mating)
Plug date and time for precise E-day calculations
Who checked — so there's always accountability
Target embryonic day (E-day) — set your intended harvest or observation point
Auto-calculated target date — Moustra does the math for you
Expected delivery window — automatically set to E18–E20 from the plug date
Outcome tracking — live birth, harvest, resorption, no pregnancy, or cancelled
Embryo count — record how many embryos were collected
Litter linking — connect the plug event to the resulting litter

Every plug event also gets a current E-day that updates in real-time, so you always know exactly where each pregnancy stands.

How It Works

1. Record the Plug

When you confirm a vaginal plug during your morning check, create a new plug event from the mating detail page or the dedicated plug events list. Select the female, pick the mating pair, and Moustra auto-fills the male. Enter the plug date (defaults to today) and optionally the time.

Behind the scenes, Moustra also creates a plug check record with the result "Plug Found" — giving you an audit trail of your observations.

2. Set Your Target

Enter your target E-day (e.g., E12.5 for a mid-gestation harvest). Moustra instantly calculates the target date so you can see at a glance when to act. No more counting days on a calendar.

3. Monitor the Dashboard

The mobile app's Active Pregnancies card on the dashboard shows all ongoing plug events at a glance. You can see which pregnancies are due soon (within 3 days) and tap into any event for full details. The web app's plug event list gives you sortable, filterable views across your entire lab.

4. Get Daily Reminders

Moustra's daily report automatically checks for plug events with a target date matching today and includes them alongside animals due for weaning. Every team member with daily reports enabled gets an email each morning listing exactly which plug events need attention that day.

5. Record the Outcome

When the pregnancy reaches its endpoint, record the outcome directly on the plug event: live birth, harvest, resorption, no pregnancy, or cancelled. If you collected embryos, log the count. If there's a resulting litter, link it.

Why It Matters

Timed pregnancies are the foundation of experiments in:

Developmental biology — studying organogenesis at specific E-days
Neuroscience — in utero electroporation, cortical development studies
Reproductive biology — implantation timing, placental research
Transgenics — embryo harvest for microinjection or CRISPR editing

Missing a target E-day doesn't just waste time — it wastes animals, reagents, and months of planning. With Moustra tracking every plug event digitally, your lab gets:

Zero mental math — E-days and target dates are auto-calculated
Team visibility — everyone sees the same data, on any device
Daily nudges — the daily report flags what's due today
Full audit trail — plug checks, outcomes, and notes are all recorded
Mobile access — check pregnancies from the vivarium floor on your phone

Common Timed Pregnancy Challenges and How to Solve Them

Timed pregnancies are among the most labor-intensive and time-sensitive workflows in mouse colony management. Here are the challenges labs encounter most frequently and practical strategies for addressing them.

Missing the Plug Window

Copulation plugs are visible for a limited time — typically the first few hours of the morning. If a technician arrives late, checks cages in the wrong order, or is pulled away by other tasks, the window closes and you miss the data for that day. In mating-intensive experiments where embryonic staging matters to the hour, a missed plug check can invalidate an entire experimental cohort.

Solution: Configure daily plug check reminders that fire before the morning facility window opens. Assign specific cage ranges to specific team members so there is no ambiguity about responsibility. Use the mobile app to log results at the cage — if a plug is found at 7:15 AM, the timestamp reflects reality rather than a batch entry made hours later at a desk.

Ambiguous Plug Readings

Not every plug is definitive. Partial plugs, displaced plugs, and false positives from mating activity without successful copulation all introduce uncertainty. Labs that do not record plug confidence levels often discover weeks later that an assumed pregnancy never occurred.

Solution: Record plug observations with a confidence indicator: definitive, probable, or uncertain. Track each category separately in your success rate metrics. Over time, this data helps you calibrate — if "probable" plugs result in pregnancies 70% of the time in your colony, that informs how many backup matings you need.

Losing Track of Gestational Timing

Once a plug is confirmed, the clock starts. Embryonic day 0.5 (E0.5) is defined as the morning the plug is found. Every subsequent day matters for experiments that require tissue collection or observation at a specific developmental stage. In busy labs managing multiple timed pregnancies simultaneously, it is easy to lose track of which female is at which stage.

Solution: Automated gestational day tracking eliminates manual date arithmetic. Moustra calculates the current embryonic day from the plug date and displays it directly on the cage record. Dashboard views show all active timed pregnancies sorted by expected harvest date, so you can see at a glance which collections are coming up this week.

Coordinating Timed Matings Across Multiple Experiments

Large labs often run multiple timed pregnancy experiments in parallel, each with different target collection dates. A neuroscience project might need E14.5 brains on Tuesday while a developmental biology project needs E10.5 embryos on Thursday — from different strains housed in different rooms.

Solution: Tag timed pregnancies by project or experiment name, and filter dashboard views accordingly. Set up project-specific notification channels so each research group receives alerts only for their relevant timelines. This prevents the coordination errors that arise when a single technician is managing timed pregnancies for three different PIs.

Metrics That Improve Timed Pregnancy Success Rates

Tracking plug events systematically generates data that helps you optimize your timed mating workflow over time.

Plug rate by strain. Some strains mate more reliably than others. C57BL/6 females typically show plugs on 30-50% of mornings when paired with a proven male. If your plug rate for a particular strain consistently falls below the expected range, investigate housing conditions, male age, or estrous cycle synchronization.

Plug-to-pregnancy conversion rate. Not every plug results in a viable pregnancy. Track how often confirmed plugs lead to visible pregnancies at the expected timepoint. A conversion rate below 60% may indicate male fertility issues, female health problems, or environmental stressors in your facility.

Time-of-day patterns. Some facilities find that mating success varies with the light cycle schedule. If your facility runs a non-standard light cycle, correlate plug detection times with success rates to determine whether your check schedule is optimally timed.

Seasonal variation. Mouse breeding performance can fluctuate with seasons, even in climate-controlled facilities. Year-over-year plug rate data helps you anticipate slow periods and plan mating schedules with appropriate buffers.

Works Across Web and Mobile

Plug event tracking is available on both the Moustra web app and the native iOS/Android mobile app. Create events at the bench, review them in your office, and get daily emails wherever you are.

The mobile app even includes an Active Pregnancies dashboard card that highlights due-soon events, so a quick glance at your phone tells you everything you need to know before heading to the vivarium.

Systematic plug event tracking transforms timed pregnancies from a source of daily anxiety into a managed, predictable workflow. The data you collect today directly improves the efficiency and reliability of every timed experiment you run in the future.

Getting Started

If you're already using Moustra, plug event tracking is built in — just navigate to any mating and create a plug event, or go to the Plug Events section from the main menu.

New to Moustra? Start your free trial and see how timed pregnancy management fits into a modern colony workflow.

Questions about plug event tracking or timed pregnancies in Moustra? Reach out at support@moustra.com — we're happy to help.